Screening of Orthodontic Patients and Age-Matched Non- Orthodontic Samples for High-Risk Oncogenic Human Papillomavirus (HPV) Strains

Introduction: The human papillomavirus (HPV) is known to cause cancer in several tissues and organs, including the cervix and the oral cavity. Several oncogenic or high-risk strains have been identified, which include HPV16 and HPV18.However, other research has demonstrated that additional oncogenic, high-risk strains exist - including HPV31, HPV33, HPV35, HPV52 and HPV58, although much less is known about their prevalence. Based upon this lack of knowledge, the primary objective of this project is to address the prevalence of these strains among pediatric and adult patients through screening of saliva samples from the UNLV-SDM and orthodontic clinic populations. Methods: The protocol for this study was reviewed and approved by the UNLV Institutional Review Board (IRB #1619329-1) titled “Retrospective analysis of Oral Health Status of Dental Population”. Clinical samples from a saliva biorepository (N=253) were screened to provide age-matched pediatric and adult samples from the orthodontic and main patient clinics. Quantitative polymerase chain reaction (qPCR) screening of samples for high-risk HPV was performed using SYBR green master mix from Applied Biosciences and validated high-risk HPV primers. Results: A total of N = 86 samples from the saliva biorepository met the quality and concentration standards and were screened for high-risk HPV. qPCR screening of adult samples revealed n = 10/45 or 22% were HPV31- or HPV33-positive. In addition, a total of n = 9/41 or 21.9% of pediatric samples were either HPV31- or HPV33-positive (or both). No samples harbored HPV35. Most samples were derived from patients within the recommended vaccination or catch-up age range (age 9-45 years). Discussion and Conclusions: No previous studies from this institution have explored these high-risk HPV strains among this patient population. These results clearly demonstrate that a significant percentage of patients harbor additional high-risk HPV strains within the oral cavity, including HPV31 and HPV33. Although many studies promote the quadrivalent HPV vaccine (covering HPV6, 11, 16, and 18), these results suggest that oral healthcare providers may need to discuss the newer nine-valent vaccine, which includes HPV31 and HPV33. It might have a beneficial effect on this certain population to make a larger emphasis on this newer vaccine and the prevention potential to the general public.