Correlation of plasma IFN-α with 25-OH vitamin D
and its levels in SLE patients and controls. (A) Plasma 25-OH vitamin D3 levels correlated negatively with IFN-α levels. Dots represent individual samples. Correlation analysis was performed by Spearman’s correlation coefficient. (B) Treatment-naïve patients displayed significantly higher levels of IFN-α compared to treated cases and healthy controls. Mean plasma levels of IFN-α in different clinical categories were compared by ANOVA followed by Tukey’s multiple comparisons test. A P value less than 0.05 was considered as significant. IFN-α, interferon alpha; SLE, systemic lupus erythematosus.