Abstract
Background and Aim: Despite the improvement in the medical care of the systemic lupus erythematosus (SLE) in the past two decades, the prognosis of lupus nephritis (LN) remains unsatisfactory. The aim of this study is to assess the relationship of urinary Foxp3 mRNA with disease activity in children with lupus nephritis as a noninvasive biomarker. Methods: This study included 40 children with SLE; 25 JSLE patients with clinical, pathological or laboratory evidence of renal disease and in renal nephritis activity (Active LN group), besides 15 patients were clinically, laboratory and biopsy diagnosed renal diseased but are not in renal activity (Inactive LN group) and 40 healthy children (control group). Disease activity was assessed by SLEDAI-2k score. Assessment of urinary Foxp3 messenger RNA (mRNA) expression was done in all subjects. Results: Active LN group had statistically significant higher Foxp3 mRNA compared to inactive LN and control groups (16.1±2.5, 5.9±2.1 and 1.1±0.6, respectively), p 3.3, it could detect cases of LN from controls with sensitivity 97.5% and specificity 87.5%. At a cutoff point > 10.3, it could detect active LN with sensitivity 96% and specificity 93.3%. Conclusion: Urinary FOXP3 mRNA expression was found to be significantly up regulated in patients with active LN, and was significantly associated with systemic and histological disease activity.