Abstract
A new antigen which is different from Epstein-Barr virion antigen was detected in NC-37 cells infected with Epstein-Barr virus (EBV). A significant elevation of the titer of antibody to this new antigen was observed in the sera of the patients with rheumatoid arthritis (RA), but not in the sera of controls. From the standpoint of the etiologic role of EBV in RA, it is interesting that the antibody to the new antigen is not detected in the healthy persons in contrast to other viral antibodies. Therefore, it differs from any other viral antibodies so far reported.
