Bone marrow miracle

Monday marks the 20th annual World AIDS Day, an event created by the World Health Organization to raise awareness of the global AIDS epidemic and memorialize the millions of lives the disease has already claimed.

While discourse surrounding a global pandemic affecting the lives of more than 40 million people must always be a sober affair, the tone of this year’s remembrance may be a little more hopeful, thanks to groundbreaking discoveries in the field of gene therapy that may represent hope for a cure.

One could imagine the Nov. 7 story of an American seemingly cured of AIDS after undergoing a bone-marrow transplant in Berlin appearing in a tabloid. But the story of the leukemia treatment that eradicated the AIDS virus broke in the Wall Street Journal.

Nobel Laureate and former Caltech President Dr. David Baltimore, who was unavailable to speak to reporters this week, told the paper that new gene-therapy strategies may in fact hold the key to unlocking a medical enigma that has puzzled top doctors and researchers for more than 25 years. 

Baltimore and colleague Dr. Irvin Chen, a molecular biologist who heads the UCLA AIDS Institute, have established a private company in Los Angeles to further the study of gene-therapy — a process of introducing genetically altered cells to combat disease — but have yet to treat any patients using these methods.

Duarte’s City of Hope Hospital, meanwhile, is already using gene therapy to treat four patients for AIDS-related lymphoma.
A specialist in pediatric infectious diseases at City of Hope, Dr. John Zaia said he actually wasn’t all that surprised by German Dr. Gero Hütter’s success in seemingly eradicating AIDS from his patient’s body by replacing bone marrow cells with others from people who have a naturally occurring genetic mutation which renders them almost immune to HIV.

“We have known that this might be possible for years, but the problem was that we did not have a patient on whom we could test it,” said Zaia. “Ethically, you cannot perform a bone-marrow transplant on an AIDS patient without a direct need for that procedure.”

Furthermore, the genetic mutation is incredibly rare. It occurs most frequently in Scandanavian countries, where it is thought to be present in roughly 1 percent of the population. Hütter rejected 60 possible bone-marrow donors for his patient before finding a sample from someone with the mutation resistant to the Human Immunodeficiency Virus (HIV), which causes AIDS.
“Sadly, Hütter’s strategy probably couldn’t have been employed in the United States,” said Zaia. “In this country, when someone is diagnosed with leukemia, they are rushed to transplant. Insurance companies would not allow a doctor to reject 60 donors before operating because of the fear that the patient would relapse before the HIV-resistant donation came through. However, from first-hand conversation with Hutter, I am confident that his patient’s life was not imminently threatened by his leukemia.” 

In the late 1990s, hopes for curing AIDS using antiretroviral drugs were unrealized because HIV integrates itself into a patients DNA, allowing it to remain dormant in some cells and capable of spreading throughout the body again. What was miraculous about Hütter’s treatment was that the introduction of genetically altered cells seems to have created a broader HIV immunity throughout the body.

But for all of the excitement, the man who first identified symptoms of the disease urges people not to jump to overly optimistic conclusions.

“In celebrating this scientific victory, we forget the horrific implications of radiation and chemotherapy involved in bone-marrow transplants,” said Dr. Michael Gottlieb, a practicing physician at Cedars Sinai Hospital who in 1981 published one of the first articles identifying the AIDS virus. “I see the success in Germany more as a proof of principle than a widespread option for AIDS sufferers.”

Zaia agreed, saying there is still a high mortality rate associated with bone marrow transplants, making them an unrealistic treatment plan for most AIDS patients. “But right now, City of Hope is starting to be a nationally recognized center for the treatment of AIDS in conjunction with leukemia, which means that more cases like this will most definitely arise,” he said.
 Aside from gene therapy, Gottleib praised progress in pharmaceutical AIDS treatments.  “Among young Americans diagnosed as HIV-positive, 50 percent will live beyond the age of 65, which is a dramatic improvement from the early-to-mid-’90s,” he said. “However, these patients must make a lifelong commitment to taking medication regularly.”
Gottlieb also emphasizes that the prognosis is significantly better for AIDS patients in developed countries than in the Third World.

“My only problem with the establishment of World AIDS Day is that I believe that every day should be World AIDS Day,” Gottlieb said. “One day in the headlines is hardly enough to combat a global pandemic.”

On Dec. 6, Pasadena’s AIDS Service Center will hold a Posada Candlelight AIDS Walk to raise public awareness to remember the victims of the disease and raise funds for the center’s operation.

On Dec. 11, City of Hope will host its second annual San Gabriel Valley AIDS/HIV Action Summit, featuring information about efforts to treat AIDS and workshops about AIDS awareness and activism.