Early Predictors of Renal Dysfunction in Pediatric Patients with Sickle Cell Disease

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.