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A-Z Glossary of Terms

A helpful A-Z glossary listing showing important CLL related terms. If you can’t find what you need on here, let us know.


Absolute Lyphocyte Count (ALC)

The total volume of the Lyphocytes in the blood. This is a key measure in CLL  management. In the UK this will appear in the Full Blood Count (FBC) as “lymphocytes” along with the White Blood Count (WBC).

Where the WBC in the blood is reported as % lymphocytes in the blood it can easily be converted to ALC. ALC = WBC * % lymphocytes.

For example, if the WBC is 30.0, and the lymphocyte percent is 65%, the absolute lymphocyte number is 30.0 X 0.65 = 19.5.


An acute condition is one which starts quickly and, if untreated, progresses quickly. Acute does not necessarily mean serious – a cold is an acute illness.

Acute Lyphoblastic Leukaemia (ALL)

In ALL, the bone marrow makes too many lymphocytes. These lymphocytes are not fully developed and are not able to work normally.

Acute Myeloid Leukaemia (AML)

In AML the white blood cells call granulocytes or monocytes become cancerous. The cells made are not fully formed so do not work normally.

 Acute promyelocytic leukaemia (APL or APML)

This is one form of Acute Myeloid Leukaemia (AML). The condition responds particularly well to a drug called retinoic acid which causes leukaemia cells to mature and die.


is a drug used in the treatment of Chronic Lymphocytic Leukaemia (CLL). It is a monoclonal antibody that binds to CD52, a protein present on the surface of mature lymphocytes.

Alkylating agents

Anti-leukaemic drugs which attach to genetic material in the cell and stop cells dividing. Drugs of this type include busulphan, chlorambucil, cyclophosphamide, melphalan.

Allogeneic Stem Cell Transplant

Also called an allograft. A transplant using stem cells collected from a ‘matched’ healthy donor, usually a brother or sister.


See Allogenic Stem Cell Transplant


is a drug used primarily to treat hyperuricemia (excess uric acid in blood plasma) and its complications. Uric acid is produced when cells are killed and their proteins break down. Large quantities of uric acid in the blood lead to crystal deposits in joints – this is the cause of gout or can lead to kidney damage.


A low number of red blood cells. Red blood cells contain haemoglobin, and so your haemoglobin will also be low. Haemoglobin carries oxygen around the body. So if you are anaemic, you may feel tired or breathless.


A class of drugs which are used in chemotherapy to treat leukaemia. They are derived from Streptomyces bacterium and prevent cell division by disrupting the structure of the DNA. Read more


Drugs which kill bacteria or stop them growing, for example penicillin.


Blood proteins produced, by white blood cells known as lymphocytes, when the body recognises that something foreign has got in, for example bacteria. The antibodies attach themselves to the invading bacteria or viruses, which are then destroyed. Each antibody will bind to a specific target antigen.


A drug to stop nausea (sickness) and vomiting or make it better.


An antigen is a substance (usually, but not always, a protein) which the body ‘sees’ as foreign. Antigens may be on the surface of a bacterium or a virus or on parasites. The immune system responds to an antigen by producing antibodies or by white cells attacking and destroying the bacterium, virus or parasite carrying the antigen.

Antilymphocyte Globulin

Antibodies which attach to and destroy lymphocytes. They may be used clinically by injection into a vein, for example in aplastic anaemia. One form, called anti-thymocyte globulin, acts specifically against T-cells.


A group of anti-cancer drugs which prevent cells growing and dividing by blocking the chemical reactions required in the cell to produce DNA. Read more


When the bone marrow does not produce blood cells because there are not enough stem cells. Usually this condition affects all types of blood cells and is called aplastic anaemia.

Aplastic Anaemia

A rare disorder where the bone marrow doesn’t produce blood cells. It may be an inherited condition or, more often, the disease develops later in life. This is called acquired aplastic anaemia. It leads to a severe shortage of all types of blood cell. This can make you tired and likely to get infections. It can also cause serious problems with bleeding. Aplastic anaemia is not a blood cancer.


is the process of programmed cell death (PCD) that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death.

Auto-Immune Haemolytic anaemia AIHA

Diseases caused when the immune system produces antibodies against tissues of its own body. This can also happen in normal healthy people but is more common in patients with CLL and hence treatment may be required for this.


See autologous stem cell transplant.

Autologous stem cell transplant (ASCT)

A stem cell transplant using the patient’s own stem cells which have been collected and stored at an early stage of the disease. It is also called an autograft. The marrow may be ‘purged’ in the laboratory. This is to reduce the chance that there is any contamination with leukaemia cells. Unlike a donor transplant, an autologous transplant can be carried out in older patients.


B lymphocyte or B cell

A type of white blood cell lymphocyte that circulates in the blood and lymphand is normally involved in producing antibodies to fight infection. Read more

Basophil granulocytes ( Basophils)

are the least common of the granulocytes, representing about 0.01% to 0.3% of circulating white blood cells which are involved in allergic reactions and inflammation.


is used in the treatment of Chronic Lymphocytic Leukaemia (CLL) and lymphomas. It belongs to the family of drugs called alkylating agents.

Binet Staging

The Binet staging system uses the number of lymphoid tissue sites affected along with the haemoglobin and platelet count so that:

Stage A = 0-2 lymphoid sites affected

Stage B = 3-5 lymphoid sites affected

Stage C = Haemoglobin less than 10g/dl or platelets less than 100 x 109/l.

