HPV16 variant analysis in primary and recurrent CIN2/3 lesions demonstrates presence of the same consensus variant

Introduction: Recurrent cervical intraepithelial lesions (rCIN2/3) after treatment of CIN2/3 occur in 5–15% of cases. rCIN2/3 can result from incomplete resection of CIN2/3, where the same HPV type and variant remains present. rCIN2/3 could also occur following a new infection with a different HPV variant of the same HPV type as the initial lesion. This study investigates HPV16 consensus variants in paired HPV16 positive scrapes from baseline CIN2/3 and rCIN2/3 lesions. Methods: Paired HPV16 positive cervical scrapes of women with CIN2/3 at baseline and rCIN2/3 6 or 12 months after treatment were selected for whole-genome amplification and Illumina sequencing. Sequences were compared and nucleotide changes over time were characterized. Results: From 14 paired samples, 10 had identical consensus variants in baseline CIN2/3 and rCIN2/3. Four paired samples showed one to three nucleotide variations at recurrent disease compared to baseline. Conclusion: Identical or nearly identical HPV16 consensus variants were found in scrapes of paired HPV16 positive baseline CIN2/3 and rCIN2/3 lesions after treatment, suggesting no need for HPV variant analysis when the same HPV type is found in both lesions. These results argue for either incomplete excision of baseline CIN2/3 or inability of clearance of the original HPV infection. Keywords: Whole-genome sequencing, HPV16, HPV genome variants, CIN, rCIN, Recurrent infection