Renal parenchymal area and risk of ESRD in boys with posterior urethral valves.

TitleRenal parenchymal area and risk of ESRD in boys with posterior urethral valves.
Publication TypeJournal Article
Year of Publication2014
AuthorsPulido JE, Furth SL, Zderic SA, Canning DA, Tasian GE
JournalClin J Am Soc Nephrol
Date Published2014 Mar
KeywordsBiological Markers, Child, Preschool, Creatinine, Disease Progression, Disease-Free Survival, Glomerular Filtration Rate, Hospitals, Pediatric, Humans, Infant, Infant, Newborn, Kaplan-Meier Estimate, Kidney, Kidney Failure, Chronic, Male, Multivariate Analysis, Philadelphia, Predictive Value of Tests, Proportional Hazards Models, Risk Assessment, Risk Factors, Sex Factors, Time Factors, Urethra, Urinary Tract Infections, Vesico-Ureteral Reflux

BACKGROUND AND OBJECTIVES: Approximately 20% of boys with posterior urethral valves develop ESRD; however, few factors associated with the risk of ESRD have been identified. The objective of this study was to determine if renal parenchymal area, defined as the area of the kidney minus the area of the pelvicaliceal system on first postnatal ultrasound, is associated with the risk of ESRD in infants with posterior urethral valves.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A retrospective cohort of boys who were diagnosed with posterior urethral valves at less than 6 months of age between 1988 and 2011 and followed for at least 1 year at a free-standing children's hospital was assembled. Cox proportional hazard regression and Kaplan-Meier analysis were used to estimate the association between renal parenchymal area and time to ESRD. Cox models were adjusted for age at presentation, minimum creatinine 1 month after bladder decompression, and vesicoureteral reflux.

RESULTS: Sixty patients were followed for 393 person-years. Eight patients developed ESRD. Median renal parenchymal area was 15.9 cm(2) (interquartile range=13.0-21.6 cm(2)). Each 1-cm(2) increase in renal parenchymal area was associated with a lower risk of ESRD (hazard ratio, 0.64; 95% confidence interval, 0.42 to 0.98). The rate of time to ESRD was 10 times higher in boys with renal parenchymal area<12.4 cm(2) than boys with renal parenchymal area‚Č•12.4 cm(2) (P<0.001). Renal parenchymal area could best discriminate children at risk for ESRD when the minimum creatinine in the first 1 month after bladder decompression was between 0.8 and 1.1 mg/dl.

CONCLUSION: In boys with posterior urethral valves presenting during the first 6 months of life, lower renal parenchymal area is associated with an increased risk of ESRD during childhood. The predictive ability of renal parenchymal area, which is available at time of diagnosis, should be validated in a larger, prospectively-enrolled cohort.

Alternate JournalClin J Am Soc Nephrol
PubMed ID24311709
PubMed Central IDPMC3944775
Grant List1K24DK078737 / DK / NIDDK NIH HHS / United States
T32HD060550 / HD / NICHD NIH HHS / United States