ABSTRACT
BACKGROUND: The low prevalence of human papillomavirus (HPV) DNA and mRNA in biopsy samples of Filipinos with head and neck squamous cell carcinoma (HNSCC) has been reported previously. Here, the HPV serologic profiles of HNSCC cases were analyzed and associated with lifestyle and sexual practices. METHODS: Serum samples were collected between May 2012 and September 2013 from HNSCC patients (n = 22) in the northwest region of the Philippines, and age- and sex-matched clinically healthy controls. Antibodies to capsid and early oncoproteins of HPV16, 18, 31, 33, 45, 52, 58, 6, and 11 were analyzed using multiplex serology. RESULTS: Most of the cases were males with tumors of the oral cavity or larynx. Two of the cases tested positive for at least one of the early oncoproteins (E6, E7, E1, and/or E2) of HPV16, and 11 did not display reactivity to any HPV early or late oncoproteins. Of the controls, four tested positive for at least one of the HPV16 early oncoproteins, and 10 were non-reactive to all HPV types. Titers to HPV16 E6 or E7 of the seropositive cases and controls were considerably lower than those typically observed in economically developed countries. CONCLUSIONS: The low HPV titers seen here are consistent with the results of molecular analyses for this population. Hence, the seropositivity of some of the HNSCC cases is likely an indication of prior exposure to the virus and not the presence of HPV-driven tumors.