A paired comparison of dot blot hybridization and PCR amplification for HPV testing of cervical scrapes interpreted as CIN 1.

The rate of Human Papillomavirus (HPV) detection in CIN 1 lesions is quite variable for several reasons. Amongst these, the sensitivity level of the HPV detection system probably ranks supreme. The prevalence of HPV DNA in cervical scrape samples from 234 patients referred for colposcopic investigation of a CIN 1 lesion was compared using dot blot hybridization (DBH) and polymerase chain reaction (PCR) amplification. Both methods were performed on the same patient sample so that determinants of HPV positivity other than the detection system could be controlled. Probes and primers to HPV 6, 11, 16, 18, 31, 33, and 35, and consensus HPV primers were used. The overall HPV positivity rate was 24% using DBH and 70% using PCR. Identified types by DBH and PCR respectively were; HPV 6/11: 1% and 2%, HPV 16/18: 16% and 41%, and HPV 31/33/35: 7% and 14%. PCR detected unidentified types in 13%. Since PCR resulted in a 2.9 times higher HPV DNA detection rate, the choice of detection system has a major impact on the HPV status of cervical smears interpreted as CIN 1.