In the Binet system the 5 lymphoid sites are neck, armpit and groin nodes along with spleen and liver enlargement. So if both sides of the neck are involved this is still only 1 site. Likewise if there is more than 1 node in a given area eg right side of groin, this is still only 1 site. This staging system was described before we had access to CT scanning so nodes identified on the CT scan outside the 5 areas described in the Binet system really should not be counted in a patients initial staging.

The Binet system is used more widely in Europe. The Rai system is used more often in the United States.


A small sample of fresh tissue, for example lymph node or bone marrow, which is taken for testing in a laboratory to establish or confirm an exact diagnosis of disease.

Blast Cells

are new immature blood cells of any type. Some blasts stay in the bone marrow to mature. Some travel through the blood system to other parts of the body before they mature. Even leukaemic white cells mature to some extent. So it is possible to have leukaemic blasts – in other words very young leukaemic white blood cells.

Blood cells

There are three main types of cells in the blood stream:

  • red cells which carry oxygen around the body
  • white cells – which fight infections
  • platelets – which help prevent bleeding.

The correct balance between each cell type must be maintained.

Blood count

A routine test. A small blood sample is taken to estimate the number and types of cells in the blood.

Bone marrow

The tissue which produces the blood cells. It is found in the hollow cavities of many of the bones of the body. Bone marrow contains the stem cells from which red and white blood cells and plateletsall blood cells develop. Examination of the bone marrow is an important part of the diagnosis of leukaemia and the monitoring of treatment.

Bone marrow aspirate

A small amount of bone marrow taken under local or general anaesthetic from either the hip bone (pelvis) or breast bone (sternum). The cells in the sample are then examined under the microscope to identify any abnormality in the developing blood cells. A trephine biopsy, may be taken at the same time.

Bone marrow transplant (BMT)

A bone marrow transplant is one type of stem cell transplant. Most transplants now use peripheral blood stem cells, rather than bone marrow.

Bone marrow is the spongy substance in the centre of the bones where are made.



Diseases caused by cells growing and dividing in an uncontrolled way, often called malignant disease.

Cancer related Fatigue (CRF)

Fatigue is common in all types of cancer and CLL is no exception. Although there’s no standard treatment for cancer related fatigue (CRF), the first step in treating CRF is often to identify and treat any of its underlying causes (such as anemia or poor nutrition) and other contributing health problems. Several therapies and lifestyle changes may help restore your energy. Read more


A type of fungus, candida infection in the mouth (oral thrush) is a common problem for immunosuppressed patients.


A tube which is inserted into the body, usually into a vein, to allow fluids or medicines to enter the body. The cannula can also be used to get blood samples.


A substance which has the ability to cause cells to become cancerous.


The development of cancer.

CT scan (or CAT scan)

CT is short for computer-assisted tomography. It is a sophisticated x-ray technique used to produce detailed internal images of the body, particularly the chest and abdomen. The patient lies on a table which gradually moves through the x-ray machine and the image is built up by a computer as a cross section through the body.


A hollow tube inserted into organs of the body so that gases or liquids can be put in or removed. For example, a catheter can remove urine from the bladder.

Cell biology

The study of the structure, composition and function of cells.

Cell markers

A cell marker is a particular chemical or protein on the outside of a cell which can be used to distinguish between different cells. This can be useful in diagnosis, in treatment or in research.


Individual units from which tissues of the body are formed.

Central line

A catheter (or tube) inserted into a large blood vessel to allow drugs to be given effectively and blood samples taken without repeated needle-pricks. Particular types include Hickman™ Line and Portacath™.


Treatment using anti-cancer drugs. A single drug or a combination of drugs may be used to kill cells or stop them growing and dividing. Although aimed at the cancer cells, chemotherapy also affects rapidly dividing normal cells such as in the hair and gut. This can cause hair loss and nausea, but this is usually temporary and reversible.


Chickenpox is caused by the varicella zoster virus (VZV), also known as human herpes virus 3 (HHV-3), is one of the eight herpes virus known to affect humans. The life cycle of VZV causes it to be very contagious.


is a chemotherapy drug that has been mainly used in the treatment of Chronic Lymphocytic Leukaemia (CLL) and can be given orally. It’s sometimes given in combination with rituximab. It can have side effects, such as low blood counts and infections, but is generally well tolerated. It’s sometimes used in people who aren’t fit enough to receive FCR or bendamustine.


Chromosomes carry the 30,000 or so genes which provide the inherited blue-print of each individual. In humans there are normally 23 pairs of chromosomes contained in the nucleus of each cell. Changes in the number or organisation of the chromosomes may play a key role in the development of cancer.


A chronic condition is one which starts slowly and progresses slowly. Chronic does not necessarily mean it is not serious. It may be diagnosed by chance following a routine blood test and before clinical symptoms appear.

Chronic Myeloid Leukaemia (CML) or Chronic Granulocytic Leukaemia (CGL)

A leukaemia which at first progresses slowly starting in bone marrow stem cells, which are the cells that produce all blood cells. There are about 500 new cases each year in the UK. People with this condition have large numbers of abnormal, mature granulocytes in the blood. Blood cells can be divided into two main types. These are:

  • lymphoid cells, which include lymphocytes and related cells and are key components of the immune system
  • myeloid cells, which are red blood cells, platelets and all other white cells – neutrophils, monocytes, eosinophils and basophils.

The disease is known as CML because the leukaemic cells in both the bone marrow and the circulating blood look like myeloid cells.

Clinical nurse specialist (CNS)

A qualified nurse who specialises in a particular clinical area. Some CNSs deal with all blood cancers while others may specialise in myeloma, lymphoma or another specific area. A CNS can provide information and expert advice about your condition and treatment.

