The International AIDS Conference , which occurs every two years, has a broader scope than any other AIDS conference. Most other AIDS conferences and meetings tend to focus on either the hard science/medical aspects of HIV disease or the social aspects of the epidemic. In contrast, the International AIDS Conference encompasses the scientific, medical, social, and personal dimensions of HIV/AIDS. It brings together medical researchers, social scientists, community activists, and persons living with the virus from around the world. It provides a unique opportunity for the various stakeholders to learn more about each other’s accomplishments, goals, and concerns, and to strategize about ways to enhance their communication and work together more effectively toward common goals.
This year’s event – the 18th International AIDS Conference (IAC) – was held in Vienna, Austria from July 18 through 23. About 19,300 people from 197 countries participated. There were nearly 250 separate conference sessions, and more than 6,000 research abstracts were accepted.
The 2012 conference will be held in Washington, D.C. – the first time in 22 years that the IAC will be held in the U.S. Until recently, the U.S. had been out of contention as a site for the IAC because of the nation’s long-standing travel restrictions on persons living with HIV. With the Obama Administration’s lifting of those restrictions, the U.S. was quickly chosen as the site for the 2012 IAC.
Since it’s nearly impossible to report on the full range of research presented at the 2010 IAC, I’m providing a series of brief summaries grouped according to some of the Conference’s main themes and topic areas. I’ve also added links to reports, statements, and articles written by reliable health reporters who attended the Conference so that you can read in greater depth about the topics that interest you most.
Trends in the HIV/AIDS Epidemic and Treatment Access Global epidemic snapshot
At the end of 2008 – the latest year for which data are available – there were 33.8 million people living with HIV, and an estimated 2.7 million new infections. The good news is that the incidence rate has dropped from about 8,000 new infections per day (2.9 million total infections) in 2001 to 7,400 infections per day in 2008. During that period, about 100 countries have reported a 25% decline in HIV incidence. A total of 200,000 infections were avoided due to measures to prevention HIV transmission from mother to child during pregnancy, birth, or breast-feeding. For more information, read: 1.
Successes and challenges in rolling out treatment. Thanks largely to national and international HIV drug-access initiatives, a total of 5.2 million HIV-infected people in low- and middle-income countries are now receiving antiretroviral drugs (ARVs) to treat HIV. At the 2010 IAC, research teams from Brazil and South Africa described the dramatic impact that expanding access to ARV therapy has had on death rates in those countries. In 1996, Brazil became the first developing nation to provide free universal access to ARVs. There, the 5-year survival rate for children diagnosed with HIV infection increased 4.5-fold from just 20% in the mid-1980s to more than 90% by the early 2000s.
Another Brazilian study looked at trends in the HIV-related deaths between 1998 and 2008 in several different risk groups, including men who have sex with men (MSM), heterosexual men, heterosexual women, and injection drug users (IDUs) of both genders. The study found a substantial decrease in the death rates in each of the risk groups studied. However, some groups benefited more than others. Heterosexual sexual women had the lowest death rates, followed by MSM, heterosexual men, and IDUs.
A South African study looked at trends in the death rates of more than 40,000 miners who have free health care. This care includes voluntary HIV testing and – beginning in mid-2003 – free ARV treatment. In 2002, over one-quarter of the men in this workforce were HIV-infected. The overall death rate in these miners dropped from about 2% per year to 1.2% per year by 2006. Unfortunately, the death rate has since risen to 1.5% per year. Researchers believe that much of the increase is due to tuberculosis, which is a major health problem in this group of miners. Other contributing factors include some miners’ unwillingness to access HIV care due to denial of their HIV status, doubts about the effectiveness of ARV treatment, and fears about lost wages if they miss work for medical reasons. For more information, read: 2.
New guidelines indicate that millions of people still need of ARV treatment. During July, the World Health Organization (WHO) revised its ARV treatment guidelines for the developing world. These new guidelines recommend that people in developing nations start ARV treatment when their CD4 T-cell count drops to 350 or below, rather than waiting until the CD4 count falls to lower levels.
