Stem cell therapy might provide a remedy for acquired immunodeficiency syndrome (AIDS) after it was used on an HIV patient in Germany, the first person known to have been cured of the disease, a Department of Health (DOH) official said Tuesday.
Dr. Gerald Belimac, program manager of the DOH National AIDS/Sexually Transmitted Infection Prevention and Control Program, said American Timothy R. Brown, the so-called Berlin Patient who had been infected with the human immunodeficiency virus, was cured after getting stem cells in 2007 from a donor who was genetically resistant to the virus that caused AIDS.
However, he said that this procedure was very complex and was still under study.
“It takes the right person, the right recipient, the right donor, for a stem cell transplantation particularly on HIV to be successful,” Belimac said.
“If it comes from other donors, there is really a high chance that the recipient would reject it,” she added.
Brown was infected with HIV in 1995 and was later diagnosed with leukemia, or cancer of the blood.
“He underwent a transplant of stem cells for the leukemia and it turned out that those stem cells had genes that were resistant to HIV,” Belimac said.
Medical research has shown that almost 5 percent of Caucasians are genetically resistant to HIV, he said, but there are still no studies showing Filipinos having similar genes.
Belimac explained that the donor was HIV-resistant because his CD4 cells, a type of white blood cells that are attacked first by the HIV virus, did not have the “CCR-5 coreceptor” needed for the virus to infect the cells.
Flushing out immune system
“So the virus could not get into the CD4 cell due to the absence of that coreceptor … (Brown’s) entire immune system was flushed out to remove the leukemic or cancer cells and was replaced by new stem cells (from the HIV-resistant donor),” Belimac said.
“These stem cells that happened to be HIV resistant became his new immune system. So, for the past three and a half years, it is said that he has been cured of HIV,” he added.
Belimac said flushing out one’s immune system could be dangerous because of complications.
“It’s treated with various chemicals. It’s exposed to radiation to kill actually the current immune system so that it could be replaced. So, there is a danger that the patient will actually develop fulminant infection because you have to kill the immune system to replace it with a new one,” he added.
Belimac said stem cell therapy was one of the treatments medical researchers were studying to find a cure for AIDS/HIV.
3 future directions
“The future of HIV is clear. At least now, there are three future directions. Number one is the continuing pursuit of better ARV (antiretroviral) drugs. Second is in the field of vaccines. There are many promising researches in vaccine. And the third is really the stem cell,” he said.
Belimac said the probability was small that a Filipino with HIV could successfully get a stem cell transplant from an HIV-resistant Caucasian.
“If you want to get a transplant, you need a donor who shares similar characteristics (with you). Meaning, if you want a donor, you’d want a donor who is a close relative and, if not a relative, at least a Filipino,” he said.
“If not Filipino, at least Asian. (But) the (HIV-resistant) genes are actually among Caucasians. So we don’t say (that there’s) a high probability that an Asian can actually receive, or accept, or tolerate a Caucasian donor.”
Originally posted: 9:00 pm | Tuesday, October 23rd, 2012