Starting antiretroviral treatment does not reduce the
incidence or prevalence of cervical infection with human papillomavirus, US
investigators report in the online journal BMC Infectious Diseases. All types
of the virus persisted, including those associated with a high risk of cervical
Nor did the investigators find any evidence that better
increases in CD4 cell count after starting HIV treatment increased the chances
of clearing cervical infection with human papillomavirus (HPV).
Moreover, many patients who were taking HIV therapy acquired
infection with high-risk strains of human papillomavirus.
“There is no immediate effect of HAART [highly active
antiretroviral therapy] on HIV-infected adolescents, especially with regard to
high-risk and vaccine-type HPV infection prevalence, persistence, or
clearances,” comment the study’s authors. “Additionally, there is no clear
pattern of HPV infection or clearance with respect to immune reconstitution
(based on CD4 T-cell counts) from HAART.”
Antiretroviral therapy has been associated with remarkable
improvements in the prognosis of many HIV-positive patients. Rates of
AIDS-defining illnesses have fallen dramatically, including those of the HIV-related
cancers Kaposi’s sarcoma and non-Hodgkin lymphoma.
Cervical cancer is also classified as an AIDS-defining
cancer, and research suggests that diagnoses of this malignancy have increased
since antiretroviral therapy was introduced.
Like anal cancer (rates of which have also increased),
cervical cancer is associated with long-term infection with certain strains of
human papillomavirus. This can cause cell changes that lead to cancer.
Information about the impact of HIV therapy on the clearance
of cervical human papillomavirus is inconsistent. Some studies suggest that the
immune restoration that results from antiretroviral therapy helps clear the
infection, but other research has found no evidence of this.
Investigators from the US REACH (Reaching for Excellence in
Adolescent Care and Health) cohort study wished to clarify this important
They therefore monitored the prevalence, persistence and
incidence of cervical human papillomavirus infection in 373 adolescents with
HIV (227) or at risk of HIV. All were aged between 12 and 19, and the
HIV-infected patients acquired the infection through sex or drug use.
These individuals were monitored for cervical human
papillomavirus infection every six months, and the HIV-positive patients had their
CD4 cell counts monitored at regular intervals.
The HIV-positive adolescents had a variety of antiretroviral
treatment histories. A total of 100 had follow-up data before and after the
initiation of HIV treatment; 57 started HIV therapy immediately they entered
the cohort; and 70 never took anti-HIV drugs.
Overall, 70% of study participants had cervical human
papillomavirus infection at baseline, and 70% of those who were uninfected at
baseline acquired the infection during follow-up.
On average the patients were followed for a little over two
Individuals starting HIV treatment showed good increases in
their CD4 cell counts from a baseline of 471 cells/mm3 to 525
Before they started antiretroviral therapy, the HIV-positive
participants had a prevalence of between 1 – 17% of infection with a high-risk
type of human papillomavirus.
Prevalence in the HIV-negative individuals was between 1%
Starting treatment with anti-HIV drugs had no impact on the
prevalence of high-risk infections (1 – 18%).
There was a high incidence of infections in both the
HIV-positive and HIV-negative patients, with a trend for higher incidence among
those with HIV.
Although CD4 cell counts increased in patients starting HIV
therapy, this did not affect human papillomavirus infections and clearance
“Overall, the results
suggest that HAART has no effect on high- or possible-carcinogenic HPV
infections”, comment the investigators.
For example, incidence of HPV 16 was 6.54 per 100 person
years before HIV treatment was started and 6.67 per 100 person years after.
Similarly, the incidence of HPV 18 was 4.66 per 100 person
years in the period before antiretroviral therapy was started and increased to
6.26 per 100 person years after patients started taking anti-HIV drugs.
Incidence of some other high-risk strains of the virus was
even higher. That of HPV 53/66 was 9.83 per 100 person years in the period
before HIV therapy, but was 12.80 after treatment was started.
“We observed higher prevalence and incident of possible
carcinogenic…HPV types in the after HAART initiation period. Thus prevention of
HPV acquisition is important, especially in vulnerable populations such as
sexually active adolescents.”
The investigators acknowledge that the study’s small sample
size is a potential limitation. Nevertheless they conclude that starting HIV
treatment “did not show immediate effect on high-risk and vaccine type HPV
incidence, clearance, and persistence.”