HPV May Lead To HIV
It seems that certain strains of the human papillomavirus (HPV) may make women more susceptible to human immunodeficiency virus (HIV). Researchers from UCSF have uncovered this new link between higher rates for the acquisition of HIV in women with specific types of HPV. A report of these findings has just been made public on April 8, 2010.
Lead author of the study is Karen Smith-McCune, MD, PhD, an associate professor in the Department of Obstetrics, Gynecology and Reproductive Sciences at UCSF. "The finding is not conclusive about the role of HPV in HIV transmission, but may offer insights into the mechanism of HIV transmission," said Smith-McCune, who is also affiliated with the UCSF Helen Diller Family Comprehensive Cancer Center. "Given the high prevalence of HPV infection in women, I am hopeful that future clinical trials on HIV prevention will address the potential importance of HPV as a risk factor."
According to the Centers for Disease Control and Infection (CDC), HPV is the most common sexually transmitted infection (STD). The disease is passed through genital-to-genital contact and there are over 40 strains of HPV that can infect men and women. While other STD's, for instance the herpes simplex virus, have been found to be associated with an increased risk for HIV infection, no one had, until now, studied the effects of HPV on HIV acquisition, say the authors.
The UCSF study was part of a larger, randomized study that was undertaken in Zimbabwe. The researchers followed 2,040 Zimbabwean women who were negative for HIV. The women had an average age of 27 years. One group of women was studied for 2 years, while another group was studied for only one year. All of the participants were given examinations every three months.
The research team tells us that most HPV infections are wiped out by the immune system. However, they posit that this process might be the cause of the increased rates for the development of HIV in which immune system cells become a target. Women in the study group suffering from persistent HPV infection were found to have a higher rate for the development of precancerous lesions though they appeared not to have an increased risk for HIV acquisition. The two types of HPV most commonly linked to cancer and which have been the focus of the recent vaccination campaign, HPV 16 and 18, were also not linked to the elevated HIV risk.
But researchers found a significantly high rate of HPV 58 and 70 among the study participants and found that non-persistent infections with these HPV types as well as with HPV 31 could be linked to an increased rate for HIV transmission. They feel that a woman's inflammatory response to the HPV infection might predispose target cells to HIV acquisition.
But study co-author George Sawaya, MD adds some further insight, "One obvious explanation for these associations is that women acquired both HPV and HIV from a high-risk partner," said Sawaya, a professor in the UCSF Department of Obstetrics, Gynecology and Reproductive Sciences, UCSF Helen Diller Family Comprehensive Cancer Center, and the UCSF Department of Epidemiology and Biostatistics. "The link between specific HPV types and acquisition, however, is intriguing and needs to be validated in other studies."