Cured or Cleared?

A growing number of HIV-positive people now have undetectable viral loads, but why are some of them not considered cured?

Thirty years into the AIDS epidemic, three men who were HIV-positive are now HIV-free. Following the famous “Berlin patient” reportedly cured of HIV, two more men have been seemingly cleared of the disease, researchers announced at the 19th International AIDS Conference in Washington, D.C. this July. The men were HIV-positive and treated for cancer with bone marrow transplants. More than two years later, HIV cannot be detected in their bodies.

Their results echo the case of “the Berlin patient,” the informal name assigned to Timothy Ray Brown, a German man allegedly cured of HIV from a bone marrow transplant. The two stem cell transplants that treated Brown’s acute leukemia came from a donor with a genetic mutation that makes cells resistant to HIV infection. The transplant replaced his infected cells with the HIV-resistant cells, clearing his body of the virus.

The procedure is risky and expensive, but since Brown’s high-profile case came about, scientists have sought similar treatments. Subsequently, doctors at Brigham and Women’s Hospital in Boston looked for HIV patients with leukemia or lymphoma who had received bone marrow stem cell transplants, hoping to observe the effects of the treatment on HIV reservoirs in their cells.

One of the new men allegedly cleared of HIV is in his 50s and had been positive since the early 1980s; the other is in his 20s and infected at birth. Both men took their HIV drugs throughout their treatment for lymphoma. Doctors could detect HIV DNA in their cells immediately before and after transplant, but as the donor cells replaced the patients’ cells, every trace of the HIV disappeared. Unlike Brown, the men received transplants with normal cells rather than cells affected by a genetic mutation. It’s been two years HIV-free for one of the men and three and a half years for the other.

But doctors are being careful not to use the word “cured” in this case. Both men are staying on AIDS drugs, and they can’t be declared “cured” until they have stopped therapy for multiple years with no rebound of HIV in their blood. Brown, on the other hand, has been free of daily antiretroviral drugs for five years. That makes him “functionally” cured, though minute traces of HIV remain in his system.

Bone marrow transplants remain too costly and potentially dangerous to perform on the millions of people still infected with HIV, but these cases offer new hope. Dr. Steven Deeks, an HIV expert at the University of California, San Francisco, told MSNBC, “(These studies) give us reason for enthusiasm, that ultimately we are going to get to where we needed to go, which is to cure people with HIV infection.”