News (Updated February 11,
2007)
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WASHINGTON (Reuters) - A naturally occurring molecule saves vital immune system cells from cellular suicide during the onslaught of the AIDS virus and might help keep the body's natural defenses working in HIV-infected people, a study found.
The findings represent a potential new avenue to fight the effects of the human immunodeficiency virus, HIV, according to U.S. National Institutes of Health scientists whose work was published on Monday in the Proceedings of the National Academy of Sciences.
Dr. Paolo Lusso and colleagues at the NIH's National Institute of Allergy and Infectious Diseases looked at the role played by interleukin 7 in averting the death of T cells, a kind of white blood cell important to the immune system.
Interleukin 7 is a substance important in maintaining proper functioning of the immune system.
AIDS has killed more than 25 million people since it was first recognized in 1981. About 40 million people now live with HIV, with sub-Saharan Africa hardest hit.
Lusso expressed "reasonable optimism" that treatment involving interleukin 7 may benefit people with AIDS, a disease for which no cure exists.
"I don't think one solution will be applicable to all the patients. It's possible that IL-7 (interleukin 7) may benefit some patients and do nothing in other cases," Lusso said in an interview.
"But I think we are moving in the right direction because we are starting to appreciate that antiretroviral therapy alone (existing AIDS drug treatment) is not sufficient to bring back a full immune competence, and we are starting to identify at least some strategies that may work."
IMMUNE SYSTEM TARGETED
An insidious aspect of HIV is that the virus attacks the body's natural defenses -- the immune system.
In assaulting the immune system, HIV hides inside certain T cells. These cells, as the infection progresses, commit cellular suicide -- called apoptosis -- undermining the body's ability to combat infections and certain cancers. In fact, the virus manages to induce the suicide of many more T cells than it directly infects.
The researchers, who also included Dr. Lia Vassena and NIAID Director Dr. Anthony Fauci, used blood samples from 24 HIV-infected people. They added interleukin 7 to the blood samples and then gauged the survival of T cells.
The actual patients themselves were not treated with interleukin 7.
The samples with interleukin 7 displayed lower levels of T cell death. The benefits differed from sample to sample based on the person's stage of infection, the study found.
The researchers believe interleukin 7 potentially could be used alongside existing AIDS drugs to bolster the immune system.
Lusso noted that existing AIDS drugs can keep the virus at bay for years, but damage to the immune system commonly persists even after years of such treatment.
Scientists want to find new ways to remedy these immune defects, with the aim to make the immune system functional even in HIV-infected people.
Lusso said apoptosis may be a major mechanism through which T cells die in AIDS. The new study is important, he said, in that it identifies how interleukin 7 may help -- by preventing these cellular suicides.
He said the next step is a study in which monkeys with the simian equivalent of HIV are given interleukin 7 to see if it blocks immune system dysfunction and immune cell depletion.
The mountainous Chinese province of Yunnan is tucked into the
country’s southwest corner, a scenic region that borders Burma, Laos and
Vietnam. The province shares its rugged topography with the surrounding
countries, but it shares a less favorable trait as well: a growing AIDS
epidemic, driven by a thriving underground commercial sex trade and by heroin
smuggled in from the opium-growing regions of its three neighbors, an area known
as the “golden triangle.” Yunnan was the point of entry for AIDS in China,
with the first cases appearing in 1989, and the mutations of the virus that
exist there are far more diverse than anywhere else in the country.
Researchers at Rockefeller University and the Aaron Diamond AIDS Research Center
(ADARC) have been doing work in Yunnan province for close to a decade. Because
all the forms of HIV in China can be traced back to the area, they’re
interested in how different subtypes of the virus are related to the
epidemic’s spread and how they’re evolving. Their most recent findings,
announced last fall, suggest that the virus may be spread via sexual
transmission more quickly than anyone believed, resulting in an HIV subtype that
has the potential to kick off a whole new Chinese epidemic.
The new research, led by assistant professor Zheiwei Chen and published in a
recent issue of PLoS Medicine, characterizes the different strains of HIV
that are currently in circulation in Yunnan and, for the first time, associates
different subtypes with different groups of people. “We wanted to do a basic
molecular epidemiology study covering the entire province,” Chen says. So his
research group — which included colleagues from the Yunnan Center for Disease
Control and Prevention in Kunming, China, and David Ho, Rockefeller's Irene
Diamond Professor and ADARC’s scientific director — gathered blood samples
from 321 HIV-infected people. The subjects lived throughout the province and
represented a wide cross-section of multiple communities, ethnicities and
professions.
