Waldenström's macroglobulinaemia secreting a paraprotein with lupus anticoagulant activity: possible association with gastrointestinal tract disease and malabsorption.

A 51 year old man with Waldenström's macroglobulinaemia presented with a malabsorptive syndrome related to extensive small bowel lymphangiectasia caused by immunoglobulin accumulation. The patient's plasma had strong lupus anticoagulant activity and the IgM lambda paraprotein displayed specificity for the negatively charged phospholipids phosphatidyl serine and phosphatidyl inositol, as well as the neutral phosphatidic acid. Despite treatment for the macroglobulinaemia the patient died and at necropsy was found to have myocardial ischaemia and segmental infarcts in the spleen and kidney. The coexistence of these relatively rare findings suggests a possible association between Waldenström's macroglobulinaemia with gastrointestinal manifestations and paraprotein specificity for phospholipid.