Impaired in vivo and in vitro antibody responses to bacteriophage phi X 174 in juvenile rheumatoid arthritis.

Immunologic abnormalities described in juvenile rheumatoid arthritis (JRA) have been largely confined to mitogen or antigen driven proliferation assays. We studied antigen specific antibody production using the neoantigen bacteriophage phi X 174 in vivo and in vitro; defective responses were found in all 8 patients with JRA studied. These could not be attributed to circulating anti-T cell antibodies, but may relate to lymphocyte subset abnormalities found by 2 color analyses. These immunologic aberrations may play a direct role in the pathogenesis of JRA or, alternatively, may be a secondary event.