Abnormalities of the biliary tract in patients with autosomal recessive polycystic kidney disease (ARPKD)

Introduction
Autosomal recessive polycystic kidney disease (ARPKD) is a ciliopathy with kidney and liver manifestations. Children with ARPKD usually remain only under the care of nephrologist due to silent liver involvement characterized by congenital hepatic fibrosis with or without bile ducts dilatation. The aim of this study is to pay attention on the occurrence of the abnormalities of the biliary tract in ARPKD patients.

Material and methods
Data on laboratory (serum total and direct bilirubin concentration, gamma-glutamyltranspeptidase [GGT] activity, serum bile acids concentration) and imaging examinations findings (intrahepatic and extrahepatic bile ducts dilatation, biliary cysts), as well as data on history of cholangitis, were analysed retrospectively in 17 patients (14 male and 3 female, aged from 2.5 to 42 years) with molecularly confirmed diagnosis of autosomal recessive polycystic kidney disease (ARPKD).

Results
Increased GGT activity was noticed in 7 patients and slightly increased direct bilirubin in 8 (46.7 and 53.3% respectively). Only one patient had a history of cholangitis. Dilatation of intrahepatic bile ducts and common bile duct on ultrasound examination was described in 10 and 5 patients respectively. There was no close correlation between laboratory and imaging examination findings. Four our patients with dilated bile ducts had normal laboratory results, while two patients had abnormalities only in laboratory tests. Both, laboratory and imaging abnormalities were found in 6 and none of them in 5 patients.

Conclusions
In patients with ARPKD abnormalities of the biliary tract can occur even when standard laboratory tests findings stay within normal limits. Detailed biliary tree imaging evaluation should be performed in each patients with increased GGT activity/bile acid concentration, history of cholangitis, before kidney transplantation, as well as in adolescents and young adults due to increased risk of cholangiocarcinoma.