Genotyping and Cytokine Profiling in Behcet's Disease

We conducted genome-wide SNP genotyping using the Infinium ImmunoArray-24 v2 BeadChip Kit with the standard protocol recommended by Illumina (San Diego, CA, USA). Genotype imputation was conducted using the Michigan Imputation Server (https://imputationserver.sph.umich.edu) with the 1000 Genomes Phase 3 v5 reference panel (http://www.1000genomes.org). The genotyped and imputed SNP data underwent quality control as previously described (29 (link)). We extracted only loci that were proven to be BD-sensitive polymorphic loci in the Japanese population from among these SNP data (30 (link)–32 (link)). Serum cytokine (IL-1β, IFN-α2, IFN-γ, TNF-α, MCP-1, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IL-18, IL-23, and IL-33) levels of patients with BD were measured using LEGENDplex™ Human Inflammation Panel 1 (13-plex, BioLegend, San Diego, CA, USA) during BDCAF score evaluation. One hundred and eleven age-sex-matched healthy human serum samples from the YCU Hospital Biobank were used as controls.