The victory over HIV is postponed
The HIV treatment experiment ended unsuccessfully
Sad news from the USA: an experiment in which two patients in Boston were supposed to be completely cured of HIV (Hopes of HIV cure in 'Boston patients' dashed) ended in failure. Six months after they stopped taking antiretroviral drugs, the virus was found again in their bodies. At the moment, they have started taking medications again and are feeling well. Their lives are not in danger, but the victory over HIV is postponed.
The principle of treatment of the two Boston patients was very similar to the case of the "Berlin patient" Timothy Brown. Two HIV carriers were found to have oncohematological diseases that cannot be treated with chemotherapy. In such cases, bone marrow transplantation is performed. The difference is that Timothy Brown in Berlin was transplanted bone marrow from a donor with a mutation that makes the lymphocytes obtained from this bone marrow resistant to infection with the immunodeficiency virus. No such donors were found for Boston patients (it's not that simple, donation requires a large number of parameters to match, and the probability of such a match for people who are not closely related is very low, and one percent of people have immunity due to mutation). Apparently, this deviation from the Berlin protocol allowed the virus to return.
Scientists, transplanting bone marrow from a donor without mutation, hoped for a "graft versus host" reaction. Even if pre-irradiation does not kill all the recipient's bone marrow cells, and a certain number of HIV-infected cells remain, then when they meet with superior forces of the donor bone marrow, they are identified as strangers and die. One patient was transplanted in 2008, another in 2010, and they continued to take HIV medications until the spring of 2013. In the spring of 2013, they voluntarily stopped taking medications. For some time, the virus was not detected in them, and at a conference in July, doctors reported success. But the joy was premature: after 12 weeks and 32 weeks, the virus was again detected in patients.
The reason for the failure, most likely, lies in one feature of the virus. Although the virus damages, first of all, the cells of the immune system, it is able to create "backups" in long-lived cells of a completely different type, for example, nerve cells. They do not cause any special harm there, but it is very difficult to eliminate them. Apparently, these backups allowed the virus to re-enter the immune system.
In conclusion, we emphasize once again that patients are not in danger, they are taking antiviral medications again and I feel good. Only the therapeutic approach, which had weaknesses from the very beginning, is under threat. It is possible that genetic engineering methods of modification of transplanted cells, which will make the cells resistant, will solve the problem of the lack of suitable donor carriers of the mutation.
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12.12.2013