[Correlations between inflammatory activity, immunoglobulins and complement components in the synovial fluid of patients with rheumatoid arthritis and arthrosis].

In 81 synovial fluids (39 from rheumatoid arthritis and 42 from osteoarthritis patients), levels of IgG, IgM, IgA, and complement components C3, C4, and C3-proactivator were estimated. Lactatedehydrogenase (LDH) was used as the parameter of inflammatory activity. With increased LDH activity, the concentrations of all immunoglobulins rose in both groups. In the complement components, this positive linear correlation was demonstrated only in the osteoarthritic group. In rheumatoid arthritis, the results were best demonstrated by means of a regression type curve of the 3rd degree (p less than 0.01). In low inflammatory activity there was a rise in the level of the complement components. With higher LDH activity (greater than 500 U/l), however, there was a drop in the curve and the positive correlation changed to negative.