T Lymphocyte Subclasses in Rheumatoid Synovia as Analysed with Monoclonal Antibodies and Functional in Vitro Tests

Abstract

Inflammatory synovial T lymphocytes were released by mincing rheumatoid arthritis (RA) affected synovium, by digesting the material with collagenase plus DNAse, and isolating by sheep red cell rosetting and density centrifugation. There was a wide variation in the T-helper (T_m, OKT4) and T suppressor (T_g, OKT8) lymphocyte ratio in the individual synovia, ranging from 0.55 to 1.57. The mean ratio of T_m/T_g lymphocytes as well as OKT4/OKT8 lymphocytes was somewhat lower in the synovium (and in the blood) of RA patients than in the blood of healthy persons, but the differences were not significant (p=0.56 and 0.09, respectively). The helper and suppressive capacity of synovial T lymphocytes on T-dependent B-cell maturation to immunoglobulin synthesis was analysed by co-culturing them with normal B or (unseparated) T+B cells in the presence of pokeweek mitogen. Eluates where the helper/suppressor ratio was above 1.2 produced at least some T cell help and lacked suppressor capacity, whereas eluates with a T helper-/suppressor ratio below 1.20 provided a strong suppression and lacked the capacity of T-cell help. On the whole, we were unable to demonstrate any uniform pattern of inflammation with regard to T-cell subsets in the rheumatoid synovium. However, it seems that monoclonal antibodies provide good markers with which to analyse the inflammatory T cells in situ, and that these markers correlate well to the functional capacity of these cells in vitro.