An Association Study Between HLA-DRB1and HLA-DQB1and Leprosy In Yi Chinese In Sichuan Province Of China

Background and Objective：Leprosy is a chronic infectious diseasecaused by Mycobacterium leprae. Although the number of registered casesdecreased in the past20years worldwide，there are250,000newly detectedleprosy cases in the world every year. Epidemiological studies have confirmedthat there is an apparent genetic susceptibility to acquiring infection withLeprosy. Molecular biological studies have confirmed that HLA controls theimmunoresponsiveness and the immunomodulation of the body，and HLA isassociated with leprosy. Previous studies analyzing the HLA-DRB1andHLA-DQB1in patients with leprosy have shown that different types of HLAalleles are significantly associated with leprosy in distinct populations. TheLiangshan Yi autonomous region is located in the southwest of Sichuan, China.This region is the relatively high-endemic area of leprosy in Sichuan.Polymerase Chain Reaction-Sequence Specific Primers (PCR-SSP) was used togenotype HLA-DRB1and HLA-DQB1alleles in patients and healthy controls.The purpose of this paper is to investigate the association of the HLA-DRB1and HLA-DQB1with leprosy in Yi Chinese in Sichuan province of China.Method: According to the Chinese WS291-2008diagnostic criteria of leprosy,all cases were diagnosed by clinical, bacteriological and pathologicalexamination of physician.100patients with leprosy(71male,29female) including those in the process of treatment and the cured patients of Yi Chinese,Sichuan Province, China were selected as the patient group. They don’t haveany blood relationship with each other. All cases have no other immunologicaldiseases. According to the clinical classification diagnostic criteria, patientswere classified into two groups: MB(multibacillary, n=76) andPB(paucibacillary, n=24). MB include BB, BL and LL of the five-categoryclassification of leprosy, PB include TT, BT of the five-category classificationof leprosy. According to their family history of leprosy, patients were classifiedinto two groups: patients with family history (n=42) and patients without familyhistory (n=58).100healthy voluntary donors of the same geographic region ofYi Chinese, Sichuan Province, China were selected as the control group.PCR-SSP was used to genotype HLA-DRB1and HLA-DQB1alleles in100patients and100healthy controls respectively. All the data was analyzed bychi-square test through the SPSS17.0software. Results:(1) The allelefrequencies of HLA-DRB1*13of the patient group and the control group are0.06and0.015respectively. There is a significant difference of the allelefrequencies of HLA-DRB1between these two groups (P=0.032, P<0.05).(2)There is a difference of the allele frequencies of HLA-DQB1between thepatient group and the control group. However, this association does not reach asignificant difference (P>0.05).(3) The allele frequencies of HLA-DRB1*03inMB patients and PB patients are0.019737and0.104167respectively. There is asignificant difference of HLA-DRB1*03between the two groups (P=0.021, P<0.05).(4) The allele frequencies of HLA-DQB1*02in MB patients and PBpatients are0.039474and0.125respectively. There is a significant difference ofHLA-DQB1*02between the two groups (P=0.04, P<0.05).(5) There is adifference of the allele frequencies of HLA-DRB1between the patients withleprosy with family history and without family history. However, thisassociation does not reach a significant difference (P>0.05).(6) There is adifference of the allele frequencies of HLA-DQB1between the patients withleprosy with family history and without family history. However, thisassociation does not reach a significant difference (P>0.05). Conclusions:(1)HLA-DRB1*13is related with the leprosy susceptibility among the Yi Chinesein Sichuan province, China.(2) HLA-DQB1are not related with leprosy amongthe Yi Chinese in Sichuan province, China.(3) The variation of theHLA-DRB1*03and HLA-DQB1*02are related to the manifestation of MBand PB.(4) HLA-DRB1and HLA-DQB1are not related to the familyinheritance of patients with leprosy.