Generic Allegra (Fexofenadine) Detailed Reviews

Scientists report that a genetic variation appears to play a major role in slowing disease progression in HIV-infected patients.

In fact, those with the variation appear to take years longer to develop AIDS and die of complications of the disease.

“We’re honing in on factors that vary across individuals that make a person more or less susceptible to HIV, in terms of how rapidly someone develops the disease,” said study co-author Mary Carrington, a senior principal investigator at the U.S. National Cancer Institute.

However, this new knowledge won’t translate into immediate benefits for patients with HIV.

AIDS remains a major killer in many parts of the world, but HIV — the virus that causes it — doesn’t affect infected people the same way. “People progress to AIDS at hugely different rates,” Carrington explained. “Some people progress within a year, while some have been infected for 20 years and still control the virus and don’t have the disease.”

It appears that three factors affect how the disease strikes a person, she said. One is the environment: the world in which a person lives. Another is the patient’s genetic makeup. And the third is the genetic makeup of the virus itself.

In the study, published in the Nov. 22 online edition of Nature Genetics, Carrington and colleagues looked at genetic and medical records for hundreds of HIV-infected men. They were trying to see if genetic variations affected how the men fared.

The researchers found that a variation linked to higher levels of a protein known as HLA-C boosted the men’s ability to avoid progressing to AIDS. It appeared to delay both the progression to AIDS and to death by years, Carrington said.

The genetic variation makes it easier for the immune system to kill cells that have been infected with the virus, she said. It does this by allowing immune cells to gain greater access to the infected cells, she explained.

Carrington said this genetic variation isn’t related to another gene-related trait that makes some people virtually immune to HIV.

The study “hints at ways we might ultimately develop a vaccine or immune-based therapies that could modify or maybe even prevent the development of HIV disease,” said Rowena Johnston, vice president of research with the Foundation for AIDS Research in New York City.

“The finding that a single piece of DNA can be strongly associated with something as complex as the control of HIV soon after infection is especially intriguing, not least because we know that early control of infection sets the stage for the entire course of the disease,” Johnston noted.

What’s next? The ultimate goal, Carrington said, is “to have a complete list of every genetic variance that is affecting how rapidly the disease develops.”

That, in turn, could help physicians figure out how to better treat patients.

Researchers are reporting that a genetic variation — a missing gene — boosts the risk that someone who’s had a bone-marrow transplant will develop a complication called graft-versus-host disease.

The immune system-related complication occurs after surgery when the recipient has the variation and the donor does not.

When that’s the case, the immune cells from the donor go on the attack against the recipient’s tissues.

“This finding gives us a glimpse into the genetic incompatibilities that can complicate transplants,” the study’s lead author, Steven McCarroll, an assistant professor at Harvard Medical School and an associate member of the Broad Institute of MIT and Harvard, said in an institute news release. “There are likely many other compatibility loci left to be found, and with the enhanced capabilities for surveying human genetic variation, it will become increasingly feasible to find them.”

As for developing a test to look for the genetic variation, McCarroll said it’s not clear yet if that’s necessary.

As many as one in four U.S. teenage girls have had a sexually transmitted disease (STD), many infected soon after their first sexual encounter, a new government report shows.

“The high burden of STDs among teen girls reminds us that we can’t ignore this,” said study author Dr. Sami L. Gottlieb, from the division of sexually transmitted disease prevention at the U.S. Centers for Disease and Prevention.

“Sexual health is an important part of the overall health and well-being of teenagers,” Gottlieb added. “For too long, we as a nation have been far too squeamish about sexual health issues for teens, but we owe it to our kids to get over it.”

The report is published online Nov. 23 and in the December print issue of the journal Pediatrics.

For the study, Gottlieb’s team collected data on 838 teen girls aged 14 to 19. Using samples provided by the teens, the researchers looked for Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, herpes simplex virus type 2 and human papillomavirus (HPV).

The study authors found that 24.1 percent of the girls had one of these STDs and among girls who were sexually experienced, 37.7 percent had an STD. HPV was the most common infection (18.3 percent), followed by chlamydia (3.9 percent).

Moreover, in the year after having their first sexual experience and with only one sex partner, 19.2 percent of the teens developed an STD, Gottlieb’s group found.

To counter these problems, teens need to have early sex education, Gottlieb noted. “The vast majority of people have sex for the first time during their teenage years, so we need them to be prepared,” she said.

In addition, Gottlieb believes that 11- and 12-year-old girls should get the HPV vaccine. “We have an effective and safe vaccine that can prevent most of the bad consequences of HPV infection — cervical cancer,” she stated.

Teen girls and young women should also have a yearly test for chlamydia, Gottlieb said. “This can prevent some of the adverse consequences of chlamydia, such a pelvic inflammatory disease and infertility,” she stressed.

Dr. David L. Katz, director of the Prevention Research Center at Yale University School of Medicine, said that “the authors make a convincing case that rates of both sexual activity and sexually transmitted infections are high in adolescent females in the U.S.”

These are the facts of epidemiology, not ideology, and should be the basis for public health policy, he said.

“Adolescent girls need early access to comprehensive sex education, and barrier contraceptives,” Katz said. “This will not increase sexual activity, but it will attenuate the resultant harms.”

This study also makes a strong case for routine vaccination against HPV, as it is the most common sexually transmitted infection, Katz said. “Since HPV is often acquired so soon after the initiation of sexual activity, early vaccination is the way to go. I speak on this as the father of two young teenage daughters, both of whom have received the Gardasil vaccine,” he added.

Another report released by the CDC last week provided more statistics.

Teen girls aged 15 to 19 accounted for the largest number (409,531) of the 1.5 million reported chlamydia and gonorrhea cases in the United States in 2008, followed by women aged 20 to 24, according to the annual federal report.

The researchers also found that black females continue to have a higher rate of STDs than any other racial or ethnic group.

Last year, there were about 1.2 million reported cases of chlamydia and nearly 337,000 reported cases of gonorrhea in the United States, according to the report.