title: Albuminuria correlates with hemolysis and NAG and KIM-1 in patients with sickle cell anemia.
abstract: BACKGROUND
  Although hyperfiltration and albuminuria are common pathological conditions, kidney injury (KI) biomarkers have been seldom studied in individuals with sickle cell anemia (SCA).
  
  
  METHODS
  We undertook a cross-sectional assessment of urine KI biomarkers in children and adults with SCA with and without albuminuria and a normal estimated glomerular filtration rate (eGFR). Albumin, KI molecule 1 (KIM-1), N-acetyl-ß-D-glucosaminidase (NAG), endothelin-1 and transforming growth factor-β1 (TGF-β1) were measured. Assays were normalized by urine creatinine. Urine intracellular hemosiderin and serum lactate dehydrogenase (LDH) were assessed as markers of hemolysis. Albuminuria was associated to the biomarkers by Pearson and Spearman correlation coefficients. Differences between the albuminuria (yes, no) groups were assessed by the t test.
  
  
  RESULTS
  Nineteen patients with albuminuria (mean urine albumin/creatinine 527.14 ± 1070 mg/g, range 38.3--190 mg/g) and 19 patients without albuminuria (mean urine albumin/creatinine 15.93 ± 5.17 mg/g, range 7.9-28.4 mg/g) were studied. The age range for the whole group was 11-48 years, and 47 % were males. Patients with albuminuria were older, had lower hematocrit, were more likely to test positive for urine hemosiderin and had a higher KIM-1 (P = 0.0035) and NAG/ creatinine ratios (P = 0.0062). Urine hemosiderin strongly correlated to a higher LDH level (P < 0.001).
  
  
  CONCLUSIONS
  Despite a normal or increased eGFR, KI biomarkers were detected in the urine of individuals with SCA. NAG, KIM-1 and urine hemosiderin correlated with the presence of albuminuria.
authors.affiliation: Division of Pediatric Hematology (D-820), University of Miami, PO Box 016960, Miami, FL, 33101, USA.
authors.forename: Dima
authors.initials: D
authors.lastname: Hamideh
authors.forename: Vimal
authors.initials: V
authors.lastname: Raj
authors.forename: Thomas
authors.initials: T
authors.lastname: Harrington
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.forename: Emilio
authors.initials: E
authors.lastname: Margolles
authors.forename: Folasade
authors.initials: F
authors.lastname: Amole
authors.forename: Monica
authors.initials: M
authors.lastname: Garcia-Buitrago
authors.forename: Phillip
authors.initials: P
authors.lastname: Ruiz
authors.forename: Gaston
authors.initials: G
authors.lastname: Zilleruelo
authors.forename: Ofelia
authors.initials: O
authors.lastname: Alvarez
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology*; D000293:Adolescent; D000328:Adult; D000419:Albuminuria / Q000209:etiology*; D000755:Anemia, Sickle Cell / Q000097:blood / Q000150:complications* / Q000652:urine; D015415:Biomarkers / Q000032:analysis*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006461:Hemolysis; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000652:urine; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000652:urine; D011991:Receptors, Virus; D055815:Young Adult
chemical_list: D015415:Biomarkers; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D008562:Membrane Glycoproteins; C117339:NBAS protein, human; D009363:Neoplasm Proteins; D011991:Receptors, Virus