Jun. 01, 2010

Which Women with Lupus Have Greater Risk for Human Papilloma Virus?

Natural history of cervical papilloma virus infection in systemic lupus erythematosus – a prospective cohort study.
Authors: Tam LS, Chan PK, Ho SC, Yu MM, Yim SF, Cheung TH, Wong MC, and Li EK. (2010). Journal of Rheumatology 37: 330-340.

What is the topic?
Infection with human papillomavirus (HPV), a common sexually transmitted disease, is linked to risk for cervical cancer. If an HPV infection can be found at two or more time points, it is considered to be “persistent.” “High-risk” HPV infections are those that seem to greatly increase the risk of cervical cancer. 

This is a study of HPV infection in women with lupus, which examined the question of whether immune-suppressing treatments have any impact on the risk of HPV infection in women with lupus. 

What did the researchers hope to learn?
The researchers hoped to learn the frequency of HPV infection in women with lupus, the risk factors for developing the infection, and risk factors for having persistent infection for at least six months.

Who was studied?
144 women with lupus participated in the study in Hong Kong, China. Only married or sexually active, non-pregnant women were included in the study. None of the women had ever received a vaccination for HPV. 

How was the study conducted?
The participants in the study were evaluated every six months for up to three years. Each woman was interviewed about her medical condition. At each visit, women received a Pap test and HPV test. When HPV infections were identified, they were categorized as either “low risk” or “high risk” depending on the known types of HPV that increase the risk for developing cervical cancer. 

What did the researchers find?
During the three-year study period, increasing numbers of women developed HPV infections. The number of high-risk infections and infections with multiple types of HPV increased, but the numbers of low-risk types of HPV infection did not. 

The time it took for women to develop low-risk HPV infection was significantly shorter than for high-risk HPV infection. HPV infections that persisted for six months or more were less likely to go away than those without first having that persistence.

Risk factors for acquiring a first HPV infection during the study included younger age at first sexual intercourse, having three or more lifetime sexual partners, any past treatment with cyclophosphamide (cytoxan), and current treatment with leflunomide (arava). 

Half of the HPV infections became persistent. Risk factors for acquiring persistent HPV infection included younger age at first sexual intercourse and having three or more lifetime sexual partners. 

Persistent HPV infection was found more frequently in study participants who had HPV infection before the study, multiple HPV infections, or a high-risk type of HPV infection at the beginning of the study. 

What were the limitations of the study?
The main limitation of the study is the lack of a group of people without lupus to compare these findings to. It is not possible to tell whether the frequency of HPV infection, or some of the risk factors that were identified, would differ in women with lupus as compared to other women.

Also, the researchers did not have information about how severe the lupus was or what doses of treatments were taken by the women who participated in the study. For example, it might be very helpful to know whether higher doses of immune-suppressing treatments were a risk factor for developing persistent HPV infection. 

What do the results mean for you?
Women with lupus are at increased risk for acquiring HPV infection if they had three or more lifetime sexual partners. Increased risk for HPV infection is also associated with younger age at first sexual intercourse, past treatment with cyclophosphamide, and current treatment with leflunomide. 

Potential risk for HPV infection in women with lupus taking immunosuppressants needs to be further studied. This study could not identify what doses of cyclophosphamide (or other immunosuppressants) are associated with increased risk for HPV infection in women with lupus.