Kidney disease progression in pediatric and adult posterior urethral valves (PUV) patients.

BACKGROUND

Posterior urethral valves (PUV) is the most common cause of obstructive uropathy in boys; approximately 15% develop kidney failure by early adulthood. However, rates of kidney function decline are poorly defined in PUV children and adults, as is the impact of potentially modifiable chronic kidney disease (CKD) progression risk factors.

METHODS

We conducted a retrospective review of all PUV patients followed at our institution from 1995 to 2018. Inclusion criteria were estimated glomerular filtration rate (eGFR) > 20 ml/min/1.73 m2 after 1 year of age, no dialysis or kidney transplant history, and ≥ 2 yearly serum creatinine values after age 1 year. eGFRs were calculated using creatinine-based estimating formulas for children (CKID U25) or adults (CKD-EPI). The primary outcome was annualized change in eGFR, assessed with linear mixed effects models. We also examined the association of acute kidney injury (AKI), proteinuria, hypertension (HTN), and recurrent febrile urinary tract infections (UTIs) with eGFR decline.

RESULTS

Fifty-two PUV patients met the inclusion criteria. Median (interquartile range) eGFR decline was 2.6 (2.1, 3.1) ml/min/1.73 m2/year. Children (n = 35) and adults (n = 17) demonstrated progressive decline. Proteinuria and recurrent UTIs were significantly associated with faster progression; AKI and HTN were also associated but did not reach significance.

CONCLUSION

PUV patients show progressive loss of kidney function well into adulthood. Proteinuria and recurrent UTIs are associated with faster progression, suggesting potential modifiable risk factors. This is the first study to report annualized eGFR decline rates in PUV patients, which could help inform the design of clinical trials of CKD therapies.