HLA-DR9 associated with the severity of acute retinal necrosis syndrome

We divided 22 patients with acute retinal necrosis syndrome into two groups depending on whether they had its mild (10 patients) or fulminant type (12 patients) and analyzed human leukocyte antigens, HLA-A, -B, -C and -DR loci, to elucidate immunogenetic differences between these two groups. The frequency of HLA-DR9 was found to be high in patients with the fulminant type (50.0%) compared with that in the patients with the mild type (0.0%), which was significant (p < 0.05) in a χ² test with Yates’ correction but did not remain significant when the probability was corrected by the number of antigens tested. The result suggests that immunogenetic predisposition plays a role in aggravation of acute retinal necrosis syndrome.