Predictive Role of Plasma Neutrophil Gelatinase-associated Lipocalin and IL-18 in Lupus nephritis

Lupus nephritis is complication of systemic lupus erythematosus. Laboratory markers have limited specificity and sensitivity for predicting the development of lupus nephritis. Therefore, utilizing, accurate, and non-invasive biomarkers for distinction between flare of nephritis and chronic kidney damage seems to be necessary. Promising biomarkers have been identified, such as Neutrophil Gelatinase -associated Lipocalin and interleukin-18. Objective: We have therefore undertaken to clarify the role of plasma Neutrophil Gelatinase -associated Lipocalin and interleukin-18 levels in detection of nephritis in patients with systemic lupus erythematosus. Methods: This study enrolled 40 patients with systemic lupus erythematosus and 40 apparently healthy persons as control. The patients were subdivided into two subgroups each one included 20 patients. Subgroup 1: with nephritis.Subgroup 2: without nephritis. All groups were subjected to measurements of, anti-double stranded DNA antibody, 24 hours urinary protein,plasma Neutrophil Gelatinase -associated Lipocalin and interleukin-18. Results: We found a highly significant rise in plasma concentrations of Neutrophil Gelatinase -associated Lipocalin (P ?0.01) and interleukin-18 (P?0.01) in patients with nephritis compared to those without and a highly significant increase of plasma Neutrophil Gelatinase -associated Lipocalin (P?0.01) and interleukin-18 (P?0.01) in all patients compared to control group. There were a positive correlation between Neutrophil Gelatinase -associated Lipocalin and interleukin-18 in group1 (P < 0.01, P = 0.856), and group 2 (P < 0.01, P = 0.979). Conclusions: we propose that in lupus nephritis the elevated plasma Neutrophil Gelatinase -associated Lipocalin and interleukin-18 may serve as markers of induction or maintaining of nephritis.