Detection of anticardiolipin antibody in patients with cocaine abuse.

Anticardiolipin antibody, an immunoglobulin that binds negatively charged phospholipids, is considered to be an in vitro inhibitor of clot-based coagulation procedures. We adapted an enzyme immunoassay using stationary cardiolipin antigen to compare anticardiolipin antibody activity in the plasma of 44 cocaine abusers with its activity in the serum of 72 blood donors and a sample of 203 random specimens from healthy volunteers. Activity of 20 of the 44 abusers and 43 of 203 random specimens exceeded the donor control reference range. Patients using intravenous cocaine were more likely to have elevated activity than those who inhaled (P less than 0.05). Of 7 patients who had seizures or thromboembolic disorders, 5 were anticardiolipin antibody positive. Enzyme immunoassay may have predictive value for ischemic disease in cocaine abusers.