In people’s impressions, AIDS is an incurable disease. Once infected with AIDS, the only way to prolong life is to rely on drugs, and the patient will be accompanied by the AIDS virus (HIV) for the rest of his life.
Good news at a conference on “Retroviral Infections” in Denver, Colorado, USA on February 15: Scientists using umbilical cord blood transplant successfully One HIV-infected patient was cured.
What’s going on here?
How difficult is HIV to deal with?
HIV attacks immune cells, and when the immune system fails to function properly, patients often die from various diseases.
HIV was first discovered in 1981, but so far there has been no cure for AIDS.
One of the important reasons is that the HIV gene mutates too quickly, making anti-HIV drugs ineffective.
Not only is there no specific medicine for HIV, but because the virus mutates too fast, there is no vaccine to successfully prevent HIV at present!
Treatment of AIDS, currently commonly used is “cocktail therapy”, that is to give patients a variety of anti-HIV drugs at the same time, but it can only control the disease and cannot achieve a cure Purpose.
(Source: wikimedia.org)
In addition, the HIV virus is able to evade attack by the body’s immune system.
Even if the HIV virus in the body is greatly reduced by the effective “cocktail therapy” treatment, the residual virus can hide in some immune cells [1], evading the recognition of the immune system.
Once the “cocktail therapy” treatment is stopped, the latent virus will “reappear” and “make waves”.
Although there is no definitive cure today, there have been two successful cases of AIDS in the past.
The two AIDS patients are also leukemia patients. Fortunately, they are:
They used chemotherapy drugs to treat leukemia, and the original immune cells in the body were almost eliminated, and then they transplanted bone marrow stem cells deficient in the CCR5 receptor to rebuild the immune system.
If the CCR5 receptor is likened to a lock on the cell, the HIV virus is the thief that can break the lock and enter the cell.
A defective CCR5 receptor is like a bad lock. If the HIV virus cannot be opened, it cannot enter cells, infect and multiply, and the disease will not recur.
However, very few people have defective CCR5 receptors, and the source of bone marrow stem cells for transplantation is very limited.
Only a very small number of people who can “match” successfully receive a transplant, otherwise immune rejection will occur.
Thus, these two AIDS patients are super lucky.
Source: Zhanku Hailuo
How does a cord blood transplant cure AIDS?
The current stem cell transplant patient is the third AIDS patient to be cured.
This is a 64-year-old woman diagnosed with HIV infection in 2013 and acute myeloid leukemia in 2017.
After treatment for leukemia, patients also need to transplant stem cells, but the transplants are umbilical cord blood stem cells, and most importantly, CCR5-deficient stem cells.
(Source: scbb.com)
14 months after cord blood transplant, HIV was no longer detectable in patient’s blood;
Three years after her cord blood transplant, doctors stopped her HIV treatment.
So far, the HIV virus in the patient has not “reappeared”, so the doctor judges that the patient has been cured.
Compared with bone marrow stem cells, the source of umbilical cord blood stem cells is more abundant, meaningIt means that more AIDS patients will have the opportunity to be cured.
It is worth mentioning that currently people with CCR5 deficiency are mainly of the Nordic race.
The woman being treated is of mixed race and is not a perfect “match”, which means she may be cured even if she is not of Nordic descent.
Extended knowledge:
In 2019, a study published in the “New England Journal of Medicine” by Professor Deng Hongkui’s research group and collaborating units of Peking University showed that by using CRISPR gene editing, the CCR5 The mutation can be used to treat AIDS patients [2].
Of course, this is only an exploratory study. Under the technical conditions at the time, the proportion of CCR5 mutations in the stem cells transplanted into patients was not high enough, so the purpose of curing could not be achieved. .
However, if this technical route is improved and verified by more clinical trials, it may actually be used to treat AIDS.
Can I use umbilical cord blood after I am born with AIDS?
When babies are born, hospitals ask parents if they want to keep cord blood.
Since the stem cells in the umbilical cord blood can treat AIDS, is there an additional reason to save the umbilical cord blood so that in case of unfortunate AIDS in the future, it can be treated with umbilical cord blood?
In fact, if you really carefully understand the case of umbilical cord blood curing AIDS, you will clearly realize this fact:
The stem cells in the umbilical cord blood of ordinary people have normal CCR5 receptors, so they will still be infected by HIV virus, which cannot achieve the purpose of curing AIDS.
It is almost impossible for Chinese people to have CCR5 deficiency, so it is impossible for everyone to save umbilical cord blood to treat AIDS under the current technical conditions.
Of course, if CRISPR technology matures in the future and can efficiently generate CCR5-mutated stem cells from umbilical cord blood, it may also be used to treat AIDS. However, this is only a possibility for now.
Because umbilical cord blood contains stem cells, it can be used for the treatment of some metabolic diseases, blood diseases, and immune diseases, but for ordinary people, the chance of actually using umbilical cord blood for treatment is very low.
It is estimated that for every 3,000 babies with stored cord blood, only one will have the opportunity to use their own stored cord blood in the future, which is a small probability event.
In contrast, the cost of storing umbilical cord blood is not cheap, so the “cost-effectiveness” of storing umbilical cord blood is very low.
However, if there is an opportunity, donating umbilical cord blood is a good choice. There is no loss for the baby and parents. The stem cells in the umbilical cord blood may also help those in need. .
References
[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.
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