[Platelet abnormalities in dysproteinemias (author's transl)].

Hémorrhagic manifestations are relatively common in dysproteinemias (7 à 15% in myeloma, 36% in macroglobulinemia) but they are not often related to a qualitative platelet defect. In the present work we have studied the influence of some monoclonal immunoglobulins on the function of isolated normal platelets. The results show that platelet aggregations to collagen and ADP are impaired in presence of high concentration of paraproteins (about 50 gm/l). The molecular size of the protein is also important. This is in agreement with most studies and support the hypothesis that paraproteins interfere with platelet activity.