Ново проучване показва втори случай на успешна ремисия на ХИВ след трансплантация на костен мозък
Най-малко един милион души умират поради причини, свързани с ХИВ всяка година и почти 35 милиона живеят с тях ХИВ. ХИВ-1 (вирусът на човешкия имунодефицит) е отговорен за повечето от ХИВ инфекциите по света и се предава чрез директен контакт с инфектирани с ХИВ телесни течности. Вирусът атакува и убива важни клетки на имунната ни система, борещи се с инфекциите. Няма лек за ХИВ. Понастоящем ХИВ може да се лекува само с лекарства, които имат способността да потискат ХИВ вирус. These drugs have to be taken life long and it is challenging plus a cost burden on the health system especially in low-and-middle-income countries. Only 59 percent of patients of HIV worldwide are receiving Antiretroviral therapy (ARV) and ХИВ virus is fast becoming resistant from many known drugs which itself is a major concern.
Трансплантация на костен мозък (BMT) is a treatment used for leukemia, myeloma, lymphoma etc. Bone marrow, the soft tissue inside bones, makes blood-forming cells including the infection fighting white blood cells. A bone marrow transplant replaces unhealthy marrow with a healthy one. In the first case of successful ХИВ remission, an ХИВ-infected individual called ‘Berlin Patient’ who later revealed his name received a bone marrow transplant a decade ago when he was targeted to treat acute leukemia. He received two transplants along with total body irradiation which led to long-term ХИВ ремисия.
В ново проучване, публикувано в природа led by UCL and Imperial College London, the only second person has been shown to experience sustained remission from HIV-1 after a bone marrow transplant and stoppage of treatment. The anonymous adult male patient from UK was diagnosed with HIV infection in 2003 and was on antiretroviral therapy treatment since 2012. He was subsequently diagnosed with Hodgkin’s Lymphoma in the same year and he underwent chemotherapy. In 2016, he was given stem cell transplant from a donor who carried a genetic mutation which prevents expression of a most commonly used ХИВ receptor protein called CCR5. Such a donor is resistant to HIV-1 strain of the virus which specifically uses CCR5 receptor and thus the virus now cannot enter host cells. Since chemotherapy kills cells which are dividing, ХИВ could be targeted. From this understanding if one’s immune cells are replaced by cells which do not have CCR5 receptor, ХИВ can be prevented from rebounding after the treatment.
Трансплантацията е извършена с незначителни странични ефекти като леко усложнение, често срещано при трансплантации, при които имунните клетки на реципиента са атакувани от донорни имунни клетки. Антиретровирусното лечение е продължило 16 месеца след трансплантацията, преди да се вземе решение за спиране на лечението, за да се оцени ремисия на HIV-1. След това вирусният товар на пациента продължава да остава неоткриваем. Пациентът остава в ремисия след 18 месеца след прекъсване на антиретровирусната терапия, тъй като имунните клетки на пациента не са били в състояние да произвеждат ключовия CCR5 рецептор. Тази обща продължителност се равнява на 35 месеца след трансплантацията.
This is a second case of a patient exhibiting sustained remission of ХИВ-1 following a bone marrow transplant. One important difference in this second patient being that ‘Berlin Patient’ had received two transplants along with total body irradiation while this UK patient received only a single transplant and underwent less aggressive and lesser toxic approach of chemotherapy. Mild complications of similar nature were seen in both patients i.e. graft versus host disease. Achieving success in two different patients points towards developing strategies based on preventing CCR5 expression which might even cure ХИВ.
Authors state that they are monitoring the patient’s condition and cannot say with affirmation yet if he has been cured of HIV. This may not be a generalized appropriate treatment for ХИВ because of adverse effects and toxicity of chemotherapy. Also, bone-marrow transplants are expensive and carry risks. Nevertheless, it is a better approach with reduced intensity conditioning and no irradiation. Research could also focus on knocking out the CCR5 receptor using gene therapy in people with ХИВ.
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Източник (и)
1. Gupta RK et al. 2019. Ремисия на HIV-1 след трансплантация на хемопоетични стволови клетки CCR5Δ32/Δ32. природата. http://dx.doi.org/10.1038/s41586-019-1027-4
2. Hütter G. et al. 2009. Дългосрочен контрол на ХИВ чрез CCR5 Delta32/Delta32 трансплантация на стволови клетки. N Engl J Med. 360. https://doi.org/10.1056/NEJMoa0802905
3. Brown TR 2015. I Am the Berlin Patient: A Personal Reflection“, Изследвания за СПИН и човешки ретровируси. 31(1). https://doi.org/10.1089/aid.2014.0224
