Genomic DNA samples were extracted from EDTA blood using a MagNA pure compact Nucleic Acid Isolation Kit on a MagNApure Compact machine. HLA alleles were genotyped using polymerase chain reaction-sequence-specific oligonucleotides (PCR-SSOs) according to the manufacturer’s protocol. In brief, diluted DNA samples were amplified by PCR using a GeneAmp®PCR System 9700 (Applied Biosystems, Waltham, MA, United States). The PCR products were then hybridized against a panel of oligonucleotide probes on coated polystyrene microspheres that had sequences complementary to stretches of polymorphisms within the target HLA-A, B alleles (a LABType®SSO, One Lambda Inc. Kit). The amplicon–probe complex was visualized using a colorimetric reaction and fluorescence detection technology (Luminex®IS 100). Data analysis for the HLA assays was performed with the software package HLA fusion 2.0.