Human leukocyte antigens (HLA) class II alleles were analyzed among Japanes
e leprosy patients to ascertain whether immunogenetic differences exist amo
ng the leprosy classification forms of Ridley and Jopling. Ninety-three unr
elated Japanese leprosy patients (21 lepromatous, 24 borderline lepromatous
. 17 mid-borderline, 26 borderline tuberculoid, 5 tuberculoid) and 114 heal
thy control subjects were investigated. The frequencies of HLA-DRB1*1501, -
DRB5*0101, -DQA1*0102 and DQB1*0602 were significantly increased in all of
the Japanese leprosy patients. The frequencies of HLA-DRB1*0405, -DQA1*03 a
nd -DQB1*0401 were significantly decreased in the Japanese patients after c
orrection of the p value. Conversely, there were no significantly different
distributions of the HLA-DRB1, -DRB5, -DQA1, DQB1 alleles in the five subg
roups of these patients. We conclude that HLA class II alleles were not ass
ociated with the form of leprosy. Other HLA, a non-HLA gene, and/or environ
mental factors may play a critical role in the different manifestations of
leprosy.