B LYMPHOCYTE -
Noun: The B cell. It is a type of lymphocyte that has matured in the bone marrow and mainly deals with bacteria and viruses that have been encountered before. Unlike T-cells , they do not circulate in the blood. Their home is in the Lymphatic System . When an invader is present, T-cells or macrophages present the invaders antigen to the B lymphocyte cell and it takes the invader into the tissues where it determines its exact size and shape. It then makes an exactly fitting straitjacket called an antibody that will fit that intruder and no other. Then it gets a production line going to produce thousands more of these antibodies. These move through the body and attach themselves to the micro-organisms which make them harmless and held until the macrophages or neutrophils come along to devour them. B-cells work with T-cells, macrophages and neutrophils to destroy harmful substances which have entered the body. B-cells can memorise the invader's antigen and become a long lived memory B-cell. This results in a quicker response to an infection. Each memory B-cell is specific to one particular antigen.

English - B = bone +

Latin - lympha = clear water +

Greek - kytos = anything hollow.

BAND CELL -
Noun: also a band, a stab, a stab cell, a band form. See stab cell for definition and pictures.

BASOPHIL -
Noun: One of the three granular white blood cells. It produces a product which prevents the blood from clotting.

This is an actual picture of a Basophil (in the centre) surrounded by some red blood cells. The basophil is named after a basic dye that stains it.

Greek - básis = basic (from the basic dye that stains it)

Greek - phîlos = lover

B-CELL -
Noun: An abbreviation for B Lymphocyte .

BIOPSY -
Noun: The surgical removal of tissue from a living body for examination and diagnosis. Also the medical examination of this tissue.

Greek - bios = life

Greek - ópsis = a viewing

BLAST -
Noun: An immature cell.

Greek - blastós = germ sprout

BLOOD -
Noun: Blood is essential for life. Blood carries oxygen, nutrients, hormones and chemicals to each of the sixty billion cells throughout the body. It plays an essential part in protecting the body from infection. Blood also helps the body remove waste and toxins. There are close to 30 trillion blood cells in an adult. Each cubic millimetre of blood contains from 4 1/2 to 5 1/2 million red blood cells and an average total of 7,500 white blood cells.

All types of blood cells are produced by the bone marrow . The bone marrow is the soft, spongy tissue found in the centre of the large bones in the body. There are four main components of blood: red blood cells, white blood cells, platelets, and liquid plasma . Since red and white blood cells are continually being destroyed, they body must continue to produce new ones in the bone marrow. About 2 1/2 million new red blood cells are created every second.

BLOOD TEST -
Noun: An action where one or more samples of blood are taken in order to determine blood levels, illness, tissue type, blood type or abnormalities.

The test result will have a number of abbreviations on it. I will outline them here so you can understand what they are about. Percentages and numbers are measured on the white blood cells so that by multiplying the percentage by the total count we have an actual number of each type of cell.

WBC -This measures the number of white blood cells in a very small quantity of blood (a billionth of a litre). It's the White Blood Cell Count

NE - is the neutrophil count or percentage. 50-60% is normal. Numbers for these and the following measurements differ for men, women and children. Those average figures can be found in booklets given to you by the support group.

LY - is the lymphocyte count or percentage. 20-40% is normal

MO - is the monocyte count or percentage. 2-9% is normal

EO - is the eosinophil count or percentage. 1 - 4% is normal

BA - is the basophil count or percentage. 0.5 - 2% is normal

RBC - is the red blood count.

HGB - is the haemoglobin count. It is considered a considerable anaemia when the haemoglobin drops below 10 for an adult.

HCT - is the haematocrit percentage of red blood cells in the sample.

MCV - is the mean (average) corpuscular volume. This measures the average volume of red blood cells. Normal is 84 to 99 fl (a femto-litre is a quadrillionth of a litre). Don't ask me how they can measure anything so small!

MCH - is the mean corpuscular haemoglobin which is a measurement of the amount of haemoglobin in an average cell. Normal is 26 to 32 pg (a picogram is a trillionth of a gram).

MCHC - is the mean corpuscular haemoglobin concentration which is a measurement of the average concentration of haemoglobin in red blood cells.

RDW - is the red blood cell distribution width.

RET - is the reticulocyte number or percentage. Don't want too many immature red blood cells.

PLT - is the platelet count. A count below 50 can result in spontaneous bleeding, and below 5, patients are at risk of severe life-threatening haemorrhaging .

MPV - is the mean (average) platelet volume which is a measurement of the average volume of platelets in the sample.

BMT -
Abbreviation: Bone Marrow Transplant

BONE MARROW -
Noun: The growth and development of normal cells are carefully controlled in the bone marrow to produce the correct numbers of each type of blood cell to keep the body healthy. Although, there are many different types of blood cells, all cells made in the bone marrow start as a single kind of cell called a stem cell . Stem cells make up only a very small proportion of the cells in the bone marrow.

