title: Glomerular hyperfiltration and albuminuria in children with sickle cell anemia.
abstract: Early manifestations of sickle nephropathy include glomerular hyperfiltration and proteinuria, typically microalbuminuria. Over time, a subset of patients develops histologic changes, decreased glomerular filtration, and ultimately renal failure. This study was designed to determine the rate of glomerular hyperfiltration and prevalence of albuminuria in a cross-sectional analysis of untreated children with sickle cell anemia (SCA), and to identify correlates of both complications. Measured glomerular filtration rate (GFR) by plasma clearance of 99-technetium diethylenetriaminepentaacetate was compared to GFR estimates calculated from published formulas. Eighty-five children (mean age 9.4 ± 4.8 years) were studied; 76% had glomerular hyperfiltration with mean GFR = 154 ± 37 ml/min/1.73 m(2). GFR declined in teenage years and was significantly correlated with increased serum cystatin C levels and higher systolic blood pressure. Measured GFR had only modest correlations with GFR estimates (Pearson correlation coefficients ≤0.5). Albuminuria, usually microalbuminuria, occurred in 15.9% and was associated with higher diastolic blood pressure and lower white blood cell and absolute neutrophil counts. Cystatin C levels inversely reflect GFR changes and are associated with albuminuria; serial monitoring may provide a sensitive and accurate marker of nephropathy in children with SCA.
authors.affiliation: Department of Hematology, St. Jude Children's Research Hospital, 262 Danny Thomas Place, MS # 800, Memphis, TN 38105-3678, USA. banu.aygun@stjude.org
authors.forename: Banu
authors.initials: B
authors.lastname: Aygun
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Mortier
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Smeltzer
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hankins
authors.forename: Russell E
authors.initials: RE
authors.lastname: Ware
mesh_terms: D000293:Adolescent; D000419:Albuminuria / Q000209:etiology*; D000755:Anemia, Sickle Cell / Q000150:complications*; D002648:Child; D003430:Cross-Sectional Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology*