Sunday, July 03, 2011


Masih ingat bahawa aku pernah kongsikan bahawa jika pembawa HIV mendapatkan rawatan HAART, kemungkinan risiko jangkitannya adalah hampir sifar. Mari kita baca maklumat ini.  

Hi, this is Paul Sax from Brigham and Women's Hospital and Harvard Medical School. HIV treatment and prevention specialists were treated this past week to a real surprise: the release of the much anticipated study results from HPTN [HIV Prevention Trials Network] 052.[1,2]
By way of background, we have known for some time that, theoretically, antiretroviral treatment (ART) would reduce the risk for transmission [of HIV]. First, it was the Rakai study,[3] which showed that heterosexual transmission risk was strongly linked to HIV RNA. Second, was the observation that effective ART dramatically lowered HIV RNA in genital secretions. Third, observational studies demonstrated that people on ART were less likely to transmit the infection to their uninfected partners. Finally, the famous Swiss statement in early 2008[4] stated that a person on treatment who had undetectable HIV RNA and didn't have any sexually transmitted infections was unlikely to transmit the infection to their uninfected partners, so much so that they even that implied that condom use wasn't necessary. A lot of controversy has arisen, but none of this really stood the test of true proof. What was the actual proof that treatment reduces transmission? Now we have it.
HPTN enrolled more than 1700 serodiscordant couples around the world. The vast majority (more than 95%) were heterosexual. The HIV-infected member of the couple could only become enrolled in the study if he or she had a CD4 count of 350-500 cells/µL, and had no symptoms. These individuals were given immediate ART, and the other patients were randomly assigned to receive ART only when the CD4 count fell to below 250 cells/µL or when they developed symptoms.
The reason that we got these early results is that the Data Safety Monitoring Board found a very strong protective effect of early ART in preventing HIV transmission. Specifically, 27 transmissions occurred in the group that had delayed therapy vs only 1 transmission in the early ART arm. The data released also suggested a personal benefit for treatment in that there were significantly fewer cases of extrapulmonary tuberculosis. An important caveat is that there weren't any survival advantages, at least on the basis of data received so far. Remember, of course, this study population was generally very healthy. We wouldn't necessarily expect to see the survival advantage.
These are very big results. Of interest, they are very similar in protective effect (more than 95%) to that observed in a study from this past year, the Donnell study[5] of HIV prevention (within the HSV treatment trial of antiretroviral therapy) where the preventive effect was virtually the same. In addition, I'm particularly impressed that the study was able to show protective effect even though the study population consisted of individuals who, arguably, would be least likely to transmit to their uninfected partners. Specifically, the patients had high CD4 counts, and likely low HIV RNA. Patients were enrolled in a clinical trial, and received prevention counseling. These are all factors that should make them less likely to transmit the infection, and yet, there was a significant protective effect. We don't yet have data on cost, resistance, or adverse effects. I would be very surprised if any of these factors were severe enough to negate the overwhelming benefits seen in this study.
Those are preliminary results of HPTN 052. Clearly, we are eagerly anticipating the full results when they are published and presented at scientific meetings. For further information on this study, take a look at the press release[6] from the HPTN group and also discussion in my blog HIV and ID Observations Thanks very much.


AHP: Terima kasih & jazakallah khier untuk mentor aku, As yang berkongsi maklumat ini.