What is Bone Marrow?

Bones are vital structures that protect the body of living things and enable movement, consisting of bone, bone marrow and a connective tissue surrounding them. One of the most important functions of bones is blood production. So, what is bone marrow, which has an important place in blood formation? What are the types of bone marrow? For questions like these about bone marrow, you can review the rest of the article.

What is Bone Marrow?

Bones, which are an important part of the movement system; They are divided into types such as long, short, flat, irregular and pneumatic bones. The length of the bones in the skeletal system, such as the femur, hip bone, and sternum, is longer than the width. When the structure of long bones is examined, there is a long structure called diaphysis, a cavity and a hard compact structure surrounding this cavity. The nutritious and spongy structure found in the cavities inside long bones is called bone marrow. The most important function of the bone marrow is; producing blood cells and circulating them. Stem cells in the bone marrow play an active role in blood production. These produce red blood cells (red blood cells), white blood cells (white blood cells) and platelets according to the body’s needs. Stem cells have the ability to replicate and replicate themselves. The copied stem cells give rise to mature blood cells. Blood cells that have reached sufficient maturity also leave the bone marrow and enter the circulation when the time comes. There are three main types of cells in the bone marrow. These; They can be listed as stem cells, progenitor cells that enable the formation of different cell series, and mature blood cells that enter the blood circulation.

What are the Types of Bone Marrow?

Bone marrow is divided into two subclasses: yellow bone marrow and red bone marrow. Yellow bone marrow and red bone marrow both contain blood vessels. However, there are some differences between the two. Some of the differences between yellow and red bone marrow can be listed as follows:

• The main reason why the two subtypes of bone marrow are called yellow and red bone marrow is that the structures they contain are different. Red bone marrow gets its name from the erythrocytes and erythrocyte series it contains. Yellow bone marrow contains many fat cells; Therefore it is yellow in color.
• During the neonatal period, only red bone marrow is present in the organism. At approximately age 5-6, red bone marrow begins to turn into yellow bone marrow. In adults, approximately half the amount of bone marrow is red and half is yellow bone marrow.
• One of the most important differences between yellow and red bone marrow relates to blood production. While blood cells are made in the red bone marrow, no blood cells are made in the yellow bone marrow.
• Red bone marrow is involved in the destruction of erythrocytes and in the storage of iron resulting from destruction. In addition to the red bone marrow, iron is also stored in organs such as the liver and spleen. Yellow bone marrow works as a fat storage.
• In cases of excessive blood loss, the yellow bone marrow turns into red bone marrow and supports the blood production process of the organism.
• The production of undifferentiated T and B lymphocyte cells, which are carried to the central lymphoid organs through the blood, takes place in the red bone marrow. The production of lymphocytes in the bone marrow mostly occurs when there is damage or disease in any of the lymphoid system organs.

Bone Marrow Diseases

Since the bone marrow plays an active role in the production of blood cells, various blood-related diseases may occur if the bone marrow does not function properly. Major bone marrow diseases can be listed as follows:

• Multiple myeloma: Multiple myeloma or myeloma is a type of cancer that originates from plasma cells, which are white blood cells. In myeloma patients, the DNA of plasma cells is damaged. These damaged cells are called myeloma cells. Unlike other types of cancer, there is no tumor in myeloma cancer. In myeloma disease, myeloma cells multiply uncontrollably in the bone marrow.

• Sickle cell anemia: Inside the red blood cells, there are structures called hemoglobin whose function is to carry oxygen. For various reasons, anomaly develops in erythrocytes containing hemoglobin and these cells take on a sickle appearance.

• Mediterranean anemia (thalassemia): Mediterranean anemia is a blood disease that is common all over the world, especially in people living in the Mediterranean region. There is a structure called globin chain in the structure of hemoglobin. A defect in the structure of the globin chain causes less or no globin production. This condition is called Mediterranean anemia, that is, thalassemia.

• Lymphoma: Lymph cancer, also known as lymphoma, is a type of cancer that occurs as a result of the uncontrolled proliferation of lymphocytes in organs such as bone marrow, spleen and liver. Lymph cancer can be treated with treatment methods such as chemotherapy and radiotherapy, and bone marrow transplantation can also be life-saving when necessary.
• Leukemia: Leukemia, also known as blood cancer or bone marrow cancer, is a type of cancer that occurs as a result of the uncontrolled proliferation of cells called myeloid and lymphoid in the white blood cells produced in the bone marrow.

What is Bone Marrow Transplantation and How is it Done?

Bone marrow transplant, also known as stem cell transplant; It is one of the treatment methods used in the treatment of diseases such as Mediterranean anemia, lymphoma and leukemia. While previously bone marrow transplantation and stem cell transplantation could be used interchangeably because only bone marrow was used to collect stem cells, today the stem cell source can also be the patient himself. This is called autologous stem cell transplant. Bone marrow transplantation usually requires a healthy donor. The process of transplanting bone marrow from a healthy donor to the patient intravenously is called bone marrow transplantation. If the main stem cells taken from the donor adapt to the patient, the new blood production process begins in the patient. General anesthesia is used during bone marrow transplantation. Doctors who are experts in their field enter the donor’s bone with the help of special needles in a sterile operating room environment and the bone marrow is drawn into the syringe. The main stem cells taken from the donor are placed in a special bag and transferred to the patient intravenously without delay. After a successful bone marrow transplant, healthy blood production begins in the patient within approximately 3 weeks. To increase the likelihood of bone marrow transplantation compatibility with the recipient, the patient is kept under control with various treatments for approximately 6 months.

Frequently Asked Questions About Bone Marrow Transplantation

Who can be a bone marrow primary-stem cell donor?

The success of bone marrow transplantation is directly proportional to the suitability of the donor. Therefore, there are certain criteria for being a bone marrow donor. Siblings with suitable tissue groups, other relatives with whom they are rarely related by blood, other people with suitable tissue groups but not blood relatives, and the patient himself can be donors in bone marrow transplantation. In addition, the patient’s own bone marrow, which was collected and stored when he was healthy, can also be given to the patient during transplantation. In some cases, it is possible to collect stem cells from the umbilical cord blood of the newborn sibling.

Are there any side effects of bone marrow transplant?

Bone marrow transplantation has very mild side effects for the donor. These side effects can include complications such as weakness, fatigue, pain in the spleen area, fever and cold. For the recipient, serious complications may occur before and after bone marrow transplantation. The main complication is that the patient’s body rejects the stem cells. Immune cells produced by the bone marrow may consider the patient’s own tissues and organs as a foreign agent and begin to attack them.

What should be taken into consideration after bone marrow transplantation?

After bone marrow transplantation, it is important for patients to see a doctor regularly. In addition, they should take care to eat a healthy and balanced diet, do light exercises, and stay away from harmful habits such as tobacco products.