Erythrocyte Disorders Flashcards
Anemia caused by sudden loss of blood volume:
- Increase in heart rate, respiratory rate, and cardiac output
- Redistribution of blood flow from skin and viscera to heart, brain, and muscle
Anemia caused by slow loss of blood:
- Decrease in hemoglobin-oxygen affinity by increasing the production of 2,3-biphosphoglycerate
- Increase in EPO production by kidneys
refers to the production of erythroid precursor cells that are defective
Ineffective erythropoiesis
these defective precursors often undergo apoptosis
Ineffective erythropoiesis
Conditions under Ineffective erythropoiesis
megaloblastic anemia,
thalassemia,
sideroblastic anemia
refers to the decrease in the number of erythroid precursor in the bone marrow
Insufficient erythropoiesis
Conditions under Insufficient erythropoiesis
iron deficiency anemia, renal disease, aplastic anemia, acquired pure red cell aplasia, infection
most important among the RBC indices
MCV
a measure of the average RBC volume in fL
MCV
key in the morphologic classification of anemia
MCV
index of variation of cell volume in a red blood cell population
RDW
the coefficient of variation of RBC volume expressed in percentage
RDW
an important tool to assess the bone marrow’s ability to increase RBC production in response to anemia
Reticulocyte count
determines whether an anemia is due to an RBC production defect or to a shortened survival defect
Reticulocyte count
serves as a quality control to verify the results produced by automated analyzers
Peripheral blood film
may help in establishing the cause of anemia
Bone marrow aspiration and biopsy
valuable if an inappropriately low reticulocyte count and a microcytic anemia are present
Iron studies
helpful in investigating a macrocytic anemia with a low reticulocyte count
Serum vitamin B12 and serum folate assays
can differentiate autoimmune hemolytic anemias from hemolytic anemias due to other causes
DAT
Central pallor is 1/3 of the red cell diameter
Normochromia
Central pallor is >1/3 of the red cell diameter
Hypochromia 1+
Central pallor is >2/3 of the red cell diameter
Hypochromia 2+
Central pallor is 3 quarter of the red cell volume
Hypochromia 3+
Thin rim of hemoglobin is left
Hypochromia 4+
Decreased or absent central pallor
Hyperchromia
variation in red cell size
Anisocytosis
characterized by an MCV of less than 80 fL with small RBCs (less than 6μm)
Microcytic anemia
are caused by conditions that result in reduced hemoglobin synthesis
Microcytic anemia
Big five conditions of Microcytic anemia
Thalassemia
Anemia of Chronic Inflammation
IDA
Lead poisoning
Sideroblastic anemia
Conditions under Defective heme synthesis
IDA,
chronic inflammatory states,
sideroblastic anemia,
lead poisoning
Conditions under Defective globin synthesis
Thalassemia,
Hb E disease
characterized by an MCV in the range of 80-100 fL
Normocytic anemia
develop due to premature destruction and shortened survival of RBCs
Normocytic anemia
Conditions under Intrinsic causes
Membrane defects,
hemoglobinopathies,
enzyme deficiencies
Conditions under Extrinsic causes
Immune and nonimmune RBC injury
characterized by an MCV greater than 100 fL with large RBCs (greater than 8 μm)
Macrocytic anemia
arise from conditions that result in megaloblastic and nonmegaloblastic red cell development
Macrocytic anemia
are caused by conditions that impair synthesis of DNA
Megaloblastic anemia
are related to membrane changes owing to disruption of the cholesterol-phospholipid ratio
Nonmegaloblastic anemia
characterized by a progressive loss of storage iron
Stage 1 of iron deficiency
