Urinary polyomavirus: novel biomarker of congenital ureteropelvic junction obstruction

Background Pregnancy is associated with reactivation and transmission of latent polyomavirus to fetus. Polyomavirus is also known to cause ureteral stenosis and hydronephrosis. Objective The aim of this study was to investigate whether the urinary polyomavirus could be used as a potential biomarker in newborns with ureteropelvic junction obstruction (UPJO). Study design Urinary polyomavirus virus was measured by PCR in 42 newborn infants with fetal hydronephrosis history. Random urine samples were obtained from newborns immediately after birth and from their mothers at the time of delivery. Results were compared with 25 healthy infants matched for gestational and postnatal ages. The diagnosis of UPJO was established by diuretic renal scintigraphy. UPJO was graded according to the Society for Fetal Urology (SFU) classification. Results The urine samples of healthy infants showed no detectable polyomavirus. No statistically significant difference was found in the median urinary polyomavirus level between grade 1 (1000 copies/mL) and grade 2 (1500 copies/mL) UPJO infants. When the median urinary BKV values were compared for each grade of UPJO, patients with grade 3 and 4 had significantly higher urinary polyomavirus levels than those with grades 1 or 2 (P < 0.001). There was a strong correlation between the median polyomavirus in the urine of pregnant women and the urine of newborns with UPJO (P < 0.001). Discussion Data suggest that routine screening of urinary polyomavirus may help to identify infants with severe obstruction in whom early surgical intervention could reduce the risk of developing progressive kidney disease. To the best of our knowledge this is the first prospective study to present the role of urinary polyomavirus in newborn infants with UPJO to distinguish between patients who would benefit from early surgical intervention. Conclusion Urinary polyomavirus is a potential biomarker of UPJO in newborns with fetal hydronephrosis. [GRAPHICS]