Role of HLA-DRB1*04 in Malay patients with Vogt-Koyanagi-Harada syndrome

Abstract

In this issue of the Malaysian Journal of Ophthalmology, Alvernia et al. report the results of their study into the association between HLA-DRB1*04 and Vogt-Koyan-agi-Harada (VKH) syndrome in patients of Malay descent. VKH is a useful condition on which to focus this type of study as, unlike many types of uveitis, it has validated international diagnostic criteria. 1,2 VKH is also among the most common causes of uveitis in Asia, where it accounts for almost one-third of all causes of panuveitis. The combination of a genetic predisposition, including HLA haplotype as well as other genetic polymorphisms, and environmental factors is generally held responsible for the breakdown of tolerance and the development of autoimmunity in many disease entities. However, with the exception of acute anterior uveitis and HLA-B27, there is a disappointing lack of correlation between clinical phenotype, disease outcome, and HLA haplotype in uveitis. This lack of clarity also applies to VKH: there are distinct HLA associations across different ethnic populations, as has been shown in Hispanic and Japanese VKH patients with their HLA-DRB1*01 and *0405 associations; similarly, whilst VKH shares almost identical phenotypical and histopathological findings with sympathetic ophthalmia, and both share an association with HLA-DR1*0405 subtypes, they have completely different precipi-tating disease triggers.