Evaluation Of Anemia Flashcards
Evaluation of Anemia
(A)- Useful equations in the evaluation of anemia:
a/ Mentzer index? = MCV/RBC
(1) Index >13 suggests iron deficiency anemia (IDA).
(2) Index <13 suggests thalassemia trait.
b/ Reticulocyte index = % reticulocytes × patient hematocrit/normal hematocrit
(1) >2 is indicative of increased RBC production in appropriate response to anemia.
(2) <2 is evidence of hypoproliferative anemia.
(B)- Other useful indices and tests
a). RBC distribution width (RDW):
(1) Normal RDW favors thalassemia but can also be elevated.
(2) Increased in IDA and sideroblastic anemia
b). Mean cell hemoglobin concentration (MCHC):
Allows for classification of anemia as hypochromic, normochromic, or hyperchromic
- Low MCHC in iron deficiency and thalassemia
- Elevated MCHC and spherocytes in hereditary spherocytosis and hemolytic disease of the newborn
C). Serum ferritin:
(1) Reflects total body iron stores after 6 months of age
(2) It is the first value to fall in early iron deficiency and is elevated with inflammation or infection.
d). Coombs test*:
(1) Direct (direct antiglobulin testing [DAT]): Detects antibody/
complement bound to patient’s RBCs by mixing prepared nonspecific antihuman globulin with patient’s blood. RBC
agglutination = positive test
(2) Indirect (indirect antiglobulin testing): Detects antibodies to RBC
antigens in patient’s plasma by mixing reagent RBCs with
patient’s serum. RBC agglutination = positive test
e. Hemoglobin electrophoresis:
(1) Involves separation of Hb variants based on molecular charge and size. All positive sickle preparations and solubility tests for sickle Hb (e.g., Sickledex) should be confirmed with electrophoresis or isoelectric focusing (component of mandatory
newborn screening in many states).
f). Blood smear interpretation?
(1) Howell-Jolly bodies = Impaired splenic function,
postsplenectomy
(2) Target cells = Hemoglobinopathies (HbSS, HbSC, HbC,
thalassemias), liver disease, postsplenectomy
(3) Bite cells, Heinz bodies = G6PD deficiency (during hemolysis)
(4) Toxic granulation of neutrophils, bandemia, atypical
lymphocytes = Infection
(5) Pencil poikilocytes = IDA, thalassemia
(6) Basophilic stippling = Lead poisoning, sideroblastic anemia
(7) Pappenheimer bodies = Sideroblastic anemia
(8) Hypersegmented neutrophils = Vitamin B 12, folate deficiencies
(9) Blasts = Leukemia, lymphoma
(10) Schistocytes (RBC fragments) = Microangiopathic hemolytic
anemia (MAHA), burns, valve hemolysis
(11) Spherocytes = Autoimmune hemolytic anemia, hereditary
spherocytosis, ABO incompatibility/hemolytic disease of the newborn
(12) Elliptocytes = Hereditary elliptocytosis, severe IDA
(13) Teardrop cells = Myelofibrosis (and other bone marrow
infiltrating processes), thalassemia
(14) Echinocytes (burr cells) = Frequent artifact finding; uremia,
pyruvate kinase deficiency
(15) Acanthocytes (spur cells) = Liver disease,
abetalipoproteinemia, hypothyroidism, vitamin E deficiency, severe malnutrition
