Urinary Interleukin-27 as a biomarker of systemic lupus erythematosus in children

Objectives Systemic lupus erythematosus (SLE) patients have a high-risk of developing lupus nephritis (LN). New markers are needed for early detection and for targeted treatment of LN. Aim This study aimed at investigating the urinary concentration of interleukin (IL)-27 of patients with SLE compared with healthy controls (HC). Patients and method An enzyme-linked immunosorbent assay (ELISA) was used to analyze urine concentration of IL-27 from 26 patients with LN, 14 patients without LN, and 25 HC. Results During activity of the disease there was an increased level of both total and corrected IL-27 in urine of LN patients compared with extra renal lupus patients and HC ( P <0.001). Urinary IL-27 level decreases following successful immunosuppressive treatment of LN patients ( P =0.001) and non-LN SLE patients ( P =0.009). Urinary IL-27 at cutoff value greater than 98 is a statistically significant discriminator of SLE from HC (area under the curve=0.919, P <0.001) with 80% sensitivity and 96% specificity. Corrected IL-27 at cutoff value greater than 56.14 is a statistically significant discriminator of SLE from HC (area under the curve=0.933, P <0.001) with 80% sensitivity and 100% specificity. Conclusions Urinary IL-27 expression decreases following successful immunosuppressive treatment of LN patients and non-LN SLE patients but still higher than HC in LN. So it can act as a biomarker for lupus nephritis in children.