Subtle cobalamin malabsorption in a vegan patient: evolution into classic pernicious anemia with anti-intrinsic factor antibody.
Classic pernicious anemia with abnormal Schilling test results developed in a previously described vegan patient who had coexisting subtle cobalamin malabsorption (demonstrable by abnormal ovalbumin-cobalamin absorption test results but normal Schilling test results). This suggests that the ovalbumin-cobalamin absorption test or a modified version may serve as a prodromal phenomenon to identify patients at risk for developing pernicious anemia. The patient's transformation was also accompanied by the appearance of serum anti-intrinsic factor antibody. A modified assay retrospectively detected this antibody a year earlier than did the standard assay, indicating that such modification enhances the sensitivity of this useful test.
D000752:Anemia, Pernicious / Q000175:diagnosis / Q000209:etiology*; D000906:Antibodies / Q000276:immunology*; D014676:Diet, Vegetarian; D005750:Gastric Juice / Q000276:immunology; D006801:Humans; D007437:Intrinsic Factor / Q000276:immunology*; D008286:Malabsorption Syndromes / Q000378:metabolism; D008297:Male; D014805:Vitamin B 12 / Q000378:metabolism*
D000906:Antibodies; D007437:Intrinsic Factor; D014805:Vitamin B 12