Glossary

see lymphocyte lymphocyte: A type of white blood cell. B lymphoctyes, or B cells, help make special proteins called antibodies that fight bacteria and viruses (immune response). T lymphocytes, or T cells, help kill tumor cells and help the body's immune response.

A telomere telomere: A telomere is the end of a chromosome. Telomeres are made of repetitive sequences of non-coding DNA that protect the chromosome from damage. Each time a cell divides, the telomeres become shorter. EVvntually, the telomeres become so short that the cell can no longer divide. is the end of a chromosome. Telomeres are made of repetitive sequences of non-coding DNA that protect the chromosome from damage. Each time a cell divides, the telomeres become shorter. EVvntually, the telomeres become so short that the cell can no longer divide.

see secondary MDS secondary MDS: A type of MDS that is caused by a previous treatment foranother another disorder or disease. Treatments typically associated with secondary MDS include radiation therapy and chemotherapy used to treat cancer. Also called therapy-related MDS, T-MDS.

(THROM-buh-site) See platelet platelet: The smallest type of blood cell. Platelets help the blood to clot and stop bleeding. Also called a thrombocyte. .

(throm-buh-sie-tuh-PEE-nee-uh) A condition in which there is a shortage of platelets in the bloodstream. This results in a low platelet platelet: The smallest type of blood cell. Platelets help the blood to clot and stop bleeding. Also called a thrombocyte. count. Bleeding and bruising often occur with thrombocytopenia thrombocytopenia: (throm-buh-sie-tuh-PEE-nee-uh) A condition in which there is a shortage of platelets in the bloodstream. This results in a low platelet count. Bleeding and bruising often occur with thrombocytopenia. .

(throm-BOE-suss) A blood clot blood clot: A mass of blood that forms when platelets stick together. Harmful blood clots are more likely to happen in PNH. The term thrombus describes a blood clot that develops and attaches to a blood vessel. The term embolus describes a blood clot or other foreign matter that gets into the bloodstream and… (thrombus) that develops and attaches to a blood vessel.

An enzyme (protein) that helps break up blood clots, especially when used as soon as possible after the clot forms. Also called tPA.

TLK-199 TLK-199: Currently TLK-199 is in Phase II of the Food and Drug Administration's (FDA's) clinical trial for the treatment of myelodsyplastic syndromes (MDS). is a small molecule drug that stimulates the bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. to produce blood cells. Currently TLK-199 is in Phase II of the Food and Drug Administration's (FDA's) clinical trial clinical trial: A type of research study that tests how a drug, medical device, or treatment approach works in people. There are several types of clinical trials. Treatment trials test new treatment options. Diagnostic trials test new ways to diagnose a disease. Screening trials test the best way to detect a… for the treatment of myelodsyplasitc syndromes (MDS).

A protein that carries iron through the blood and to the organs where it is stored.

No longer needing any type of blood transfusion blood transfusion: A procedure in which whole blood or one of its components is given to a person through an intravenous (IV) line into the bloodstream. A red blood cell transfusion or a platelet transfuson can help some patients with low blood counts. .

A donor that is not a sibling or other familial relation of the patient (recipient).

Blood clot Blood clot: A mass of blood that forms when platelets stick together. Harmful blood clots are more likely to happen in PNH. The term thrombus describes a blood clot that develops and attaches to a blood vessel. The term embolus describes a blood clot or other foreign matter that gets into the bloodstream and… in a vein

A complex vitamin found in animal products. Vitamin B12 Vitamin B12: A complex vitamin found in animal products. Vitamin B12 helps maintain healthy red blood cells and nerve cells. A shortage of Vitamin B12 and folate can reduce blood cell production in the bone marrow. Also called B complex vitamin. helps maintain healthy red blood cells and nerve cells. A shortage of Vitamin B12 and folate folate: (FOE-late) A B-vitamin that is found in fresh or lightly cooked green vegetables. It helps the bone marrow make normal blood cells. Most people get enough folate in their diet. Doctors may have people with paroxysmal nocturnal hemaglobinuria (PNH) take a man-made form of folate called folic acid. can reduce blood cell production in the bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. . Also called B complex vitamin.

Cells in the body that fight disease and infection by attacking and killing germs. There are several types of white blood cells including neutrophils, eosinophils, basophils, lymphocytes and monocytes. Each type of cell fights a different kind of germ. Also called WBC, leukocyte leukocyte: (LEW-kuh-site) See white blood cell. .

The most current system for classifying leukemia and myelodysplastic syndromes myelodysplastic syndromes: (my-eh-lo-diss-PLASS-tik SIN-dromez) A group of disorders where the bone marrow does not work well, and the bone marrow cells fail to make enough healthy blood cells. Myelo refers to the bone marrow. Dysplastic means abnormal growth or development. People with MDS have low blood cell count for at… (MDS), it was developed by the World Health Organization (WHO). This system is based on patient data from around the world and on the most up-to-date knowledge of MDS. WHO Classification consists of 6 subtypes based on tests of the blood and bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. .