Smooth muscle antibody in patients with warts.

Sera from fifty-four patients with warts were tested for the presence of commonly found autoantibodies. Smooth muscle antibody (SMA) was detected at a significantly higher level than in a control group of healthy blood donors matched for age and sex, and was in the IgM class. The SMA-positive sera gave a microfilamentous staining pattern also in the IgM class, on fixed HEp2 tissue culture cells. Absorption of positive sera with smooth muscle removed both SMA staining and the anti-cellular staining.