BACKGROUND: ABO autoantibodies are rare. Most reported examples have been antibodies with 4 degrees C titers not greater than 256 in @entity1 without apparent @entity5714 . Most high-titer, high-thermal-amplitude, complement-activating cold agglutinins are associated with @entity5714 . STUDY DESIGN AND METHODS: A 52-year-old @entity1 presented with acrocyanosis and mild @entity21374 , but no evidence of obvious @entity5714 . Regular plasmapheresis treatment was helpful in relieving the clinical symptoms associated with acrocyanosis. Serologic methods were used to study the @entity1 's RBCs and sera. RESULTS: The @entity1 's RBCs were strongly reactive with anti-C3 and anti-IgM and weakly reactive with anti-IgA. The patient's serum contained a high-titer, high-thermal-amplitude, IgMkappa autoanti-B, capable of activating complement in vitro. CONCLUSION: A @entity1 with a powerful ABO autoantibody is described. This @entity1 had acrocyanosis but did not appear to have an obvious @entity5714 . This case is a good example of the lack of correlation between in vitro serologic tests and in vivo reactions in individual @entity1 .

A high-titer, high-thermal-amplitude autoanti-B associated with acrocyanosis but no obvious XXXX .

@entity1 :: ('9606', 'Species') :: ['patients', 'patient', 'man'] @entity21374 :: ('MESH:C564372', 'Disease') :: ['small-vessel brain disease'] @entity5714 :: ('MESH:D000743', 'Disease') :: ['hemolytic anemia']
@entity5714 :: (MESH:D000743,Disease) :: ['hemolytic anemia']
