Lineage and Sublineage Analysis of Human Papillomavirus Types 66 and 68 in Iran During 2021–2023: A Cross-Sectional Study

Background and Aims

Knowing the distribution of HPV lineages and sublineages can provide more information on this virus's epidemiology, evolution, and pathogenicity. The present study intends to investigate the sequence variations of the E6 gene to know the distribution of lineages and sublineages of HPV 66 and 68 types in Iran.

Methods

Seventy-one HPV 66 and 59 HPV 68-positive samples were investigated to identify their lineage/sublineages by hemi-nested PCR and sequencing.

Results

Most of the HPV 66-infected samples belonged to lineage B (77.5%) and the remaining (22.5%) were classified as lineage A. For sublineage classification, 22.5%, 12.7%, and 64.8% were sublineages A1, B1, and B2, respectively. Most of the HPV 68-positive samples were classified as lineage C (66.1%), followed by lineage A (25.4%), lineage D/E (6.8%), and lineage F (1.7%). According to detected sublineages, C1 was dominant (62.7%), followed by A1 (22%), D/E (6.8%), A2 (3.4%), C2 (3.4%), and F2 (1.7%). No statistically significant differences were observed concerning HPV 66 or 68 distinct lineages by histology/cytology status.

Conclusion

Our results showed that the B2 sublineage of HPV 66 and the C1 sublineage of HPV 68 were dominant in Iranian women. However, to elucidate the role of HPV 66 and 68 lineages in the pathogenicity risk of these two types, more studies with larger sample sizes are required.