In the impression of many people, AIDS is an incurable disease, once infected with AIDS, can only rely on drugs to prolong life, the rest of the patient's life will be accompanied by HIV.
On February 15, at a conference on "retroviral infection" in Denver, Colorado, USA, there was good news: Scientists had successfully cured an HIV-infected person using cord blood transplants.
What's going on?
How hard is the HIV virus to deal with?
The HIV virus attacks immune cells, and when the immune system loses its normal function, patients often die of various diseases.
Hive was first detected in 1981, but so far, no specific drugs have emerged to target AIDS.
One of the important reasons is that the GENES of HIV mutate too quickly, resulting in the failure of anti-HIV drugs.
Not only is there no specific drug against HIV, because the virus mutates too quickly, and there is currently no vaccine to successfully prevent AIDS!
The treatment of AIDS is currently commonly used as "cocktail therapy", that is, giving patients a variety of anti-HIV drugs at the same time, but it can only control the disease and cannot achieve the purpose of cure.
(Source: wikimedia.org)
In addition, the HIV virus is able to escape the attack of the body's immune system.
Even though patients are treated with effective "cocktail therapy" and hive in the body is greatly reduced, the residual virus can lurk in some immune cells [1] to evade recognition by the immune system.
Once the "cocktail therapy" treatment stops, the latent virus will "re-emerge" and "make waves".
Although there is no definitive cure today, there have been two successful cases of AIDS that have been successfully cured.
These two AIDS patients are also leukemia patients, and the misfortune is that:
Because they used chemotherapy drugs to treat leukemia, the original immune cells in the body were almost cleared, and then they transplanted MARROW stem cells with defective CCR5 receptors to rebuild the immune system.
If the CCR5 receptor is likened to a lock on a cell, the HIV virus is a thief who can open the lock into the cell.
Defective CCR5 receptors are like a bad lock, the HIV virus can not open, it can not enter the cell, can not infect, proliferation, the disease will not recur.
However, very few people have cCR5 receptor defects, and the sources of bone marrow stem cells available for transplantation are very limited.
Only a very small number of people who can successfully "match" can receive transplant treatment, otherwise there will be immune rejection.
Therefore, these two cases of AIDS patients are also super lucky.
Source: Stand Cool Helo
How does cord blood transplant cure AIDS?
The patient who received a stem cell transplant is currently the third patient to have been cured of AIDS.
This is a 64-year-old woman who was diagnosed with HIV infection in 2013 and acute myeloid leukemia in 2017.
After treating leukemia, patients also need to transplant stem cells, but the transplanted stem cells are cord blood stem cells, and the most critical is the CCR5 defective stem cells.
(Source: scbb.com)
14 months after receiving a cord blood transplant, the HIV virus is no longer detected in the patient's blood;
Three years after receiving a cord blood transplant, doctors stopped her HIV treatment.
So far, the HIV virus in the patient's body has not "re-emerged", so doctors judge that the patient has been cured.
Cord blood stem cells are more abundantly sourced than bone marrow stem cells, meaning more AIDS patients will have access to a cure.
It is worth mentioning that the current people with CCR5 deficiencies are mainly the Nordic race.
The woman being treated was of mixed race and was not a perfect "match," which meant that even if she wasn't of The Nordic race, she could be cured.
Knowledge Extension:
In 2019, a study published in the New England Journal of Medicine by Professor Deng Hongkui's research group and collaborators at Peking University showed that CCR5 mutations in stem cells can be used to treat AIDS patients by using CRISPR gene editing [2].
Of course, this is only an exploratory study, under the technical conditions at that time, in the transplanted stem cells of patients, the proportion of CCR5 mutations is not high enough, so the purpose of cure can not be achieved.
However, if this technology route is improved and validated by more clinical trials, it is possible to truly use it for the treatment of AIDS.
Just born with umbilical cord blood, can I use IT later when I get AIDS?
When a baby is born, the hospital asks parents if they want to keep cord blood.
Since the stem cells in the cord blood can treat AIDS, is there now another reason to save the cord blood, in case of unfortunate AIDS in the future, you can use the cord blood to treat?
In fact, if you really understand the case of cord blood curing AIDS, you will clearly understand the fact that:
The stem cells and CCR5 receptors in the general human cord blood are normal, so they will still be infected by HIV virus and cannot achieve the purpose of curing AIDS.
In Chinese, it is almost impossible for people with CCR5 defects, so the cord blood saved by everyone, under the current technical conditions, is simply not possible to treat AIDS.
Of course, if CRISPR technology matures in the future and can use cord blood to efficiently produce stem cells with CCR5 mutations, it may also be used to treat AIDS. However, this is only a possibility for now.
Because cord blood contains stem cells, it can be used for the treatment of some metabolic diseases, blood diseases, and immune diseases, but for the average person, the chance of really using cord blood for treatment is very low.
It is estimated that in every 3,000 babies who store cord blood, only one has the opportunity to use their own stored cord blood in the future, which is a small probability event.
In contrast, the cost of saving cord blood is not cheap, so the "cost performance" of storing cord blood is very low.
However, if there is an opportunity, donating cord blood is a good choice, there is nothing to lose for babies and parents, stem cells in cord blood, and possibly help people in need.
bibliography
[1]. Hiener B, Horsburgh B A, Eden J-S, et al. Identification of Genetically Intact HIV-1 Proviruses in Specific CD4T Cells from Effectively Treated Participants. Cell Reports 2017; 21: 813-822.
[2]. Xu L, Wang J, Liu Y, et al. CRISPR-Edited Stem Cells in a Patient with HIV and Acute Lymphocytic Leukemia. New England Journal of Medicine 2019; 381: 1240-1247.
*The content of this article is a popularization of health knowledge and cannot be used as a specific diagnosis and treatment recommendation, nor is it a substitute for face-to-face consultation by a practicing physician, for reference only.
*The copyright of this article belongs to Tencent Medical Code, unauthorized media reprinting is prohibited, and illegal reprinting will be investigated for legal responsibility according to law. Individuals are welcome to forward to the circle of friends.
* Welcome to WeChat search and pay attention to the public account "Tencent Medical Code" to get more health science knowledge.