Detection and quantitation of HPV 16 and 18 in plasma of Indian women with cervical cancer

Objective.: HPV infection is a necessary but insufficient cause of cervical cancer. The significance of HPV DNA in blood however is debatable because of variable detection rates due to the differences in the methodology used. The aim of this study was to detect and quantitate HPV 16 and 18 plasma viremia in women with cervical neoplasia. Methods.: HPV DNA was detected in cervical tissue using consensus PGMY primers and genotyped using reverse line blot hybridization. HPV 16 and 18 quantitation in tissue and detection and quantitation in plasma was performed using sensitive real time PCRs targeting E6/E7 region of HPV 16/18 genome respectively. Results were correlated with viral loads in corresponding tissue and with clinical disease stage. Results.: Viremia was detected in 56.4% of HPV 16 positive women and 20% of HPV 18 positive women. The prevalence of HPV 16 DNA in plasma increased with advancing disease stage (p = 0.001), although HPV 16 absolute plasma viral load was not significantly associated with advancing disease stage (p = 0.281). There was no correlation between absolute plasma viral load and viral load in corresponding cervical tissue (Spearman's rho = 0.184, p = 0.187). The prevalence of HPV 18 viremia and absolute HPV 18 plasma viral load were not associated with advancing disease stage (p = 0.620, p = 0.508). Conclusion.: The presence of HPV 16 in plasma is a marker of advancing cervical disease.