Clinical trial

A carefully monitored trial of new forms of treatment. They can vary in design and size from trials of new treatments involving small numbers of patients to large national trials which compare variations in current therapies. Patients will always be informed when their treatment is part of a trial.


A clone is a group of genetically identical cells which all come from the same mother cell.

Clotting factors

Chemicals in the blood (factors I to XIII) which interact to make the blood clot.


Clotting of the blood. A complex reaction depending on a series of proteins (clotting factors) and platelets in the blood.

Consolidation treatment

A course of treatment with anti-cancer drugs given to a patient who is in remission with the aim of killing any remaining malignant cells.

Corticosteroids (steroids)

A group of man-made hormones used to treat some leukaemias and myeloma. May also be used to make it less likely that a graft will be rejected or that a patient will get graft versus host disease after a stem cell transplant. Side-effects include an increased risk of infection, rise in blood pressure, peptic ulcers, diabetes, and osteoporosis.


Cyclophosphamide is used to treat cancers and autoimmune disorders.


A drug used to prevent and treat rejection and graft versus host disease in transplant patients by suppressing their normal immune system.


The study of the structure of chromosomes. Cytogenetic tests are carried out on samples of blood and bone marrow taken from leukaemia patients to detect any chromosomal abnormalities associated with the disease. These help in diagnosing the condition and selecting  the best treatment.


A virus which is harmless in healthy people but may cause serious disease in severely immunosuppressed patients. Particularly dangerous following a stem cell transplant.


A condition in which there are fewer cells circulating in the blood.

Cytotoxic drugs

Anti-cancer drugs which act by killing or preventing the division of cells.



A chromosome abnormality in which all or part of a single chromosome has been lost.


A laboratory procedure to reduce the numbers of specific cell types in bone marrow donated for transplantation, for example removing some types of lymphocytes. This may be to avoid “mismatch” problems (particularly with unrelated donor transplants) or to selectively remove potentially leukaemic cells in an autograft.


We all go through spells of feeling down, but when you’re depressed you feel persistently sad for weeks or months, rather than just a few days.

Some people still think that depression is trivial and not a genuine health condition. They’re wrong. Depression is a real illness with real symptoms, and it’s not a sign of weakness or something you can “snap out of” by “pulling yourself together”. Read more

Diabetes Mellitus Type 2 – Type 2 Diabetes

Type 2 diabetes mellitus is a metabolic disorder that results in hyperglycemia (high blood glucose levels) due to the body:

Being ineffective at using the insulin it has produced; also known as insulin resistance and/or

Being unable to produce enough insulin


Differentiation is the process by which an immature stem cell becomes a mature cell which has a special function, such as a red cell or a platelet.


A drug to stimulate the excretion of urine by the kidneys. May be used during chemotherapy to ensure the excretion of anti-cancer drugs.


stands for deoxyribonucleic acid. It provides the essential building blocks for storing genetic material. There are four different building blocks of DNA (bases) arranged in coded sequence as genes which determine an individual’s inherited characteristics.

Donor lymphocyte infusion

If a patient has had an allogeneic stem cell transplant but the original disease returns, they may be given lymphocytes from the donor. This may get rid of the leukaemia cells.

Down Syndrome

A congenital condition in which some or all of the body cells have three copies of chromosome 21. This form of genetic abnormality is associated with an increased risk of leukaemia.


Eosinophil granulocytes ( Eosinophils)

are white blood cells and one of the immune system components responsible for combating multicellular parasites and certain infections. Along with mast cells, they also control mechanisms associated with allergy and asthma. Usually present in the circulation in very low numbers.


The science of studying the occurrence of disease in populations and relating this to genetic and/or environmental causes.


A rare cancer of the blood affecting immature red blood cells. This is a subtype of acute myeloid leukaemia.



Fatigue is a feeling of extreme tiredness which does not go away after rest or sleep. It may be caused by the disease itself or may be a side effect of treatment. It is one of the most common problems experienced by patients with cancer.

FCR = Fludarabine+Cyclophosphamide+Rituximab

treatment regimen typically used for fit patients as they consist of moderately intensive chemotherapy which although unlikely to cause hair loss, nausea, vomiting or diarrhoea do suppress the immune system making one prone to serious and potentially life threatening infections. The gold standard treatment for ‘fit’ patients.

Folic acid

A form of vitamin B obtained from green leafy vegetables, e.g. spinach. It is essential for copying of DNA and therefore the growth and division of cells.

Folic acid antagonist

A chemical which inhibits a cell’s capacity to use folic acid and to prevent cell division, for example methotrexate.


Fludarabine or fludarabine phosphate is a chemotherapy drug used in the treatment of hematological malignancies (cancers of blood cells such as leukaemias and lymphomas). It is a purine analog, which interferes with DNA synthesis.

 Full Blood Count (FBC)

A full blood count, or FBC, is a very common blood test. Doctors use this to check a person’s general health as well as screening for specific conditions, such as anaemia. The number of red cells, white cells and platelets in the blood are checked but it fails to capture the vast majority of white blood cells hiding out in the lymph nodes, spleen, bone marrow etc. Only roughly about 5-10% of the total number of WBC are seen in the peripheral blood.

FBC numbers are useful, but they do not give the whole picture.


An infective agent such as a mould or yeast, for example candida. Yeast infections can cause particular problems in immunosuppressed patients.


Gamma Globulin

Antibodies, which the body produces to fight infection, are a particular type of protein called gamma globulin. If patients cannot produce their own antibodies it may be possible to give gamma globulin to protect them against infection.