Under the new guidelines, 10 million additional people in developing nations are now in need of ARV treatment, rather than the 5 million additional people who met the criteria for treatment under the old WHO guidelines. Expanding treatment access to these persons will require substantial investments from sources including The Global Fund to Fight AIDS, Tuberculosis, and Malaria (The Global Fund) and PEPFAR (the President’s Emergency Plan for AIDS Relief). For more information, read: 3 .
Major funding commitments are essential to ensure the continued success of ARV access programs in the developing world. Many IAC participants expressed concern that the current underfinancing of The Global Fund – due, in part, to the global economic recession – and the leveling off of PEPFAR funding could make it very difficult to provide ARV treatment to the millions who need it. To address the funding shortfall, leading scientists and advocates at the IAC issued a statement calling for the commitment of at least $20 billion in additional monies to The Global Fund.
“We need commitment from our governments, from the international community, and from the leadership of rich countries,” said Uganda researcher Peter Mugyenyi at an IAC session focusing on universal access to HIV care. “The emergency has not gone away. We have a financial crunch. AIDS, more than anything else, requires that resources be increased so that we can continue to solve the century’s most devastating health problem.” For more information, read: 4 , 5 , 6 , 7 , 8 .
Injection drug use fuels the epidemic in Eastern Europe and Central Asia. In sharp contrast to the declines in HIV infection rates seen in much of the world, the greatest increase in infections is now occurring in Eastern Europe and Central Asia. Much of this rise is the result of HIV infections acquired through injection drug use (IDU) and high-risk sexual activity. The situation is particularly dire for the region’s more than one million street youth who are regularly exposed to multiple risks, including IDU, commercial sex work, exploitation, and abuse. The criminalization and social stigma of drug use, together with the lack of drug substitution therapy, such as methadone treatment, are major contributing factors to IDU transmission in Eastern Europe and Central Asia.
Concerns over the negative effects of IDU criminalization prompted the International AIDS Society, the International Center for Science in Drug Policy, and other groups to draft “The Vienna Declaration,” which was issued to coincide with the 2010 IAC. The introduction to the Declaration states, “The criminalization of illicit drug users is fueling the HIV epidemic and has resulted in overwhelmingly negative health and social consequences. A full policy reorientation is needed.” The Declaration urges policy-makers to adopt drug policies based on scientific evidence, rather than ideology. Such policies should be based on effective public health interventions rather than drug law enforcement. For more information, read: 9 , 10 , 11 , 12 , 13 .
High HIV infection rates continue among men who have sex with men (MSM) worldwide. A global survey of HIV infection among MSM found very high infection rates in nations around the world. The survey, which was done by Johns Hopkins University and the World Bank, showed that nearly one-quarter (23%) of MSM in Thailand were infected with HIV, with very high rates in many other countries, including Malawi (21%) and Peru (14%). In a press release about the study, an advocacy group called the Global Forum on MSM and HIV noted that the HIV epidemic among MSM is characterized by “ongoing epidemics in low- and middle-income countries, resurgent epidemics in high-income countries, and the discovery of new epidemics in areas that previously had no data.”
As is the case with IDU, criminalization and stigmatization play a major role in the spread of HIV among MSM. Michel Sidibé, Executive Director at UNAIDS, noted that, “Our vision of zero AIDS will never see the light unless we end criminalization of people by their sexual orientation.” For more information, read: 14 , 15 .
Penal reform needed to effectively address HIV in prisons. HIV infection rates among inmates in prisons, jails, and detention centers are much higher than in the general population. In addition, high-risk behaviors, including IDU and unprotected sex, are common in many correctional settings. Speaking at the IAC, an expert panel described how poor prison conditions increase the risk of HIV transmission and harm those already living with HIV. Few prison systems worldwide have implemented harm-reduction programs, such as the distribution of condoms or clean syringes to inmates. In some prisons, HIV-infected inmates are isolated, ostracized, and have limited access to food and water – much less medical care.
The panelists stressed that this situation is unlikely to improve without widespread penal reform, which should include decriminalization of drug use. Kristian Crole of the U.N. Office on Drugs and Crime’s HIV/AIDS unit said that increased advocacy – including efforts by prisoners, ex-inmates, and prison staff – could play in important role in spurring prison reform and improving the conditions behind bars. 16 , 17 .