This is a picture of normal bone marrow at medium magnification. About one half of the marrow is filled with red blood cells, white blood cells, platelets,and the cells which produce them. The large white cells are fat cells called steatocytes .

The bone marrow stores stem cells until the body needs a specific type of mature blood cell. Then, by using the stem cells in reserve, the bone marrow can rapidly produce many red cells, white cells or platelets. As stem cells mature, their features become more and more distinct until the stem cells develop into a specific type of blood cell. See Haematopoiesis for a picture of the process.

BONE MARROW BIOPSY -
Verb: In all patients with aplastic anaemia or myelodysplasia , a sample of bone, and bone marrow will be required. This involves obtaining a small amount of marrow from inside the bone with a needle and a sample of the bone itself showing the structure of the bone marrow cavity (small holes in the bone where the bone marrow grows). This is called a Bone Marrow Aspirate . The small piece of bone is called a bone marrow trephine. The samples used are usually obtained from the back of the hip bone. The procedure causes some discomfort but does not take very long. The procedure is usually carried out with sedation as well as local anaesthetic. It may be necessary to sample more than one site in aplastic anaemia or myelodysplasia to confirm that there is no other bone marrow disease present.

The main bone marrow finding which defines aplastic anaemia is that the few blood producing cells which are present, appear normal. The cells in aplastic anaemia do not show chromosome abnormalities.

In myelodysplasia or myelofibrosis , the numbers of blood producing cells are considerably reduced. The cells which are present in the bone marrow in these diseases are very abnormal under the microscope.

These are some red blood cells from a patient with Myelodysplasia. They are larger than normal and very irregular.

BONE MARROW TRANSPLANT -
Verb: A procedure used to treat Aplastic Anaemia , Myelodysplasia , Acute Leukaemia and some rare birth disorders with varying success. Healthy bone marrow is taken from the donor and infused into the bloodstream of the recipient: from here, it 'homes' in on the bone marrow, where it will grow. There is only a one in four chance that a full brother or sister will be a match.

Bone marrow transplantation is a risky procedure but success rates as high as 80% have been reported when the donor is a closely matched brother or sister. See graft-versus-host disease for a full appraisal of the risks.

The other major risk is that the immunosuppressant drugs used to control GVHD make the patient more susceptible to infections.

Patients with aplastic anaemia should be transplanted without the use of irradiation. Rejection of the graft is prevented by using a drug called cyclophosphamide often together with antibodies including antilymphocyte globulin which immunosuppress the recipient. The risk of graft failure, that is rejection of the bone marrow transplant, is greater for patients with aplastic anaemia than for patients with leukaemia .

There are some clear recommendations for treatment choices. Children, adolescents and young adults with brothers or sisters who are matched donors should be transplanted. Patients who have no brothers or sisters who are able to donate should be treated with immunosuppressive drugs. High risk patients, who have very low neutrophil counts, should receive intensive supportive treatment of blood and platelets prior to treatment.

For older patients who have brothers or sisters who are able to donate their bone marrow, the opinion is more divided. Some specialists recommend transplantation for any patient below the age of 50 years. In Europe, I am told they only will recommend it for patients below the age of 40 years. Other experts have recommended an initial trial of immunosuppressive drugs followed by a bone marrow transplant if the immunosuppressive drugs fail to work or if myelodysplasia or leukaemia later develop. Patients who fall into this group should discuss the choices carefully with their specialist before arriving at a decision on treatment.

Any patient diagnosed with severe aplastic anaemia or myelodysplasia should have rapid HLA tissue typing performed to identify possible marrow donors. Blood transfusions from prospective marrow donors should be avoided.

BONE MARROW TREPHINE -
Noun: 1. An instrument used for cutting out a piece of bone. In all patients with aplastic anaemia or myelodysplasia , a sample of bone, and bone marrow will be required. This involves obtaining a small amount of marrow from inside the bone with a needle and a sample of the bone itself showing the structure of the bone marrow cavity (where the bone marrow grows).

2. The small piece of bone is also called a bone marrow trephine. The samples used are usually obtained from the back of the hip bone. The procedure causes some discomfort but does not take very long. The procedure is usually carried out with sedation as well as local anaesthetic. It may be necessary to sample more than one site in AA or MDS patients to confirm that there is no other bone marrow disease present.

BUFFY COAT -
Noun: The superficial layer of yellowish or buff coagulated (clotted) plasma from which the red blood cells have settled out in slowly coagulated blood. It forms the scab on a scrape.

French - buffle = buffalo (the colour of its leather).

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