title: Tubular proteinuria in steroid sensitive multi-relapsing nephrotic syndrome.
abstract: The urinary excretion of N-acetyl-beta-D-glucosaminidase (UNAG) and retinol binding protein (URBP) was studied in 65 children with steroid sensitive multirelapsing nephrotic syndrome (MRNS): 28 on cyclosporin A (CyA) therapy, 22 on prednisolone (P), 15 off-treatment and in 32 normal children to assess renal tubular damage or dysfunction. The urinary protein excretion was expressed in relation to that of creatinine (UNAG/UC in mumol pnp/h/mmol; URBP/UC in microgram/mmol). There was a weak but significantly negative correlation between age and both, UNAG/UC (r = -0.38, p < 0.01) and URBP/UC (r = -0.50, p < 0.05) in normal children, but not in nephrotics. In normals and in patients off steroids an association between these two proteins was found (r = 0.38, p < 0.05; r = 0.56, p < 0.05 respectively). Geometric mean UNAG/UC was significantly higher in nephrotics on CyA therapy (26.5 +/- 4.0), and on P (37.0 +/- 7.9) as well as in those off-treatment (16.3 +/- 3.1) compared to normal children (9.3 +/- 3.4). There was a further increase in those with raised urinary albumin: creatinine ratio (UA/UC) (> 0.1 mg/mg). URBP/UC was not increased in any of the groups of children with MRNS. Raised NAG in urine may therefore indicate active nephrotic syndrome rather than being due to the drug therapy.
authors.affiliation: Medical Unit, Institute of Child Health, London, UK.
authors.forename: A I
authors.initials: AI
authors.lastname: Piqueras
authors.forename: V
authors.initials: V
authors.lastname: Shah
authors.forename: S A
authors.initials: SA
authors.lastname: Hulton
authors.forename: T M
authors.initials: TM
authors.lastname: Barratt
authors.forename: M J
authors.initials: MJ
authors.lastname: Dillon
mesh_terms: D000118:Acetylglucosaminidase / Q000652:urine*; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016572:Cyclosporine / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D007677:Kidney Function Tests; D007684:Kidney Tubules / Q000187:drug effects / Q000503:physiopathology*; D009404:Nephrotic Syndrome / Q000175:diagnosis / Q000188:drug therapy / Q000652:urine*; D011239:Prednisolone / Q000627:therapeutic use; D012008:Recurrence; D012177:Retinol-Binding Proteins / Q000652:urine*
chemical_list: D012177:Retinol-Binding Proteins; D016572:Cyclosporine; D011239:Prednisolone; D000118:Acetylglucosaminidase