Anti-RANA antibody: a marker for seronegative and seropositive rheumatoid arthritis.

Without prior knowledge of the diagnosis or clinical status, sera from patients with various arthritides were screened for antibody against rheumatoid-arthritis-associated nuclear antigen (RANA) with indirect immunofluorescence on cytocentrifuged Raji cell preparations. 93% of 103 seropositive rheumatoid patients had anti-RANA antibody, in contrast to 16% of 50 normal controls and a mean of 19% (10-29%) of 122 patients with other arthritides. Anti-RANA antibody was also demonstrated in 95% of 21 patients with seronegative rheumatoid arthritis characterised by symmetrical erosive peripheral polyarthritis. No correlation was found in rheumatoid arthritis between anti-RANA antibody and disease activity, duration of disease, drug therapy, or extra-articular manifestations. RANA staining was absent in a non-Epstein-Barr-virus (EBV) cell line (Ramos). In 10 rheumatoid patients, discordance between the presence of antibodies to EBV antigens (viral capsid antigen [VCA] and EBNA) ANd RANA antibody was demonstrated. Anti-RANA antibody could be a useful marker for rheumatoid arthritis.