Hematology Vocab

Question 1

1) Cytokines

Answer 1

proteins that are involved in cell-to-cell communication and control stem cell differentiation into specific cell types. (For example, will the stem cell eventually become an erythrocyte, a leukocyte or a platelet?)

Question 2

2) Erythropoietin

Answer 2

a cytokine that influences stem cells to develop into red blood cells (erythrocytes).

Question 3

3) Blasts

Answer 3

These are blood cells that are in an immature stage of development; they are between the stem cell stage and the fully-differentiated stage. Blasts should only be found in bone marrow, and not in circulating blood. If they are found in circulating blood, a malignancy is likely.

Question 4

4) Innate immune response

Answer 4

this is how granulocytes respond to foreign cells. It is an inborn, non-specific response that does not arise from a previous infection and has no memory. It includes the complement cascade which involves >30 proteins that act in sequence to neutralize, attract, enhance, kill, etc.

Question 5

5) Adaptive immune response

Answer 5

(acquired immunity) this is how T-lymphocytes respond to foreign substances. It involves a method of learning and remembering specific antigens. (FYI: Monocytes play roles in both innate and acquired immunity.)

Question 6

6) Humoral immunity

Answer 6

this involves B-lymphocytes, which become plasma cells, which can produce antibodies which target antigens for destruction. The interaction of antibody and antigen will activate the complement cascade. Humoral immunity has both innate and adaptive properties; it is the type of response that occurs with an incompatible blood transfusion or an Rh incompatibility. It results in the destruction of the donor’s RBCs.

Question 7

7) Anemia

Answer 7

Low red blood cell count (RBC) and/or low hemoglobin (Hgb) and hematocrit (Hct). Caused by decrease in production, (such as in bone marrow failure), increase in destruction, (such as a hemolytic anemia), or blood loss (such as colon cancer).

Question 8

8) Reticulocyte count

Answer 8

lab value that measures immature erythrocytes/RBC and is used to determine bone marrow activity.

Question 9

9) Ferritin level

Answer 9

a lab test that is used to determine available iron stores in the body.

Question 10

10) Hemoglobin

Answer 10

– a protein-iron compound in erythrocytes that carries O2 and CO2. There are many different types of Hb; infants have Hb F; most adults have Hb A1.

Question 11

11) Hemoglobinopathy

Answer 11

a group of inherited disorders characterized by structural variations of the hemoglobin molecule. For example, Hb S, seen in patients with sickle cell anemia.

Question 12

12) Hemoglobin Electrophoresis

Answer 12

Lab test that identifies hemoglobin type.

Question 13

13) Aplastic anemia

Answer 13

anemia due to decreased red cell production. Usually seen with pancytopenia (all blood elements are low) and results from the failure of bone marrow to generate new cells.

Question 14

14) Hemolysis

Answer 14

break down or destruction of RBCs

Question 15

15) Hemolytic anemia

Answer 15

a disorder involving a premature destruction of RBCs. Causes can be an inherited defect in RBCs, or non-inherited causes such as an immune disorder.

Question 16

16) Iron deficiency

Answer 16

inadequate iron supply for normal hemoglobin synthesis. May result from poor diet, poor absorption, or chronic bleeding.

Question 17

17) Thalassemia

Answer 17

an inherited hemolytic hemoglobinopathy caused by deficient synthesis of hemoglobin polypeptide chains. Classified according to which chain is involved, resulting in two major categories of alpha-thalassemia or beta-thalassemia.

Question 18

18) Sideroblastic anemia

Answer 18

a group of disorders that have reduced hemoglobin synthesis resulting in iron accumulation in the mitochondria of erythroblasts. (Erythroblasts are erythrocytes that are not fully developed and are still in the bone marrow; they contain nuclei and mitochondria, which are not found in mature erythrocytes.) Sideroblasts, which are erythroblasts with iron deposits, are found in the bone marrow of patients with sideroblastic anemia. Causes vary, but include chronic alcoholism and lead poisoning.

