Immune System Linked to Leprosy Susceptibility
Genome-wide association study shows association between innate immunity and leprosy
WEDNESDAY, Dec. 16 (HealthDay News) -- Host genetic factors involving the innate immune system are associated with susceptibility to leprosy infection, according to a study published online Dec. 16 in the New England Journal of Medicine.
Fu-Ren Zhang, M.D., from the Shandong Academy of Medical Science in China, and colleagues performed a genome-wide association study of 491,883 single-nucleotide polymorphisms (SNPs) in 706 leprosy patients and 1,225 unaffected controls who were all Han Chinese. The 93 SNPs showing the strongest association were examined further in three independent groups totaling 3,254 patients and 5,955 controls who were Han Chinese or from Chinese ethnic minorities.
The researchers found that SNPs from six genes were significantly associated with leprosy and a SNP from another gene tended towards an association. Four of these genes were more strongly associated with multibacillary leprosy than paucibacillary leprosy. Four of the genes were present at the NOD2 gene locus regulating innate immunity, and a network analysis showed that five of the identified genes lay in the same biological pathway.
An attractive aspect of the study "is the apparently narrow focus of the genetic control, which highlights early antigen sensing and signaling in the pathogenesis of both leprosy and Crohn's disease," Erwin Schurr, Ph.D., and Philippe Gros, Ph.D., from McGill University in Montreal, write in an accompanying editorial. "It is tempting to speculate that these common genetic signatures support, albeit indirectly, the proposal that a proportion of Crohn's disease cases may have a mycobacterial cause."