United States update. The new U.S. National AIDS Strategy, which was announced by President Obama in mid-July, was also the subject of discussion at the 2010 IAC. The Strategy provides a comprehensive plan for tackling the HIV/AIDS epidemic in the United States. Its three main goals are to: 1) reduce the number of new HIV infections; 2) increase access to care and optimize the health outcomes for people living with HIV; and 3) reduce HIV-related health disparities.At the 2010 IAC, researchers discussed a new study from the Centers for Disease Control and Prevention (CDC) showing a strong link between poverty and HIV infection in U.S. urban areas. The CDC analysis showed that, in addition to the high HIV infection rates seen in traditional high-risk groups (such as MSM and IDUs), heterosexuals living in high-poverty urban areas are also disproportionately affected – with HIV infection rates over 2 percent. “These findings have significant implications for how we think about HIV prevention,” according to CDC’s Dr. Jonathan Mermin. “We can’t look at HIV in isolation from the environment in which people live . . . . This analysis points to an urgent need to prioritize HIV prevention efforts in disadvantaged communities.” For more information, read: 18 , 19 , 20 .
Prevention News and ResearchSouth African study shows that a microbicidal gel can substantially reduce HIV transmission. The encouraging results of the CAPRISA 004 microbicide study were probably the biggest highlight of the 2010 IAC. The study involved the use of a vaginal microbicide gel containing tenofovir – the same active ingredient used in the ARV drug Viread. Researchers found that, over a 2.5-year period, the tenofovir gel prevented about four out of ten HIV infections (39% efficacy) in a group of heterosexual women using the gel. The results were even better for the women who used the gel most consistently (more than 80% of the time). In these women, the gel prevented more than half of the HIV infections (54% efficacy). The CAPRISA research team also reported that the tenofovir gel reduced the transmission of the genital herpes virus (HSV-2) by about half – an important added benefit. AIDS Action’s Ashley Smith wrote an excellent summary of the research in the agency’s blog. If read you Ashley’s posting, be sure to check out HIV advocate Jim Pickett’s perspective on rectal microbicide development in his comments below the blog. For more information, read: 21 , 22 , 23 , 24 , 25 , 26 , 27 . (See also a recent blog post by AIDS Action’s Ashley Smith, “Microbicide breakthrough may dramatically improve HIV prevention” .)
PrEP pill appears safe in early tests. Another innovative approach now being tested for HIV prevention is known as pre-exposure prophylaxis, or PrEP. The idea behind PrEP is to give uninfected persons ARV drugs to keep them from becoming infected with the virus. At the IAC, researchers reported on a PrEP study involving nearly 400 MSM from Boston, Atlanta, and San Francisco. The study team, which included researchers from Fenway Health, found that once-daily dosing of the drug tenofovir appeared to be safe in uninfected men. Additional research is now under way to learn whether tenofovir is actually effective in reducing HIV transmission. For more information, read: 28 , 29 , 30 , 31 , 32 , 33 . (See also a recent blog post I wrote for the AIDS Action Blog, “Use of HIV Pill for Prevention Appears Safe in Early Tests” .)
Updates on male circumcision for HIV prevention. Over the past few years, researchers have reported that male circumcision can reduce, by up to 60 percent, a man’s risk of becoming infected with HIV during heterosexual intercourse. On the strength of this evidence, UNAIDS recommended that circumcision be an important element of HIV prevention efforts. Several research teams at the 2010 IAC provided new information about the potential benefits and limitations of male circumcision as a prevention tool.Some groups estimate that scaling up male circumcision to reach 80 percent of adult men and newborn males in Southern and Eastern Africa by 2015 could avert more than 4 million new HIV infections between 2009 and 2025 and could save $20 billion in avoided health care costs during that period. African researchers reported that, to achieve the greatest effect, male circumcision programs must engage the target community, use streamlined techniques, and have the flexibility for doctors and nurses to share responsibility for circumcision procedures. Unfortunately, however, a San Francisco-based survey indicated that circumcising MSM would probably have a negligible effect on reducing new HIV cases in the United States. For more information, read: 34 , 35 , 36 , 37 .
