also reactivate itself, and begin replicating once more. This is why an infected individual cannot stop taking ARVs, since some of the latent viruses will inevitably reactivate. This latent ÂreservoirÊ, along with the extensive damage to the immune system is the major barrier to the eradication of HIV. 9 At the moment, the best treatment available is highly active anti-retroviral therapy (HAART), which consists of a combination of at least three ARVs. There are six classes of ARVs. 10 Each of the first five classes are a different enzyme inhibitor, which block the action of certain enzymes used by the virus to infect a host cell, e.g. they stop conversion of RNA into DNA, or the manufacture of proteins required to maintain cell structure. 11 CCR5 antagonists are the final and most important class. These act to dampen the sensitivity of the CCR5 receptor – a protein on the surface of white blood cells. 12 Although it seems illogical to attack your white blood cells – the very cells fighting off the virus, studies have shown that the CCR5 protein is used by the virus to enter and infect host cells. 13 Thus, by shutting off the CCR5 protein, these antagonists reduce the ability of the virus to infect cells. In fact, people who have a mutation called the ÂCCR5- ∆ 32 mutationÊ do not have any CCR5 proteins on their white blood cells, and so have natural immunity to HIV. 14 Clearly, HAART is a sophisticated programme of treatment for HIV sufferers. And in high-income regions such as North America, Western Europe and Australia, HAARTÊs impact has been dramatic. Opportunistic infections are now uncommon, and average life expectancy is at an all time high at 63 years, which is only 13 years below 9 [PLOS Pathogens, Rapid Quantification of the Latent Reservoir for HIV-1⁄ , 2013] 10 [Patient.co.uk, Antiretroviral Agents , 2012] 11 [Aidsmap, Integrase Inhibitors , 2013] 12 [Wikipedia, CCR5 , 2013] 13 [Wikipedia, Receptor Antagonist, 2013] 14 [FoundCare, What is HIV antiretroviral treatment?, 2013] HAART
that of the general population in these regions. 15 However, HAART is not without disadvantages. In regions most affected by HIV, sufferers are unable to afford the costly HAART cocktails, and partial treatment often proves to be a poor alternative. 16 HAART medications also receive criticism due to their schedules. Often confusing and easy to forget, such regimens may be risky since missing a time-tabled ingestion can have serious consequences on efficacy. Also, as with any potent, lifelong therapy, side effects are common, including bone problems, liver damage, diarrhoea, nausea and more. 17 One of the first major breakthroughs in combating HIV came off the back of years of painstaking research and a large helping of luck. Timothy Ray Brown, the ÂBerlin patientÊ, was diagnosed with HIV in 1995 and with leukaemia (a cancer of the blood) in 2006. Brown had already undergone chemotherapy, but needed a bone marrow transplant. His doctor, Gero Hutter, suggested they seek a donor with the CCR5- ∆ 32 mutation, which gives the carrier natural immunity to HIV. 18 Hutter theorized that a transplant from such a donor could make the recipient resistant to HIV also. No one apparently had tried this, and his idea received mixed reaction from other doctors. But within weeks, tests showed promise that Brown was cured – the virus in his blood had dropped to undetectable levels, and the cancer had disappeared. However, researchers in California recently found traces of HIV in his tissues, leading to speculation that the virus had returned. 19 Mr Brown and his doctors dismissed the The Berlin patient 15 [NHS, What is the life expectancy for someone with HIV? , 2013] 16 [HIV Positive Voices, Highly Active Antiretroviral Therapies (HAART) For Treating HIV , 2013] 17 [Live Strong, The Side Effects of HAART , 2010] 18 [Huffington Post, Timothy Ray Brown, ÂBerlin PatientÊ, And His Doctor Are Convinced⁄ , 2012] 19 [Daily Mail, First man believed cured of AIDS says the disease is gone forever⁄ , 2012]
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