The expression and activation of the AIM2 inflammasome correlates with inflammation and disease severity in patients with acute pancreatitis.

BACKGROUND: Acute pancreatitis is an inflammatory disorder of the pancreas that is responsible for significant morbidity and mortality. The inflammasome pathway has acquired significant relevance in the pathogenesis of many inflammatory disorders, but its role in patients with acute pancreatitis still awaits clarification.

METHODS: We performed a prospective study in which 27 patients with acute pancreatitis and 16 healthy controls were included. We isolated peripheral blood mononuclear cells (PBMCs) and we assessed the expression and activation of different inflammasomes as well as their association with the clinical course of the disease.

RESULTS: Our results show that PBMCs from patients with acute pancreatitis have elevated expression of several components of the inflammasome complex, including the inflammasome-forming receptor absent in melanoma 2 (AIM2), early during the onset of the disease. Activation of the AIM2 or NLRP3 inflammasomes in PBMCs from patients with acute pancreatitis results in exacerbated IL-1β and IL-18 production compared with PBMCs from healthy controls. Furthermore, both AIM2 mRNA expression and AIM2-mediated production of IL-1β by PBMCs correlated with increased systemic inflammation in these patients. Last, AIM2 expression was further increased in those patients that developed transient or persistent organ failure (moderate or severe acute pancreatitis).

CONCLUSIONS: Our data demonstrates that AIM2 inflammasome expression and activation is increased early during the course of acute pancreatitis, and suggests that AIM2 activation may affect systemic inflammation and organ failure in these patients.