Pseudo-thrombotic thrombocytopenic purpura: A rare presentation of pernicious anemia

Context: Schistocytes are fragmented red blood cells due to the flow of blood through damaged capillaries and indicate endothelial injury. They are typical of microangiopathic hemolytic anemia seen in life threatening conditions like disseminated intravascular coagulation or thrombotic thrombocytopenic purpura/hemolytic uremic syndrome .We report a rare sub-acute presentation of pernicious anemia with hemolysis, thrombocytopenia and numerous schistocytes that was initially diagnosed as a more serious thrombotic thrombocytopenic purpura. Case Report : A 31-year-old Caucasian woman presented with fatigue and paresthesia of both feet for 1 week. Past medical history included hypertension and gastro-esophageal reflux disease. Examination revealed scleral icterus and pallor. Examination of the abdomen did not show hepatosplenomegaly. Initial laboratory tests showed severe anemia, and low platelets. Indirect bilirubin and serum Lactate De Hydrogenase were elevated. Prothrombin time, partial thromboplastin time, serum fibrinogen, and serum fibrin degradation product levels were normal. Peripheral smear revealed numerous schistocytes, anisocytosis and macro-ovalocytes. Thrombotic thrombocytopenic purpura (TTP) was suspected due to the constellation of sub-acute onset of fatigue and paresthesia along with thrombocytopenia, schistocytes and an elevated LDH. Plasmapheresis was initiated for possible TTP. However, platelet count worsened despite plasmapheresis for 4 days. On re-evaluation, vitamin B 12 was found to be low. Treatment with intra-muscular vitamin B 12 led to symptomatic and hematologic improvement. Pernicious anemia was confirmed by the presence of anti-intrinsic factor antibodies, elevated serum gastrin level and atrophic gastritis. Conclusion : Clinicians must be aware of unusual clinical presentation of vitamin B 12 deficiency with schistocytes as the management is simple and effective.