Antibodies to Epstein-Barr viral antigens in familial rheumatoid arthritis.

Serum antibodies to Epstein-Barr virus (EBV) were measured in members of twenty-nine families in which two or more first degree relatives had rheumatoid arthritis (RA). These patients were assessed clinically for activity of disease and their treatment recorded. A higher proportion of seropositive individuals was found among patients and affected kindred than among the non-affected groups. Antibody titres to Viral Capsid Antigen (VCA) tended to be higher in patients and affected kindred. In those individuals in whom antibody to Early Antigen (EA) was present there was a lower titre of antibody to Epstein-Barr Nuclear Antigen (ENBA). The results suggest that an immunoregulatory defect may exist in some patients with RA which allows for enhanced expression of EBV.