Complications of heparin administration in normal individuals.

The incidence, severity, and pathogenic mechanism of heparin-associated thrombocytopenia with both bovine and porcine heparin administration were studied in forty normal males randomized to one of four treatment groups: beef lung heparin #1, beef lung heparin #2, porcine gut heparin, and saline control. All of the subjects receiving heparin developed a reversible increase in serum transaminases (SGOT, SGPT). However, other measurements of liver function were normal. Thirty-three percent of these heparinized normals had decreased platelet counts. The incidence of platelet count decrease was similar for both bovine and porcine heparins, but 4 of the 20 normals receiving bovine heparin had platelet counts less than 150,000/microliters. Immune pathogenesis was investigated by analyzing plasma from the volunteers for both platelet antibody and immune complexes. None of the men had increased platelet-associated IgG. Among the ten subjects with decreased platelet counts, IgG immune complexes were detected in three and C1q in seven. The heparin-associated thrombocytopenia appears not to be mediated by a platelet antibody. More probably it reflects a direct effect of the heparin on platelets.