Hereditary pancreatitis in a family of Aboriginal descent

The clinical and genetic features of hereditary pancreatitis in South Australia

Objective

To characterise the clinical phenotypes and genetic variants of hereditary pancreatitis in people diagnosed in South Australia.

Design, setting, participants

Cross‐sectional study of people who received molecular diagnoses of hereditary pancreatitis from one of four major diagnostic services in South Australia, 1 January 2006 – 30 June 2021.

Main outcome measures

Genotypic and clinical features of people with hereditary pancreatitis, including age at onset, attack frequency, pain indices, use of opioid medications, and physical and mental health impact of hereditary pancreatitis.

Results

We identified 44 people from ten families who received molecular diagnoses of hereditary pancreatitis during 2006–21 (including 25 Indigenous people [57%] and 27 women [61%]): 36 with PRSS1, five with SPINK1, and three with PRSS1 and SPINK1 mutations (determined by whole exome sequencing). Symptom onset before the age of ten years was reported by 37 people (84%). Pancreatitis‐related pain during the preceding four weeks was described as moderate or high by 35 people (79%); 38 people regularly used opioids (86%). Fifteen patients had diabetes mellitus (34%), and eight had undergone pancreatic surgery (18%). The estimated prevalence of hereditary pancreatitis was 1.1 (95% CI, 0.72–1.4) cases per 100 000 population for non‐Indigenous and 71 (95% CI, 66–77) cases per 100 000 population for Indigenous South Australians. Among people with adult‐onset chronic pancreatitis admitted to South Australian public hospitals during 2001–2019, the proportions of Indigenous people (12%) and women (38%) were smaller than we report for hereditary pancreatitis.

Conclusion

The estimated prevalence of hereditary pancreatitis in South Australia is higher than in Europe. PRSS1 gene mutations are important causes, particularly among Indigenous young people.

The Epidemiology and Burden of Childhood Chronic Pancreatitis in South Australia

OBJECTIVE

To assess longitudinal, population-based data on the prevalence and impact of chronic pancreatitis in children.

STUDY DESIGN

Administrative data linkage was used to ascertain an index cohort consisting of all individuals who had an initial diagnosis of chronic pancreatitis before age 19 years in the South Australian public hospital system between June 2000 and June 2019. Age- and sex-matched controls were drawn from the general population of South Australia, children with type 1 diabetes, and children with type 2 diabetes. Main outcomes and measures included hospital visits, days in hospital, emergency department (ED) visits, intensive care unit (ICU) admissions, education comparators, and incidence and prevalence estimates.

RESULTS

A total of 73 incident cases were identified. The crude prevalence and incidence of pediatric chronic pancreatitis were estimated at 6.8/100 000 and 0.98/100 000 per year, respectively. Of the index cohort, 24 cases (32.8%) of pediatric chronic pancreatitis were identified as occurring in children of Aboriginal and/or Torres Strait Islander descent. Compared with matched general population controls, children with chronic pancreatitis averaged 11-fold more hospital visits, 5-fold more ED visits, and 9-fold more ICU admissions; spent 10-fold more days in the hospital; and had a 2-fold higher rate of absence from school (P < .001 for all). Similarly, children with chronic pancreatitis used substantially more health resources than children with type 1 or 2 diabetes.

CONCLUSIONS

Pediatric patients with chronic pancreatitis consume a high volume of public health services and are significantly impacted in their ability to engage in education.

Australian experience with total pancreatectomy with islet autotransplantation to treat chronic pancreatitis

BACKGROUND

This study aimed to describe the clinical outcomes of total pancreatectomy with islet autotransplantation (TP-IAT) in Australia.

METHODS

Individuals selected for TP-IAT surgery according to the Minnesota Criteria (Appendix) without evidence of diabetes were evaluated including time to transplantation from pancreatectomy, islet numbers infused and post-transplantation HbA1c, C-peptide, total daily insulin and analgesic requirement.

RESULTS

Sixteen individuals underwent TP-IAT from Australia and New Zealand between 2010 and 2020. Two recipients are deceased. The median islet equivalents/kg infused was 4244 (interquartile range (IQR) 2290-7300). The median C-peptide 1 month post-TP-IAT was 384 (IQR 210-579) pmol/L and at median 29.5 (IQR 14.5-46.5) months from transplant was 395 (IQR 139-862) pmol/L. Insulin independence was achieved in eight of 15 (53.3%) surviving recipients. A higher islet equivalents transplanted was most strongly associated with the likelihood of insulin independence (P < 0.05). Of the 15 surviving recipients, 14 demonstrated substantial reduction in analgesic requirement.

