This year's International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention, held in Kuala Lumpur, Malaysia, made major headlines when Timothy Henrich, an American doctor, announced that two more cancer patients may have been cured of HIV after receiving bone-marrow transplants to treat lymphoma. Both patients had been taking retroviral medication, and continued to do so after the transplants as their viral levels sank until doctors were unable to find any traces of HIV in the patients' blood. The doctors then consulted with the patients before stopping their HIV treatments, but have remained watchful, regularly performing blood tests to check for the reappearance of HIV.

Unlike the Berlin patient, the first person to have been cured of HIV through bone-marrow transplantation, these patients did not receive bone marrow from donors with a genetic resistance to HIV. While this may open the door to providing more HIV-infected cancer patients with a potential cure, doctors are remaining cautious. They are concerned that the patients could still have undetected reservoirs of HIV in their bodies and that the virus could once again attack the patients at a later date.

The research group monitoring the patients believes that the transplanted bone-marrow cells may have played a role in destroying HIV reservoirs in the patients' bodies by attacking the patients' infected cells in a phenomenon known as graft-versus-host.

Dr. Henrich explained, "For six to nine months after the … transplant, we see a mingling of the donor and host cells, and what happens over time is that the donor cells clear out the host cells. The peripheral blood lymphocytes that it clears out are a major reservoir for HIV."

This destruction of HIV reservoirs by donor cells, coupled with antiretroviral therapy that protected these new cells from being infected with HIV, may have led to what doctors refer to as a "functional cure" (a patient no longer needing treatment for HIV, regardless of HIV infection) in both of these patients.

More hopeful, if tragic, news came from a case in Minnesota where Eric Blue, a 12-year-old boy fighting HIV and leukemia, died on July 5 from complications caused by a cell-transplant along the lines of the one given to the Berlin patient. In April, Blue was given transplant cells from a donor who was resistant to HIV in a move that was meant to combat the HIV and cancer in his system.

The transplant seemed to be doing its work as Blue's test and tissue samples showed no trace of leukemia and HIV, and remained clean after doctors stopped administering his HIV medications.

Sadly, bone-marrow transplants carry a significant risk of complications, and the transplanted cells began to attack Blue's body, giving him a severe case of graft-versus-host disease that eventually proved fatal.

But doctors explained that not performing the transplant was not an option.  Dr. Michael Verneris, the doctor who treated Blue, said, "This patient absolutely needed to have this transplant. And if he hadn't developed a very common side effect of bone-marrow transplant and died from it, we were hopeful this was all going to work well."

Despite the death of their patient, the doctors and researchers who cared for Blue have gained valuable knowledge from his treatment that they will be able to use to help other cancer and HIV patients in the future. CA

Tech Bytes

» China's Internet Users Going Mobile

The most recent count by the China Internet Network Information Center has determined that the Asian nation now has 591 million Internet users. This is an increase of nearly 5 percent from the 564 million reported at the end of last December, and over 50 million more online users than the center reported at the same time last year.

The center's statistical report put the number of people accessing the Internet via mobile phones at 464 million. This is 42 million more than the number reported six months ago. Increasingly affordable smartphones make the number of Chinese mobile Internet users first surpass the number of desktop users in 2012, and this gap is continuing to grow.