SOLUBLE HLA-I IN RHEUMATIC DISEASES

Objective: To study serum levels of Class I soluble HLA (sHLA-I) in pa tients with systemic lupus erythematosus (SLE), rheumatoid arthritis ( RA), polymy ositis or dermatomyositis (PM/DM) or scleroderma and to as sess the possible influence of ethnic factors on concentration in each disease group. Methods: Solid-phase enzyme linked immunoassay was use d to measure sHLA-I in the serum of 385 patients with varied ethnic ba ckgrounds (American-Caucasians, African-Americans, Georgian-Caucasians ) with rheumatic diseases. Studies on patients were compared to simila r measurements of 183 healthy individuals, Results: Mean sHLA-I levels were significantly higher in patients with SLE than those observed in healthy individuals or other rheumatic diseases. Highest concentratio ns were present in Georgian-Caucasian patients with SLE. American-Cauc asian patients with RA or scleroderma had higher sHLA-I levels than no rmal Caucasian individuals. The majority of patients with PM/DM in all ethnic subgroups were low secretors of sHLA-I, Conclusion: Mechanisms underlying the secretion of sHLA-I appear to differ among the rheumat ic diseases studied and various ethnic groups. These genetic differenc es in sHLA-I secret ion could be associated with ethnic and pathophysi ologic differences among these rheumatic diseases. (C) American Societ y for Histocompatibility and Immunogenetics, 1998. Published by Elsevi er Science Inc.