Normally the blood contains a variety of different gamma globulins (antibody molecules) to fight different infections. In some conditions there are large numbers of identical plasma cells (a clone) all producing the same gamma globulin – this is known as monoclonal gammopathy.


Formed from DNA and carried on the chromosomes, genes direct the activities of cells. They are responsible for the inherited characteristics which distinguish one person from another. Each human being has an estimated 23,000 separate genes.

Genetic code

DNA is made up of strings of four chemicals called bases, sometimes referred to as ‘letters’. The sequence of these bases makes up the ‘words’ of the genetic code.

Graft rejection

Rarely, when a patient has an allogeneic stem cell transplant, the new bone marrow will fail to start producing blood cells. When this happens it is called graft rejection. It may be possible to do a second transplant when this happens.

Graft versus host disease (GvHD)

A common, and potentially serious, complication of stem cell transplantation. This happens when some of the donor’s immune cells reject the patient’s own cells as foreign. The skin, liver and gut may be affected. It can occur in either chronic or acute forms and can be treated with immunosuppressive drugs.

Graft versus leukaemia (GvL)

When the allografted stem cells attack the patient’s leukaemia. If graft versus host disease is present but not severe, it may help to kill of leukaemia cells.


A type of white blood cell which includes basophils, eosinophils and neutrophils. They are filled with tiny granules which contain important proteins.

Growth factors

These are proteins which the body produces to control production of blood cells in the bone marrow. Some are available as drugs and can be used to stimulate normal white cell production.


Haematocrit (HCT)

(sometimes called, PCV) The proportion of the blood which is made up of red blood cells. The value is given as a percentage of red blood cells in a volume of blood. Normal values are 40-54% in males, 35-47% in females.


A doctor who specialises in diagnosing and treating blood disorders.


The study of blood diseases including leukaemia, lymphoma and myeloma.

Haemopoiesis or haematopoiesis

Term to describe the production and maturation of blood cells from very primitive stem cells. This takes place in the bone marrow which is a spongy tissue in the middle of the bones.

Haemoglobin (HgB, Hb)

​This is the protein in red blood cells which contains iron and carries oxygen around the body. Low haemoglobin levels means the red cells cannot carry out the vital oxygen transport efficiently. Lack of haemoglobin is called anaemia.


Bleeding either to the outside through the skin or internally.

Hairy Cell leukaemia (HCL)

HCL is a rare type of chronic leukaemia related to CLL. It develops slowly from white cells called B lymphocytes. When doctors look at the cells under a microscope, they have hair like outgrowths on their surfaces. It occurs in middle age onwards.


Inflammation of the liver.


Enlargement of the liver.

Herpes zoster

Herpes zoster commonly known as shingles is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body (left or right), often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute, short-lived illness chickenpox which generally occurs in children and young adults. Once an episode of chickenpox has resolved, the virus is not eliminated from the body and can go on to cause herpes zoster often many years after the initial infection.

Hickman™ line

A kind of central line in which the end of the line is outside the body, unlike a Portacath™. This makes it easier to give chemotherapy.


The investigation of tissue samples by chemical and microscopal analysis.

Hodgkin Lymphoma

was named after the doctor who first recognised it in 1832 – Thomas Hodgkin. Hodgkin lymphomas have a particular appearance under the microscope and they contain cells called Reed Sternberg cells.

Non-Hodgkin lymphomas look different under the microscope and do not contain Reed Sternberg cells.

HLA antigens

A complex family of genetically inherited proteins which are found on the surface of cells throughout the body. They determine the “match” between patient and potential donor in bone marrow transplantation. HLA- factors are inherited from the mother and father and so the greatest chance of having the same HLA-type is between brothers and sisters, i.e. 1 in 4.


Increased levels of calcium in the blood. It is often found in multiple myeloma because the bones are being damaged by the disease. It is dangerous if not controlled.



Term applied to diseases to indicate that their cause is unknown.


Immature cells are cells which can divide to produce new cells but they have not yet developed a specialised function. Immature cells differentiate and develop specialised functions such as a red cell or platelet. Differentiated cells no longer have the ability to divide and make new cells.

Immature Reticulocyte Fraction (IRF)

A useful parameter for blood transfusion assessment in anaemia.

Immune Thrombocytopenic Purpura (ITP)

A common disorder characterised by a shortage of platelets. This can cause bruising and spontaneous bleeding. Anti-platelet antibodies can be found in the blood in some cases. It may take an acute or chronic form. (The acute form is more common in children or following an infection. The chronic form is more common in adults.)

Immune deficiency

This is when the body is less able to defend itself against infections by bacteria, viruses and fungi. It may be caused by leukaemia or a related disease or by treatment for such a condition.

 Immune response

The immune response is how your body recognizes and defends itself against bacteria, viruses, and substances that appear foreign and harmful like tissues of another individual as in the rejection of an organ transplant..

Immune system

The immune system is a network of cells, tissues and organs which defend the body against infection by bacteria, parasites, fungi or viruses. It can also detect and destroy cancer cells but this does not always work effectively.


Proteins in the blood plasma which act as antibodies and play an important part in controlling infections. For examples  IgG, IgM, IgA, IgD and IgE.


This is when the body’s immune system is weakened by treatment. Deliberate immunosuppression is a necessary part of a stem cell transplant.


This is a term used to describe conditions which progress slowly. Lymphoma of this kind is usually called indolent rather than chronic.


Infection is the invasion of a host organism’s body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Chronic Lymphocytic Leukaemia (CLL), patients are prediposed to infections because of immunodeficiency related to the leukaemia itself and as a results of cumulative immunosuppression related to CLL treatment.


