The natural history of human papillomavirus (HPV) infections is complex, and more information is greatly needed to identify the host genetic and immunological factors that contribute to the infection susceptibility and its progression. HPV is the most common sexually transmitted infection. However, in the last few decades, more data on non-sexual HPV transmission routes have become available. The knowledge on vertical HPV transmission from the mother/father to the child remains insufficient.

This doctoral dissertation evaluated 319 mothers, 132 fathers and their 321 newborn offspring from the prospective Finnish Family HPV (FFHPV) Study cohort. Participants’ HPV status and HLA-G genotypes were determined. The aim was to investigate the vertical HPV transmission from parents to newborn, and the role of HLA-G in the father-newborn HPV transmission and the fathers’ HPV infection outcomes. In Study I, the associations between the fathers’ human leukocyte antigen G (HLA-G) alleles/genotypes and the fathers’ HPV infection outcomes were evaluated. The allele G*01:01:02 showed to be protective against oral HPV infections whereas the allele G*01:01:03 increased the risk of genital highrisk HPV infection. Fathers with the allele G*01:01:01 showed a reduced risk for incident and persistent oral infections. Study II evaluated the association between the father-newborn HLA-G allele/genotype concordance and the father-newborn HPV concordance at birth as well as at the postpartum period; the father-newborn HLA-G allele concordance, but not genotype concordance, was associated with the HPV concordance. In Study III the HPV genotype concordances between 321 mother-newborn pairs and 134 father-newborn pairs were evaluated. The HPV concordances were statistically significant with HPV6, HPV16, HPV18, HPV31 and HPV56 between the mother-newborn pairs, and with HPV6 and HPV31 between the father-newborn pairs, respectively.

While the results of the genotype-specific HPV concordance between parents and their newborns are suggestive of a vertical HPV transmission, the fathernewborn transmission remains more uncertain. The father’s HLA-G may potentially influence HPV infection outcomes and his child’s risk of acquiring a perinatal HPV infection.