Serum Soluble Interleukin 2 Receptor Alpha vs. Urinary Parameter and Serum Immunological Markers as a Monitoring Tool of Treatment Response of Lupus Nephritis and their Relation to Lupus Nephritis Class on Renal Biopsy

Abstract

Background: Lupus Nephritis (LN) is one of the most common and serious manifestations in SLE patients that causes significant morbidity and mortality. Current conventional biomarkers for LN are sometimes unable to predict treatment response of lupus nephritis. Recently serum soluble interleukin-2 receptor alpha (sIL-2 R alpha) is shown to be a good marker to predict treatment response of LN. Objective: To compare serum sIL-2R alpha with other commonly used markers as a marker of treatment response of LN and their relation to the LN class in renal biopsy. Methods: This prospective observational study was conducted in the Department of Nephrology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh from July 2018 to August 2019. Twenty seven patients who were diagnosed with lupus nephritis after kidney biopsy were included in this study. Serum soluble interleukin-2 receptor alpha, 24 hrs UTP, anti-dsDNA, complements level (C3 & C4) were measured in all patient at baseline, 3-months and 6- months after treatment. Serum soluble interleukin-2 receptor alpha level was measured by ELISA and is expressed as pg/mg. Serum sIL-2R alpha as well as conventional biomarker value were compared before and after treatment and in between treatment response and non-response group. Results: Serum sIL-2R alpha levels were significantly higher in patients of proliferative lupus nephritis (Class III & Class IV) than non-proliferative lupus nephritis (Class V) at baseline (3934.3 ± 1095.2, 3934.3 ± 1095.2 & 1801.98 ± 205.8 pg/L respectively) and levels were decreased significantly 6 months after treatment (p <0.001). Serum sIL-2R alpha levels were also significantly higher in non-remission proliferative group then remission proliferative group (4071.60 ± 769.91 vs 5169.20 ± 394.76) with p value 0.008 at baseline. In contrast no significant difference were observed for 24 hrs UTP levels at baseline between this group which suggest that serum sIL-2R alpha are more sensitive marker than 24 hrs UTP in predicting treatment response of lupus nephritis. Conclusions: Serum sIL-2R alpha might be a valuable serological biomarker to diagnose and to predict and monitor the treatment response of lupus nephritis.