Pathophysiology
1) family of six separate but related syndromes – common elliptocytosis, pyropoikilocytosis, spherocytic hereditary elliptocytosis, stomatocytic elliptocytosis (rare) and South Asian ovalocytosis (rare) 2) all are caused by defects in dimer interactions of the cytoskeleton protein spectrin, which causes fragmentation and disruption of the cytoskeletal lattice 3) acquired elliptocytosis can occur in myelodysplastic disorders
Signs and Symptoms
1) can range from being clinically silent and discovered only on exam of peripheral blood smear to a severe hemolytic anemia 2) any of the variants that are homozygous and hereditary pyropoikilocytosis have moderate to severe anemia 3) splenomegaly
Characteristic Test Findings
Laboratory – 1) mild to severe anemia 2) decreased haptoglobin levels 3) increased reticulocyte count 4) increased osmotic fragility test
Histology/Gross Pathology
1) common elliptocytosis – at least 15% of RBCs are elliptical on peripheral blood smear 2) pyropoikilocytosis – has red cell fragments, poikilocytes, or microspherocytes 3) spherocytic hereditary elliptocytosis – has ovalocytes and spherocytes
Associated Conditions
1) protein 4.1 defects and glycophorin C deficiency 2) some resistance to malaria occurs 3) renal tubular acidosis
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