Internal Medicine

0521779407-09 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:13

Hereditary Spherocytosis 699

■hemolytic anemia of varying degree

■mean corpuscular hemoglobin (MCHC) increased >35%

■mean cell volume (MCV) normal or slightly decreased

➣red cell distribution width (RDW) increased >14

➣hyperchromic, dense cells on RBC histogram

■if significant hemolysis – increased reticulocyte count, serum biliru-

bin, urinary and fecal urobilinogen, lactate dehydrogenase and

decreased haptoglobin

■negative antiglobulin (Coombs’) test

■increased osmotic fragility with “tail” of conditioned cells seen before

splenectomy

Imaging

■splenomegaly on abdominal ultrasound or radionuclide scanning

■cholelithiasis on abdominal ultrasound

differential diagnosis

■spherocytes seen in autoimmune hemolytic anemia, liver dis-

ease, thermal injury, micro and macroangiopathic hemolytic ane-

mias, Clostridial sepsis, transfusion reaction with hemolysis, severe

hypophosphatemia, ABO incompatibility, poisoning with certain

snake, spider, and hymenoptera venoms

■may be confused with rare Rh deficiency and intermediate hereditary

stomatocytosis syndromes

management

What to Do First

■assess degree of anemia, hemolysis, and potential complications

■RBC transfusion if symptomatic anemia

General Measures

■provide folate supplementation

■counsel/diagnose other family members

specific therapy

■splenectomy alleviates anemia and eliminates RBC transfusion

■indications for splenectomy are controversial; consider degree of

anemia and hemolysis, transfusion dependence, recurrent crises,

failure to thrive, signs of extramedullary erythropoiesis

■immunize with Streptococcus pneumoniae, Meningococcus, and

Haemophilus influenzae vaccines prior to splenectomy

■overwhelming post-splenectomy infection risk unknown