Group A variants defined with a monoclonal anti-A reagent.

Unusual serologic findings mimicking the B(A) phenomenon were noted in two group B blood donors using blended murine monoclonal anti-A reagent. With additional studies, including a binding experiment using affinity chromatography, the presence of aberrant group A activities was confirmed. This observation suggests that persons with atypical B(A) phenotype may warrant further investigation to delineate the ABO blood group.

Paroxysmal cold hemoglobinuria in a patient with Klebsiella pneumonia.

A case of paroxysmal cold hemoglobinuria (PCH) occurring in a patient with Klebsiella pneumonia is described. The first sign of PCH in the patient was erythrophagocytosis. The Donath-Landsteiner (D-L) antibody exhibited anti-P specificity both serologically and biochemically.