A Pilot Study on Salivary HPV DNA Detection to Monitor Active Disease from Patients with Recurrent Respiratory Papillomatosis

Purpose: Recurrent respiratory papillomatosis (RRP) is a human papillomavirus (HPV)-related disease affecting the upper airway and saliva could be an important non-invasive sampling source for viral screening and clinical monitoring. We investigated whether HPV DNA could be detected in saliva (cellular pellets and supernatant) from RRP patients and influence on clinical manifestation of the disease. Materials and methods: In this pilot study, saliva samples from 14 RRP patients were obtained in preoperative condition (n = 7) and in disease-free interval (DFI; n = 7). Healthy donors (n = 14) were also included. HPV DNA was investigated by polymerase chain reaction (PCR)-based assays. Results: From cellular pellets, HPV-positive saliva was only detected from preoperative collections (5/7; 71.4 %) and showed a mean cycle threshold (Ct) value of 24.33 (+/- 1.25), whereas all patients in DFI were HPV-negative (Ct >= 32.16), revealing significant difference between these two clinical moments (p = 0.021). Patients in DFI and healthy donors showed similar Ct values. From saliva supernatant, detectable HPV cell-free DNA (cfDNA) occurred in 42.9 % (3/7) and 57.1 % (4/7) of preoperative collections using the commercial cfDNA kits from Norgen and Qiagen, respectively. Salivary cfDNA size distribution obtained by TapeStation analysis showed a predominant size range of 150 to 400 bp in both patients and healthy controls, corresponding to mononucleosomal and dinucleosomal fragments. Conclusions: In conclusion, HPV DNA screening in saliva (both cellular pellets and cfDNA) may have clinical utility to monitor active disease of RRP patients.