[Epstein-Barr virus infection in patients with systemic lupus erythematosus]

To verify the association of SLE activity to the avidity of IgG anti-EBV immune globulins.

Peripheral blood of 66 patients was analyzed, 22 had active SLE and 44 had inactive SLE. Presence and avidity index of IgG anti-EBV antibodies were determined by the ELISA method (Enzygnost anti-EBV/IgG - Dade Behring).

IgG anti-EBV test was positive for 21 (95.5%) patients in the active SLE group and 40 (90.9%) in the inactive group. The avidity index was 40 for 54 (88.5%) patients of which 34 (85%) belonged to the inactive SLE group and 20 (95.2%) to the active group. For 5 (12.5%) inactive SLE patients, the avidity index reached values ranging from 20 to 40; while for only 2 (3.3%) patients this index was lower than 20. Adopting 20, 30 or 40 as a cutoff point of the avidity index for diagnosis of reactivation of the EBV infection, the author classified as having reactivated infection, for active and inactive SLE groups, respectively: 1 (4.8%) x 1 (2.5%) patient; 1 (4.8%) x 4 (10%) patients and 1 (4.8%) x 5 (12.5%) patients.

Association between EBV activity and SLE was not demonstrated. This appears to indicate that persistence of infected B lymphocytes may be due to failure in the apoptosis mechanism or to the action of T cytotoxic lymphocytes, permitting evolution of SLE.