Question 19

19) Megaloblastic anemias

Answer 19

characterized by abnormal production of large, immature and dysfunctional erythrocytes. Includes B12 and folate deficiencies.

Question 20

20) Coagulation Cascade

Answer 20

the series of steps that ultimately leads to the formation of a clot. Each step requires activation of an enzyme (“factor”) before the next step can proceed. Initial activation is usually through either the intrinsic pathway or the extrinsic pathway.

Question 21

21) Prothrombin Time (PT) and (INR)

Answer 21

A laboratory test that detects deficiencies in the extrinsic pathway of the coagulation cascade

Question 22

22) Activated Partial Thromboplastin Time (APTT)

Answer 22

A laboratory test that detects deficiencies in the intrinsic pathway of the coagulation cascade.

Question 23

23) D-dimer

Answer 23

a lab test that screens for venous thrombosis

Question 24

24) Thrombocytopenia

Answer 24

a decrease in platelet number as a result of decreased production, increased destruction or consumption, or splenomegaly. It is the most common cause of bleeding disorders.

Question 25

25) Idiopathic thrombocytopenic purpura

Answer 25

a deficiency of platelets that results in bleeding into the skin and other organs (purpura). May be either acute or chronic. Easy bruising and mucosal bleeding.

Question 26

26) Thrombotic thrombocytopenic purpura

Answer 26

a disorder that includes a deficiency of platelets, hemolytic anemia, fever, neurologic abnormalities and purpura with the deposition of microthrombi within the capillaries. Usually seen in adults.

Question 27

27) Thrombophilias

Answer 27

inherited hypercoaguable blood disorders.

Question 28

28) Lymphocytic leukemia

Answer 28

a malignant disease where bone marrow is replaced with proliferating leukocyte precursors, specifically involving lymphocytes.

Question 29

29) Myeloid leukemia

Answer 29

a type of leukemia with acute and chronic forms. Involves precursor cells and mature cells in the myeloid line (i.e. non-lymphocytes).

Question 30

30) Myeloproliferative disorders

Answer 30

a broad term for a group of conditions that are characterized by proliferation of myeloid tissue in the bone marrow. Includes CML, but also polycythemia vera (increase in both myeloid cells and RBCs, Hgb, and blood volume) and several others.

Question 31

31) Lymphoma

Answer 31

A neoplastic disease involving lymphocytes and the lymphatic system. Two major classifications are Non-Hodgkin lymphomas and Hodgkin lymphomas.

Question 32

32) Multiple Myeloma

Answer 32

neoplastic disease of plasma cells. Bone pain and kidney dysfunction are common.

Question 33

Immunohematology

Answer 33

the study of blood cell reactions for the therapeutic replacement of blood. Principles of immunohematology are used in blood banks.

Question 34

Blood bank

Answer 34

responsible for collecting, storing and processing blood for transfusions, as well as providing patient compatible transfusions with the hope of preventing a transfusion reaction.

Question 35

35) Transfusion components

Answer 35

blood transfusions may involve whole blood (rare), plasma only (fluid portion of blood without the cellular elements; it contains all coagulation factors), packed RBCs, cryoprecipitates, or platelets only.

Question 36

36) Cryoprecipitates

Answer 36

a transfusion component that is prepared by thawing fresh frozen plasma and collecting the precipitate. High in factor VIII and fibrinogen. Used in massive hemorrhage.

Question 37

37) Transfusion complications

Answer 37

can be categorized as acute (within 24 hours), or delayed, and infectious or non-infectious. The most common fatal complication is TRALI (transfusion-related acute lung injury) where antibodies in the transfusion activate the recipient’s immune system and trigger non-cardiogenic pulmonary edema.

Question 38

38) Umbilical cord blood

Answer 38

parents can donate their infant’s cord blood for stem cell transplants to treat oncologic, genetic, hematologic and immunodeficiency disorders.