Correlation of plasma IFN-α with SLEDAI scores and association with organ involvement. (A) Plasma levels of IFN-α positively correlated with SLEDAI scores. Dots represent individual samples. Correlation analysis was performed by Spearman’s correlation coefficient. A P value less than 0.05 was considered as significant. (B) Based on clinical phenotype SLE patients were categorized into two broad groups and plasma levels of IFN-α were compared. Patients with major disease manifestation displayed significantly higher plasma levels of IFN-α than those with minor disease manifestation. Mean plasma levels of IFN-α were compared by unpaired t test and a P value less than 0.05 was taken as significant. IFN-α, interferon alpha; SLEDAI, systemic lupus erythematosus disease activity index; SLE, systemic lupus erythematosus.