In what can be considered as encouraging news, scientists appeared to have cured an HIV (human inmmunodeficiency virus) patient, the third such case of HIV remission in the world. Interestingly, this is the first case where a woman patient has been cured of HIV by a technique involving stem cell transplantation.
It is worth recalling at this point that the earlier two cases of HIV remissions also involved similar kind of transplantation technique, where the ‘Berlin Patient’ and the ‘London Patient’ showed no detectable HIV in their bodies even after stopping the anti-retroviral drugs.
The third case of HIV remission is from the US where researchers presented their findings at a Conference on Retroviruses and Opportunistic Infections in Denver, as reported by New York Times.
The patient was diagnosed with HIV in 2013 and four years later, she was found to have developed leukemia, a type of blood cancer. As a treatment for blood cancer, the patient was given a transplant of umbilical cord blood. The benefit of transplantation of cord blood (the process is called Haplo-Cord Transplant) is that it is more widely available in comparison to the adult stem cells. Moreover, cord blood transplant does not require a close match between donor and the recipient, as in adult stem cells. The previous cases of HIV remission involved adult stem cells as part of bone marrow transplantation.
In the realm of stem cell transplantation, the physician primarily looks for finding donor stem cells that match the recipient’s HLA (Human Leukocyte Antigen). The HLA system is an extremely important part of the immune system (the defense mechanism of the body. Any transplantation strictly requires the matching of the HLAs between donor and recipient, failing which the immune system of the recipient would react adversely to the transplant.
The ideal match for stem cell transplantation is a sibling donor, but only 30% patients generally get a matching donor in their family. In the case of haplo-cord transplantations, there is no stringent requirement of matching between the HLAs between donor and recipient.
In this case, the HIV patient was administered umbilical cord blood from a partially matched donor as a means to treating leukemia. The cord blood contained the mutation that blocks the entry of HIV into the body.
In addition, a close relative of the patient also gave her blood in order to boost her immune system while the transplantation was in progress. After a patient receives umbilical cord blood transplantation, additional adult stem cells are also administered. The stem cells grow quickly, but are replaced soon by the umbilical cord blood cells.
The additional adult stem cells are given to patients who receive cord blood as it does not yield sufficiently to serve as an effective cancer treatment in adult cancer patients. The additional stem cells help in compensating the scarcity in the case of umbilical cord blood transplantations.
The woman received cord blood transplant in 2017 and her leukemia was remitted for more than four years. Again, three years after the transplant, her doctor stopped giving her the anti-retroviral treatment, which is the standard treatment in HIV patients. Fourteen months after the cessation of anti-retroviral drugs, the patient has not experienced any resurgence by the HIV.
The research was conducted by the International Maternal Pediatric Adolescent AIDS Clinical Trial Network P1107 observational study led by Yvonne Bryson of University of California Los Angeles, and Deborah Persaud of Johns Hopkins University, according to an NIH (National Institute of Health, USA) release.
Dr. Steven Deeks, an AIDS expert at the University of California, San Francisco, who was not involved in the study commented in New York Times: “The fact that she’s mixed race, and that she’s a woman, that is really important scientifically and really important in terms of the community impact,.” However, he remained apprehensive in seeing the new approach becoming a common treatment paradigm—“These are stories of providing inspiration to the field and perhaps the road map”—he said.
