Background: Repeated episodes of jaundice and pruritus are common in a group of autosomal recessive liver diseases known as benign recurrent intrahepatic cholestasis. Benign recurrent intrahepatic cholestasis (BRIC) is divided into two types, type 1 and type 2, and is caused by mutations in the ATP8B1 and ABCB11 genes. Here, we report a rare case of BRIC type 2 mutation.
Case presentation: A 45-year-old Chinese man had three frequent episodes of jaundice marked by extensive excoriation and severe pruritis, although he had no prior history of jaundice. Laboratory investigations showed no evidence of liver damage caused by viral, autoimmune, or acquired metabolic etiologies. The CT scan revealed an enlarged gallbladder with numerous punctate high-density shadows, while no wall thickening was observed. Endoscopic ultrasonography showed no evidence of dilation of the intrahepatic and extrahepatic bile duct, as well as the absence of gallstone.
Diagnostic evaluation: Immunohistochemical examinations of liver biopsy samples showed cytokeratin-7 positive hepatocytes, suggesting chronic intrahepatic cholestasis. The reticulin fiberstaining demonstrated that the portions of the hepatic plate in the center of the lobule were asymmetrically organized,and somewhat enlarged, with collapsed areas indicating intralobular inflammation. Moreover, there were areas of collapse that indicated the presence of intralobular inflammation. Whole exome sequencing revealed mutations in the ABCB11 gene; c.3084A>G, p.A1028A homozygous mutation (chr2-169789016), and c.2594C>T, p.A865V heterozygous mutation (chr2-169801131). Based on these findings, the final diagnosis of the patient was metabolism-related jaundice.
Treatment: Apart from receiving tapering dosage of prednisone to lower bilirubin levels, the patient received no extra care.
Conclusion: The comprehensive diagnosis of a middle-aged male patient with BRIC-2, which involved extensive radiological, hematological, and genetic investigations, informed a tailored tapering prednisone regimen, highlighting the importance of personalized medicine in managing atypical presentations of this rare cholestatic disorder.