Heparin Precipitability of the Macroglobulin in a Patient with Wa1denstr in’s Macroglobulitiemia

By DAVID MuLlER T HE (.)CCURRENCE of high molecular weight serum globulins as a prominent feature of certain blood dyscrasias was first noted by Waldenstrom and has been the subject of many reports and of several recent reviews.’ Although in many of the patients there are features suggesting multiple myelcma, lymphocytic leukemia, or one of the malignant lymphomas, in mcst instances the picture is not characteristic enough to permit a diefinite diagnosis. This circumstance, together with the striking biochemical abnormahitv noted in these cases, has led to the general acceptance of \Valdenstrom’s macroglobuhinemia as a definite clinical entity. It is now considered! to he a neoplasm of the reticuuloendothelial system characterized by the proliferation cf an abnormal cell type, best described! as a l mphoid plasm L cell. from which the abnormal macroghohuulins probably originate. \Vith the excel)tion of several stuidies of the effect of the abnormal proteiml oh 1)100(1 coagulation, little is known regarding specific reactions of the macroglobuhin with substances normally found iii the body. Recently, in a