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CONGRESS OF THE ESPU
13:36–13:39
S1-3 (PP)
TERMINAL MARKERS OF UROTHELIAL DIFFERENTIATION:
A COMPARISON OF NEWBORN AND DELAYED BLADDER
EXSTROPHY CLOSURES TO CONTROLS
Matthew KASPRENSKI
1
, Zhiming YANG
2
, Mahir MARUF
1
, Karl BENZ
1
,
Jonathan EPSTEIN
2
, Heather DI CARLO
1
and John GEARHART
1
1) Johns Hopkins Hospital, Johns Hopkins Medical Institutions, Division of Pediatric Urology, James Buchanan Brady
Urological Institutions, Baltimore, USA - 2) Johns Hopkins University School of Medicine, Department of Pathology,
Baltimore, USA
PURPOSE
There is debate in pediatric urology whether primary closure in patients with bladder exstrophy (BE)
should be performed as a newborn or in the delayed setting. The authors examined expression of
urothelial markers of terminal differentiation in exstrophic bladders obtained at the time of primary
closure in both newborn and delayed closures.
MATERIAL AND METHODS
Bladder biopsies were obtained between 2012 and 2017 from 36 BE patients at the time of primary
closure (10 newborn and 26 delayed closures). These specimens were compared to bladder speci-
mens from normal infants (age 7 days to 3 years). Specimens underwent immunohistochemical
staining for uroplakin II (UPII) and p63. Specimens were graded by a blinded pathologist using
a scoring system of 0–3.
RESULTS
When compared to controls, delayed closures had a lower proportion of UPII grade 3 expression
(0 % vs 62.5 %; p<0.001) and a higher proportion of UPII grade 0 expression (81.5 % vs 0 %;
p<0.001). This trend persisted in the neonatal BE closure and control comparison. Neonatal clo-
sures had a lower proportion of UPII grade 3 expression than controls (10 % vs 62.5 %; p=0.048)
and higher proportion of UPII grade zero expression (40 % vs 0 %; p=0.048). When comparing
delayed to neonatal closures, a higher proportion of UPII grade 0 was found in the delayed closures
(81.5 % vs 40 %; p=0.013). There was no statistical difference in p63 expression scores when the
three groups were compared.
CONCLUSIONS
The delayed closure group had decreased UPII expression compared to the control group and the
newborn group, suggesting less urothelial differentiation.