Molecular variants of human papilloma viruses type 16 and 6 in women with different cytological results detected by RFLP analysis

HPV infections are common and the presence of the same high-risk type in cervical specimens can be due to reinfection or persistence. Persistent infection is the most important predictor for development of cervical carcinoma. The aim of this study was to validate PCR-RFLP with two sets of primers: MY09/MY11 that amplify a fragment of L1 and P1/P2 that amplify a fragment of E1 ORF. PCR product of MY09/MY11 was digested with a set of 6 restriction enzymes (RE) and PCR product of P1/P2 with a set of 12 RE. Cervical samples from 110 women patients of the University Gynecologic Clinic CHC Zagreb were analyzed. There were 98 (89.1%) PCR positive samples detected with P1/P2 primers, and 94 (85.5%) PCR positive samples detected with MY09/MY11 primers. Seven HPV types were detected with P1/P2-RFLP technique and 17 with MY09/MY11-RFLP PCR positive samples amplified with both primer pairs agreed with each other in 82 samples; 16 samples were only positive with P1/P2 and 12 samples were only positive by MY09/MY11. HPV 16 was detected in 39 samples with MY09/11-RFLP, out of these two variants (two different patterns) were found with P1/P2 using Dde I, Hae III and Eco I. HPV 6 was detected in 9 samples with MY09/11-RFLP, out of these two variants were found with P1/P2 using HinfI. Combining these two PCR-RFLP methods subtypes of HPV 16 and HPV 6 were detected.