Better approaches are needed for effective HIV prevention in high-risk groups. Several research teams discussed the shortcomings of current prevention efforts, particularly for young people and high-risk groups. For example, in Eastern Europe and Central Asia, nearly 90% of national HIV prevention spending is on programs serving the general population, despite the fact that these nations’ epidemics are dominated by injection drug use. The Global HIV Prevention Working Group likewise reported that many HIV prevention programs are underperforming because they often overlook the highest-risk groups and are not properly planned and managed. In their recent report card on global prevention efforts, the Working Group found that only about 10% of national HIV prevention programs are well-matched with the needs of their affected groups. An American research team reported that delivering effective prevention messages and programs to young MSM at earlier ages would increase their impact on the men’s sexual behavior. At a pre-conference meeting organized by the Global Forum on MSM and HIV, speakers discussed the largely untapped potential of the internet for providing prevention information and support to MSM in Africa and Asia. And researchers from Africa and the U.S. spoke about their successes using cash incentives and phone support to promote healthy behaviors in young women.To address current shortcomings in global HIV prevention efforts, UNAIDS announced the formation of a new High Level Commission on HIV Prevention designed to “bring about a prevention revolution” by galvanizing support for effective HIV prevention programs. Some IAC officials also called for improved access to scientifically proven HIV prevention interventions; they characterized the lack of access to science-based interventions as a human rights violation. In addition, a group known as the Global HIV Vaccine Enterprise urged conference participants to back a “new era” of vaccine research combining rapid exploration of promising approaches with increased collaboration and funding. For more information, read: 38 , 39 , 40 , 41 , 42 , 43 , 44 .
Reduced HIV infection rates seen among young people in some African countries. Fortunately, significant progress is being made in reducing HIV infections in parts of the world. For example, the number of young persons aged 18 to 24 who are living with HIV infection fell at least 25% in seven African countries between 2000 and 2008. Smaller, but substantial, reductions in HIV cases have also been reported in another nine countries, according to a research team from UNAIDS. In many of these countries, young people reported they have taken steps to reduce their sexual risk behaviors. For more information, read: 45 .
Huge potential impact of effective prevention programs and technologies. In a session called “Building on success: A roadmap for HIV prevention,” billionaire philanthropist Bill Gates presented research showing that the efficient and targeted use of currently available resources – including male circumcision, timely ARV treatment, and preventing mother-to-child transmission – could reduce new HIV infections nearly 40%. The addition of new prevention technologies, such as microbicides and PrEP, could cut new infections by more than 50%. Finally, the widespread distribution of a partially effective HIV preventive vaccine, when combined with other interventions, could reduce new infections by 90%. Gates noted that, “If we push for a new focus of efficiency in both treatment and prevention and continue to innovate new tools, we can start writing the story of the end of AIDS.” For more information, read: 46 , 47 .
Treatment News and Research
Treatment as prevention. Effective ARV treatment dramatically reduces an HIV-infected person’s viral load – often to very low (undetectable) levels. People who receive ARV therapy and achieve an undetectable viral load have a much lower risk of transmitting the virus than do untreated persons. Bill Gates, former President Bill Clinton, and many other speakers described how the wider use of HIV treatment could prevent literally millions of new infections and deaths. Researchers from the Institute for Global Health have calculated that a full-scale rollout of ARV treatment, combined with the use of available prevention methods, could prevent 6.75 million new HIV infections and avert 4.7 million AIDS-related deaths in China and South Africa alone during the next 20 years. On a similar note, UNAIDS released a report describing the potentially dramatic benefits of a proposed “Treatment 2.0″ approach. Treatment 2.0 would involve both simplifying the way ARV treatment is currently provided and scaling up access to life-saving drugs. According to UNAIDS, this approach could avert 10 million deaths by the year 2025 and prevent up to 1 million new HIV infections each year.The benefits of a “treatment as prevention” approach are not limited just to resource-poor nations where HIV-infected persons have historically had very limited access to ARVs. Even in comparatively wealthy countries like the U.S. and Canada, many HIV-infected persons are unaware of their HIV status. In addition, many people who know they are infected are not accessing HIV care, either by choice or because of social and economic barriers to care. Canadian researchers have calculated that increased access to ARV treatment between 1996 and 2009 was associated with about a 50% reduction in new HIV diagnoses in British Columbia. They also calculated that, if all HIV-infected persons in Vancouver were treated according to the current ARV treatment guidelines, the rate of new infections in that city would decrease by nearly half. For more information, read: 48 , 49 , 50 , 51 , 52 .
