One of the challenges of treating patients with lupus nephritis (LN) is to assess disease activity. The aim of this study was to measure the urinary neutrophil gelatinase-associated lipocalin (uNGAL) and urinary soluble chemokine (C-X-C motif) ligand 16 (CXCL16) levels in children and adolescents with systemic lupus erythematosus (SLE) and investigate whether they are elevated in active LN. This study was conducted on 80 patients diagnosed as SLE by the Systemic Lupus International Collaborating Clinics criteria and 60 apparently healthy individuals as controls. Global and renal disease activities were evaluated by Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) and renal SLEDAI, respectively. uNGAL and urinary CXCL16 were measured for all participants by ELISA. Renal biopsy was done for all cases at initial diagnosis and was graded using ISN/RPS classification. uNGAL and CXCL16 were higher in patients than in the controls (8.9 ± 3.56 ng/dl and 1067 ± 367 ug/L vs. 2.26 ± 1.95 ng/dl and 471 ± 106 ug/L, respectively). uNGAL had higher sensitivity and specificity than urinary CXCL16 as predictor of LN (95% and 90% vs. 85% and 80%, respectively). There was significant positive correlations between uNGAL levels, 24-h urinary proteins (r = 0.732, P = 0.001), and SLEDAI (r = 0.359, P = 0.001). There was also significant positive correlations between urinary CXCL16 levels, 24-h urinary proteins (r = 0.47, P = 0.001), and SLEDAI (r = 0.17, P = 0.001). uNGAL and CXCL16 were reliable indicators of the activity of LN.

Sickle cell disease (SCD) is a hereditary hemoglobinopathy characterized by abnormal hemoglobin production which leads to hemolytic anemia and intermittent occlusion of small blood vessels, which further leads to tissue ischemia, chronic organ damage, and organ dysfunction including urinary system. To measure the serum levels of cystatin-C and beta 2 microglobulin in pediatric patients with SCDand to investigate their significance as early biomarkers of glomerular and/or renal tubular dysfunction. This study was conducted among 70 children with SCD and 40 age and sex-matched children as a control group. All subjects underwent a full medical history, through physical examination, laboratory investigations including blood urea, serum creatinine, serum ferritin, estimated glomerular filtration rate (eGFR) using the Schwartz formula, creatinine clearance, urinary albumin/creatinine ratio, serum cystatin-C, and β-2 microglobulin levels. Pediatric patients with SCD had significantly higher serum cystatin-C and β-2 microglobulin levels compared to controls. In addition, serum cystatin-C and β-2 microglobulin levels were positively correlated with blood urea, serum creatinine, serum ferritin, urinary albumin/creatinine ratio, duration of iron chelating agents and frequency of blood transfusion/year. Serum cystatin-C and β-2 microglobulin levels were negatively correlated with hemoglobin. Our data concluded that serum cystatin-C and β-2 microglobulin had highersensitivity and specificity (91%, 90% and 85.7%, 100%, respectively) than serum creatinine (79% and85%, respectively). Serum Cystatin-C and β-2 microglobulin are early specific and sensitive biomarkers for evaluating glomerular and tubular dysfunction in children with SCD.