News (Updated July 6, 2008)

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Sangamo technology shows promise in treating HIV

Monday June 30, 9:23 am ET

RICHMOND, Calif. (AP) -- Sangamo BioSciences Inc., which develops genetic-based therapies, said Monday data shows the company's technology can make certain cells in the immune system resistant to the HIV virus.

The technology, known as zinc finger DNA-binding proteins, acts on the CCR5 gene (a co-receptor that enables HIV to enter and infect cells of the immune system), essentially "knocking-out" the gene.

The results were published online Sunday in the journal Nature Biotechnology.

Sangamo said that while drugs exist that block the binding of HIV to the CCR5 gene, they require a constant high concentration of the drug in the system and have side effects, while its technology requires only a one-time exposure.

Sangamo's ZFNs are designed to permanently modify the DNA sequence covering CCR5. Individuals carrying a naturally occurring mutation of their CCR5 gene have been shown to be resistant to HIV infection.

"The modified cells preferentially survive and expand in an animal after HIV infection, providing a reservoir of healthy and uninfectable immune cells," said Dale Ando, M.D., Sangamo's chief medical officer, in a statement.

Sangamo expects to initiate a clinical trial to evaluate this approach by the end of the year.

 

Anti-retroviral drug cocktails slash AIDS deaths: study

Tue Jul 1, 6:40 PM

WASHINGTON (AFP) - Anti-retroviral drug therapy has slashed AIDS death rates in the first five years after infection to equal the normal death rates in developed countries, scientists said Tuesday.

In a report published in the July 2 edition of JAMA, the Journal of the American Medical Association, researchers said the use of multiple anti-retroviral drug "cocktails" to fight HIV/AIDS infections -- called highly active anti-retroviral therapy (HAART) -- by 2006 had lowered first-five-year mortality to virtually the same level of the uninfected population.

After five years, the death rates still diverge with AIDS/HIV infected patients succumbing at an accelerating rate, the researchers said -- especially among older patients.

But HAART regimes have proven to have a strong impact in helping people survive the infection.

"Our results show the progress in reducing mortality among HIV-infected individuals toward the levels experienced by the general uninfected population," the researchers, led by Kholoud Porter and Krishnan Bhaskaran of the Medical Research Council Clinical Trials Unit of London, said in a summary of the research.

Their research was based on monitoring 16,534 HIV-infected individuals between 1981 and 2006.

Overall during the period 2,571 patients died, more than ten times the likely 235 deaths that would have been expected from a similar uninfected population.

But that excess mortality rate reflected a very high rate of deaths in the early years of the study before HAART regimes were widely available, the study said.

"Considering the first years following the widespread introduction of HAART, we have estimated an 88 percent reduction in excess mortality in 2000-2001 compared with pre-1996," it said.

"Our more recent data show that reductions have continued to 2004-2006, with excess mortality in this period 94 percent lower than pre-1996 levels."

By 2006, they added, "there was no evidence of any excess mortality to five years" among HIV/AIDS-infected individuals.

 

Drug-resistant TB demands new approaches

03 Jul 2008 18:21:58 GMT

Source: IRIN

Reuters and AlertNet are not responsible for the content of this article or for any external internet sites. The views expressed are the author's alone.

DURBAN , 3 July 2008 - The increasing number of South Africans contracting drug-resistant tuberculosis (TB) demands a radically different approach than the current policy of isolating patients in specialised facilities for long periods. This was the message of several presentations at the first national TB conference, held in Durban this week.

In 2007, South Africa recorded over 7,000 cases of multidrug-resistant (MDR) TB, which is resistant to the two most powerful anti-TB drugs, and 536 cases of extremely drug-resistant (XDR) TB, which is resistant to almost all anti-TB drugs.

In the last year a number of South African newspapers have reported on patients with MDR and XDR-TB breaking out of prison-like hospitals in a desperate bid to see their families.

"Why do we need barbed wire and security guards to stop people getting out of a hospital?" asked Mark Heywood, executive director of the AIDS Law Project, during a presentation about the need to incorporate human rights into TB programming.

Pointing out that there was no legal basis for the forced hospitalisation of patients with drug-resistant TB, Heywood suggested that the protection of public health did not justify an abuse of human rights.

"We're not against hospitalisation per se, but we have a number of problems with the way it's being implemented," Heywood told IRIN/PlusNews after his presentation. "This is something we'd like to engage the Department of Health on."

But Dr Lindiwe Mvusi, manager of the health department's TB programme, said the policy of isolation would not change until two community-based pilot programmes dealing with MDR-TB in KwaZulu-Natal and Western Cape provinces had yielded results.

One of the pilot programmes, being run by the City of Cape Town in partnership with the international medical humanitarian organisation, Medecines Sans Frontieres (MSF), in Khayelitsha, a township outside Cape Town , arose partly out of necessity. The Brooklyn Chest Hospital , Cape Town 's specialist TB hospital, simply did not have enough beds to accommodate all the patients with MDR-TB, said Dr Virginia Azevedo of the City's health department.

But, more importantly, she told delegates, the "one-size-fits-all, centralised approach doesn't work."

An analysis of treatment outcomes at Brooklyn Hospital between 2005 and 2006, before the service was decentralised, found that high numbers of patients did not complete treatment, and that 19 out of 131 patients had ultimately died.

The patients' HIV status did not appear to be linked to treatment success; in fact, patients who were already taking antiretroviral (ARV) medication were more likely to adhere to TB treatment.