Because the virus evolves so quickly, the researchers could track HIV subtypes
using their genetic variation and were able to determine that certain subtypes
were associated with certain populations. Of those people who had known risk
factors, intravenous drug users composed nearly 91 percent of the virus’s
“BC” variants, while 85 percent of the “AE” variants appeared to be
sexually transmitted. “We thought that the majority of HIV cases in Yunnan
were intravenous drug users,” Chen says. But by linking particular risk
factors to genetic subtypes, they could see a new pattern emerging. “A
substantial number of people acquired their infections through sexual
contact.”
Chen notes that the AE variants are also sexually transmitted strains in
Thailand, Vietnam and Burma, and he’s interested in performing a detailed
analysis on the population that lives right on Yunnan’s borders. “We want to
do a comparison study and see how fast the virus is disseminated from the border
inland to the province,” he says, as the studies could give them insight into
how the HIV epidemic may spread in other parts of the country.
It could also have implications for vaccine development. Because the virus is so
genetically diverse, researchers must either tailor a vaccine to a particular
subtype or create a number of vaccines that can be recombined depending on the
variant they’re targeting. Chen, Ho and their associates at ADARC and in China
are working hard to produce a vaccine and move it to human trials in Yunnan.
Knowing where the different HIV subtypes are dominant can also give them a leg
up, letting them test their vaccine in an area where the patients will be more
likely to have a viral subtype that matches it.
Public Library of Science Medicine 3(11): e443 (November 14, 2006)
Thursday February 8, 1:51 pm ET
By Matthew Perrone, AP Business Writer
The FDA said Thursday its antiviral drugs advisory committee will meet April 24 to assess the safety and effectiveness of Pfizer's maraviroc, according to documents posted to the agency's Web site. FDA is not required to follow the guidance of its outside experts, though it often does.
Maraviroc is part of a class of drugs called CCR5 antagonists, which block HIV from entering white blood cells through a pathway present in the majority of patients who carry the virus. Roughly 1 million people in the U.S. are HIV positive, according to the Centers for Disease Control.
Pfizer plans to offer the drug alongside a test developed by Monogram Biosciences Inc. that gauges whether patients are likely to respond to the treatment.
A twice-a-day pill, maraviroc will primarily be marketed to patients who have developed a resistance to other HIV drugs.
Most companies pursuing the HIV market are also developing HIV drugs that serve as a second line of defense against the disease, says CIBC World Markets Corp. analyst Brian Abrahams.
"The current first-line treatments are so effective and so well-entrenched that most of the drugs being developed now are for treatment-resistant patients, since manufacturers see that as the faster path to market," Abrahams said.
While Pfizer's clinical trials of Maraviroc have progressed smoothly, similar products being developed by rival companies have raised safety issues.
In 2005, British drug maker GlaxoSmithKline plc said it decided to scrap its drug aplaviroc after signs of liver damage appeared in some patients. Schering-Plough Corp. is continuing in mid-stage trials of a similar drug after reporting several patients developed lymphomas, a form of cancer.
The FDA news on Pfizer's drug came on the same day as a leading AIDS organization said it is banning the company's sales representatives from its treatment centers. The AIDS Healthcare Foundation issued a statement Thursday saying it believes the company's "questionable marketing" of Viagra, its erectile-dysfunction drug, encourages recreational use of the medication, which helps spread HIV and other sexually transmitted diseases.
Last month the group filed a lawsuit against Pfizer, alleging its advertisements for Viagra are "false and misleading." Pfizer has denied the allegations about the marketing of its blockbuster drug. The company had $860 million in U.S. Viagra sales in 2005, according to IMS Health Inc.
Tue Feb 6, 2007 7:54 PM GMT
JOHANNESBURG (Reuters) - South Africa said on Tuesday it had ordered an inquiry following reports that participants in the clinical trial of a microbicide gel to help prevent HIV infection among women had instead contracted the virus.
The U.S. reproductive health group CONRAD said last month it was halting trials of Canada-based Polydex Pharmaceutical's ushercell gel which were underway in South Africa, India, Benin and Uganda.
Johannesburg's City Press reported on Sunday that some of the 600 women in the South Africa trial had reported contracting HIV after using the gel, which is applied to the vagina an hour before sexual intercourse.
"I have asked the National Health Research Ethics Council to conduct a thorough investigation into this matter," Health Minister Manto Tshabalala-Msimang said in a statement.
