Role of interleukin-6 and interferon-α in systemic lupus erythematosus: A case–control study and meta-analysis
Sarit Sekhar Pattanaik, Aditya K. Panda, Abhijit Pati, Sunali Padhi, Rina Tripathy, Saumya Ranjan Tripathy, Manoj Kumar Parida, Bidyut Kumar Das
Abstract
Background Systemic lupus erythematosus (SLE) is an autoimmune disorder affecting various organ systems with unknown etiology. Interleukin-6 (IL-6) and interferon-alpha (IFN-α) have been shown to have a major role in disease pathogenesis, and they correlate with SLE disease activity, but reports in the literature are conflicting. The present study aims to investigate the significance of IL-6 and IFN-α levels in SLE pathogenesis in an eastern Indian cohort. Material and Methods 70 SLE patients fulfilled SLICC 2012 criteria, and 40 age- and gender-matched healthy controls (HC) were enrolled. Baseline characteristics along with disease activity were recorded for all patients. Levels of IL-6 and IFN-α were measured by using ELISA. For the meta-analysis, published articles were searched through different databases. Two independent researchers extracted data, and the meta-analysis was performed with CMA v3.1. Results The plasma levels of IL-6 and IFN-α in SLE patients were significantly elevated compared to HC (IL-6: p < .0001, IFN-α: p = 0.01). SLEDAI score correlated positively with plasma IL-6 ( p < .0001, r = 0.46) and IFN-α levels ( p < .0001; r = 0.47). Meta-analysis of previous reports, including our case–control data, revealed higher IL-6 ( p < .0001) and IFN-α ( p = .005) in SLE patients compared to HC. Furthermore, IL-6 ( p < .0001, r = 0.526) and IFN-α ( p < .0001; r = 0.371) levels positively correlated with the disease activity. Conclusion IL-6 and IFN-α levels are elevated in SLE and they correlate with disease activity. Further studies with a larger sample size in different populations are required to validate our findings.