Hematology Vocab Flashcards
1) Cytokines
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?)
2) Erythropoietin
a cytokine that influences stem cells to develop into red blood cells (erythrocytes).
3) Blasts
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.
4) Innate immune response
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.
5) Adaptive immune response
(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.)
6) Humoral immunity
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.
7) Anemia
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).
8) Reticulocyte count
lab value that measures immature erythrocytes/RBC and is used to determine bone marrow activity.
9) Ferritin level
a lab test that is used to determine available iron stores in the body.
10) Hemoglobin
– 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.
11) Hemoglobinopathy
a group of inherited disorders characterized by structural variations of the hemoglobin molecule. For example, Hb S, seen in patients with sickle cell anemia.
12) Hemoglobin Electrophoresis
Lab test that identifies hemoglobin type.
13) Aplastic anemia
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.
14) Hemolysis
break down or destruction of RBCs
15) Hemolytic anemia
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.
16) Iron deficiency
inadequate iron supply for normal hemoglobin synthesis. May result from poor diet, poor absorption, or chronic bleeding.
17) Thalassemia
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.
18) Sideroblastic anemia
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.
19) Megaloblastic anemias
characterized by abnormal production of large, immature and dysfunctional erythrocytes. Includes B12 and folate deficiencies.
20) Coagulation Cascade
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.
21) Prothrombin Time (PT) and (INR)
A laboratory test that detects deficiencies in the extrinsic pathway of the coagulation cascade
22) Activated Partial Thromboplastin Time (APTT)
A laboratory test that detects deficiencies in the intrinsic pathway of the coagulation cascade.
23) D-dimer
a lab test that screens for venous thrombosis
24) Thrombocytopenia
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.
