Prevalence, Treatment, and Outcomes of Renal Conditions in Pediatric Sickle Cell Disease James R. Stallworth, MD, Avnish Tripathi, MD, MPH, and Jeanette M. Jerrell, PhD Objectives: Vaso-occlusive events in pediatric sickle cell disease (SCD) may cause various renal complications and lead to renal failure. We describe the renal conditions that develop among young patients with SCD and the factors associated with the prevalence of these nephropathies. Materials and Methods: Medicaid medical and pharmacy claims for an 11-year period were used to identify 2194 pediatric patients with SCD (HbSS homozygous). Survival analysis identified the most significant predictors of acute kidney injury and chronic renal fail- ure, using demographics, SCD severity and pain medication, comor- bid hypertension, hematuria, and proteinuria as the initial covariates. Results: Prevalence of renal complications in our cohort was found to be relatively low, predominantly hematuria (6.3%) and proteinuria (3.2%). The multivariable analysis indicated that earlier development of acute kidney injury was significantly associated with older age (ad- justed hazard ratio [aHR] 1.16, confidence interval [CI] 1.06Y1.27), preexisting hypertension (aHR 3.05, CI 1.09Y8.60), and preexisting hematuria (aHR 2.87, CI 1.05Y7.93). Earlier development of chronic renal failure was significantly associated with older age (aHR 1.20, CI 1.08Y1.32), preexisting hematuria (aHR 4.67, CI 1.57Y13.94), and preexisting proteinuria (aHR 8.25, CI 2.12Y10.38). Conclusions: These prevalence findings are novel in the US SCD pediatric population. The predictors of nephropathies identified in these children confirm clinical expectations. In addition, they suggest not only that pediatric nephrologists should be consulted earlier in the treatment of patients with SCD who are diagnosed as having co- morbid hypertension or who develop hematuria or proteinuria during the course of their SCD treatment but also that both hydroxyurea and angiotensin-converting enzyme inhibitor therapies may be better used in these cases. Key Words: kidney conditions, pediatrics, outcomes, sickle cell disease P atients with sickle cell disease (SCD; HbSS) may present with a wide spectrum of renal dysfunction. In patients with SCD, relative hypoxia in the renal medulla and slow blood flow through the vasa rectae predisposes red blood cells to sickling, resulting in significant veno-occlusion and subsequent local infarction. 1Y3 The early manifestations of sickle cell nephropathy include impaired urinary concentrating ability; supranormal proximal tubular function manifested by a mild degree of hypophosphatemia and increased clearance of creatinine; and defects in both urinary acidification and potassium excretion. 1,3 With increasing age and additive tu- bulointerstitial nephritis secondary to analgesic overuse, renal abnormalities may progress to manifestations such as hema- turia, proteinuria, papillary necrosis, glomerulonephritis, and acute and chronic renal failure. 1Y4 The present hypothesized model of sickle cell nephropathy suggests that destruction of the renal medulla and resulting hyperfiltration may lead to Key Points & The prevalence of renal disease in a cohort of US children with sickle cell disease (HbSS) is examined. The results confirm that earlier development of various nephropathies was associated with diagnosis of primary hypertension, he- maturia, or proteinuria during the course of treatment for HbSS. & There appears to be some underutilization of hydroxyurea (HU) and angiotensin-converting enzyme inhibitors (ACE-Is) in children with HbSS and renal abnormalities. & No significant association was found between nonsteroidal anti-inflammatory drug treatment and the development of any form of nephropathy in children with HbSS taking into consideration all other significant influences. Original Article 752 * 2011 Southern Medical Association From the Departments of Pediatrics and Neuropsychiatry and Behavioral Science, University of South Carolina School of Medicine, and the De- partment of Epidemiology and Biostatistics, University of South Carolina Arnold School of Public Health, Columbia, South Carolina. Reprint requests to Dr Jeanette M. Jerrell, Department of Neuropsychiatry and Behavioral Science, University of South Carolina School of Med- icine, 3555 Harden Street, Suite 301, Columbia, SC 29203. Email: Jeanette.Jerrell@uscmed.sc.edu The views expressed in the article do not represent official findings of the South Carolina Department of Health and Human Services (Medicaid). The authors have no financial relationships to disclose and no conflicts of interest to report. Accepted July 27, 2011. Copyright * 2011 by The Southern Medical Association 0038-4348/0Y2000/104-752 DOI: 10.1097/SMJ.0b013e318232d9ab Copyright © 2011 The Southern Medical Association. Unauthorized reproduction of this article is prohibited.