Modulation of serum smooth muscle antibody levels by levamisole treatment in patients with oral lichen planus.

BACKGROUND/PURPOSE: Serum autoantibodies have been found in patients with oral lichen planus (OLP). This study evaluated whether OLP patients had significantly higher frequencies of serum smooth muscle antibody (SMA) than healthy control individuals, and assessed whether levamisole treatment could modulate the serum SMA levels in OLP patients.

METHODS

This study used an indirect immunofluorescence technique to measure the baseline serum SMA levels in a group of 647 OLP patients and 53 controls. Ninety-five SMA-positive OLP patients were treated with levamisole under a regular follow-up schedule, and their serum SMA levels were measured after treatment.

RESULTS

The frequencies of serum SMA in patients with OLP (21.9%), erosive OLP (EOLP, 21.6%), major EOLP (17.9%), minor EOLP (24.2%), and nonerosive OLP (24.4%) were all significantly higher than that (0%) in healthy controls (all p < 0.001). Of 142 SMA-positive OLP patients, 95 were treated with levamisole under a regular follow-up schedule. Treatment with levamisole for a period of 2-29 months (mean, 9.4 ± 6.0 months) effectively reduced the high mean serum SMA titer (71.0 ± 7.2) at baseline to an undetectable level (0) in all SMA-positive OLP patients, regardless of different initial serum SMA titers.

CONCLUSION

There was a significantly higher frequency of serum SMA (21.9%) in OLP patients than in healthy controls. Treatment with levamisole for 2-29 months significantly reduced the high serum SMA to an undetectable level, and significantly improved the signs and symptoms in all treated OLP patients.