Gamma globulin inhibition of fibrin clot formation.

Myeloma gamma globulins have been reported to interfere with fibrinogen-fibrin conversion. A patient with multiple myeloma is described with a gamma globulin IgG1lambda concentration of 11 g per dl, prolonged thrombin time and poor clot retraction. Purified gamma globulin from the patient's serum and from normal serum caused prolongation of the thrombin time and reptilase clotting time assays in both normal plasma and in solutions of bovine fibrinogen. In addition, fibrin clots formed during the thrombin time assays were found to be ultrastructurally abnormal. This data suggests that the interaction of gamma globulin in the polymerization of fibrin may, in at least some cases, be due to nonspecific protein interaction.