In 2007 an out-patient clinic was opened at Brooklyn Hospital , and since then only MDR-TB patients in the initial, intensive phase of treatment, when daily injections need to be administered, have been hospitalised.

Other MDR-TB patients take their medication at home, after receiving extensive education and adherence counselling. An infection control practitioner, employed by MSF, visits patients' homes and assesses the need for modifications to reduce the chance of transmission, such as installing additional windows or a low-tech wind turbine.

Brooklyn Hospital is only 30km from Khayelitsha, but Azevedo noted that very few people could afford public transport to visit loved ones. A "step-down" in-patient facility was opened in Khayelitsha for patients not well enough to return home, but who want to be closer to their families.

Although it is still too soon to determine whether the programme is an improvement on previous outcomes, Azevedo said the goal was to improve MDR-TB case detection, reduce the level of patients defaulting on treatment, "demystify" drug-resistant TB through community and patient education, and come up with a model that could be replicated in other parts of the country.

 

People with HIV living longer, study shows

Tue Jul 1, 2008 4:31pm EDT

By Michael Kahn

LONDON (Reuters) - People with HIV in the developed world are no more likely to die in the first five years following infection than men and women in the general population, British researchers said on Tuesday.

The risk for people infected through sex creeps up after that, according to the study published in the Journal of the American Medical Association that highlights the power of AIDS drugs introduced in the mid-1990s.

The findings did not include men and women infected through injected drug use, and their death risk remained higher in the five years after infection, said Kholoud Porter of Britain's Medical Research Council, who led the study.

"This is looking really good that life expectancies are becoming close to the uninfected population," said Porter, an epidemiologist. "It also underscores the importance that people are identified and treated early."

The advent of combination drug therapy in the 1990s called highly active antiretroviral therapy, or HAART, has greatly extended the lives of many HIV-infected people, particularly in developed countries.

There is no cure or vaccine but the drugs, which interfere with HIV at several levels, can keep people healthy for years even if they never eradicate the virus. This means people must take them for life.

Leading manufacturers of AIDS drugs include GlaxoSmithKline, Gilead Sciences Inc, Roche, Pfizer, Merck Inc, Bristol-Myers Squibb and Abbott Laboratories.

The British team compared the death risk in the five years following infection of 13,000 men and women to uninfected people of the same age and gender who were living in the same country at the same time.

Before 1996 when the drug cocktails were not widely available, the heightened death risk ranged from nearly 8 percent to 20 percent depending on age before falling each year to zero in the year 2000 for all age groups, Porter said.

The risk rises again after five years, possibly because people become less likely to take the drugs regularly or maybe because they are less able to tolerate the drugs, Porter said.

"From a practical point of view, people with HIV infections want to know how long they can expect to live for," she said in a telephone interview.

The youngest group - people aged 15 to 24 when infected - had a 5 percent higher risk of dying at 10 years following infection and a 7 percent greater risk at 15 years than average healthy people.

For people over 45, the raised risk was 5 percent at 10 years and 12 percent at 15 years, Porter said.

The AIDS virus infects an estimated 33 million people globally, mostly in sub-Saharan Africa, and has killed 25 million.

 

New drug-resistance test gives hope to TB fight

Mon Jun 30, 2008 1:53pm EDT

By Laura MacInnis

GENEVA (Reuters) - A new diagnostic test unveiled by the World Health Organization (WHO) on Monday will allow doctors in poor countries to find out within hours -- instead of months -- whether patients have drug-resistant tuberculosis.

Mario Raviglione, director of the WHO's Stop TB department, said the molecular test developed by Hain Lifescience and Innogenetics represented a big breakthrough in the fight against tuberculosis, a contagious respiratory ailment that kills 1.5 million people a year.

"We are capable now of making a diagnosis of MDR-TB within hours," he said, using the acronym for multi-drug resistant tuberculosis, an infection that cannot be cured with a standard course of antibiotics.

The new test can determine directly from a patient's saliva whether the tuberculosis bacteria can be treated with the two main antibiotics, isoniazid and rifampicin, making it easier to prescribe the drug to cure the disease and prevent its spread.

Previous tests required saliva samples to be incubated for as many as 60 days in order for microbacteria to grow and be tested against different antibiotic compounds.

Drug-resistant tuberculosis strains are particularly lethal for HIV/AIDS sufferers and those with weak immune systems. Errors in prescribing antibiotics can worsen drug resistance problems and lead to XDR-TB, an untreatable form that has emerged in 49 countries including the United States, France, Russia, South Africa, Brazil and Australia.

The Germany-based Hain Lifescience is also working on a test to diagnose XDR, which remains in an experimental stage, a WHO spokesman said.

Lesotho will be the first country to get the lab equipment and training to use the new diagnostics under a program supported by the WHO's partners UNITAID and the Foundation for Innovative New Diagnostics, Raviglione told a news briefing.

The other countries due to receive support to use the new test in the next four years are: Azerbaijan, Bangladesh, Cote d'Ivoire, the Democratic Republic of Congo, Ethiopia, Georgia, Indonesia, Kazakhstan, Kyrgyzstan, Lesotho, Moldova, Myanmar, Tajikistan, Ukraine, Uzbekistan, and Vietnam.

The WHO said this deployment, as well as efforts to make second-line antibiotics more affordable, should increase to 15 percent the proportion of patients with multi-drug resistant tuberculosis who are diagnosed and treated appropriately.

At present, that rate is only 2 percent.


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