Inflammation is a local defence response to injury or tissue damage. An inflamed area is hot, swollen, red and tender.

Intramuscular injection

Injection into a muscle.

Intravenous infusion

Delivering antibiotics, blood products, anti-cancer drugs or nutrients into a patient’s vein over a long period of time.

Intravenous injection

Delivering drugs into a vein through a syringe.



An examination of cells to check the number, form and structure of chromosomes. This can give invaluable information to help in diagnosing the disease and deciding on treatment.

Karyotypic abnormality

Abnormality in the number, form and structure of chromosomes. Particular abnormalities are associated with particular subtypes of


Large granular lymphocytic leukaemia (LGL)

A chronic leukaemia of T lymphocytes that is usually linked with a decrease in other white cells and platelets or anaemia. LGL is a rare disease with important clinical differences from Chronic Lymphocytic Leukaemia (CLL).


From the Greek meaning ‘white blood’. Often referred to as blood cancer. The blood forming system is found in your bone marrow. The bone marrow is the soft inner part of some of your bones. People with leukaemia have large numbers of abnormal blood cells, usually of the white cell lineages, which take over the bone marrow and often spill out into the blood stream. There are many different types of leukaemia and the treatment varies for different types.

There are 2 main types of rapidly developing leukaemia:

Acute Myeloid Leukaemia (AML) and

Acute lymphoblastic leukaemia.

and 3 main types of slow developing leukaemia:

Chronic myeloid leukaemia,

Chronic Lymphocytic Leukaemia (CLL),

Hairy cell Leukaemia.


The development of leukaemia.


A way of collecting white blood cells before returning the remainder of the blood to the patient. It is used to reduce the white cell count when chemotherapy has to be avoided, for example during pregnancy.


Collective term for white blood cells.


Condition in which the number of white cells in the blood is greatly reduced. Leads to increased risk of infections.

Lymph Glands

see lymph nodes which can be referred to as lymph glands.

Lymph Nodes

A network of small glands throughout the body – particularly in the armpits, neck and groins – which contain both mature and immature lymphocytes.These glands are also called lymph nodes. They drain away waste fluid, waste products and damaged cells, and contain cells that fight infection.

Lymphatic system

This consists of the spleen, lymph nodes and areas of lymphoid tissue such as the tonsils. It plays a major part in the body’s immune response.


means swelling of the lymph nodes. The most common cause of lymphadenopathy is infection. For example, the lymph nodes in the neck often become swollen when you have a sore throat. Lympadenopathy can also be caused by cancer like CLL making the lymph nodes get bigger.


make up a quarter to a third of the white blood cells. There are two types of lymphocytes – B and T cells.The B lymphocytes make antibodies inresponse to disease or any cells the body recognises as foreign or damaged. This is part of the immune response. A cancer of the B lymphocytes is called a B cell lymphoma


This refers to the lymphatic system including lymphocytes and lymph nodes.


A cancer which originates in lymphoid tissue, including the lymph glands, liver, spleen, bowel, bone marrow, brain and occasionally other organs. The disease results from the uncontrolled production of lymphocytes. The general term includes over 30 different forms of the disease but there are two main categories: Hodgkin disease and non-Hodgkin lymphoma.


An increase in the production of lymphocytes. This may occur as a normal response to infection.



A macroglobulin is a large protein molecule, such as an antibody. In certain conditions, abnormal lymphocytes produce an excess amount of an abnormal antibody known as IgM. This is called macroglobulinaemia.


A type of white blood cell which leaves the blood and enters into tissues and acts as a scavenger, taking in and destroying particles such as bacteria.

Magnetic resonance imaging (MRI)

A body scanning technique which uses an intense magnetic field to build up a picture of organs inside the body. X-rays show bones clearly but not other tissues, MRI shows all tissues and organs clearly. It can often, but not always, tell the difference between normal and cancerous tissues.

Maintenance treatment

Treatment given for a period of months or years to maintain remission and get rid of any remaining leukaemic cells in the body, usually for acute lymphoblastic leukaemia.


A term applied to diseases where there is uncontrolled production of cells. See also cancer and benign.


Large cell in the bone marrow which produces platelets.

Minimal residual disease (MRD)

In cancer treatment, particularly leukaemia, MRD testing has several important roles: determining whether treatment has eradicated the cancer or whether traces remain, comparing the efficacy of different treatments, monitoring patient remission status as well as detecting recurrence of the leukaemia or cancer, and choosing the treatment that will best meet those needs .


Monoclonal cells are genetically identical cells, all of which come from the same mother cell. When the body responds to an infection it will produce a large number of monoclonal antibody-producing plasma cells. Because they are monoclonal, they all produce an identical antibody.

Monoclonal antibodies

Monoclonal antibodies – a type of protein made in the laboratory that can bind to substances in the body, including cancer cells. There are many kinds of monoclonal antibodies. A monoclonal antibody is made so that it binds to only one substance. Monoclonal antibodies are being used to diagnos and treat some types of cancer. They can be used alone or to carry drugs, toxins, or radioactive substances directly to cancer cells.

Monoclonal gammopathy

A healthy person’s blood contains a mixture of many different antibodies. In some diseases very large amounts of identical antibodies are produced; in these cases the antibodies produced are of no use to help fight infection. This is known as a monoclonal gammopathy (gamma globulin is another name for antibody molecules).

