Multiple HPV 16 infection with two strains: a possible marker of neoplastic progression.

Our results suggest that single HPV infections have a greater risk of developing SCC with respect to multiple infections. Multiple HPV infections are relevant only in the first phase of the lesion (CIN1-CIN2), while they are absent in carcinomas, where infections are of a single genotype. In particular, among multiple infections, HPV16 infection with 2 HR genotypes is associated significantly with CIN2 / CIN3 (21/30) and has 4 times greater risk of developing a high-grade lesion. Thus, it is probable that only specific combinations of HPV (HPV16,18 - HPV 16,31) can be associated with a clinically significant impact, while other combinations can simply be correlated because of a common infection or diagnostic method used. Therefore, multiple HPV16 infections with two high-risk genotypes is a major risk of CIN2/CIN3.