The minister said the investigations began last month and that she had held a meeting on Tuesday with researchers involved in at least five of the trials.
The South Africa trials have centered mainly on KwaZulu-Natal, its most populous province and epicentre of an HIV scourge affecting some 5.5 million of the country's 45 million people.
The minister said the investigation would seek to establish whether the trials followed all ethical protocols and whether the women were given sufficient information to make informed decisions on their participation.
It would also look into other microbicide trials in the country to ensure they were following necessary guidelines.
The statement did not say how many of the women were known to have contracted HIV, but health ministry spokesman Sibani Mngadi said he had heard a figure of 22.
He said it was not clear whether those infected were from the group given the gel or from a control group that did not receive the microbicide.
"The KZN (KwaZulu-Natal) trial has been stopped and we hope the gel has been retrieved from the community, and those who are infected are receiving support," Mngadi said.
City Press said health ministry officials had fanned out across KwaZulu-Natal trying to track down the participants, many of whom had disappeared.
It said the gel had become so popular some participants had sold their supplies to other women not involved in the trial.
South Africa is grappling with one of the world's highest HIV infection rates and experts at an AIDS conference in Cape Town last year hailed microbicides as the possible breakthrough to curbing the epidemic.
When CONRAD halted the trials last month, Plydex president and CEO Goerge Usher was quoted as saying the ushercell gel had shown a consistent safety profile to that point having undergone 11 clinical safety and contraceptive trials involving more than 500 participants before entering the HIV prevention trial.
Fri Feb 9, 2007 5:36 PM GMT
NEW YORK (Reuters Health) - The majority of HIV-infected unmarried parents have not legally designated a guardian to care for their children in the event of their death, research suggests.
"Guardianship planning is believed to help children cope with the loss of a parent, perhaps by reducing the likelihood that a child is shuffled from one home to another, spends prolonged periods in foster care, or is separated from siblings," the researchers say.
The new findings, which appear in the journal Pediatrics, are based on a study of 222 HIV-infected unmarried parents with 391 children who were interviewed regarding guardianship planning.
Dr. Burton O. Cowgill, from the University of California at Los Angeles, and colleagues focused on unmarried parents since guardianship planning would be unnecessary with married parents because the surviving parent is usually given automatic custody.
Just 28 percent of parents had a legal guardianship plan, but 53 percent of parents reported having a person identified who agreed to guardianship, the report indicates. Twelve percent of parents had yet to identify a guardian.
Grandparents were the most commonly cited preferred guardians, noted by 36 percent of respondents, followed by other relatives in 34 percent of cases and other biological parents in 17 percent.
Predictors of completed guardianship planning were a low CD4+ cell count, indicating more advanced HIV infection, and living without other adults, the report indicates.
Pediatricians and caregivers could play a key role in facilitating guardianship planning, the authors say.
SOURCE: Pediatrics, February 2007.
CAIRO, 7 February (IRIN) - At least five million people in Egypt are infected with the hepatitis C virus (HCV), a new committee formed by the country's government to tackle the disease has said. It added that action must be taken now to combat rising mortality.
"The annual infection rate is more than 70,000 new cases, of which at least 35,000 would have chronic hepatitis C," said Dr Manal el-Sayed, Professor of Paediatrics at Cairo's Ain Shams University and member of the National Hepatitis Committee which is currently formulating an action plan to fight the disease.
Hepatitis C is a lethal virus which can cause liver cirrhosis and cancer. Egypt has one of the highest prevalence rates of the virus in the world, say specialists. An estimated 10-15 percent of the population, some 8-10 million people, are carrying hepatitis C antibodies, meaning that they either have or at one time had the virus. Five million of those are actively infected, according to government figures.
No vaccine is available for HCV although it can be treated with a combination of drugs if detected early enough.
Egypt's very high prevalence of HCV is largely the legacy of government campaigns prior to 1980 to treat rural populations for schistosomiasis (or bilharzia), a water-borne disease which at one time was endemic in Egypt. The treatment campaigns, which involved repeated injections, did not follow rigorous hygiene standards, and as such spread blood-borne HCV throughout the population.
As it may take up to 30 years for a patient to display symptoms of HCV or for the disease to become active, the full extent of the problem has only recently become known.
"The main risk factor [for HCV now], according to all the studies done in Egypt, is treatment in the past for schistosomiasis," said Dr Amr Kandeel, Director of the Communicable Disease Department at the Egyptian Ministry of Health and Population.
