Do common PRSS1/PRSS2 variants such as rs10273639 increase pancreatitis risk and progression to exocrine pancreatic insufficiency?

Genetic and clinical research confirms that specific genetic variations at the PRSS1/PRSS2 locus, particularly those tagged by the rs10273639 variant, significantly influence the risk of developing pancreatitis. This susceptibility is driven by alterations in the expression and activation of trypsin, which can lead to a cycle of recurrent injury and long-term pancreatic damage.

Clinical and Genetic Evidence

Large-scale genomic studies have identified the rs10273639 variant as a critical marker for pancreatitis risk. This variant functions as an expression quantitative trait locus (eQTL), meaning it directly correlates with the levels of PRSS1 mRNA and its protein product, cationic trypsinogen.

• Genetic Susceptibility: Variations at this locus are associated with both acute and chronic pancreatitis across diverse populations. Meta-analyses show that these variants modulate the "dosage" of trypsinogen available in the pancreas, with higher expression levels increasing disease vulnerability.
• Progression to Insufficiency: Clinical data indicates that recurrent pancreatic injury is a primary driver of exocrine pancreatic insufficiency (EPI). Systematic reviews show that approximately 35-39% of patients who survive acute pancreatitis will develop EPI. This risk nearly doubles in cases involving necrotizing pancreatitis or recurrent acute episodes (RAP), where repeated inflammatory insults lead to permanent parenchymal loss.

Mechanistic Pathways

The link between the PRSS1 locus and disease progression is rooted in the "trypsin-dependent" pathway of pancreatic injury.

• Trypsin Activation: PRSS1 encodes cationic trypsinogen. Under normal conditions, this enzyme is safely activated only in the duodenum. Genetic variants at the PRSS1/PRSS2 locus can lead to premature intrapancreatic activation of trypsin.
• Autodigestive Cascade: Once activated within the pancreatic acinar cells, trypsin triggers an autodigestive cascade by activating other potent enzymes like elastase and phospholipase A2. This leads to cell death, localized inflammation, and necrosis.
• Fibrosis and EPI: Over time, repeated episodes of trypsin-mediated injury overwhelm the organ's regenerative capacity. This results in the replacement of functional acinar cells with fibrotic tissue. As the mass of enzyme-producing cells declines, the pancreas can no longer secrete sufficient digestive enzymes, culminating in EPI.

Bottom line

Common variants at the PRSS1/PRSS2 locus, including rs10273639, are well-supported markers of pancreatitis risk. These variants influence the expression of trypsinogen, leading to a predisposition for premature trypsin activation and a cascade of pancreatic autodigestion. Recurrent injuries through this pathway frequently progress to permanent exocrine pancreatic insufficiency due to cumulative fibrotic damage.