When to start ARV treatment. The 2010 IAC featured new research on the controversial question of when to start HIV treatment. Over the years, there has been a growing body of evidence indicating that persons with low CD4 counts before starting ARV therapy are less likely to achieve the robust immune recovery often seen in those who start treatment with higher counts. People who are diagnosed with advanced HIV disease and who start treatment late also have an increased risk of death due to infections and other conditions such as heart disease and certain cancers. In addition, the currently available ARV treatment regimens are generally simpler and have fewer side effects than the regimens of a decade or more ago. These developments have prompted HIV experts to recommend starting ARV treatment at higher CD4 counts – in other words, at an earlier stage in HIV disease – than in years past. But, to date, no consensus has yet been reached on the best time to start treatment. Some HIV experts believe that all persons should have the option of starting ARV treatment. They cite recent studies indicating that early HIV treatment may provide some modest health benefits even in people with relatively high CD4 counts (over 500). In addition, widespread ARV treatment would be expected to reduce the total amount of HIV in the community at large, which could, in turn, decrease HIV transmission rates, as described in the “treatment as prevention” section above.Other HIV experts believe that most people should begin ARV treatment when their CD4 count falls to between 350 and 500. They are not yet convinced that the existing evidence showing modest health benefits from early treatment is compelling enough to justify starting treatment sooner. They point to the potential disadvantages of early treatment, including: higher ARV treatment costs, at least in the short term; the risk of developing HIV drug resistance if people don’t take their ARVs as prescribed; and the possibility of long-term drug toxicities that might develop in people taking ARVs for many years or decades.
At the 2010 IAC, researchers reported on findings from a very large, long-term study called CASCADE, which showed significant health benefits for persons who started ARV treatment at CD4 counts between 350 and 499, compared to those starting at lower levels. Using CASCADE data, the researchers calculated that, for people with CD4 counts between 350 and 499, 34 people would have to be treated to prevent one new AIDS case or death over a 3-year period, and that 71 would have to be treated to prevent one death.
The CASCADE researchers did not find any differences in the rates of death or progression to AIDS in persons starting treatment at CD4 counts over 500, compared to those starting treatment at lower levels. It is worth noting, however, that, unlike some earlier studies, this CASCADE analysis did not compare the risk of developing non-AIDS-related conditions at different CD4 counts – an important concern for many people living with HIV. So the question of whether ARV treatment is beneficial at CD4 counts above 500 is still unresolved. For more information, read: 53 , 54 , 55 .
Using existing ARVs in new ways. In the years since effective ARV therapy first became available in the mid-1990s, there have been many advances in HIV treatment, but some things have remained the same. For nearly all people starting ARV therapy – and for many switching their treatment due to side effects or drug resistance – the standard approach has been to use one of the following combinations:
Over the years, the specific drugs recommended for ARV therapy have changed as the number of available ARVs has greatly expanded and continuing research has revealed the benefits and drawbacks of particular drugs and combinations. Nevertheless, the mainstay of treatment, especially for persons just beginning ARV therapy, has been either two nukes plus a boosted PI or two nukes plus a non-nuke.
Three additional classes of ARVs have become available since 2003: fusion inhibitors, CCR5 blockers, and integrase inhibitors. To date, the drugs in these three newer ARV classes have been used mostly for treating persons with HIV that is resistant to one or more nukes, PIs, or non-nukes. However, in the past few years, researchers have been exploring whether these newer ARV classes might be used effectively earlier in ARV treatment. They have also studied whether ARVs from both these newer and older classes might be combined in different ways to provide alternatives to the standard ARV treatment approach described above.