Monoclonal gammopathy of unknown significance (MGUS)

When a person is found to have a monoclonal gammopathy with no clear cause, this is called MGUS. MGUS is important because, although it is not an illness and does not cause any signs or symptoms, people with MGUS have a higher risk of developing myeloma. Each year on average about one in 100 people with MGUS will develop myeloma (or a related condition).


are a type of white blood cell (leukocyte) which is relatively large. They are the largest of all leukocytes and are part of the immune system. It acts as a scavenger and takes in larger bacteria and cell debris.

Monocytes constitute 2% to 10% of all leukocytes in the human body.

Monocytic leukaemia

Cancer of the blood due to overproduction of cells of the monocyte lineage.


Inflammation of the mouth and throat which may be caused by anti-leukaemia drugs.

Multidisciplinary Team MDT

A multidisciplinary team (MDT) is a group of doctors and other health professionals. An MDT will include experts from different fields such as pharmacists, nurses, dietitians. Together they will discuss an individual patient’s care and agree on a treatment plan.

Multi-Drug Resistance (MDR)

Multi-drug resistance occurs when malignant cells become resistant to a wide range of anti-cancer drugs. This usually happens because the cells can get rid of anti-cancer drugs before a high enough concentration to kill the cells is achieved. Resistance against most drugs will make the condition very difficult to treat.

Multiple Myeloma

A cancer caused by uncontrolled production of the white blood cells called plasma cells in the bone marrow. The malignant cells are not usually found in the blood and the tumour growth is restricted to the bones. This will damage bones and cause kidney problems unless it is treated.


A minute genetic change to DNA caused, for example, by exposure hazardous chemicals or copying errors during cell division. If these affect normal cell function they can lead to disease development.


Immature myeloid cells.


Collective term for all blood cells except lymphocytes. It includes granulocytes, monocytes, red cells and platelets.


A condition which affects both the myeloid and monocytic cells.


The process of production and maturation of myeloid cells.



Damage to the nerves which may occur as a complication of anti-leukaemia treatment. It usually affects the peripheral nerves (nerves to the arms and legs) and may be reversible when treatment is stopped or reduced.


A condition in which there are fewer neutrophils in the blood than normal. It may be caused by high dose chemotherapy and carries an increased risk of infection.

 Neutrophil Granulocytes (Neutrophils)

Are the most abundant (40% to 75%) type within the granulocyte group of white blood cells and form an essential part of the immune system. They are formed from stem cells in the bone marrow.

Non-Hodgkin lymphoma

A group of lymphomas which differ in important ways from Hodgkin disease and are classified according to various features of the lymphoma cells. The disease is said to be either low grade (slowly growing) or high grade (rapidly growing) and may be treated in a variety of ways depending on the exact diagnosis.



Genes carrying the potential to cause cancer.


A specialist in the diagnosis and treatment of cancer.


Packed Cell Volume (PCV)

see Haematocrit HCT


A condition in which there are reduced numbers of all types of blood cells.


A paraprotein is an abnormal protein similar to an antibody produced in certain conditions, for example in multiple myeloma. Its presence in the blood acts as an important marker of disease. Unlike normal antibodies, paraproteins do not fight infection.

Paroxysmal nocturnal haemoglobinuria (PNH)

A rare disorder characterised by an increased rate of break-down of red blood cells and decreased production of white blood cells and platelets. This leads to excretion of the red blood pigment, haemoglobin or chemicals produced when the body breaks down haemoglobin, in the urine. There may be thrombosis of veins. The cause is unknown and the severity of diseases variable. There is an association with aplastic anemia.


Development of a disease.


A doctor who specialises in the cause and diagnosis of disease and how disease affects the organs of a body.

Peripheral blood stem cell (PBSC)

Most blood-producing stem cells are found in the bone marrow. There are normally small numbers of stem cells in the circulation. These are known as peripheral blood stem cells.

Peripheral blood stem cell transplant

This is a stem cell transplant which uses stem cells collected from the blood rather than bone marrow .


Small red or purple pin-head spots on the skin. They are small haemorrhages and usually the result of a shortage of platelets.


The study of the action of a drug in the body over a period of time, including the processes of absorption, metabolism and excretion.


The characteristic appearance and function of a cell or tissue.

Philadelphia chromosome

An abnormal chromosome found in almost all cases of chronic myeloid leukaemia and in some cases of acute lymphoblastic leukaemia or other conditions. The Philadelphia chromosome is formed when part of chromosome 9 attaches to chromosome 22.


The liquid part of the blood which is left when the cells have been removed but the blood has not been allowed to clot. The only difference between plasma and serum is that serum cannot form a clot. There are some blood tests which are normally done on serum and some on plasma.

Plasma cell leukaemia

The end stage of myeloma when immature plasma cells are found circulating in the blood.

Plasma cells

Large cells which develop from B lymphocytes and form antibodies. These are not normally found in circulating blood but are restricted to the bone marrow and lymph nodes.


A solid tumour made up of myeloma cells, either in a bone or in the other tissues of the body. If there is only one such area, it is called solitary plasmacytoma. The key difference from myeloma is that plasmacytoma is localised with little or no involvement of bone marrow.

Plateau phase

Stable stage of disease in multiple myeloma following good response to anti-cancer treatment.

Platelets (Thrombocytes) (PLT)

are tiny cells produced by the bone marrow which are very important in preventing and controlling bleeding. They clump together to form a plug when bleeding occurs. They then release other chemicals that help the blood to clot and the blood vessel to heal.

Polycythemia rubra vera – PRV

A condition in which too many red blood cells are produced by the bone marrow. The total number of white blood cells and platelets may also be increased. The spleen is usually enlarged. How it is treated depends on the age of the patient and severity of the disease. This condition carries a small risk of developing into acute leukaemia.


