Frequencies of epstein‐barr virus—inducible IgM anti‐IgG B lymphocytes in normal children and children with juvenile rheumatoid arthritis

Abstract

The relative frequencies of IgM antilgG autoantibody (rheumatoid factor) producing cells induced by the polyclonal B cell activator Epstein‐Barr virus were measured in peripheral blood lymphocyte cultures of normal children and patients with juvenile rheumatoid arthritis. The frequencies of rheumatoid factor precursor B cells in normal children were lower than adults, but higher than neonates. The frequency increased with the age of the donor. In seronegative children with the systemic‐onset or pauclarticular‐onset types of juvenile rheumatoid arthritis, the number of IgM antiIgG inducible B cells was not significantly different (P>0.05) from age‐matched controls. Patients with seropositive juvenile rheumatoid arthritis or seropositive adult rheumatoid arthritis had significantly higher IgM antiIgG precursor cell frequencies than age‐matched normal subjects (PPP<0.05), analogous to results previously noted in adult seronegative rheumatoid arthritis. Thus, both children and adults with seronegative polyarticular rheumatoid arthritis had a deficiency in B cells that produce IgM antiIgG and that are induced by Epstein‐Barr virus. This distinguished them from seropositive juvenile rheumatoid arthritis and rheumatoid arthritis patients, normal subjects, and patients with the pauciarticular‐onset and systemic‐onset types of seronegative juvenile rheumatoid arthritis.