At the 2010 IAC, researchers described promising results in several studies that looked at alternative ways to use existing ARVs. These included:
These innovative approaches for using existing ARVs offer several potential advantages. They could significantly expand the menu of ARV treatment options available for people starting or switching therapy. Regimens could also be better tailored to the medical needs and preferences of each patient. For example, a patient at high risk for heart disease could avoid using specific drugs or drug classes that might increase their risk. Similarly, patients concerned about developing particular side effects such as lipodystrophy (unwanted body shape changes) might avoid the ARVs associated with these side effects. Once-daily dosing and drug simplification regimens offer patients greater convenience, with fewer pills or doses per day. Simpler regimens make it is easier for patients to take their pills consistently, as prescribed, thereby reducing the risk of ARV drug resistance. These different options for using existing drugs will also give people wider choices when they must switch regimens due to side effects or drug resistance. For more information, read: 56 , 57 , 58 , 59 , 60 , 61 .
News about experimental ARVs. The availability of new drugs could further expand the array of HIV treatment options. These drugs are especially useful for persons with virus that is resistant to many of the approved ARVs. The scientific presentations at the 2010 IAC included updates on the several experimental ARVs that are now being studied in clinical trials. Three of these – rilpivirine, GSK-572, and TBR-652 – are new drugs in existing ARV classes that have shown promise in clinical trials.
Rilpivirine (also called TMC-278) is a new non-nuke drug that could be used as an alternative to existing non-nukes, such as efavirenz (Sustiva) or nevirapine (Viramune). At the IAC, researchers reported the results of a study comparing a regimen containing rilpivirine to an otherwise similar regimen containing efavirenz. They found that the rilpivirine and efavirenz regimens were nearly equally likely to reduce HIV levels to undetectable levels. The rilpivirine regimen also caused fewer side effects than the efavirenz regimen. In late July, the drug’s manufacturer Tibotec applied for FDA approval of the rilpivirine, which could occur in late 2010 or early 2011. A tablet combining rilpivirine with two existing nukes – FTC and tenofovir – is also being studied and might eventually provide a new one-pill, once-a-day treatment option. For more information, read: 62 , 63 , 64 .
GSK-572 is a new integrase inhibitor developed by the companies Shionogi and ViiV Healthcare. Two research studies presented at the Conference found that the GSK-572 effectively suppresses HIV. Most people taking the drug had only mild side effects, if any. GSK-572 also appears to be effective in fighting some strains of HIV that are resistant to raltegravir (Isentress), the only FDA-approved integrase inhibitor. On the strength of these findings, Shionogi and ViiV announced that they will soon begin Phase 3 clinical trials of the drug. For more information, read: 65 , 66 .
Tobira Pharmaceuticals’ TBR-652 is a new CCR5 blocker, a class of drugs that includes just one FDA-approved drug, maraviroc (Selzentry). In addition to blocking the CCR5 receptor that HIV uses to attach to cells, TBR-652 also blocks CCR2. CCR2 is cell receptor that has been associated with some inflammation-related diseases that are relatively common in persons with long-term HIV infections. These diseases include atherosclerosis (hardening of the arteries) and insulin-resistance – a condition in which the hormone insulin becomes less effective in lowering a person’s blood sugar levels. At the 2010 IAC, researchers described a small study in which TBR-652 was tested at various daily doses over a 10-day period. They found that the drug effectively suppressed HIV with minimal side effects. In early 2011, researchers plan further studies of TBR-652’s safety and effectiveness, as well as its effect on inflammation. For more information, read: 67 , 68 .
Pursuing an HIV cure. Several sessions at the 2010 IAC focused on the need for a sustained research effort to cure HIV disease. Despite the great strides that have been made in reducing illness and extending the lives of HIV-infected persons, little progress has been made toward a cure.
There are several important reasons to continue pursuing a cure. Even today’s best ARV treatment regimens aren’t able to completely stop HIV from replicating – making new copies of itself. This means that, when some HIV viruses and infected cells die off, there are always others to take their place. However, if HIV could be eradicated, then formerly infected persons would no longer have any virus in their bodies. Their ARV treatment could be safely stopped without fear that the virus would return. Their immune system would suffer no further HIV-related damage and would hopefully recover to a normal, healthy state. There would also be no additional treatment-related side effects and no risk of transmitting the virus to others. A true cure for HIV disease would also save many billions of dollars in avoided ARV treatment and other medical costs.
In the mid-1990s, some researchers speculated that potent ARV treatment might completely shut down the growth of HIV. If that were possible, then the virus might be eradicated simply by treating people until all their HIV viruses and HIV-infected cells died off. Some researchers calculated that two to three years of potent treatment might be enough to clear HIV from the body.
