In-vitro synthesis of an anti-BI cold agglutinin complicating a case of lymphoma.

A woman of 47 with lymphocytic lymphoma was found to have a high-titer cold autoagglutinin of anit-BI specificity. Her group B erythrocytes autoagglutinated of anti-BI specificity. Her group B erythrocytes autoagglutinated in vitro and the direct antiglobulin reaction was positive, but she had no symptom of cold intolerance, no evidence of hemolysis, and she could receive transfusions of compatible group O erythrocytes. In addition, evidence for synthesis of the autoantibody by the lymphoma cells was obtained by short-term bone-marrow culture.