A kind of central line in which the whole of the line is surgically implanted within the body, unlike a Hickman line™. A membrane just below the skin gives access by a simple skin puncture to a line running straight into one of the main blood vessels. This makes it easier to give chemotherapy.


The likely course of disease for a patient, particularly their chances of cure and complete recovery or length of survival.

Programmed Cell Death (PCD)

is death of a cell in any form, mediated by an intracellular program. PCD is carried out in a regulated process, which usually confers advantage during an organism’s life-cycle.


An immature lymphocyte. Not commonly seen in the blood but in prolymphocytic leukaemia they may be present in large numbers.

Prolymphocytic Leukaemia (PLL)

A variant of chronic lymphocytic leukaemia (CLL) in which the malignant cells look more immature. The disease requires chemotherapy and/or radiotherapy and sometimes removal of the spleen (splenectomy).


Precautionary treatment given to prevent a disease occurring.


A protein is a long string of building blocks called amino acids. Most proteins are folded into complex shapes. Structural proteins are, in turn, the building blocks of which cells are made. There are also specialised proteins such as enzymes, which control the chemical reactions of the body, and antibodies.


A schedule of treatment. For example, the number, frequency and timing of courses of anti-cancer drugs.


Itching, sometimes severe; this may be a significant problem in CLL.


The laboratory treatment of bone marrow harvested for an autologous bone marrow transplant or peripheral blood stem cell transplant to remove any remaining leukaemic cells so that there is less risk of relapse. The use of this procedure varies between treatment centres and depends on the type of leukaemia being treated.

Purine Analogue

are antimetabolites that mimic the structure of metabolic purines. Read more


A condition characterised by the occurrence of purple spots on the skin, often accompanied by bleeding from the gums.



Radiography is the use of x-rays, and other techniques, in diagnosis or in treatment of disease.


A radiographer is a person who is trained in radiography. Radiographers specialise in diagnostic radiography or therapeutic radiography. Diagnostic radiographers take x-rays, MRI or CAT scans to assist in diagnosis of disease or injuries. Therapeutic radiographers use x-rays, or other forms of radiation in treatment of disease.


A radiologist is a qualified doctor who specialises in diagnosis using X-rays or other scanning methods or in treatment using radiation.


The use of X-rays in the diagnosis of a disease.


The use of X-rays and other kinds of radiation in treatment. Radiotherapy kills cancer cells in the area of the body being treated, so it can be an effective treatment for localised disease, particularly in lymphoma and multiple myeloma. Side effects vary according to the type of treatment and the hospital staff will discuss these with the patient.

Rai system

A system for staging of chronic lymphocytic leukaemia (CLL) based on the clinical findings and on laboratory tests. It is used to decide whether to start treatment. An international or Binet staging system may also be used.

Stage 0 = Lymphocyte count greater than 5 x 109/1

Stage i = As stage 0 plus enlarged lymph nodes

Stage ii = As stage 0 plus enlarged liver or spleen

Stage iii = As stage 0 plus Haemoglobin less than 10g/dl

Stage iv = As stage 0 plus platelet count less than 100 x 109/l

The Rai system is used more often in the United States. The Binet system is used more widely in Europe.

Red blood cells (Erythrocytes)

The cells of the blood which contain the red protein haemoglobin and carry oxygen to all the tissues of the body. They give the blood its red colour.

Reed Sternberg cells

are a type of white blood cell called a B lymphocyte, that has become cancerous.


Not responding to treatment.

Refractory anaemia

A form of myelodysplasia which mostly affects red cell production by the bone marrow. In some cases the developing red cells show an internal ring of iron granules. These cells are called sideroblasts. Refractory anameia (RA) and refractory anaemia with sideroblasts (RAS) are the msot common forms of myelodysplasia.


This is when the disease comes back. In leukaemia this may show up in changes in the blood, bone marrow, CNS or tests even before the patient experiences any symptoms.


This is when the blood, bone marrow and general health of the patient return to normal, after treatment.


Immature red blood cells present in the blood stream in very low numbers (0.2-2%). Reticulocytes develop and mature in the bone marrow and then circulate for about a day in the blood stream before developing into mature red blood cells.

Raised numbers of reticulocytes may be found as a result of increased red cell production in the bone marrow, for example following haemorrhage.

Reticulocyte count is used to help determine if the bone marrow is responding adequately to the body’s need for red blood cells. The proportion of reticulocytes, haemoglobin and/or haematocrit in the blood can be used to evaluate the severity of any anaemia.


A class of virus including the HTLV-1 retrovirus that causes a rare form of human leukaemia.


Rituximab is a chimeric monoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells. Rituximab destroys B cells and is therefore used to treat diseases which are characterized by excessive numbers of B cells, overactive B cells, or dysfunctional B cells.

Richter syndrome

Development of a high grade, often localised, lymphoma in a patient who has Chronic Lymphocytic Leukaemia (CLL).


Secondary leukaemia

A leukaemia which develops following previous chemotherapy or radiotherapy or a pre-existing condition, such as myelodysplasia or polycythaemia rubra vera.


A general term to describe serious bacterial infection of the blood stream often associated with high fever.


The liquid part of the blood which remains after cells have been removed and the blood has been allowed to clot. The only difference between plasma and serum is that serum cannot form a clot. There are some blood tests which are normally done on serum and some on plasma.


Shingles, also known as herpes zoster, is an infection of a nerve and the skin around it. It is caused by the varicella-zoster virus, which also causes chickenpox. Anyone who has had Chickenpox can suffer from shingles. All CLL patients have a damaged immune system. This means that you can get shingles more often, it can spread through your body faster, and you could be in pain for some time.

