Strong association of HLA class II sequences in Mexicans with Vogt-Koyanagi-Harada's disease

Vogt-Koyanagi-Harada's syndrome (VKH) is an autoimmune disease prevalent in Mongoloids with evident participation of KLA. The aim of this study was to identify the class II DNA sequences involved in the etiopathogenesis of VK H in Mexican Mestizos, This study included 46 VKH patients and 170 controls , 75% were females (mean age at onset of 33.5 years). The disease evolved t o chronicity (68%) and 25% of the patients were unresponsive to corticother apy. DNA typing of HLA-DRB1, DQA1 and DQB1 was done following the 12th Inte rnational Histocompatibility protocols. VKH was strongly dependent of DRB1 gene; DRB1*04 was found in 78.2% of the patients vs, 50.6% of the controls (p = 0.001). No particular DRB1*04 subtype was significantly increased, sug gesting that residues E-9 V-11; H-13; H-33 and Y-37 shared by all DR4s are implicated in susceptibility to VKH. However DRB1*0101 (p = 0.009, OR = 4.2 ) was clearly associated. This allele shares the motif LLEQRRAAG located at position 67-74 and 86 of DRB1 with *0405 associated in Japanese. Two HLA a ssociated mechanisms may be triggering the autoimmune phenomena. One involv ing critical polymorphic residues expressed in different alleles. Secondly, some peptides may anchor to the conserved residues leaving other sequences to bind to the T cell receptor. (C) American Society for Histocompatibilit y and Immunogenetics, 1999. Published by Elsevier Science Inc.