CD79A and systemic lupus erythematosus: Consistent with previous studies implicating EBV reactivation in SLE disease flare [36], SLE patients with high disease activity had higher EBV-VCA IgA (mean ISR 1.34 vs. 0.97; p = 0.041) and EBV-EA IgG levels (mean ISR 1.38 vs. 0.90; p = 0.007) compared to those with low disease activity (Table 2).