9th Annual BMRP Investigator Meeting - Abstract
Role of Mycobacterium Paratuberculosis (MAP) in Family Members with Crohn’s Disease: Genetic Link and Environmental Influence
Saleh A. Naser1,a; Hamza Boukhriss1, Sammer El-Wasila1, Manuel Perez2 and John F. Valentine3
1Department of Molecular Biology and Microbiology, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida (Orlando, Florida, U.S.A.); 2Nanoscience Technology Center, Department of Chemistry, University of Central Florida (Orlando, Florida, U.S.A.); 3Department of Medicine, University of Florida (Gainesville, Florida, U.S.A.)
A total of 21 families consisting of 16 biological families and 5 non-biological families participated in this study. A biological family consisted of a parent and a sibling where as a non-biological family consisted of husband and wife. Blood samples from each subject were investigated for the presence of Mycobacterium paratuberculosis (MAP) by MGIT-PCR and for comprehensive genotyping of NOD2, ATG16L1, IRMG and 9 loci of IL23R genes. In Biological family groups, MAP was detected in 56% (9/16) of the members with CD and in 25% (4/16) of healthy family members (P<0.05). Three families were negative for MAP. In the non-biological family groups, MAP was detected in 4/5 (80%) partners with CD and absent in all healthy partners (P<0.05). The incidence of NOD2 gene polymorphism in both groups was rare compared to a much higher rate for ATG16L1, IRMG and IL23R mutations in all subjects. ATG16L1 [T300A (898A>G); rs2241880] mutation occurred in 11/16 CD (5/11 MAP+) compared to 8/16 (4/8 MAP+) healthy biological family relatives. IRMG [-4299C>T; rs13361189] gene mutation occurred in 7/16 CD (4/7 MAP+) compared to 4/14 (0/4 MAP+) healthy biological family relatives. Similar results were observed for non-biological family members. Of the 9 IL23R loci investigated, [IL23R (T>G); rs11465804], [IL23R (T>C), rs1343151], and [IL23R (1142G>A), rs11209026] had neither association with CD or MAP detection in both family groups. The mutation incidence in association with MAP presence in the remaining six IL23R loci occurred similarly in both CD and healthy family members.
In conclusion, MAP association with CD is real and significant. The association of key genes’ mutation with MAP presence in CD patients compared to controls is not significant. The genotyping results and the life style data (diet, exposure to animal farm, etc) had no significant impact on the occurrence of MAP in CD patients in biological or non-biological families.
a Principal Investigator