Small Molecules

is a low molecular weight , <900 daltons, organic compound that may help regulate a biological process, with a size on the order of 10−9m. Most drugs are small molecules.


The spleen is a body organ on the left of the body, just under the diaphragm. It is part of the lymphatic system and filters the blood of old red blood cells and bacteria and other foreign bodies. The spleen also acts as a store for platelets and contains lymph node tissue and many lymphocytes. The spleen is often enlarged in leukaemia and may be removed as part of treatment for some cancers.


Surgery to take out the spleen. This is sometimes done in leukaemia or lymphoma as part of a patient’s treatment.


Enlargement of the spleen.


An assessment of the spread of disease through the body, for example in lymphoma. It is important for deciding on the best treatment. There are two schemes commonly used in CLL.

Binet Staging   commonly used in Europe

RAI Staging     commonly used in United States

Stem cells

The most primitive cells in the bone marrow from which all the various types of blood cell which develop into

Myeloid stem cells – become white blood cells called monocytes and neutrophils (a type of granulocyte)

Lymphoid stem cells – become white blood cells called lymphocytes

Erythroblasts – become red blood cells

Megakaryocytes – become platelets

Stem cell transplant

A procedure used to treat a variety of blood disorders including leukaemia, lymphoma and sometimes myeloma. The patient receives very high doses of chemotherapy and/or radiotherapy to treat the disease and suppress the immune system. This damages the bone marrow and makes the blood count fall. Replacement stem cells are taken from a matched donor – allogeneic stem cell transplant or from the patient themselves -autologous stem cell transplant under a general anaesthetic and returned to the patient through a vein (or central venous line) in a similar way to a blood transfusion. Peripheral blood stem cells are now used more commonly than bone marrow. Cord blood stem cells also may be used.

Subcutaneous injection

An injection into tissue immediately under the skin.

Supportive care

Supportive care includes aspects such as prevention and treatment of infection, blood transfusions, mouthcare, diet, pain management and dealing with complications of your illness or of your treatment.



An over-production of platelets.


Shortage of platelets, leading to problems with bleeding.


When blood clots form in a blood vessel, usually in a vein but sometimes in an artery. It is potentially life-threatening if left untreated.


A gland at the base of the neck which is part of the immune system. T cells are produced in the bone marrow but they cannot work as part of the immune system until they have passed through the thymus.

T Cell T lymphocyte

A type of white blood cell which matures in the thymus (hence T cells). It is involved in controlling immune reactions and in fighting viral infections. Uncontrolled production of this type of cell gives rise to T-cell leukaemia/lymphoma.

Total body irradiation

Radiotherapy often given in several doses before bone marrow transplantation. The aim is to kill any remaining abnormal cells in the patient. It also “clears” a space where in the bone marrow for the new marrow to occupy. It is used along with high does anti-cancer drugs. The hospital team will discuss the procedure and its side-effects individually with the patient.


The change of normal cell into a cancerous cell, or the acceleration of chronic myeloid leukaemia to a more acute phase with the production of large numbers of blast cells.


A chromosome abnormality in which the part of one chromosome has become transferred to another.

Trephine biopsy

Taking out a small piece of bone marrow under local anaesthetic. Unlike a bone marrow aspirate this includes bone and can be used to assess bone marrow structure, the number and distribution of all the blood cell types. The trephine biopsy is normally done at the same time as a bone marrow aspirate.


There are normally two copies of each chromosome – one inherited from each parent. When there are three copies of a chromosome present, this is called trisomy. One example of a condition caused by trisomy is Down syndrome. Leukaemia cells may have trisomy present even when other cells in the body are normal.


A mass of abnormal cells which may be benign or malignant.



A painless test which uses sound waves to create images of organs and structures inside your body.


Varicella Zoster Virus – VZV

This is the virus responsible for Chickenpox


A minute infectious agent which depends on the cell it infects to survive and to produce new virus particles.

Vitamin D

is a steroid hormone long known for its important role in regulating calcium and phosphorus, and in bone mineralization. Researchers are finding that vitamin D is a significant factor in CLL survival.


Waldenstrom macroglobulinaemia

A rare condition which has features in common with an indolent non-Hodgkin lymphoma and with multiple myeloma. The way the condition progresses is more like indolent non-Hodgkin lymphoma.

Watch and Wait, Watchful Waiting

Doctors often recommend a “Watch and wait” approach for those CLL patients found by chance or with asymptomatic stable disease as there is currently no evidence that treating patients leads to a better outcome in the long term.

White Blood Cells WBC Leucocytes

There are several different types of white cells in the blood. There are more of some types than others. They all play a part in the immune response – the response of the body to infection, or anything else the body recognises as foreign. These blood cells can be made very quickly and generally have a short life. Some only live for a few hours, others for a few days.

White blood cells are produced by the immune system to help defend the body against infection. They and their precursors are formed in the bone marrow and then travel through the blood to various parts of the body. There are several different types of white blood cells, the major ones being neutrophils (also called granulocytes), T-cells and B-cells.

They are part of the immune system. There are three main types:

  • granulocytes, mainly consisting of neutrophils
  • lymphocytes
  • monocytes.

They are formed in the bone marrow and it is their uncontrolled production which leads to leukaemia.



Used to diagnose and stage lymphoma and multiple myeloma. Also used to diagnose, for example, a chest infection.


Zoster Immune Globulin – ZIG

Gamma globulin against the chickenpox virus which can be given to an immunosuppressed patient following direct contact with the disease to prevent infection.

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