Complex Genetics in Pancreatitis: Insights Gained From a New Candidate Locus Panel

Pediatric-to-Adult Transfer of Care in Patients With Pancreas Disease: Recommendations for Care and Research Opportunities

Young adults who have experienced recurrent acute pancreatitis and chronic pancreatitis as children or adolescents are vulnerable to poor follow-up and disease management during the transfer from the pediatric to adult healthcare system. Although formalized transition programs for young adults have been developed and described for other disease conditions, no such program has been described for young adults with pancreatic disease. This document is the first expert opinion outlining the important aspects of a transitional care and transfer program tailored to youth with recurrent acute and chronic pancreatitis. We emphasize the unique needs of these patients as they transfer to adult health care and the need for further research. The goal of improved transitional care and transfer is to enhance the services provided to adolescents/young adults with pancreatic disease in both healthcare settings and improve continuity of follow-up care.

Genetic Evaluation of Pancreatitis

Hereditary pancreatitis (HP) is a rare inherited chronic pancreatitis (CP) with strong genetic associations, with estimated prevalence ranging from 0.3 to 0.57 per 100,000 across Europe, North America, and East Asia. Apart from the most well-described genetic variants are PRSS1, SPINK1, and CFTR, many other genes, such as CTRC, CPA1, and CLDN2 and CEL have been found to associate with HP, typically in one of the 3 main mechanisms such as altered trypsin activity, pancreatic ductal cell secretion, and calcium channel regulation. The current mainstay of management for patients with HP comprises genetic testing for eligible individuals and families, alcohol and tobacco cessation avoidance, pain control, and judicious screening for complications, including exocrine and endocrine insufficiency and pancreatic cancer.

Impact of genetic testing and smoking on the distribution of risk factors in patients with recurrent acute and chronic pancreatitis

OBJECTIVE

The aim of the present study is to assess the impact of smoking dose and duration on the distribution of risk factor(s) in patients with RAP and CP, and the impact of genetic testing on the distribution of risk factor(s) in patients with idiopathic RAP and CP.

METHODS

All adult patients with RAP and CP referred to a multidisciplinary pancreatitis clinic between 2010 and 2017 were evaluated. Risk factors included alcohol and smoking, hypertriglyceridemia, biliary, and other etiologies. Genetic testing was only pursued in patients with idiopathic RAP or CP.

RESULTS

Among the 1770 patients evaluated, 167 had RAP and 303 had CP. After genetic testing and smoking, the most common risk factors for RAP and CP were pathogenic variant(s) (23%) and the combination of alcohol and smoking (23%), respectively. Genetic testing and smoking assessment decreased the proportion of patients with alcoholic RAP from 17% to 5%, alcoholic CP from 33% to 10%, idiopathic RAP from 49% to 12%, and idiopathic CP from 54% to 14%. Pathogenic CFTR variants were the most common variant in patients with RAP (51%) and CP (43%). Among the 68 patients with pancreas divisum, other risk factor(s) were identified in 72%.

CONCLUSION

Genetic testing and a detailed assessment of smoking dose and duration reduce the proportion of patients with alcoholic and idiopathic pancreatitis. Other risk factor(s) for pancreatitis are found in the majority of patients with pancreas divisum further questioning its role as an independent risk factor.1. What is the current knowledge?Approximately 30% of patients with pancreatitis have no clear risk factor(s) and are categorized as having an idiopathic etiology.Pathogenic variant(s) as well as smoking dose and duration are well-established risk factors for recurrent acute and chronic pancreatitis but are not widely recognized or incorporated into clinical practice.2. What is new here?Genetic testing and a detailed assessment of smoking dose and duration reduced the proportion of patients with alcoholic and idiopathic acute recurrent and chronic pancreatitis.Approximately three-fourths of patients with pancreas divisum have a risk factor for pancreatitis.

Comparison of idiopathic recurrent acute pancreatitis [IRAP] and recurrent acute pancreatitis with genetic mutations

BACKGROUND

Idiopathic recurrent acute pancreatitis (IRAP) describes frequent episodes of pancreatitis without an etiology found using current testing. We compared the natural history of IRAP with recurrent acute pancreatitis with genetic mutations.

METHODS

Retrospective cohort of patients with recurrent acute pancreatitis (≥2 episodes) and negative conventional testing. All patients had ≥1 episode after cholecystectomy and completed genetic testing. Primary outcomes were chronic pancreatitis incidence, pancreatic cancer, and mortality. Secondary outcomes included opioid and ERCP utilization.

RESULTS

128 patients met criteria for presumed IRAP. 35 patients met criteria for true IRAP. 12 patients had recurrent acute pancreatitis with gene mutations. Chronic pancreatitis developed in 27 (77.1%) IRAP patients over a median of 6 years. Chronic pancreatitis incidence was similar in IRAP and CFTR mutation carriers; but developed later in SPINK1 carriers. No patients developed pancreatic cancer or died from pancreatic-related causes. Patients were frequently treated with oral opioids and ERCP, without significant differences within or between groups.

CONCLUSION

IRAP and pancreatitis in mutation carriers is associated with chronic pancreatitis. Important differences in natural history were observed, but no association was found with cancer or pancreas-related mortality. Efforts to understand the genetic contributions to IRAP, minimize opioids and unnecessary ERCPs are encouraged.

Precision medicine for pancreatic diseases

PURPOSE OF REVIEW

We describe and contrast the strengths of precision medicine with Western medicine, and complex trait genetics with Mendelian genetics. Classic genetics focuses on highly penetrant pathogenic variants in a single gene believed to cause or confer a high risk for well-defined phenotypes. However, a minority of disorders have a single gene cause. Further, even individuals with identical Mendelian disease-associated genotypes may exhibit substantial phenotypic variability indicative of genetic and environmental modifiers. Still, most diseases are considered complex traits (or complex diseases).

RECENT FINDINGS

New insights into the genetic underpinnings of complex traits provide opportunities for advances in diagnosis and management. Precision medicine provides the framework for integrating complex trait knowledge into clinical care through a sophisticated analysis pipeline. Multidimensional modeling of acquired diseases includes multiple genetic risks scattered over many genes and gene regulators that must be interpreted on the basis of functional evidence (e.g., genomics, transcriptomics) with structured models and expert systems; strengthened with machine learning and artificial intelligence. The choice of genotyping approaches (shotgun sequencing, single nucleotide polymorphism chips, targeted panels) is discussed.

SUMMARY

The result of a good precision medicine tool is clinical-decision support and guidance to tackle complex disorders such as pancreatitis, diabetes, and pancreatic cancer oncogenesis.