Smooth muscle antibody in heroin addicts.

The occurrence of autoantibodies and the concentrations of serum immunoglobulins were studied in 102 heroin addicts, 20 former addicts who had abstained from heroin for 1 year or more, and 40 normal control subjects. Antibodies to smooth muscle (46%) and lymphocytotoxic antibodies (30%) were detected in the active heroin users, and there was a significantly positive correlation between these autoantibodies. Absorption experiments strongly suggested antigenic cross-reactivity between smooth muscle and lymphocyte membrane antigens. The presence of smooth muscle antibody in addicts was not clearly correlated with signs of active liver disease. The occurrence of smooth muscle antibody (10%) and lymphocytotoxic antibodies (15%) was significantly lower in the former heroin addicts than among active drug users. A significant elevation of IgM was found in the active heroin addicts. Gamma-M globulin was lower among the former heroin addicts but still elevated when compared with normal controls.