"At that time, the Ministry treated people in the villages without using disposable syringes," he added.
New infections
In addition to cases among the older population, new infections are still being recorded, due to poor medical practices and behavioural factors. Deaths from liver disease are, therefore, expected to increase in Egypt within the next 20 years.
"If we consider that by the year 2020 we are going to have so many patients who are having liver failure and liver cancer, treating them now is more effective than leaving them to that outcome," said el-Sayed.
Egypt's hepatitis committee is now making plans to prevent and treat hepatitis C. Treatment of HCV is usually done with a drug called Interferon. However, the most typical type of HCV in Egypt has about a 40 percent resistance to the drug. Although research is ongoing, no more effective treatment is yet available.
Nevertheless, the committee has succeeded in brokering a deal with the manufacturers of Interferon to supply the drug to Ministry of Health hospitals for one third of the usual price, and treatment under the committee's programme has begun in selected centres.
Even with the cost of Interferon reduced, the financial burden of Egypt's HCV problem is huge. The committee estimates that of the five million people actively infected with the virus, around one million currently need treatment. A year's treatment for a person with signs of liver damage from HCV costs around LE 25,000 (about US $4,500) – a sum few can afford.
In January this year, the committee began fundraising activities with the help of NGOs and international organisations including USAID, the World Health Organisation and UNICEF. The committee hopes to be able to provide free treatment to those most in need.
"We would also like to appeal to the international community to help with this campaign by whatever means possible," said el-Sayed.
Due to the cost and difficulty of treating chronic HCV patients, promoting awareness to prevent the disease, and detecting those infected before they develop liver damage are critical factors.
Screening the population
"We are going to promote screening for high-risk populations – including healthcare professionals who are at risk from needle injuries, and those who are undergoing repeated blood transfusion treatment," said el-Sayed.
The hepatitis committee has stressed the need for good infection control programmes in hospitals, and among healthcare professionals, to stem the transmission of the virus. The Egyptian Ministry of Health is co-operating through its National Infection Control Programme, which began in 2003.
Those at risk of new HCV infections in Egypt are not just those in medical contact with existing patients, however. The children and relatives of individuals affected during the schistosomiasis campaign are also a high-risk group, as widespread behavioural practices – such as the re-use of syringes, sharing of toothbrushes and even circumcision – all increase the risk of contracting blood-borne viruses such as HIV and Hepatitis C.
And although the circumcision of girls is officially banned in Egypt, the practice still continues, placing girls who are being circumcised at a very high risk of contracting HCV.
"Sometimes there is a sort of celebration for mass circumcision in certain communities. Girls are at a higher risk because it is a very bloody procedure. However, female circumcision has dramatically decreased, with more awareness and a ban by law," said el-Sayed.
As part of its Unite for Children, Unite Against Aids campaign, UNICEF Egypt has also been trying to raise awareness of the more common dangers of contracting HCV. Changing people's behaviour and attitudes toward blood safety is key, according to Wessam el-Beih, UNICEF's Unite Against Aids Egypt co-ordinator.
"Many people share razors and re-use syringes. They see no harm in just washing them and using them again. So there is a big behavioural component to the plan," she said.
Friday February 9, 6:14 pm ET
Gilead and Achillion said Thursday preliminary trial results of the drug had shown an increase in the level of serum creatinine, which indicates abnormal kidney function.
The companies said they are continuing their partnership and will be back underway in the first half of 2008 in testing with other similar compounds.
Needham & Co. analyst George Fulop said Gilead and Achillion are now "a couple of years behind."
Adam Cutler, an analyst with JMP Securities, said there's "a silver lining as the drug has a totally novel mechanism," and called the share movement an "overreaction."
However, analysts say moving toward a new combination treatment, or a "cocktail," as is used against HIV, is showing the greatest potential to treat the hepatitis virus, and is the most likely outcome. The hepatitis C virus mutates and can easily become resistant to drugs.
Hepatitis C, an infection passed through the blood, often by sharing needles or through blood transfusions is the main reason for liver transplants in the U.S. About 170 million people worldwide and more than 3 million Americans are infected.
Wall Street has been betting on a drug from Vertex Pharmaceuticals Inc., which has shown promising results with little side effects so far. Analysts are waiting for results from three large studies in the U.S. and Europe in the first half of 2007, which together involve 1,000 patients. The company has said it expects to file an application for approval of the drug in the United States in the second half of 2008.