I. What is bone marrow?
Bone marrow is a spongy tissue that exists in the marrow cavity of long bones (e.g. humerus, femur) and in the mesh between the sparse bone of flat bones (e.g. iliac bone). The bone marrow that produces blood cells is slightly red and is called red marrow. At birth, red bone marrow fills the bone marrow cavity throughout the body. As people age, fat cells increase and a significant portion of the red bone marrow is replaced by yellow bone marrow, and eventually almost only the flat bone marrow cavity contains red bone marrow. This change may be due to the fact that adults do not need all of the bone marrow cavity for blood production, and some of the bone marrow cavity for blood production is sufficient to replenish the required blood cells. When the body is severely deprived of blood, some of the yellow bone marrow can be replaced by red bone marrow, and the hematopoietic capacity of the bone marrow is significantly increased.
How much bone marrow is there in the human body?
The amount of bone marrow in the human body is related to body weight and other factors, and the amount of bone marrow in adults is generally about 3 kg.
What is hematopoietic stem cell? Can it be regenerated?
Hematopoietic stem cells are a type of cells that can renew themselves, have strong differentiation and regeneration ability, and can produce various types of blood cells. Hematopoietic stem cells originate from red bone marrow and can migrate to the peripheral blood circulation through the blood stream, and the hematopoietic function will not be damaged by blood donation or hematopoietic stem cell donation.
IV. What is hematopoietic stem cell transplantation?
Hematopoietic stem cells from normal people are infused into the patient’s body through intravenous infusion to rebuild the patient’s hematopoietic and immune functions for the purpose of treating certain diseases, and this process is called hematopoietic stem cell transplantation.
V. What is the classification of hematopoietic stem cell transplantation?
According to the source of hematopoietic stem cells, there are bone marrow hematopoietic stem cell transplantation, peripheral blood hematopoietic stem cell transplantation and cord blood hematopoietic stem cell transplantation.
What diseases can hematopoietic stem cell transplantation treat?
Hematopoietic stem cell transplantation can be used to treat tumor diseases such as leukemia and certain malignant solid tumors, as well as non-tumor diseases such as aplastic anemia, severe immunodeficiency disease, acute radiation sickness, thalassemia, etc.
7.Does the donation of blood stem cells affect my health?
The hematopoietic stem cells in the human body have a strong regenerative capacity. Under normal circumstances, all kinds of cells in human body are metabolized every day, and the cycle of generation, aging and death is repeated. The following two main methods are introduced.
1. Bone marrow stem cell extraction: The donor is under general anesthesia or local anesthesia, and bone marrow blood is extracted from the donor’s iliac bone.
2. Collection of stem cells from peripheral blood: The donor is injected with mobilizer and blood component mono-collection is performed to collect blood stem cells from the donor’s peripheral blood.
The collection method advocated by the China Blood Stem Cell Donor Database is to collect HSCs from peripheral blood. The HSCs are collected from the donor’s arm veins, and the HSCs are extracted through a blood cell separator, while other blood components are returned to the donor.
So far, there are no reports of donor harm caused by the collection of peripheral blood stem cells.
XI. How much blood stem cells do donors need to collect?
Approximately 10 grams of blood stem cells need to be collected.
XII. Why is it necessary to use blood stem cell mobilizer drugs for donors before collecting blood stem cells? Are there any side effects on human body?
Under normal physiological conditions, the amount of hematopoietic stem cells in peripheral blood is very small and cannot meet the needs of transplantation. After mobilization, the drug accelerates the production of bone marrow hematopoietic stem cells and releases them into peripheral blood, which can increase peripheral blood hematopoietic stem cells by 20-30 times to meet the needs of transplantation. According to years of clinical observation and current international reports, drug mobilizers have no side effects on human health.
XIII. What is HLA and what is its role in hematopoietic stem cell transplantation?
HLA is Human Leucocyte Antigen, which exists on the surface of various nucleated cells in human body. It is the biological “identity card” of the human body, inherited from parents; it can recognize “self” and “non-self” and eliminate “non-self” through immune response, thus maintaining the integrity of the individual. It can recognize “self” and “non-self” and exclude “non-self” through immune response, thus maintaining the integrity of the individual. Therefore, HLA plays an important role in the success or failure of HSCT, and HSCT requires HLA matching between the donor and the transplant recipient.
Why do donors and patients need HLA typing?
Since the HLA of different races and individuals are very different, certain methods must be used to determine the HLA type of the donor and the patient, so that the donor who matches the HLA of the patient can be selected for transplantation, which is the key to successful HSCT treatment.
XV. What is the HLA compatibility rate of siblings?
It is 100% for identical (homozygous) twin siblings and 1/4 for non-identical (heterozygous) twin or biological siblings.
XVI. What are consanguinity and non-consanguinity?
Blood relationship refers to siblings, parents, cousins; non-blood relationship refers to those who do not have any blood relationship with the patient.
XVII. What is the HLA match rate between non-related donors and patients?
The HLA compatibility rate of human non-blood relatives is 1 in 400-10,000, and in the rarer HLA types, the chance of compatibility is only 1 in tens or even hundreds of thousands. Due to the prevalence of one-child families, the number of people with high compatibility rates has decreased, and future transplants will rely primarily on finding matches among unrelated donors.