STUDY OF HLA CLASS-II ALLELES BY PCR OLIGOTYPING IN LEPROSY PATIENTS FROM NORTH-INDIA

Host factors seem to play an important role in determining the immune response and the differential manifestations of lepromatous (LL) and t uberculoid (TT) leprosy. In order to investigate the role of immunogen etic factors in determining the form of leprosy, the HLA class II alle les of DRB1, DRB3, DRB5, DQA1, DQB1 and DPB1 were studied by a PCR oli gotyping technique in 93 patients and 47 healthy controls. DRB11501 a nd DRB11502 (two of five tested subsets of the serologically defined DR2) accounted for 81.5% of the multibacillary patients (relative risk 16.3) and 60.7% of the TT patients (relative risk 5.7) compared to 21 .3% in normal, ethnically- and geographically-matched controls. The mu ch stronger association of DRB11501 with the multibacillary form than with the TT type of leprosy suggests a possible role in the different ial immune response to M. leprae antigens. DQB10601 was found signifi cantly more often than in controls throughout the leprosy spectrum, wh ile DQA10103 was most frequent in the LL group and DQA1*0102 was sele ctively increased in the borderline lepromatous (BL) patients. On the other hand, DRB10701, DQBI*0201 and DQA1*0201 were decreased in the m ultibacillary leprosy patients (MLP) compared to TT patients and contr ols, and DQB10503 was selectively decreased in TT patients, suggestin g that these HLA alleles might play a role in modulating the immune re sponse that determines the form of le rosy that develops in each patie nt.