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The Leukemia/Bone Marrow Transplant Program of BC

Hematology Dictionary
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H

Haematocrit
see packed cell volume

Hematologist
A doctor specializing in the diagnosis and treatment of blood diseases.

Hematology
The study of blood diseases including leukemia.

Hematopoiesis
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 bones.

Hemoglobin
The iron containing pigment in red blood cells, which carries oxygen around the body. Lack of hemoglobin is called anemia. Normal values are between 12-18 grams per 100 ml of blood.

Hemopoiesis
See hematopoiesis

Hemorrhage
Bleeding either to the outside through the skin or internally.

Hairy Cell Leukemia
A rare leukemia related to chronic lymphocytic leukemia and characterized by the presence of abnormal cells with "hair- like" projections. It occurs in middle age onwards. Treatment may involve removal of the spleen. Current therapy includes the use of interferon and, more recently, new cytotoxic drugs.

Hepatitis
Inflammation of the liver.

Hepatomegaly
Enlargement of the liver.

"HICKMAN"® Catheter
A narrow plastic tube or catheter, which is inserted, under anesthetic, into a major blood vessel in the chest. It is used for patients undergoing intensive therapy and provides a route for taking blood samples and administering drugs without repeated needle puncture of a vein. "HICKMAN"® is a registered trademark of C.R. Bard, Inc. and its related company, BCR, Inc.

Histiocytosis
Histiocytes are cells produced in the bone marrow and assist in recognizing invading bacteria and parasites. Histiocytes are normally found in skin, liver, lung, gut, lymphatic glands, spleen, bones and parts of the brain but in histiocytosis they wander elsewhere in the body.

Histiology
The investigation of tissue samples by chemical and microscopical analysis.

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 that is 1 in 4.

Hodgkin's Disease
A type of lymphoma. There are approximately 1,300 new cases per year in the UK.

HTLV
Human T cell Lymphotropic virus. A family of viruses, which invade T cells. Includes a rare leukemia virus, HTLV-1, found primarily in Japan and the Caribbean causing an increased incidence of T cell leukemia's in these populations. The family also includes the AIDS causing-virus, HIV.

Hypercalca
Increased levels of calcium in the blood. It is often associated with multiple myeloma due to degradation of the bones. It is dangerous if not controlled.

Hypersinophilic Syndrome
In some patients the number of eosinophils in the blood is markedly and persistently raised with no obvious cause such as a parasite infection. These patients have either hypereosinophilic syndrome (HES) or eosinophil leukemia.

 

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The information in this glossary is cited with permission from the Leukemia Research Foundation web site.

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