title: How to diagnose (and not misdiagnose) pernicious anaemia.
abstract: The diagnosis of pernicious anaemia requires the demonstration that megaloblastic haemopoiesis is present, that vitamin B12 deficiency is present and that gastric intrinsic factor is lacking. The first, generally requires marrow aspiration, the second is satisfied by a low serum B12 level and the third by B12 absorption tests with and without intrinsic factor. The reasons why these three criteria are the minimum criteria for diagnosis are discussed as well as pitfalls in the performance of tests and in interpretation of data. Finally, a low serum vitamin B12 with impaired B12 absorption improved by the addition of intrinsic factor in the absence of blood changes indicates severe atrophic gastritis but not pernicious anaemia.
authors.affiliation: Department of Haematology, Northwick Park Hospital, Harrow, Middlesex, UK.
authors.forename: I
authors.initials: I
authors.lastname: Chanarin
mesh_terms: D000752:Anemia, Pernicious / Q000175:diagnosis*; D003951:Diagnostic Errors; D006801:Humans