NEJM: specific bone marrow or stem cell transplantation can cure AIDS
    

News Source: Xinhuanet 2009-2-16 8:49:18
     According to "Nature" Web site reported that a risk of AIDS and leukemia in men receiving special stem cell transplantation surgery, the two diseases are "cured." Transplantation using stem cells derived from one pairs of innate immunity with AIDS donors. Now 2 years have passed, even if the patients did not use anti-retroviral drugs, has not found HIV virus.

     Doctor in Germany in November 2008 had announced their discovery, from then on
, The results have been peer-reviewed and eventually published in the famous "New England Journal of Medicine" (New England Journal of Medicine) on.

     Any poor response to chemotherapy in patients with leukemia should be subject to a bone marrow transplant, doctors will search for bone marrow donor register information, to find the appropriate matching of patients and preparation for transplant.

     But Germany柏林夏Morante Medical School (Charité Universit? Tsmedizin) scientist Gero Hütter blood work done than the average bone marrow transplant also goes a step further, Hütter is not a scholar specializing in AIDS, but when he realized one of his patients required a bone marrow transplant, he think of more than 10 years ago he had read a paper, some people are talking about a special genetic variation, so that they have a resistance to AIDS.

     This variability means that a small deletion on the CCR5 gene. This gene encodes a receptor, the HIV receptor to make use of this invasive called CD4 + T cells in immune cells. Has around 1% of Europe's population of all of its CCR5 gene has two copies of this variant, which makes them difficult to HIV infection. If Hütter use this lack of CCR5 receptor cell replacement patients immune cells, then the patient might not be so vulnerable to HIV infection has.

     Hütter bone marrow donation center in Germany for this patient found 80 matching suitable, of which 61 bone marrow donors was confirmed with this CCR5 mutation, in February 2007 on patients with Hütter the transplant.

     PA American University AIDS researcher James Riley said that although up to now only one case of such a surgery, but the results are valuable. He said: "This provides ample evidence that most of the body cells of resistance to AIDS, the body really be able to resist the virus."

     Hütter, said another group of doctors are ready to test another HIV-positive patients with leukemia the same operation, this will be the second case of this surgery, a few years we will be able to see the result.

     Well, what patients have not been to cure it? It also said that bad, although the patients were around 2 years without recurrence, but may have the virus still will return. Virus may be hidden in the doctor can not test the cells, such as brain or heart cells.

     In addition, there is one type of HIV is not the use of CCR5 receptor to invasive cells. Such viruses usually do not have normal immune system in patients who appear, though they may eventually be in the in vivo proliferation of this patient.

     To be sure, the majority of AIDS in people who test positive will probably not willing to accept such treatment. Bone marrow transplantation has certain risks, compared to several years of antiretroviral drug therapy, even taking into account the drug's side effects, the risk of bone marrow transplantation or larger. In bone marrow transplant before the patient to accept the drugs and radiation treatment to kill their own hematopoietic stem cells, this process, the patient vulnerable to infection and, ultimately, the patient's body may be of the transplanted stem cells produce rejection.

     Has a number of medicines can play a similar role in the United States by Pfizer pharmaceutical company producing a CCR5 inhibitor, known as maraviroc, has been approved in the United States and Europe. Other companies are busy with further research and development of drugs targeting CCR5.

     Unfortunately, maraviroc can not completely prevent HIV binding to CCR5, and this drug was with other antiretroviral drugs used in combination together. Riley said: "HIV is basically to find some way to bypass the drug and continue to use CCR5", he added, HIV may be able to beat the inhibitory drugs, or can bind to other parts of CCR5, and the drugs can not.

     Other researchers are experimenting with gene therapy to fully prevent the emergence of CCR5. For example, Riley has called Sangamo BioSciences with a biotechnology company to identify the company a target for gene knock-out to see whether the technology can be used CCR5 gene knockout. Sangamo, announced last week that the company has begun Phase I clinical trial, the trial moved out of the participants will include a sample of T cells, CCR5 gene knockout, and the final will be the altered cells to re-inject patients. This test is to understand the safety of such techniques rather than the efficacy of the first step, and participants were not altered T cell will not be destroyed. (Xu Qing / compiler)

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