Duodenal fluid analysis of 13 patients with progressive familial intrahepatic cholestasis type 2 from a single institution

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is an autosomal recessive disease caused by homozygous or compound heterozygous mutations in the bile salt export pump (BSEP). The diagnosis has mainly depended on genetic tests. Little research has been conducted to assess the BSEP function, which may help the clinical diagnosis. The present study aimed to quantitatively assess the BSEP function by collecting duodenal fluid of patients with PFIC2. This is a single-center retrospective study. The clinical presentations, laboratorial and genetic data of 13 patients with PFIC2 were collected for analysis. Eight patients with progressive familial intrahepatic cholestasis 1 and 13 with idiopathic neonatal cholestasis were chosen as the 2 control groups. The diagnostic values of total bile acid in duodenal fluid (dTBA) and dTBA/total bile acid in serum (sTBA) ratio on PFIC2 were assessed. DTBA was significantly lower in patients with PFIC2 than in those with progressive familial intrahepatic cholestasis 1 and idiopathic neonatal cholestasis. The dTBA/sTBA ratio was also significantly lower in patients with PFIC2. Both dTBA and dTBA/sTBA showed high diagnostic sensitivity, specificity, positive and negative predictive values according to the receiver operating characteristic curve analysis. The present study found that duodenal tube test would help to understand PFIC2 and quantitatively access the function of BSEP.