Decrease in circulating DNA, IL-10 and BAFF levels in newly-diagnosed SLE patients after corticosteroid and chloroquine treatment

► Untreated SLE patients were examined before & after steroid ± chloroquine treatment. ► All patients had elevated circulating DNA which notably decreased after treatment. ► Serum IL-10 and BAFF levels in untreated patients decreased after treatment. ► BAFF level in PBMC culture was not altered by chloroquine but correlated with SLEDAI. ► Chloroquine abolished CpG-induced B cell activation and IL-10 release in culture.