SOLUBLE CLASS-I HLA ANTIGENS IN PATIENTS WITH RHEUMATOID-ARTHRITIS AND THEIR FAMILIES

Objective. To study Class I soluble HLA in black patients with rheumatoid arthritis (RA) and their families, and to compare the findings to a group of healthy families of the same racial background. Methods. ELISA was developed to measure soluble HLA Class I (sHLAI) in the serum of 25 patients with RA. Family studies were performed in seven patients with RA and their 28 first degree relatives. These family studies were compared to similar measurements from 66 members of 13 healthy families. Results. Mean sHLAI values were higher in patients with RA than those observed in healthy black individuals. Patients with RA were characterized by elevated serum HLAI, while no change was observed between patients with RA positive or negative for rheumatoid factor. The relatives of patients with RA had high concentrations of sHLAI, compared to families without RA. Highest serum concentrations of sHLAI were found in individuals who were HLA-A23 or HLA-Aw33 positive. Conclusion. sHLAI may play a role in the pathophysiology of RA, and there is an association between either augmented release or production of sHLAI and specific HLA allotypes.