HLA Alleles are Genetic Markers for Susceptibility and Resistance towards Leprosy in a Mexican Mestizo Population.

Despite the use of multidrug therapy, leprosy remains endemic in some countries. The association of several human leucocyte antigen (HLA) alleles and gene polymorphisms with leprosy has been demonstrated in many populations, but the major immune contributors associated to the spectrum of leprosy have not been defined yet. In this study, genotyping of HLA-A, -B, -DR, and -DQ alleles was performed in leprosy patients (n = 113) and control subjects (n = 117) from the region with the highest incidence for the disease in México. The odds of developing leprosy and lepromatous subtype were 2.12- and 2.74-fold higher in carriers of HLA-A*28, and 2.48- and 4.14-fold higher for leprosy and dimorphic subtype in carriers of DQB1*06. Interestingly, DQB1*07 was overrepresented in healthy individuals, compared to patients with leprosy (OR = 0.08) and the lepromatous subtype (OR = 0.06). These results suggest that HLA-A*28 is a marker for predisposition to leprosy and the lepromatous subtype and DQB1*06 to leprosy and the dimorphic subtype, while DQB1*07 might be a resistance marker in this Mestizo population.

Association of genetic polymorphism of HLA-DRB1 antigens with the susceptibility to lepromatous leprosy.

Despite the introduction of multidrug therapy and the overall reduction of leprosy prevalence in Mexico, the disease remains endemic in certain regions of the country. A genetic basis for the immune susceptibility to Mycobacterium leprae has already been established in different populations worldwide. In this study, we investigated the possible association of the HLA-DRB1 alleles with leprosy in a Mexican Mestizo population. The results demonstrated that the HLA-DRB1*01 allele is associated with lepromatous and dimorphic leprosy [P<0.001, odds ratio (OR)=4.6, 95% confidence interval (95% CI): 1.8-11.4; and P=0.03, OR=6.2, 95% CI: 1.1-31.6, respectively] and the frequency of the HLA-DRB1*08 allele was found to be significantly lower among leprosy patients compared to controls (P=0.046, OR=2.4, 95% CI: 1-5.8). In conclusion, although the association of the HLA-DR locus with leprosy has been established in different populations and several studies have demonstrated significant differences in the DR alleles, this study demonstrated an association of the HLA-DRB1*01 allele with susceptibility to lepromatous and dimorphic leprosy, as well as an association of the HLA-DRB1*08 allele with protection against leprosy in a Mexican Mestizo population.