Study suggests HPV16 can skirt the immune system.

2003 AUG 7 - (NewsRx.com & NewsRx.net) -- In a large study of HIV positive women, human papillomavirus 16 (HPV16), the virus responsible for approximately half of all cervical cancers, appeared to be better at dodging the immune system than other HPV strains.

The findings, published in the July 16, 2003, issue of the Journal of the National Cancer Institute, may help explain why HPV16 plays such a major role in causing cervical cancer in the general population.

Whereas other HPV types have a lower prevalence and incidence among women with stronger immune systems (in theory, the stronger the immune system, the better it is at fighting off infections), researchers detected similar levels of HPV16 in women with both weak and strong immune systems.

More than 30 types of HPV are known to infect the genital epithelium. HPV16 has been the strain most strongly associated with cervical cancer and its precursor lesions. What sets HPV16 apart from other HPV types has not been clear. A preliminary analysis of a study on HPV infection among women positive for HIV, the virus that causes AIDS, suggested that HPV16 may be less associated with immune status than other HPV types.

To test this, Howard D. Strickler, MD, and Robert D. Burk, MD, of the Albert Einstein College of Medicine in Bronx, New York, and their colleagues compared the prevalence and incidence of different HPV types among HIV positive women with varying levels of T cells, an indicator of immune status.

The final analysis included 2,058 HIV positive women from the Women's Interagency Human Immunodeficiency Virus Study and 871 HIV positive women from a separate HIV Epidemiology Research Study. The women were examined during repeat study visits where cervical tissue samples were collected and HPV-type analysis was performed.

The researchers found that the ...