Value of serum and synovial fluid activin A and inhibin A in some rheumatic diseases

Aim: The purpose of the study is to measure serum and synovial fluid levels of activin A and inhibin A in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and osteoarthritis (OA) and correlate them with disease activity parameters. Subjects and methods: This study included 60 patients with various rheumatic diseases (20 with RA, 20 with SLE and 20 with OA), as well as 10 healthy controls. All of them were subjected to complete history-taking, examination and estimation of disease activity index. The following investigations were done for all subjects: serum and synovial activin A, inhibin A, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), anti-dsDNA and complements 3 and 4. Results: Serum levels of activin A were significantly higher in RA, SLE and OA than controls and in RA and SLE versus OA The mean values of serum inhibin A were significantly higher in all studied groups than controls. Synovial activin A and inhibin A were significantly higher in RA than OA. Positive correlations were found between serum activin A and disease activity parameters of RA. In SLE, positive correlations were found between serum activin A and inhibin A with ESR and SLE Disease Activity Index. Conclusions: Serum activin A and inhibin A were significantly higher in RA and SLE. Serum levels correlated positively with disease activity parameters of RA and SLE. However, synovial levels were significantly higher in RA than OA but showed no correlation or negative correlation with disease activity. We recommend further studies to detect the exact role of activin A and inhibin A in these conditions.