The HIV virus is an ace of camouflage. It infects healthy cells and integrates into their genetic material to go unnoticed and not face. It hides in the infected cells themselves and prevents the immune system from finding it and eliminating it. That is his best survival tactic and it does not hurt him. The antiretrovirals to fight it are becoming more effective, have fewer side effects, and reduce the virus to a minimum. But HIV never completely disappears and they remain, in a kind of den to shelter (viral reservoir), infected cells latent in the body. That is why the cure, today, does not exist. Except in one case – the so-called Berlin Patient, Timothy Brown, who has been HIV free for 11 years after a stem cell transplant – and a second in the making: an international consortium, in which the IrsiCaixa research center in Barcelona participates, has another patient was identified who, after a stem cell transplant, stopped taking antiretrovirals and has been undetectable for 18 months. Physicians, prudent, still talk about remission, not healing.
“It’s something amazing. The patient from Berlin was not an anecdote. We have a second case. We do not want to talk about cure, but in the other cases where the treatment was interrupted, the virus rebounded, “celebrates Javier Martínez-Picado, a researcher at IrsiCaixa and co-leader of the international consortium IciStem, who has published the finding in the journal Nature. With his differences, this second patient replicates what has been achieved with the patient in Berlin, Timothy Brown, the HIV-positive man who, after undergoing a bone marrow transplant -where the stem cells are found- to cure a leukemia that he suffered, the patient was withdrawn. antiretroviral treatment and HIV, far from spreading, disappeared.
In the transplant was then part of the key that explains the case of Brown. Treatment for leukemias such as yours or other similar hematological diseases begins with a powerful chemotherapy that destroys the bone marrow, where the malignant tumor is located and is, in turn, one of the reservoirs of HIV. The chemo fulminates, at the same time, the tumor cells and the infected latent cells. Then, with a transplant of stem cells from a healthy donor, the marrow is rebuilt with an army of healthy cells, the hematological disease is cured and HIV is eliminated.
But in addition to the decisive factor that was the transplant, Brown had the peculiarity that he had a mutation in one of the two alleles of the Delta 32 CCR5 gene, a genetic error that prevents the virus from penetrating the cell. When the mutation, which affects 1% of the European population, is in the two alleles of each gene, HIV can not open the floodgates to enter the cell. The Berlin patient was transplanted with stem cells from a donor who had that mutation and has not had a virus for 11 years.