Unfortunately, this didn’t turn out to be true for a couple of reasons. First, as mentioned above, even the best ARV regimens don’t completely shut down HIV replication. In addition, some of the cells that HIV infects can live in the body for a very long time. For example, so-called memory T-cells may remain in an inactive – resting – state for many years. As long as the infected memory cells are inactive, they are unaffected by ARVs and by the parts of the immune system that fight germs and destroy infected cells.
However, when these resting T-cells are activated, they produce many new HIV particles before dying. In this way the memory cells can serve as a sort of reservoir for HIV, with the potential to rekindle HIV infection for as long as the cells survive. Some researchers have estimated that, even it were possible to completely shut down HIV replication, it could take many decades for all HIV-infected memory T-cells to die off naturally. For these reasons, the strategy of waiting for the death of all HIV viruses and infected cells won’t work.
So researchers have been exploring other approaches that might eventually lead to a cure. One such strategy involves trying to activate HIV-infected resting cells and then using ARVs to quickly suppress any virus those cells produce. Once activated, the formerly resting HIV-infected cells would quickly die. The overall effect would be to flush HIV out of its hiding places and clear it from the body. This approach has been tried with very limited success with a few compounds, including interleukin-2, interleukin-7, and valproic acid (trade name Depakote), which is a drug used to treat epilepsy and bipolar disorder.
At the IAC, a scientist from Merck Research Laboratories reported that, through an extensive chemical screening process, her company has identified several dozen compounds that could potentially flush HIV from resting cells. In a study published shortly before the Conference, a University of Colorado team also described research on using a compound called ITF2357 to activate resting cells. They found that ITF2357 was up to 15 times more potent than valproic acid in flushing HIV from resting T-cells. Since it appears to be safe for human use, ITF2357 and similar compounds might eventually play an important role in strategies to eradicate HIV.
At a pre-conference meeting, physician Gero Hütter gave an update on the highly publicized case of an HIV-infected American man living in Berlin, Germany, who may have been cured of HIV disease after undergoing radiation therapy, chemotherapy, and a bone marrow transplant for life-threatening acute leukemia. When screening potential bone marrow donors for that patient, Dr. Hütter’s medical team looked for a particular gene mutation called the CCR5 delta 32. People who inherit this mutation from both parents – about one in every 60 White Americans and Europeans – have a natural immunity to the most common forms of HIV; they lack a receptor called CCR5 that HIV uses to infect cells.
The doctors found a bone marrow donor with the CCR5 mutation and transplanted the marrow into the Berlin patient. They hoped that, with its CCR5 delta 32 mutation, this transplanted marrow might help the patient fight HIV more effectively. They also stopped his ARVs at that time due to concerns that the drugs might harm the transplanted marrow cells. They planned to restart his ARV treatment when detectable levels of the virus reappeared in his blood.
However, to their delight and surprise, the doctors found that there was no detectable HIV in his blood – nor was there any detectable HIV in his bone marrow, lymph nodes, intestines, or brain. Now, three years later, the Berlin patient continues to have no detectable HIV.
The high medical risk and very high cost of bone marrow transplants make it unfeasible for HIV-infected persons to undergo such procedures to cure their disease. Nevertheless, the Berlin case offers hope that the goal of eradicating HIV from infected persons may someday be achieved – perhaps through the use of gene therapy to make cells resistant to HIV infection. In a keynote address at the IAC, Australian researcher Sharon Lewin called for a collaborative effort focusing on an HIV cure, involving research scientists, physicians, drug companies, and funders worldwide. She noted that, while the Vienna IAC would not be the place where a cure is announced, “it will mark the beginning of a future where we seriously prioritize finding a cure.” For more information, read: 69 , 70 , 71 , 72 .
Official AIDS 2010 Conference website and Kaiser Global Health’s Conference home page .
AIDS Action’s “ 2010 International AIDS Conference ” page. This web page created by the HIV Health Library has links to more than 125 articles from various sources about the 2010 IAC.
Other Sites with Extensive Coverage of the 2010 IAC
Clinical Websites that Covered the 2010 IAC (registration may be required to access some materials)
Photo © IAS/Marcus Rose/Workers’ Photos