48 Hereditary Spherocytosis
Michelle To and Valentin Villatoro
Images of hereditary spherocytosis peripheral blood smears demonstrating marked spherocytosis and polychromasia. From MLS Collection, University of Alberta.
Image 1: 100x oil immersion. https://doi.org/10.7939/R34B2XK9F
Image 2: 50 x oil immersion. https://doi.org/10.7939/R3HM53096
Note:
The hereditary condition results in the formation of spherocytes with a decreased life span, decreased deformability, and a reduced surface-to-volume ratio causing increased osmotic fragility.1
Mutation:
Genetic mutations in the vertical protein linkages between the membrane and cytoskeleton: α-spectrin, β-spectrin, band 3, ankyrin, and protein 4.2.1-4 Results in loss of unsupported membrane overtime, and spherocyte formation.
Inheritance:1,3
Autosomal dominant or recessive depending on which mutations are inherited.
Clinical Features:1,3,4
Jaundice
Fatigue
Pallor
Splenomegaly
Iron Overload
Extramedullary erythropoiesis
Laboratory Results:1-3
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CBC: Hb: Decreased MCV: Decreased to Normal MCH: Normal to Increased MCHC: Increased (>360 g/L) RETIC: Increased RDW: Increased |
PBS: Spherocytes (Variable amounts) Polychromasia Increased inclusions (HJ bodies, pappenheimer bodies) +/- NRBCs |
BM: M:E Ratio: Decreased Erythroid Hyperplasia |
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Other Tests: Osmotic Fragility: Increased Eosin -5’-maleimide Binding Test: Decreased fluorescence DAT: Negative (AIHA with spherocytes are DAT positive)
Markers of EVH: Bilirubin: Increased LD: Increased Urobilinogen: Increased |
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References:
1. Gallagher PG. Abnormalities of the erythrocyte membrane. Pediatr Clin North Am [Internet]. 2013 Dec 15 [cited 2018 Jun 26];60(6):1349–62. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4155395/
2. Keohane EM. Intrinsic defects leading to increased erythrocyte destruction. In: Rodak’s hematology clinical applications and principles. 5th ed. St. Louis, Missouri: Saunders; 2015. p. 367–93.
3. Andolfo I, Russo R, Gambale A, Iolascon A. New insights on hereditary erythrocyte membrane defects. Haematologica [Internet]. 2016 Nov 22 [cited 2018 Jun 26];101(11):1284–94. Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5394881/
4. Da Costa L, Galimand J, Fenneteau O, Mohandas N. Hereditary spherocytosis, elliptocytosis, and other red cell membrane disorders. Blood Rev [Internet]. 2013[cited 2018 Jul 24];27(4):167–78. Available from: http://www.sciencedirect.com/science/article/pii/S0268960X13000192
