Coinfection of torque teno virus (TTV) and human papillomavirus (HPV) in cervical samples of women living in Tehran, Iran

Torque Teno virus or transfusion-transmitted virus (TTV) is a non-enveloped virus with a single strand circular DNA genome that currently is classified in the Alphatorquevirus genus and the family of Anelloviridae. Unlike other DNA viruses, TTV has an extremely wide genomic diversity. This virus, based on previous studies, infects both healthy people, as well as those who have HCV and human papillomavirus (HPV). This study aimed to evaluate the coinfection of torque teno virus (TTV) and HPV in cervical samples from Iranian women.

In this case-control study, the fresh cervical cytobrush specimens were collected from 150 women referred to Dena laboratory in Tehran. Viral DNA was extracted from samples. The HPV-DNA was detected and genotyped. Then, nested polymerase chain reaction (Nested PCR) was performed for TTV using specific primers.

Among 50 cervical specimens without HPV, 14 were TTV positive (28%); among 50 low-risk HPV cervical specimen, 23 were TTV positive (46%), and from 50 high-risk HPV cervical specimen, 48 were TTV positive (96%). There is a significantly higher prevalence of TTV virus in low-risk and high-risk papillomavirus-infected specimens than in healthy specimens (p 0.0001). Additionally, TTV is more prevalent in samples containing high-risk papillomaviruses than in samples with low-risk papillomaviruses (P = 0.048).

The higher prevalence of TTV among people infected with papillomavirus than in non-infected people indicates that both viruses are transmitted by the same mechanism (sexual route). In addition, the prevalence of TTV in samples containing high-risk papillomavirus is significantly higher than that in samples containing low-risk papillomavirus. The presence of papillomaviruses, particularly high-risk types, may be associated with TTV proliferation, which requires further research in the future.