Clonal analysis of B cells in the synovial membrane of patients with rheumatoid arthritis

Objective: To investigate the clonal characteristics of B cells in the synovial membranes of rheumatoid arthritis (RA) patients.Methods: The clonality of B cells at separate sites of the synovial membrane and other tissues from RA patients were investigated by a reverse transcriptase‐polymerase chain reaction with a VH framework 3 consensus primer and a subsequent single‐strand conformation polymorphism analysis.Results: Several dominant bands were observed in all synovial membrane samples and some of the dominants bands were common among the 2 or 3 separate regions of each synovial sample. The persistent existence of clonal B cells was observed in metachronous synovial fluid samples.Conclusion: Infiltrating B cells are oligoclonal and antigen‐driven mechanisms may play a role in the generation of clonal B cells in RA synovium. The stable presence of B cell clones in synovial fluid suggests the involvement of these clones in the perpetuation of the chronic inflammation in RA.