[Changes in the acid-base status of the synovial fluid in rheumatoid arthritis patients]

The study of changes in joint fluid (JF) acid-base balance in RA patients to evaluate severity of joint lesions, efficacy of on-going therapy and to predict appearance and persistence of RA remission.

A routine examination and measurements of JF pH of the affected joints and venous blood before and during the treatment were performed in 65 RA patients with articular or articular-visceral forms (46 and 19 patients, respectively). 19 patients were seropositive and 20 seronegative by rheumatoid factor. A group of 17 patients suffering from osteoarthritis deformans with synovitis served control.

Inflammation in RA is running with lowering of JF pH in the affected joints and with acidic shift in the acid-base balance manifesting as compensated metabolic acidosis in blood. JF pH of the affected joints inversely correlated with activity of the inflammation. Its changes were more pronounced in RA systemic lesions and in the seropositive variant.

JF pH may be used for assessment of inflammation activity in RA.