HLA and KIR associations of cervical neoplasia

BackgroundCervical cancer is the fourth most common cancer in women, and we recently reported human leukocyte antigen (HLA) alleles showing strong associations with cervical neoplasia risk and protection. HLA ligands are recognized by killer immunoglobulin-like receptors (KIRs) expressed on a range of immune cell subsets, governing their proinflammatory activity. We hypothesized that the inheritance of particular HLA-KIR combinations would increase cervical neoplasia risk. MethodsHere, we used HLA and KIR dosages imputed from single-nucleotide polymorphism genotype data from 2143 cervical neoplasia cases and 13858 healthy controls of European decent. ResultsThe following 4 novel HLA alleles were identified in association with cervical neoplasia, owing to their linkage disequilibrium with known cervical neoplasia–associated HLA-DRB1 alleles: HLA-DRB39901 (odds ratio [OR], 1.24; P = 2.49 × 10⁻⁹), HLA-DRB50101 (OR, 1.29; P = 2.26 × 10⁻⁸), HLA-DRB59901 (OR, 0.77; P = 1.90 × 10⁻⁹), and HLA-DRB30301 (OR, 0.63; P = 4.06 × 10⁻⁵). We also found that homozygosity of HLA-C1 group alleles is a protective factor for human papillomavirus type 16 (HPV16)–related cervical neoplasia (C1/C1; OR, 0.79; P = .005). This protective association was restricted to carriers of either KIR2DL2 (OR, 0.67; P = .00045) or KIR2DS2 (OR, 0.69; P = .0006). ConclusionsOur findings suggest that HLA-C1 group alleles play a role in protecting against HPV16-related cervical neoplasia, mainly through a KIR-mediated mechanism.