Friday, 23 December 2022

All about hematopoietic stem cell transplantation.


Hematopoietic stem cell transplantation (HSCT) is a treatment for some types of cancer and other diseases. Stem cells can come from blood or bone marrow.

Stem cells are non-differentiated cells. They can develop into various “specialist” cells in the body.

Doctors are already using stem cells in some treatments. With further research, expertsTrusted Source hope that stem cell transplantation will have more uses and lead to new treatments.

In this article, learn about the uses of stem cell transplantation and how it works.

Who donates stem cells?

Peripheral blood

Circulating blood contains stem cells, and a person with cancer may receive stem cells from their own blood after chemotherapy. There must be no cancer cells left in the body when the person has stem cell treatment.

Chemotherapy and radiation that targets bone marrow can remove stem cells from the area. So after treatment, it can help to reintroduce stem cells into the body. These new stem cells can take root without competition from cancer cells and help produce healthy blood.

This process, called autologous HSCT or “conditioning,” involves the following steps:

  • The person takes medication to stimulate stem cell production for around 4 days.
  • They have a blood test to check whether there are enough stem cells to harvest.
  • If there are, the person undergoes a process that involves drawing blood, which passes through a machine and reenters the body through the other arm.
  • This process takes about 3 hours, and the person remains awake.
  • The person may need to repeat the process the next day if too few cells were collected the first time.

Umbilical cord blood

Bone marrow

Complications for donors

HSCT for immune and neurological diseases

  • Researchers are looking into other uses of stem cell transplants. Because these cells have regenerative properties, they may help repair damaged tissues and treat diseases that involve nerve damage, for example.

    In one 2016 studyTrusted Source, people with severe MS experienced significant improvements after undergoing HSCT. Inflammation decreased, symptoms stopped worsening, and some people had better mobility.

    A 2017 review also supported the use of HSCT as an MS treatment and suggested that it might help treat other neurological and neuroinflammatory diseases, such as:

    • stiff person syndrome, which involves muscles stiffness and spasms
    • various peripheral neuropathies
    • myasthenia gravis

    Meanwhile, a 2019 reviewTrusted Source suggested that stem cells might help treat neurodegenerative diseases, such as Parkinson’s and Alzheimer’s, and might also support the healing of wounds, including those in dental tissue.

    The researchers note that while many obstacles remain, HSCT and other stem cell therapies might one day provide cures for a range of diseases.

How much blood is in the human body?

The amount of blood in a person’s body will depend on their age and size. Losing a certain amount of blood will not cause any harm to the body.

According to an older review article in Critical CareTrusted Source, blood accounts for:

  • approximately 7–8% of an adult’s body weight
  • approximately 8–9% of a child’s body weight
  • approximately 9–10% of an infant’s body weight

In this article, learn more about the average volume of blood in adults and children. Learn, too, what causes blood loss, how it affects the body, and what to do if it happens.

Severe bleeding can be dangerous. In medical terms, shock means that not enough oxygen is reaching tissues in the body. Low oxygen levels can cause damage to the brain and other organs.

If someone is losing blood, the body will start to direct blood toward the vital organs and away from the skin, fingers, and toes. A person may begin to look pale or feel numbness in their extremities.

According to a 2019 articleTrusted Source, when a person loses around 15% of their blood volume, they can start to experience shock, although their blood pressure and other signs will likely be normal at this point.

After losing 20–40%, the person’s blood pressure will start to fall, and they will begin to feel anxious. If they lose more blood, they will start to feel confused. Their heart rate may rise to around 120 beats per minute (bpm), as the body tries to maintain blood supply to the vital organs.

When blood loss is 40% or more, the person will be in severe shock. Their pulse rate will rise over 120 bpm. They will feel lethargic and may lose consciousness.

Causes of bleeding and shock

Getting help

Transfusions

The body makes around 2 million red blood cells per second. Blood cells develop from stem cells in the bone marrow. Stem cells are a type of cell that can create other cells. This process happens continually throughout a person’s life.

Blood consists of different parts:

  • Red blood cells carry oxygen and carbon dioxide.
  • White blood cells help defend the body against disease and infection.
  • Platelets help stop bleeding.
  • Plasma carries blood cells, platelets, and other components and supports the immune system. The American Red Cross state that it makes up 55% of blood and is 92% water.

The Red Cross also state that body takes around 24 hours to replace lost plasma, but 4–6 weeks to replace red blood cells.

Red blood cells get their color from hemoglobin, which contains iron. It can take several months for iron levels to return to normal after losing or donating blood. The Office of Dietary SupplementsTrusted Source note that frequent donors may have low levels of iron in their blood.

People who have experienced blood loss due to donation or another reason may benefit from:

  • drinking plenty of fluids, especially water
  • consuming iron-rich foods, such as beef liver and fortified foods

Many people now donate plasma. Are there any risks?

Around 7–8% of an adult’s body weight is blood. The body can easily replace a small amount of lost blood, which makes blood donation possible.

If a person loses around 15% or more of their blood, there may be a risk of shock. Anyone who has signs of significant internal or external bleeding should seek immediate medical help.

Source - Medical News Today


 


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