Recurrent Cholangitis in a Patient with Autosomal Dominant Polycystic Kidney Disease (ADPKD) and Caroli's Disease

LncRNA-mRNA coexpression analysis reveals distinct pathogenic mechanisms for subtypes of congenital biliary dilatation

BACKGROUND/PURPOSE

Congenital biliary dilatation (CBD) is a bile duct malformation often associated with pancreaticobiliary maljunction. Different subtypes of CBD have been noted for clinical differences, but their pathogenic mechanisms are unclear.

METHODS

To elucidate the genetic basis of CBD, we performed lncRNA and mRNA sequencing and bioinformatic analysis on 18 cystic and 18 fusiform CBD samples.

RESULTS

We identified differentially expressed mRNAs and lncRNAs between the two types of CBD, and constructed coexpression modules that correlated with clinical characteristics of CBD using weighted gene coexpression network analysis. We found that the brown module was the highest positive correlation with fusiform CBD (R = 0.67, p = 7.9e-6) and contained the most genes. We then built a lncRNA-mRNA coexpression network to identify potential target genes of lncRNAs in CBD, and a protein-protein interaction network to investigate the hub genes from the target genes and the brown module. Finally, we performed enrichment analyses and found differences between cystic and fusiform CBD in hepatobiliary system development, liver and pancreas development involving hub genes ONECUT1 and HNF1B that could be regulated by corresponding lncRNAs.

CONCLUSION

Our study suggests that lncRNAs may modulate pancreaticobiliary duct development differently in cystic and fusiform CBD, providing new insights for etiology studies and clinical treatment.

Pathogenesis of Choledochal Cyst: Insights from Genomics and Transcriptomics

Choledochal cysts (CC) is characterized by extra- and/or intra-hepatic b\ile duct dilations. There are two main theories, “pancreaticobiliary maljunction” and “congenital stenosis of bile ducts” proposed for the pathogenesis of CC. Although family cases or CC associated with other anomalies have been reported, the molecular pathogenesis of CC is still poorly understood. Recent advances in transcriptomics and genomics analysis platforms have unveiled key expression signatures/genes/signaling pathways in the pathogenesis of human diseases including CC. This review summarizes insights from genomics and transcriptomics studies into the pathogenesis of CC, with the aim to improve (i) our understanding of its underlying complex pathomechanisms, and (ii) clinical management of different subtypes of CC, in particular their associated hepatic fibrotic change and their risk of malignancy transformation.

Caroli Disease Revisited: A Case of a Kidney Transplant Patient With Autosomal Polycystic Kidney Disease and Recurrent Episodes of Cholangitis

Polycystic kidney disease (PKD) is a genetic disorder leading to end-stage renal disease more commonly in the fourth to sixth decades of life. Cyst formation in the kidneys and other organs such as the liver and pancreas is the main characteristic of this disease. A significant number of patients with PKD undergo kidney transplantation and receive significant immunosuppression, predisposing them to comorbidities such as infections and malignancies. The link between these cystic syndromes and Caroli disease (which is radiologically demonstrated as bile duct ectasia, segmental cystic dilation of intrahepatic bile ducts, with a normal common bile duct and absence of hepatic fibrosis or portal hypertension), is extremely important. Suspicion, screening, and timely diagnosis of the presence of Caroli disease in patients with PKD prior or post receiving a kidney transplant will reduce morbidity in these patients and possibly prolong both graft and patient survival. We describe a patient with autosomal dominant polycystic kidney disease who underwent recurrent admissions for presumed cholangitis and was eventually diagnosed with Caroli disease.

Caroli Syndrome in a 6-Year-Old Rottweiler Dog

A 6-year-old entire female rottweiler dog with a recent history of ascites and respiratory disease was submitted for necropsy examination. The dog had been diagnosed ultrasonographically with biliary cysts as a puppy. Grossly, the liver was smaller than expected with an irregular surface. Islands of hepatocytes were separated by bands of fibrosis and many bile ducts were markedly dilated. Histologically, extensive fibrosis extended beyond the limiting plate and into the surrounding hepatic parenchyma and was associated with abundant small bile ducts throughout. In conjunction with the detection of biliary cysts early in life, the gross and histological findings were consistent with a diagnosis of Caroli syndrome. In man, Caroli syndrome is frequently associated with renal and pancreatic cysts; a single renal cyst was identified in this case.

Hepatointestinal complications in polycystic kidney disease

Background

The objective of this study was to determine the incidence of major hepatointestinal complications in patients with polycystic kidney disease (PKD).

Methods

We analyzed the Taiwan National Health Insurance claims data (2000-2010) of 6031 patients with PKD and 23,976 non-PKD hospitalized controls. The control cohort was propensity score matched with the PKD cohort at a 1:4 ratio. All patients were followed up from the index date to the first inpatient diagnosis of hepatointestinal complications, death, or 31 December, 2011. Cox proportional hazard regression models were used to identify the risk of outcome after adjustment for potential confounders.

Results

The incidence rates of acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis were 5.72, 4.01, 19.9, and 5.46 per 1000 person-years, respectively, in the PKD cohort. Compared with the non-PKD controls, patients with PKD exhibited an increased risk of hospitalization for acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis (adjusted subhazard ratio [aSHR]: 2.36, 95% confidence interval [95% CI], 1.95-2.84]; 2.36, [95% CI, 1.95-2.84]; 2.41, [95% CI, 1.93-3.01]; 2.41, [95% CI, 2.17-2.67]; and 1.39, [95% CI, 1.16-1.66], respectively; all p < 0.001). PKD, chronic kidney disease, and alcoholism were independent predictors of all these hepatointestinal complications. Kaplan-Meier analysis revealed an increased overall mortality in patients with PKD who developed acute pancreatitis and peptic ulcer bleeding (log-rank p < 0.05).

Conclusion

PKD is associated with clinically significant extrarenal complications including acute pancreatitis, cholangitis, peptic ulcer bleeding, and cirrhosis.

Biliary Tract and Liver Complications in Polycystic Kidney Disease

Polycystic liver disease is a well described manifestation of autosomal dominant polycystic kidney disease (ADPKD). Biliary tract complications are less well recognized. We report a 50-year single-center experience of 1007 patients, which raised a hypothesis that ADPKD is associated with biliary tract disease. We tested this hypothesis using all England Hospital Episode Statistics data (1998-2012), within which we identified 23,454 people with ADPKD and 6,412,754 hospital controls. Hospitalization rates for biliary tract disease, serious liver complications, and a range of other known ADPKD manifestations were adjusted for potential confounders. Compared with non-ADPKD hospital controls, those with ADPKD had higher rates of admission for biliary tract disease (rate ratio [RR], 2.24; 95% confidence interval [95% CI], 2.16 to 2.33) and serious liver complications (RR, 4.67; 95% CI, 4.35 to 5.02). In analyses restricted to those on maintenance dialysis or with a kidney transplant, RRs attenuated substantially, but ADPKD remained associated with biliary tract disease (RR, 1.19; 95% CI, 1.08 to 1.31) and perhaps with serious liver complications (RR, 1.15; 95% CI, 0.98 to 1.33). The ADPKD versus non-ADPKD RRs for biliary tract disease were larger for men than women (heterogeneity P<0.001), but RRs for serious liver complications appeared higher in women (heterogeneity P<0.001). Absolute excess risk of biliary tract disease associated with ADPKD was larger than that for serious liver disease, cerebral aneurysms, and inguinal hernias but less than that for urinary tract infections. Overall, biliary tract disease seems to be a distinct and important extrarenal complication of ADPKD.