HLA Association With AQP4-IgG-Positive Neuromyelitis Optica Spectrum Disorder in the Korean Population

Association of human leukocyte antigen (HLA) with anti-aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-IgG NMOSD) has been reported. However, this association in the Korean population has not been previously investigated. We aimed to evaluate whether specific HLA subtypes were associated with Korean patients with AQP4-IgG NMOSD and whether the HLA genotype is associated with specific clinical features. We compared the HLA subtypes of 122 patients with AQP4-IgG NMOSD with those of 485 (HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1) and 173 (HLA-DPB1) healthy controls. In addition, we compared the clinical features of patients with and without specific HLA genotypes. The most significant risk allele for AQP4-IgG NMOSD was HLA-DRB1*03:01 (24 patients [19.67%], odds ratio [OR]: 3.997, pc value = 0.0001). Susceptibility of AQP4-IgG NMOSD was significantly associated with the HLA-DRB1*03:01-DQB1*02:01 (23 patients [18.85%], OR: 3.792, pc value = 0.0002) and DRB1*12:02-DQB1*03:01 (23 patients [18.85%], OR: 3.402, pc value = 0.0009) haplotypes. Patients with the DRB1*12:02-DQB1*03:01 haplotype showed more frequent spinal involvement, a higher Expanded Disability Status Scale score at disease-onset nadir, and a shorter time to second attack than patients without this haplotype. In a Korean cohort of patients withAQP4-IgG NMOSD, the HLA-DRB1*12:02-DQB1*03:01 haplotype was associated with disease severity at onset. HLA-DRB1*03:01, broadly reported as a significant susceptibility allele across diverse ethnic groups, showed a significant risk association in Korean patients with AQP4-IgG NMOSD.