The Impact and Correlation of Epstein-Barr Virus Infection on Disease Activity of Systemic Lupus Erythematosus.

OBJECTIVE

To investigate the effect of Epstein-Barr virus (EBV) infection on immunological and biochemical parameters in patients with systemic lupus erythematosus (SLE) and its disease activity.

METHODS

Patients were categorized into mild-moderate (n=64, SLE DAI ≤6 and 7~12) and severe (n=36, SLE DAI >12) groups based on the SLE Disease Activity Index (SLE DAI). Clinical data and immunological indices of SLE patients were retrospectively analyzed and compared between the two groups. Pearson's correlation analysis was performed to analyze the relationship between EBV DNA load and complement 3 (C3) level and between ESR and SLE DAI score in SLE patients.

RESULTS

It was shown that the EBV DNA, CD4+/CD8+ ratio, and ESR in mild-moderate group were significantly lower than in severe group, but the frequency of CD8+ T cells and C3 level in mild-moderate group was higher than that in severe group. Multifactorial logistic regression analysis showed that elevated EBV DNA level was an independent predictor of disease activity in SLE (P<0.001, OR=6.106). Correlation analysis showed EBV DNA load was negatively correlated with C3 level (r=-0.6213, P<0.001), but positively correlated with ESR (r=0.6257, P<0.001) and SLE DAI score (r=0.8518, P<0.001) in SLE patients.

CONCLUSION

SLE disease activity was associated with patients' EBV DNA load, CD8+ T-cell ratio, complement C3, and ESR. Furthermore, elevated EBV DNA load is an independent influence on disease activity in SLE.