Genetic Risk Factors in Early-Onset Nonalcoholic Chronic Pancreatitis: An Update

Pro-inflammatory cytokines stimulate CFTR-dependent anion secretion in pancreatic ductal epithelium

BACKGROUND

Loss of CFTR-dependent anion and fluid secretion in the ducts of the exocrine pancreas is thought to contribute to the development of pancreatitis, but little is known about the impact of inflammation on ductal CFTR function. Here we used adult stem cell-derived cell cultures (organoids) obtained from porcine pancreas to evaluate the effects of pro-inflammatory cytokines on CFTR function.

METHODS

Organoids were cultured from porcine pancreas and used to prepare ductal epithelial monolayers. Monolayers were characterized by immunocytochemistry. Epithelial bicarbonate and chloride secretion, and the effect of IL-1β, IL-6, IFN-γ, and TNF-α on CFTR function was assessed by electrophysiology.

RESULTS

Immunolocalization of ductal markers, including CFTR, keratin 7, and zonula occludens 1, demonstrated that organoid-derived cells formed a highly polarized epithelium. Stimulation by secretin or VIP triggered CFTR-dependent anion secretion across epithelial monolayers, whereas purinergic receptor stimulation by UTP, elicited CFTR-independent anion secretion. Most of the anion secretory response was attributable to bicarbonate transport. The combination of IL-1β, IL-6, IFN-γ, and TNF-α markedly enhanced CFTR expression and anion secretion across ductal epithelial monolayers, whereas these cytokines had little effect when tested separately. Although TNF-α triggered apoptotic signaling, epithelial barrier function was not significantly affected by cytokine exposure.

CONCLUSIONS

Pro-inflammatory cytokines enhance CFTR-dependent anion secretion across pancreatic ductal epithelium. We propose that up-regulation of CFTR in the early stages of the inflammatory response, may serve to promote the removal of pathogenic stimuli from the ductal tree, and limit tissue injury.

The PANcreatic Disease ReseArch (PANDoRA) consortium: Ten years' experience of association studies to understand the genetic architecture of pancreatic cancer

Pancreatic cancer has an incidence that almost matches its mortality. Only a small number of risk factors and 33 susceptibility loci have been identified. so Moreover, the relative rarity of pancreatic cancer poses significant hurdles for research aimed at increasing our knowledge of the genetic mechanisms contributing to the disease. Additionally, the inability to adequately power research questions prevents small monocentric studies from being successful. Several consortia have been established to pursue a better understanding of the genetic architecture of pancreatic cancers. The Pancreatic disease research (PANDoRA) consortium is the largest in Europe. PANDoRA is spread across 12 European countries, Brazil and Japan, bringing together 29 basic and clinical research groups. In the last ten years, PANDoRA has contributed to the discovery of 25 susceptibility loci, a feat that will be instrumental in stratifying the population by risk and optimizing preventive strategies.

Genetic determinants of pancreatitis: relevance in severe hypertriglyceridemia

PURPOSE OF REVIEW

Not all patients with severe hypertriglyceridemia develop acute pancreatitis. We surveyed recent literature on inter-individual genetic variation in susceptibility to pancreatitis.

RECENT FINDINGS

Genetic determinants of pancreatitis include: rare Mendelian disorders caused by highly penetrant pathogenic variants in genes involved in trypsinogen activation; uncommon susceptibility variants in genes involved in trypsinogen activation, protein misfolding as well as calcium metabolism and cystic fibrosis, that have variable penetrance and show a range of odds ratios for pancreatitis; and common polymorphisms in many of the same genes that have only a small effect on risk. The role of these genetic variants in modulating pancreatitis risk in hypertriglyceridemia is unclear. However, among genetic determinants of plasma triglycerides, those predisposing to more severe hypertriglyceridemia associated with chylomicronemia appear to have higher pancreatitis risk.

SUMMARY

Currently, among patients with severe hypertriglyceridemia, the most consistent predictor of pancreatitis risk is the triglyceride level. Furthermore, pancreatitis risk appears to be modulated by a higher genetic burden of factors associated with greater magnitude of triglyceride elevation. The role of common and rare genetic determinants of pancreatitis itself in this metabolic context is unclear.

Acute pancreatitis precedes chronic pancreatitis in the majority of patients: Results from the NAPS2 consortium

INTRODUCTION

The mechanistic definition of chronic pancreatitis (CP) identifies acute pancreatitis (AP) as a precursor stage. We hypothesized that clinical AP frequently precedes the diagnosis of CP and is associated with patient- and disease-related factors. We describe the prevalence, temporal relationship and associations of AP in a well-defined North American cohort.

METHODS

We evaluated data from 883 patients with CP prospectively enrolled in the North American Pancreatitis Studies across 27 US centers between 2000 and 2014. We determined how often patients had one or more episodes of AP and its occurrence in relationship to the diagnosis of CP. We used multivariable logistic regression to determine associations for prior AP.

RESULTS

There were 624/883 (70.7%) patients with prior AP, among whom 161 (25.8%) had AP within 2 years, 115 (18.4%) within 3-5 years, and 348 (55.8%) >5 years prior to CP diagnosis. Among 504 AP patients with available information, 436 (86.5%) had >1 episode. On multivariable analyses, factors associated with increased odds of having prior AP were a younger age at CP diagnosis, white race, abdominal pain, pseudocyst(s) and pancreatic duct dilatation/stricture, while factors associated with a lower odds of having prior AP were exocrine insufficiency and pancreatic atrophy. When compared with patients with 1 episode, those with >1 AP episode were diagnosed with CP an average of 5 years earlier.

CONCLUSIONS

Nearly three-quarters of patients were diagnosed with AP prior to CP diagnosis. Identifying which AP patients are at-risk for future progression to CP may provide opportunities for primary and secondary prevention.