To investigate the rate and extent of infection by Epstein-Barr virus (EBV), cytomegalovirus, and herpesvirus 6 in families (affected and nonaffected members) with multiple cases of rheumatoid arthritis (RA).
Viral DNA was detected by polymerase chain amplification in cells from saliva and peripheral blood. Human leukocyte antigen pedigrees were characterized.
Viral DNA, particularly EBV, was detected in increased frequency (p = 0.029) in the patients with RA compare to their nonaffected relatives.
We suggest that in RA multicase families, increased frequency of viral infection is likely a consequence of the disease state and/or due to gene(s) as yet unidentified.