title: Urinary NGAL is a useful clinical biomarker of HIV-associated nephropathy.
abstract: BACKGROUND
  Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is expressed by kidney tubules that are acutely damaged, but few studies have investigated the association of neutrophil gelatinase-associated lipocalin (NGAL) with different forms of chronic kidney disease (CKD). HIV-associated nephropathy (HIVAN) is a progressive form of CKD characterized by collapsing focal segmental glomerulosclerosis and microcytic tubular dilatation that typically leads to end-stage renal disease (ESRD).
  
  
  METHODS
  Previously, we reported that microcystic tubular dilatations specifically expressed NGAL RNA, implying that the detection of uNGAL protein could mark advanced HIVAN. To test this idea, we performed a comparative study of diverse proteinuric glomerulopathies in 25 patients who were HIV positive.
  
  
  RESULTS
  Eighteen patients had HIVAN and seven had other glomerulopathies (four membranoproliferative glomerulonephritis, one membranous glomerulonephritis, one amyloid and one malarial GN). HIVAN and non-HIVAN patients did not differ with respect to age, ethnicity, serum creatinine, estimated GFR, proteinuria or the prevalence of hypocomplementemia (6 versus 29%, P = 0.18), but HIVAN patients were less likely to have HCV infections. HIVAN patients expressed 4-fold higher levels of uNGAL than the patients with other glomerulopathies [387 ± 338 versus 94 ± 101 μg/g urine creatinine (uCr), P = 0.02]. A cutpoint of 121.5 μg uNGAL/g uCr demonstrated 94% sensitivity and 71% specificity for the diagnosis of HIVAN, with an area under the receiver operator characteristic curve of 0.88.
  
  
  CONCLUSIONS
  In summary, while HIVAN disease is currently diagnosed only by kidney biopsy, uNGAL can distinguish HIVAN from other proteinuric glomerulopathies in the HIV-infected patient, likely because of its specific expression from characteristic microcysts.
authors.affiliation: Division of Nephrology, Department of Medicine, Columbia University Medical Center, New York, NY, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Sola-Del Valle
authors.forename: Sumit
authors.initials: S
authors.lastname: Mohan
authors.forename: Jen-Tse
authors.initials: JT
authors.lastname: Cheng
authors.forename: Neal A
authors.initials: NA
authors.lastname: Paragas
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Sise
authors.forename: Vivette D
authors.initials: VD
authors.lastname: D'Agati
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barasch
mesh_terms: D016263:AIDS-Associated Nephropathy / Q000175:diagnosis* / Q000652:urine*; D000209:Acute-Phase Proteins / Q000652:urine*; D000328:Adult; D000419:Albuminuria; D015415:Biomarkers / Q000652:urine*; D003404:Creatinine / Q000378:metabolism; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D005923:Glomerulosclerosis, Focal Segmental / Q000175:diagnosis / Q000652:urine; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000652:urine; D007677:Kidney Function Tests; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011507:Proteinuria; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012372:ROC Curve; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine