Following genotyping using a custom content Affymetrix Axiom SNP array, imputation of classical HLA alleles per locus (i.e. class I: HLA-A, HLA-B, HLA-C and class II: HLA-DP, HLA-DQ, HLA-DR) at four-digit resolution was performed with HIBAG[25 (link)]. The genotyping and HLA imputation have been described previously[15 (link)]. As part of the exploratory nature of these analyses, we aimed to explore associations with HLA alleles carried by ≥10 participants including those observed at low frequencies.