CONCLUSION

The TP-IAT programme in Australia has been a successful new therapy for the management of individuals with chronic pancreatitis including hereditary forms refractory to medical treatment to improve pain management with 50% insulin independence rates.

Hereditary chronic pancreatitis

Hereditary chronic pancreatitis (HCP) is a very rare form of early-onset chronic pancreatitis. Apart from young age at diagnosis and a slower progression, the clinical course, morphological features and laboratory findings of HCP do not differ from those of patients with alcoholic chronic pancreatitis. Diagnostic criteria and treatment of HCP also resemble those of chronic pancreatitis of other causes. The clinical presentation is highly variable and includes chronic abdominal pain, impairment of endocrine and exocrine pancreatic function, nausea and vomiting, maldigestion, diabetes, pseudocysts, bile-duct and duodenal obstruction, and rarely pancreatic cancer. Fortunately, the disease is mild in most patients. Mutations in the PRSS1 gene, encoding cationic trypsinogen, play a causative role in chronic pancreatitis. It has been shown that the PRSS1 mutations increase autocatalytic conversion of trypsinogen to active trypsin, and thus probably cause premature, intrapancreatic trypsinogen activation, disturbing the intrapancreatic balance of proteases and their inhibitors. Other genes--such as the anionic trypsinogen (PRSS2), the serine protease inhibitor Kazal type 1 (SPINK1), and the cystic fibrosis transmembrane conductance regulator (CFTR)--have also been found to be associated with chronic pancreatitis (idiopathic and hereditary). Genetic testing should only be performed in carefully selected patients by direct DNA sequencing, and antenatal diagnosis should not be encouraged. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications such as pseudocysts and bile-duct or duodenal obstruction. The disease course and prognosis of patients with HCP is unpredictable. The risk of pancreatic cancer is elevated. Therefore, HCP patients should strongly avoid environmental risk factors for pancreatic cancer.

Hereditary chronic pancreatitis

Hereditary chronic pancreatitis (HCP) is a very rare form of early onset chronic pancreatitis. With the exception of the young age at diagnosis and a slower progression, the clinical course, morphological features and laboratory findings of HCP do not differ from those of patients with alcoholic chronic pancreatitis. As well, diagnostic criteria and treatment of HCP resemble that of chronic pancreatitis of other causes. The clinical presentation is highly variable and includes chronic abdominal pain, impairment of endocrine and exocrine pancreatic function, nausea and vomiting, maldigestion, diabetes, pseudocysts, bile duct and duodenal obstruction, and rarely pancreatic cancer. Fortunately, most patients have a mild disease. Mutations in the PRSS1 gene, encoding cationic trypsinogen, play a causative role in chronic pancreatitis. It has been shown that the PRSS1 mutations increase autocatalytic conversion of trypsinogen to active trypsin, and thus probably cause premature, intrapancreatic trypsinogen activation disturbing the intrapancreatic balance of proteases and their inhibitors. Other genes, such as the anionic trypsinogen (PRSS2), the serine protease inhibitor, Kazal type 1 (SPINK1) and the cystic fibrosis transmembrane conductance regulator (CFTR) have been found to be associated with chronic pancreatitis (idiopathic and hereditary) as well. Genetic testing should only be performed in carefully selected patients by direct DNA sequencing and antenatal diagnosis should not be encouraged. Treatment focuses on enzyme and nutritional supplementation, pain management, pancreatic diabetes, and local organ complications, such as pseudocysts, bile duct or duodenal obstruction. The disease course and prognosis of patients with HCP is unpredictable. Pancreatic cancer risk is elevated. Therefore, HCP patients should strongly avoid environmental risk factors for pancreatic cancer.

Mutations of human cationic trypsinogen (PRSS1) and chronic pancreatitis

Ten years ago, the groundwork for the discovery of the genetic basis of chronic pancreatitis was laid by linkage analyses of large kindreds with autosomal dominant hereditary chronic pancreatitis. Subsequent candidate gene sequencing of the 7q35 chromosome region revealed a strong association of the c.365G > A (p.R122 H) mutation of the PRSS1 gene encoding cationic trypsinogen with hereditary pancreatitis. In the following years, further mutations of this gene were discovered in patients with hereditary or idiopathic chronic pancreatitis. In vitro the mutations increase autocatalytic conversion of trypsinogen to active trypsin and thus probably cause premature, intrapancreatic trypsinogen activation in vivo. The clinical presentation is highly variable, but most affected mutation carriers have relatively mild disease. In this review, we summarize the current knowledge on trypsinogen mutations and their role in pancreatic diseases.