Immunoglobulin V genes in rheumatoid arthritis.

Recent studies have revealed that a broad spectrum of Ig V genes (VH, V kappa, V lambda) contribute to the rheumatoid factor (RF) and non-RF produced by B cells in patients with rheumatoid arthritis (RA). This result contrasts with the restricted V gene use of paraprotein IgM RF. Certain VH and VL genes, however, appear more often in RA than expected from random expression, including some of the paraprotein-associated V genes. Many V genes expressed in RA are the same as those found in the fetal/CD5+ repertoire, suggesting an important role for CD5+ B cells in RA. Somatic mutations suggest that the B-cell response in RA is at least in part antigen-driven, although many Ig in RA have little or no mutation. Improved detection of V-gene polymorphisms now enable study of Ig V gene RFLP in RA.