title: Profiling proteinuria in pediatric patients.
abstract: This study was designed to characterize proteinuria in children with kidney disease. Random urine samples from 250 pediatric patients were examined by quantitative measures of total protein (pr), albumin (Alb), and creatinine (cr). Patient diagnoses were subjectively categorized as "Glomerular" (GD) or "Tubulo-interstitial" disease (TD) in origin. Proteinuria was quantitated by the random urine protein-to-creatinine (Upr/cr) ratio, and glomerular proteinuria was assessed as the albumin-to-creatinine ratio (Ualb/cr) and percentage albuminuria (%Alb=Alb/pr*100). The non-albumin fraction (1-Alb/pr) includes low-molecular-weight proteins and micro- and macroglobulins. Of the 250 patients, 112 (45%) had GD and 138 (55%) had TD. Both proteinuria and albuminuria correlated with a decline in glomerular filtration rate (GFR) (r=-0.4; p<0.0001). Those with GD averaged significantly greater %Alb than those with TD at all levels of proteinuria (p<0.0001). With loss in GFR, %Alb increased significantly in patients with TD (18+/-13 to 47+/-30%; p<0.001) and GD (56+/-26 to 74+/-15%; p<0.01), respectively. The %Alb at all levels of GFR averaged <50% in those with TD and >50% in those with GD. In conclusion, random Ualb/cr, Upr/cr, and %Alb provide a simple and inexpensive assessment of proteinuria and may profile renal disease activity and response to therapy in pediatric patients.
authors.affiliation: Department of Pediatrics, Division of Pediatric Nephrology, University of Miami School Of Medicine/Holtz Children's Hospital, Miami, FL, USA. cabitbol@med.miami.edu
authors.forename: Carolyn L
authors.initials: CL
authors.lastname: Abitbol
authors.forename: Jayanthi
authors.initials: J
authors.lastname: Chandar
authors.forename: Ali Mirza
authors.initials: AM
authors.lastname: Onder
authors.forename: Obioma
authors.initials: O
authors.lastname: Nwobi
authors.forename: Brenda
authors.initials: B
authors.lastname: Montané
authors.forename: Gastón
authors.initials: G
authors.lastname: Zilleruelo
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007674:Kidney Diseases / Q000150:complications / Q000652:urine*; D011507:Proteinuria / Q000652:urine*; D011897:Random Allocation