The Challenges of Keeping HIV Suppressed

Last  year when the media announced the great advances being made against HIV, many  speculated about cures and even the end of AIDS.   Unfortunately, even with the most potent drug treatments now available, suppressing   HIV-1  remains an incredibly frustrating challenge.  Last year's excitement was fueled by dramatic findings about powerful three-drug combinations which attempt to squelch HIV-1 replication.  This potent three-drug cocktail significantly reduces HIV-1 replication; two of the drugs interfere  with the virus's reverse transcriptase enzyme while a third blocks the function of the viral protease enzyme.  These treatments can drive viral load, or the amount of HIV-1 in a person's blood, down to very low levels.  However, sensitive testing shows that even the best treatments cannot completely suppress viral replication.  Because HIV-1 mutates at an incredibly fast rate, any viral replication allows drug-resistant mutants a chance to appear.  Once HIV-1 mutates,  few viable treatment options remain for an infected individual.

John Mellors of the University of Pittsburgh Medical Center notes that, "triple drug combination therapy can fail for several reasons."  One of the main reasons drug-resistant HIV-1 strains develop has to do with the patient's failure to comply with treatments.  These therapies require taking dozens of pills- many of which have serious side-effects and dietary restrictions- each day.  Even one missed dose may allow drug-resistant mutants to develop.  However, drug resistant viruses may still emerge even in those who do adhere rigidly to treatment schedules.  For example, treatment failure may occur in those who who have unusually high metabolisms, processing the drugs so promptly that they have very little chance to do their work.  Margaret Fischel of the University of Miami Medical School notes, "I think three-drug therapy is an incredible advance, but our ability to treat people who fail is troubling; we don't have anything to offer them."   So, even though treatments for HIV infection have vastly improved, the medical and scientific communities are far from finding a 'cure'.  For these reasons new research advances in genetic resistance to HIV  and the CCR5 chemokine receptor have profound implications for the future treatment of HIV infection and AIDS.