Bone marrow transplant potentially linked to cure of patient with AIDS

Thursday, November 13, 2008

Scanning electron micrograph of HIV-1.
Image: Centers for Disease Control and Prevention.

In what could be a major medical breakthrough, or a once-in-a-lifetime occurrence, a 42-year-old American man was cured of AIDS after receiving a bone marrow transplant in Berlin, Germany two years ago. The transplant was performed as part of a treatment for his leukemia.

The unnamed man received the marrow from a donor who had a very rare genetic mutation which doctors say leaves a person almost 100% immune to AIDS and the virus that causes it. After radiation treatment for his cancer, and treatments involving several types of AIDS medications, the transplant was performed. As a result of the transplant, the man appears to have been cured of AIDS.

Dr. Gero Hütter, a doctor at Medical University of Berlin, Germany, presented his findings in a paper earlier in the year titled Treatment of HIV-1 Infection by Allogeneic CCR5-Δ32/Δ32 Stem Cell Transplantation: A Promising Approach. In the report, Hütter and his team stated that the man was free of AIDS in just under 70 days. The American Foundation for AIDS Research stated in September during a conference that the man was "functionally cured" of AIDS.

"High active antiretroviral therapy (HAART) was stopped from day of transplantation. GvHDprophylaxis followed standard regimens and engraftment was achieved on day +13. Complete chimerismas detected by competitive PCR was observed on day +60. The virus load was measured both by RNA-PCR and proviralDNA-PCR. DNA-PCR was negative from day +68 (Table 1)," stated Hütter in his report. Hütter is not an AIDS specialist.

"In the past, the attempts to prolong survival during HIV-1 disease by stem cell transplantation failed. Here, we demonstrate the first successful allogeneic stem cell transplantation in an HIV+ patient", added Hütter.

Only 1% of people in Europe have the mutation to stop the receptor module CCR5, a vital component that helps HIV, the virus that causes AIDS, enter healthy cells. The mutation allows CCR5 to be blocked, along with virtually any other strain of HIV, leaving the individual immune to the virus and AIDS. At least 80 people were tested for the mutation, and only one, the 61st person, was found to have the mutated genes inherited from both parents. The transplant gave the man new and healthy cells, which stopped his infection in its tracks.

Now, two years after his transplant, the man has been free of the illness and did not take any medication for AIDS in that period. Doctors said the medicine could interfere with the new cells ability to reproduce and survive. The man would only be ordered to start taking medication if his AIDS had reappeared, but it didn't.

One doctor says that more tests need to be done in order to determine if similar stem cell treatments can be used on other AIDS patients.

"A lot more scrutiny from a lot of different biological samples would be required to say it's not present," said Mayo Clinic AIDS immunology researcher Dr. Andrew Badley.

According to the Medical Hypotheses journal, between the years of 1982 and 1996, at least 32 patients received similar treatments. Of them, only two are reported to have been cured of AIDS. Hütter said he read the report in 1996 and after doing so, he decided to try the treatment.

Bone marrow transplants kill nearly 30% of those who receive them and are very difficult to perform.


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