CIRCULATING FC-GAMMA RECEPTOR-SPECIFIC AUTOANTIBODIES IN LOCALIZED AND SYSTEMIC SCLERODERMA

Background. Anti-Fc gamma receptor (anti-Fc gamma R) autoantibodies occur in patients with systemic scleroderma. Their clinical significance is unknown. Objective: Our purpose was to determine the incidence of anti-Fc gamma R autoantibodies in patients with localized and systemic scleroderma and to examine the relation between these autoantibodies, the severity of the disease, and the presence of other autoantibodies. Methods: Patients were placed into three clinical groups: three had diffuse systemic scleroderma, 47 had limited systemic scleroderma, and nine had localized systemic scleroderma. Antinuclear antibody titer and pattern were measured by indirect immunofluorescence with human epithelial (HEp)-2 cells and tissue sections, whereas anti-Scl-70 antibodies were measured by gel diffusion technique, Anti-Fc gamma R autoantibodies were measured in serum from patients and from 25 healthy persons by enzyme-linked immunosorbent assay with human recombinant Fc gamma RII (CD32) and Fc gamma RIII (CD16). Results: Anti-Fc gamma R autoantibodies were detected in 54% of patients and in none of the healthy control subjects. Autoantibodies were present in all three clinical groups and were most frequently directed against Fc gamma RIII. Correlation between patients' clinical and laboratory data and anti-Fc gamma R autoantibodies could not be demonstrated. Conclusion: The presence of anti-Fc gamma R autoantibodies in the serum of patients with either systemic or localized scleroderma and the lack of these autoantibodies in healthy persons suggest that they may play a role in the pathogenesis of these diseases.