Two HIV-positive men underwent bone marrow transplants and were free from the virus in about 8 months. Now, both men tested positive again of HIV. Is this a sign that bone marrow transplant fails to cure the AIDS-causing virus?

Reoccurrence of HIV

Approximately 8 months ago, two HIV-positive men with cancer was free from HIV after undergoing bone marrow transplant in 2008 for the first male and 2010 for the other, as part of routine treatment at Brigham and Women's Hospital in Boston.

Within 8 months, HIV was not detected in their system after the transplant with continuous antiretroviral drug therapy, and then later stopped after doctors believed the men were cured of the virus.

However, an unfortunate event happened in 2013 as one of them has tested positive for HIV and the second patient rolled the same on December 6 this year.

"The return of detectable levels of HIV in our patients is disappointing, but scientifically significant. We have demonstrated HIV can be reduced at undetectable levels by very sensitive research assays and the virus persists. Our current standards of probing for HIV may not be sufficient to inform us if long-term HIV remission is possible if antiretroviral therapy is stopped," stated by Timothy Henrich, M.D., physician-researcher in the Division of Infectious Disease at Brigham and Women's hospital, quoted by the Weather Channel.

The undetectable levels of HIV on both men revealed that somehow, the virus is still living inside their cells. Researchers are now working hard on how to disable the ability of HIV to reside in cells and stay dormant for an indefinite time.

"The cells that are latently infected with HIV were inactive for a very long time. At some point, for reasons not very well understood, the genetic information is recalled and activated," said by Michael Gaisa, M.D., assistant professor of Medicine and Infectious Disease at Mount Sinai Hospital in New York.

Bone Marrow Transplant versus HIV

Timothy Brown remains free of HIV due to his different donor having CCR5 delta32 genetic mutation.

The genetic mutation makes the body highly-resistant against HIV wherein the virus cannot effectively attach itself to T-cells. Brown also underwent bone marrow transplant for his blood cancer and later 'cure' of HIV.

Bone marrow transplant may remain effective but not in totality, since a donor must have a genetic mutation to help the recipient fight off HIV and even resist the hiding reservoirs inside the cells.

Nevertheless, the reoccurrence on the two patients proved that HIV can really hide inside host cells until it desires to wake up, which makes antiretroviral ineffective on clearing the virus even with years of treatment.