Researchers at UT Southwestern Medical Center have found that non-AIDS-defining malignancies such as anal and lung cancer have become more prevalent among HIV-infected patients than non-HIV patients since the introduction of anti-retroviral therapies in the mid-1990s.

AIDS patients with suppressed immune systems are at higher risk for so-called AIDS-defining malignancies - HIV patients are diagnosed with more non-AIDS-defining malignancies simply because anti-retroviral drugs now used enable them to live longer, but the results of the UT Southwestern study suggest that other factors may be at work.

The researchers, using data from more than 100,000 patient records in the U.S. Veterans Affairs Healthcare System, found that when the statistics were adjusted for gender, race/ethnicity and age, HIV-infected patients were 60 percent more likely to have anal, lung, Hodgkin’s, melanoma or liver cancer than patients without HIV. The rate of prostate cancer was similar between the two groups, according to the report.

“It’s a genuine increase in the incidence of these cancers,” said Dr. Roger Bedimo, assistant professor of internal medicine at UT Southwestern and lead author of a study appearing online and in the October edition of the Journal of Acquired Immune Deficiency Syndromes. “The increase is more visible because these patients are living longer, but our findings suggest that the increased number of non-AIDS-defining malignancies is not simply the result of their longer lives.”

For the study, researchers compared the rates of non-AIDS-defining malignancies between patients with and without HIV who received care at a VA system facility between 1997 and 2004. For each HIV-positive patient, researchers identified at least two HIV-negative patients who received care the same year and matched them on age, sex, race and geographic location. The final study population included 33,420 HIV-infected patients and 66,840 non-infected patients.

The non-AIDS-defining malignancies included all forms of cancer except skin, lymphoma, cervical carcinoma, Kaposi’s sarcoma and ill-defined cancers. Dr. Bedimo said the researchers examined anal, lung, melanoma, prostate, Hodgkin’s and liver cancers - all non-AIDS-defining - individually.

Dr. Bedimo, chief of infectious disease at the Veterans Affairs North Texas Health Care System, said it’s unclear exactly why non-AIDS-defining malignancies are more common in HIV patients than the general population. One controversial theory, he said, is that the anti-retroviral therapy itself might increase the risk of those cancers in HIV patients.

“The second hypothesis is that HIV-infected patients somehow, either by their lifestyle or other circumstances, are more subject to the traditional risk factors than non-HIV patients,” he said. “The third hypothesis is that HIV or another undetected virus increases a patient’s risk for developing cancer intrinsically.”

Dr. Bedimo said that one major limitation of the study is the overrepresentation of males in the study. Males account for about 98 percent of the study population.

The next step is for researchers to examine other measures of immune function in patients with and without cancer.

“The hallmark of chronic HIV is a decline in CD4 T-cells, but we also know that HIV does a lot more to your immune system than just decrease the number of these cells,” Dr. Bedimo said. “It’s very possible that it is an immune dysfunction that impairs the cancer immune surveillance in patients even after their CD4 counts have increased.”

Other researchers involved in the study include Dr. Melinda Dunlap, former assistant professor of internal medicine at UT Southwestern, as well as scientists from the VA Pittsburgh Healthcare System, the Michael E. DeBakey VA Medical Center and Yale University School of Medicine.

The work was supported by the National Institute on Alcohol Abuse and Alcoholism and the Veterans Health Administration.

Source
UT Southwestern Medical Center

Among heterosexuals in the United Kingdom (UK), HIV transmission can occur
within networks of as many as 30 people, according to a new study by
researchers at the University of Edinburgh, Scotland, and the Medical
Research Council Clinical Trials Unit, London. Details are published
September
25 in the open-access journal PLoS Pathogens.

The number of HIV-infected heterosexuals in the UK has been growing
dramatically and now exceeds the number of HIV-infected homosexual men.
Most are
immigrants from sub-Saharan Africa, a group for which the pattern of virus
transmission is poorly documented.

To better understand the dynamics of the heterosexual HIV epidemic within
the UK, the research group, led by Professor Andrew Leigh Brown, applied
the
novel technique of phylodynamics, which reconstructs the pattern of viral
sequence divergence in time in order to reveal the size of transmission
clusters and the dynamics of transmission within them.

The team studied virus gene sequences from over 11,000 infected
individuals, comprising 40% of the HIV-infected heterosexual population in
the UK,
making this one of the largest studies of its kind to date. By analyzing
differences between the viral strains, they found clusters of related
viruses
that showed 5% of HIV transmissions to have occurred in networks of more
than 10 people

The authors note the importance to their work of the UK HIV Drug
Resistance Database, which contains viral DNA sequence information from
over 30,000
infected individuals. Using this database, the researchers discovered that
transmission clusters in the heterosexual population were smaller than
those found among HIV-infected homosexual men and that transmission was
also much slower. The study concludes that heterosexual transmission could
be
significantly reduced by early diagnosis and treatment.

“The slower dynamics of the heterosexual epidemic thus offer more
opportunity for successful intervention, but it is essential that
diagnosis is
achieved as early as possible,” said Professor Leigh Brown.

Financial Disclosure: This work was supported by the Medical Research
Council. The UK HIV Drug Resistance Database is partly funded by the
Department
of Health; the views expressed in the publication are those of the authors
and not necessarily those of the Department of Health. Additional support
was provided by Boehringer Ingelheim, Bristol-Myers Squibb, Gilead,
Tibotec (a division of Janssen-Cilag Ltd) and Roche. The funders had no
role in
study design, data collection and analysis, decision to publish, or
preparation of the manuscript.

Competing Interests: The authors have declared that no competing interests
exist.

Citation:
“Molecular Phylodynamics of the Heterosexual HIV Epidemic in the United Kingdom.”
Hughes GJ, Fearnhill E, Dunn D, Lycett SJ, Rambaut A, et al. (2009)
PLoS Pathog 5(9): e1000590. doi:10.1371/journal.ppat.1000590

Source
PLoS Pathogens

On October 2nd, 2009, Henry Gabelnick PhD, Executive Director of The CONRAD Program, will give the prestigious Alan F. Guttmacher lecture at the 2009 Association for Reproductive Health Professionals conference being held in Los Angeles, California. Reproductive Health 2009 is a partnership among the Association of Reproductive Health Professionals, the Planned Parenthood® Federation of America National Medical Committee, and the Society of Family Planning. This is the 5th joint annual meeting of these three organizations.

Dr. Gabelnick’s lecture, “The Challenge of Providing Dual Protection”, draws attention to the increasing need for scientists, government and non-government agencies to fund and develop methods of contraception that also prevents HIV and STI infections. Global figures estimate that there are 76 million unwanted births, 50 million abortions, 536,000 maternal mortalities, 2.7 million new HIV infections and 340 million new cases of curable STIs each year.

A call to action for dual protection began over two decades ago among reproductive health professionals and since then, the CONRAD Program of the Eastern Virginia Medical School has been a leader in developing physical barrier methods of contraception, such as the Female Condom, the SILCS diaphragm, vaginal rings and sponges and chemical spermicides that also have various mechanisms of action that prevent HIV and STIs. CONRAD and other organizations are currently testing combination methods that use both a barrier such as a vaginal ring, impregnated with microbicides.

While USAID, PEPFAR and other organizations are making programmatic progress in terms of funding dual protection methods, there remain scientific challenges and improving prevention technology is largely dependent on funders recognizing that broad spectrum microbicidal activity combined with contraception needs to be funded more vigorously. Dr. Gabelnick will detail current developments, scientific challenges and potential solutions in his lecture.

Reproductive Health 2009 is being held at the Renaissance Hollywood Hotel and Spa in Los Angeles, California on September 30-October 3, 2009.

Source:
Annette Larkin

CONRAD