Wide Spectrum Analysis of Human Papillomavirus Genotypes in External Anogenital Warts

Abstract

External anogenital warts (EGW) are primarily associated with the low-risk human papillomavirus (HPV) genotypes 6 and 11, though coinfection with other low-risk and oncogenic high-risk HPV genotypes also occurs. Although there have been many studies on HPV-associated disease, the prevalence of HPV genotypes associated with EGW is not well characterized. The objective of our retrospective study was to determine the prevalence of HPV genotypes among patients diagnosed with EGW in the south-west of Hungary. Archived formalin-fixed paraffin-embedded tissues from 94 patients were processed in our study. HPV genotypes were determined, applying HPV Direct Flow CHIP test. The overall prevalence of HPV DNA in the EGW samples was 100%, yielding 131 infections among the 94 samples. Of these cases, 72.3% were mono while 27.6% were multi-infections. Out of the 131 infections, the cumulative prevalence of HPV 6 and 11 was 71%. A total of 98.9% of the samples were carrying at least one of these genotypes, while 19.1% of the cases occurred with at least one high-risk genotype. Data from our study could provide invaluable information concerning the prevalence of HPV types among patients with EGW, enabling improved assessment of the actual and future efficacy of vaccination programs, vaccine development, and forecast changes in infection patterns.

Keywords: HPV Direct Flow CHIP; HPV genotyping; external anogenital warts; multi-infection; prevalence.

Figure 1

Histological characteristics of external genital warts. Note, the cauliflower-like architecture at the low power (I/a), Acanthosis, and parakeratosis with the presence of koilocytes in mid power image (I/b).

Figure 2

HPV genotype detection with Direct Flow CHIP test. I: Low-risk 6, 42, 44/55 and 67 HPV genotype multi-infection in patient with external anogenital warts. (I/a, I/b): snapshots before and after processing with hybriSoft software. Controls and the HPV genotypes were tested in duplicates. II: Low-risk 6 and high-risk 73 HPV genotype coinfection in patient with external anogenital warts. (II/a, II/b): snapshots before and after processing with hybriSoft software. Spot B: Hybridization control (5 signals to orientate the CHIP). Spot C: Internal DNA control (genomic human DNA probe). Spot U: HPV universal probe.

Figure 2

HPV genotype detection with Direct Flow CHIP test. I: Low-risk 6, 42, 44/55 and 67 HPV genotype multi-infection in patient with external anogenital warts. (I/a, I/b): snapshots before and after processing with hybriSoft software. Controls and the HPV genotypes were tested in duplicates. II: Low-risk 6 and high-risk 73 HPV genotype coinfection in patient with external anogenital warts. (II/a, II/b): snapshots before and after processing with hybriSoft software. Spot B: Hybridization control (5 signals to orientate the CHIP). Spot C: Internal DNA control (genomic human DNA probe). Spot U: HPV universal probe.