Analysis of the NOD2/CARD15 gene in patients affected with the aseptic abscesses syndrome with or without inflammatory bowel disease.

Objectives: NOD2/CARD15 is a susceptibility gene for Crohn's disease (CD). It is also involved, via different mutations, in the Blau syndrome. The syndrome of aseptic abscesses (AA) is characterized by visceral sterile collections of mature neutrophils that do not respond to antibiotics but regress quickly with corticosteroids. It is associated in two cases out of three with inflammatory bowel disease (IBD), and in particular with CD. We wanted to assess if changes on gene NOD2/CARD15 could contribute to the development of AA in patients with and without IBD.

Methods: Seventeen unrelated patients with AA from the French national register were genotyped for c.802C>T (p.Pro268Ser) and the three main CD associated variants, c.2104C>T (p.Arg702Trp), c.2722G>C (p.Gly908Arg) and c.3019_3020insC (p.Leu1007fsX1008), and 16 were screened for the 11 coding exons of NOD2/CARD15.

Results: The main variants associated with CD were found at a similar frequency in patients free of IBD and in those with CD. There was no significant difference in the main variants between patients with CD and those without IBD in our study and patients with CD and controls, respectively, from a large study of an ethnically similar population. No rare variant was found. A significant association between carriers of the silent variant c.1377 C>T and markers of severity of AA was observed.

Conclusions: These results suggest that the emergence of AA is not closely related to gene NOD2/CARD15. NOD2/CARD15 and other susceptibility genes might enhance the expression of AA as the result of a combination of polymorphisms.