This article is cross posted from A&U Magazine's Destination: Cure.
Several months ago a media frenzy reported Danish researchers as being months away from curing AIDS. During this time, countless individuals discontinued their HIV medication, believing the cure would soon be available.
With the recent flurry of HIV "cure" reports, it's becoming increasingly more difficult to sort out who's actually been cured and what stories are media hype, wishful thinking, or premature reports of success.
Most people recognize headlines depicting cures in the form of herbal remedies or drugs yet to be tested in a single human being as either media hype or outright rubbish aimed at selling newspapers, stock or a product.
But what about the cases we hear announced at respected scientific conferences that sound completely realistic? How many of the cases of "functional cures" we've celebrated over the past three years are really actual cures?
Several of these cases come complete with a wake of conflicting reports and opinions creating confusion as to their merit.
In my black-and-white way of thinking it seems an obvious enough question to ask who, by scientific standards, is actually cured?
I posed this question to several HIV researchers and cure activists and received many different answers. This is really not surprising as the in-depth parameters of exactly what defines a cure are not all that clearly outlined.
Currently there are two types of HIV cures. They're defined by the International AIDS Society (IAS) as follows:
- Sterilizing/eradication cure: Complete eradication of HIV-infected cells from the body.
- Functional cure: Undetectable viremia without ART; no disease progression; no CD4 loss; lack of HIV transmission.
One aspect that creates confusion is there is no specifically defined time frame for when a person is deemed functionally cured. How long should an undetectable viral load and a normal CD4 count in the absence of ARVs be present before it's considered a functional cure?
There's also no clear identification of what significance circulating HIV fragments in the body retain. What does having a "very low level" of HIV fragments as found in Timothy Ray Brown (the Berlin Patient) and the Mississippi baby, who was treated early with ARVs, actually mean? What importance do they have? How can eradication be determined if single cell assays used to measure very low levels of virus can't differentiate between HIV competent of replicating and HIV "debris."
Shouldn't the development and standardization of assays specifically designed to identify replication-competent HIV, as well as to detect HIV in certain difficult to reach places, be a main priority? These are issues that are being looked at but maybe we should hold back on the "c" word until they are better understood.
It's also becoming more and more apparent that the current definition of a "cure" really could do with a broader sub-classification to include all the different types of "cures" based on how the cure was obtained, i.e., bone marrow transplant, early use of ARVs, or a new therapeutic agent.
As of right now, there is no one who has achieved a sterilizing cure -- at least no one upon whom everyone can agree.
The terms "HIV remission" and "post-treatment controllers" are being used by some in the scientific arena. Hopefully they will be adopted by the media to further separate and define cases currently referred to as simply "functional cures."
The courses each "cure" took to obtain this state are quite different. The types of ways each cure was reached further define the cures themselves and it may be helpful to break them down even more.
These are the main cases that some are calling cured of HIV, and, from my best understanding, this is how they are currently defined:
- Timothy Ray Brown: Some believe Timothy to be a case of a sterilizing cure but other experts feel more comfortable calling this a functional cure.
- The Boston Patients: Some are calling this a functional cure while others believe it is too soon to tell.
Very early treatment with ARVs:
- The Mississippi baby: Conservatively called "HIV remission."
- The VISCONTI Study (fourteen individuals): Being called "HIV remission."
- A sixty-seven-year-old German man (treated within ten weeks of exposure to HIV and off ARVs for nine years): Many are calling this a functional cure.
It's time for the formulation of more precise definitions of HIV "cures" to be devised and utilized not only within the HIV scientific community but also to curtail the media from inaccurate "cure" reports.
Hope is a beautiful thing. False hope can be dangerous and cruel to those hoping to be cured. Shouldn't we more accurately define a "cure" before counting the cured?
This blog entry is dedicated to Eric Blue for his bravery and selfless contribution to cure research. The 12-year-old who lived with HIV and leukemia passed on July 5, 2013, three months after receiving an umbilical cord transplant which attempted to cure him of HIV and leukemia. You will be forever remembered little brother.