Detection of antibodies to the Epstein-Barr virus nuclear antigens in the sera from patients with systemic lupus erythematosus

The sera from 65 patients with systemic lupus erythematosus (SLE) were examined by the immunoblotting method to detect antibodies to Epstein-Barr virus (EBV)-associated antigens, especially EBV nuclear antigens (EBNA), and compared with the sera from 66 healthy subjects roughly age- and sex-matched to the patients. Most sera from patients with SLE defined three major EBV-associated antigens with molecular weights (MW) of 70,000 (70K), 90K and 140K in Raji cells, which must correspond to the EBNA-1, 2, and 3, respectively. Approximately 70% of the sera from SLE patients demonstrated the antibodies to the 90K and 140K antigens, whereas the positive rates of these two antibodies were less than 10% in the sera from healthy subjects. The differences of these positive rates of the antibodies between SLE patients and healthy subjects were statistically highly significant. Antibody to EBNA-1 was conspicuously detected in the sera from both SLE patients and healthy subjects, although the difference between the two groups was still significant. The possible role of EBV infection was discussed on the basis of the pathogenesis of SLE.