All are seen in sickle cell anemia EXCEPT:
High-Yield Explanation
ANSWER: (D) High hematocritREF: Harrisons Internal Medicine 17' edition Chapter 99. Disorders of Hemoglobin, CMDT2009 chapter 13 Blood Disorders > AnemiasSickle Cell Syndromes:Autosomal recessive disorderThe sickle cell syndromes are caused by a mutation in the -globin gene that changes the sixth amino acid from glutamic acid to valine.HbS polymerizes reversibly when deoxygenated to form a gelatinous network of fibrous polymers that stiffen the RBC membrane 8j increase viscosity. These changes also produce the sickle shape. These abnormalities provoke unpredictable episodes of micro vascular vasoocclusion and premature RBC destruction (hemolytic anemia).Clinical features:Most patients with sickling syndromes suffer from hemolytic anemiaProminent manifestations include episodes of ischemic pain (i.e.f painful crises) and ischemic malfunction or frank infarction in the spleen, central nervous system, bones, liver, kidneys, and lungsAutosplenectomy is seenJaundice, pigment (calcium bilirubinate) gallstones, splenomegaly, and poorly healing ulcers over the lower tibiaLaboratory FindingsThe hematocrit is usually 20-30%Reticulocytosis (10-25%)Irreversibly sickled cells comprising 5-50% of red cellsHallmarks of hyposplenism such as Howell-Jolly bodies and target cellsThe white blood cell count is characteristically elevated to 12,000-15,000/mcLThrombocytosis may occurIndirect bilirubin levels are highTreatmentNo specific treatment is available for the primary disease.Patients are maintained on folic acid supplementationTransfusions for aplastic or hemolytic crises.Pneumococcal vaccination reduces the incidence of infections with this pathogen.