Curing HIV

Structural diagram of zidovudine (AZT). Create...

Structural diagram of zidovudine (AZT). Created using ACD/ChemSketch 10.0 and Inkscape. (Photo credit: Wikipedia)

This story has been all over the news for the past 48 hours; a case study reported at the 20th annual Conference on Retroviruses and Opportunistic Infections describes the first “cure” of HIV infection, apparently by the administration of antiviral medicines. In brief, a baby girl in Mississippi born to an HIV positive mother (and consequently was herself at high risk for being HIV positive at birth) was immediately started on combination therapy antiviral medicines shortly(30 hours) after delivery. Antiviral therapy is commonly given to HIV positive babies, and drugs such as AZT show good success at preventing maternal-fetal virus transmission, however aggressive antiviral treatment in infants is not generally done due to the toxic effects of these drugs. This story was then atypical, first because of the very rapid start to the antivirals in the patient, and second because of the combination of drugs administered.

After just 1 month of this treatment, levels of the virus in the baby’s body were essentially undetectable by standard laboratory testing. By the time she was 18 months of age, her mother had stopped bringing her in for treatment, and when the mother and baby were relocated by the time she was two years old, she had been off medication for at least 5 months of time. Repeated laboratory testing at this point was completely unable to detect any presence of virus particles in her system, suggesting that she was virus-free, or completely cured.

This story has been pretty widely reported throughout the media, and many of the more science-based venues have begun to focus on what the next steps would be. The patient needs to be thoroughly followed up to ensure that she remains HIV-free, and also that the combination of drugs have not had any as yet undetermined toxic side effects. Limited clinical trials will likely be initiated to see if the success can be duplicated, and undoubtedly there will be doctors and patients who may proceed in the absence of further controlled studies. I suspect however that given the large number of HIV positive pediatric patients (currently 900 new infections daily, worldwide) since the start of the pandemic, and that this is the first documented cure of the disease using drugs that have been available for a long time, that the results observed for the treatment regimen reported in this case study may not be typical.

There has also been another documented case where a “cure” for HIV infection has been observed (see this BIO230 comment thread for a citation.) In this case, whole body irradiation to treat leukemia of an HIV positive individual was followed up by a bone marrow stem cell transplant. The transplanted stem cells produced CD4 positive leukocytes that were resistant to HIV infection, due to the lack of a functional co-receptor on the donor cells. The patient was later found to be completely HIV negative. Taken together, these two case studies suggest that there is complex interplay between host and virus. Further study of the pediatric patient will be important, and will hopefully quickly shed light on why this treatment was successful in this situation.

Advertisements

About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on March 5, 2013, in Microbes in the News and tagged , , , . Bookmark the permalink. 2 Comments.

  1. I saw the story break on CNN just before my flight, as well as a bit of the coverage on the BBC news. It was interesting seeing firsthand the difference in presentation of the same information. Unfortunately, I missed the BBC exposé that promised to explain the real story (stoopid jetlag). Thank you for clearing up my misconceptions. CNN had me believing the mother actually overdosed the baby.

    • I commented over on FB where this was cross-posted that I think the media frenzy over this is a bit excessive. Although this case study is a potentially promising use of current antivirals, HIV isolates vary significantly throughout human populations, and consequently the course of disease is variable between individuals as well.

%d bloggers like this: