Urinary cytokines as markers of reflux nephropathy.
OBJECTIVE
We established whether the urinary cytokines interleukin-6 (IL-6), tumor necrosis factor (TNF)-alpha and soluble TNF receptor-1 have a role as noninvasive markers of renal damage in children with vesicoureteral reflux.


METHODS
We performed an observational study in a surgical and urological unit at a pediatric teaching hospital. Urine cytokine levels of IL-6, TNF-alpha and soluble TNF receptor-1 were measured using a standard enzyme-linked immunosorbent assay technique in children stratified into group 1--11 with vesicoureteral reflux and reflux nephropathy, group 2--6 with vesicoureteral reflux only and no associated nephropathy, and group 3--15 age and sex matched controls.


RESULTS
Urinary levels of the cytokines IL-6 and soluble TNF receptor-1 were significantly elevated in group 1 versus group 3 (0.048 to 13.25 pg./micromol. creatinine, mean 3.658 versus 0.027 to 0.677, mean 0.247 and 102.89 to 4,502.9 pg./micromol. creatinine, mean 1,395.3 versus 13.06 to 569.6, mean 145.357, respectively). Neither cytokine in group 2 (0.074 to 10.96 pg./micromol. creatinine, mean 2.94 and 51.52 to 1,115.48, mean 413.137, respectively) was elevated compared to that in group 3. TNF-alpha was not elevated in group 1 or 2 compared to that in group 3 (0.104 to 2.518 pg./micromol. creatinine, mean 0.56, 0.094 to 1.278, mean 0.334 and 0.065 to 0.694, mean 0.241, respectively).


CONCLUSIONS
Measuring the urinary levels of the cytokines IL-6 and soluble TNF receptor-1 may be useful as a noninvasive marker of reflux associated renal damage. Further studies with larger patient groups are necessary to locate the source of production of the elevated urinary cytokines measured in our study.
Ninan
G K
GK
Department of Paediatric Surgery and Paediatric Urology, Royal Aberdeen Children's Hospital, University of Aberdeen Medical School, Foresterhill, United Kingdom.
Jutley
R S
RS
Eremin
O
O
D000293:Adolescent; D015415:Biomarkers / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D015850:Interleukin-6 / Q000652:urine*; D008297:Male; D018124:Receptors, Tumor Necrosis Factor / Q000032:analysis*; D014409:Tumor Necrosis Factor-alpha / Q000652:urine*; D014718:Vesico-Ureteral Reflux / Q000175:diagnosis* / Q000652:urine*
D015415:Biomarkers; D015850:Interleukin-6; D018124:Receptors, Tumor Necrosis Factor; D014409:Tumor Necrosis Factor-alpha