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

Background. Anti-Fc gamma receptor (anti-Fc gamma R) autoantibodies oc cur 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 a nd pattern were measured by indirect immunofluorescence with human epi thelial (HEp)-2 cells and tissue sections, whereas anti-Scl-70 antibod ies were measured by gel diffusion technique, Anti-Fc gamma R autoanti bodies were measured in serum from patients and from 25 healthy person s by enzyme-linked immunosorbent assay with human recombinant Fc gamma RII (CD32) and Fc gamma RIII (CD16). Results: Anti-Fc gamma R autoant ibodies were detected in 54% of patients and in none of the healthy co ntrol subjects. Autoantibodies were present in all three clinical grou ps and were most frequently directed against Fc gamma RIII. Correlatio n between patients' clinical and laboratory data and anti-Fc gamma R a utoantibodies could not be demonstrated. Conclusion: The presence of a nti-Fc gamma R autoantibodies in the serum of patients with either sys temic 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.