Changes in the Th1 or Th2 cytokine dominance in the synovium of rheumatoid arthritis (RA): a kinetic study of the Th subsets in one unusual RA patient

Objective. To perform a kinetic study of the Th1/Th2 balance in the rheumatoid arthritis (RA) synovium. Methods. Three different synovial tissue (ST) samples were obtained from one patient with erosive RA. The characterization of Th1 and Th2 responses was performed by interferon‐γ and interleukin‐4 measurements and by expression of the chemokine receptors CCR5 and CCR3. Measurements of secreted and surface immunoglobulin determined the types of B cells. Results. The first ST sample yielded 31 CD4+ T cell clones which showed an unusual Th2 dominant pattern in the inflamed synovium. The Th2 response was associated with predominantly synovial IgG B cells, and a predominantly Th1 profile in the peripheral blood. In contrast, ST samples obtained 2 and 2.5 yr later displayed first a Th0 and thereafter a Th1 profile, and the synovial B cell response was predominantly of IgM type. The T cell lines from the Th1/Th0 tissues expressed the Th1 marker CCR5 but not CCR3, while the T cells from the Th2 tissue expressed the Th2 marker CCR3 and no CCR5. Conclusion. These results demonstrate that a predominantly Th2 response can be associated with active erosive RA. However, the Th2 profile was not permanent and changed into a Th0 and thereafter a Th1 profile.