Bone marrow is rich in glycine and conjugated linoleic acid, nutrients that reduce inflammation and lower the risk of heart disease, depression, arthritis and Alzheimer’s. It also contains platelets, which help blood clot and stop bleeding.
For an allogeneic transplant, doctors search donor registries for people who match your tissue type. The more your tissue types match, the easier it is for donated marrow to take hold and start producing new blood cells.
Bone marrow biopsies are done to look for cancerous cells and other abnormalities that may cause problems. Often, these tests are used to diagnose blood disorders such as leukemia and lymphoma. They also help doctors decide whether a person needs more tests, procedures or follow-up care.
Before the test, your healthcare provider will put a numbing cream on the biopsy site. Then the doctor will clean the area and insert a needle into the bone. They will either use a syringe to withdraw liquid marrow (aspiration) or they will remove a small piece of solid marrow (biopsy). For a biopsy, the doctor will use a different kind of needle than for an aspiration. Then they will put a bandage over the biopsy site. Your doctor may ask you to keep the bandage on for 24 hours or longer. You should not shower, bathe or swim until then. You should also avoid vigorous activity or exercise until then. If you have pain, your doctor may recommend a pain reliever such as acetaminophen or ibuprofen.
The procedure is done in a hospital or hematology clinic and usually is performed by a doctor who specializes in blood disorders, such as a hematologist or oncologist. A nurse, a phlebotomist and a laboratory technician may also be present to assist with the test.
You will lie on a table and the doctor will numb the area with a local anesthetic, usually in your hip bone. Children often need sedation before the test, especially when having a bone marrow biopsy.
After the test is over, your doctor will send the samples to a lab for analysis. A pathologist or hematologist will evaluate the samples to see if there are any abnormalities. The results of the biopsy are often available within a few days, but sometimes the results may take longer.
If the results show that a person has an abnormal type of cell, it can give the doctor clues about what’s causing the problem and how to treat it. For example, if the bone marrow shows suppressed red blood cell production (aplastic anemia), the doctor may be able to treat it with chemotherapy.
A bone marrow transplant, also called hematopoietic cell transplantation or a stem cell transplant, is used to treat leukemia, multiple myeloma cancer, lymphoma and other blood and immune system diseases. The transplant replaces diseased marrow with healthy marrow that produces blood cells. This treatment is sometimes combined with other therapies such as chemotherapy, radiation therapy or immunosuppression therapy.
The healthy marrow may come from your own bone marrow (autologous transplant), or it can be donated from another person (allogeneic transplant). Before the transplant, you will receive a treatment known as conditioning therapy. This includes high doses of chemotherapy and/or radiation. These treatments destroy cancer cells but also damage your bone marrow. To compensate for the damaged marrow, your body will produce extra healthy stem cells. These cells are the building blocks of blood cells.
During this treatment, your doctor will give you medications to prevent infection and reduce your immune system’s response to the transplant. This is done to protect you from complications such as graft-versus-host disease, in which the donor’s stem cells attack your body’s tissues and organs.
Your blood counts will be closely monitored after the transplant. When the new marrow takes over, your blood counts will go up and your disease should begin to go into remission. Your doctor will determine if the transplant was successful by looking at your blood counts again and by comparing them with the levels before your treatment.
Your marrow transplant will be an important part of your overall care at Mayo Clinic. You will work with a team of doctors and nurses who specialize in this treatment. We will help you make decisions about your care, including the type of transplant and how it is best given in your situation. We will also help you understand the risks of the procedure and what to expect. Many people with bone marrow transplants live normal lives after their transplants. They may experience some difficult days during the transplant process, but they also can enjoy their family, friends and hobbies. Many find support groups helpful.
The body uses stem cells to make new blood and bone cells. If the bone marrow is damaged by cancer or its treatment, stem cells can replace it. Stem cells are also able to kill cancerous cells and prevent them from spreading, or metastasizing, to other parts of the body.
Stem cells can differentiate into specialized cells of the blood, bone marrow, skin, and other tissues. They can also help repair wounds and other injuries. Stem cell therapy can also be used to treat autoimmune conditions, such as arthritis and Crohn’s disease.
Different types of stem cells have different abilities to differentiate into specialized cells. Stem cells that can create any type of cell are called pluripotent, or multipotent. Other types of stem cells can only specialize into cells of their own kind. Hematopoietic stem cells in the bone marrow give rise to red blood cells (erythrocytes), white blood cells (leukocytes), and platelets, which help with blood clotting after injury.
Healthcare professionals harvest hematopoietic stem cells from the bone marrow or from peripheral, or circulating, blood. They then freeze and store the stem cells until needed. Then, they thaw the stem cells and put them into the patient’s blood through a vein, just like a blood transfusion. The stem cells travel to the bone marrow and begin making blood cells, a process called engraftment. Healthcare professionals regularly check the patient’s blood to see if the new blood cells are working.
In a reduced intensity transplant, healthcare professionals lower the dose of chemotherapy and radiation before the stem cell infusion. This makes it easier for people with other health problems to receive a stem cell transplant.
Cord blood stem cells are allogeneic, meaning they come from a donor. Healthcare professionals remove these cells from the umbilical cord at birth and freeze them until needed for a transplant. They are very immature, so they don’t require a perfect match with the recipient. They have also been given to thousands of patients worldwide without any cases of rejection. The graft-versus-host reaction is also much less severe with these cells than with a traditional bone marrow transplant.
A cancer treatment called immunotherapy uses the body’s natural defenses to fight tumors. It may include bone marrow transplantation or a treatment that boosts your immune system, like BCG (Bacillus Calmette-Guerin), a type of bacteria that’s used to treat bladder cancer. Immunotherapy also includes medicines that target proteins on the surface of cells, which can stop tumors from growing or spreading.
Blood cells called lymphocytes help the body fight infection and disease. They start out as immature blood cells that develop in red bone marrow and mature in lymphatic tissues, such as the thymus gland, spleen, and lymph nodes. Lymphocytes produce natural antibodies that attack invading germs and destroy the microorganisms. They also trigger other white blood cells to kill cancerous and other abnormal cells.
Platelets, another type of blood cell, are necessary for the blood to clot at the site of an injury or wound. A low platelet count can cause the skin to bruise easily, and it increases your risk of internal bleeding at an accident site or after surgery.
Healthy bone marrow produces blood cells that help the body fight infection and disease. It also provides the stem cells that generate other types of blood cells as needed. A transplant can replace diseased, nonfunctioning bone marrow to restore normal blood cell production in conditions such as leukemia and some genetic blood disorders.
Healthcare professionals use a test called HLA typing to match patients with potential bone marrow donors. A donor’s blood and bone marrow must be a perfect match for the patient to have successful results.
If you have a disease that suppresses your immune system, such as an autoimmune disorder like lupus or rheumatoid arthritis, your transplanted marrow will have trouble producing enough healthy white blood cells to fight off an infection. Then you’ll need a more potent type of immunotherapy.
For example, a therapy called checkpoint inhibitors targets the proteins on the surface of T cells, which control the way they respond to cancerous or other cells. By blocking these receptors, immunotherapy lets your immune system “turn on” to kill cancerous cells and “turn off” so that it doesn’t damage healthy tissue.
Bone marrow tests check your blood cells for problems such as a low count of healthy red and white blood cells, or platelets (blood that helps your body clot). These tests include a bone marrow aspiration.
This involves a needle that withdraws liquid from a small area in the hipbone. You may feel a brief sharp pain.
Bone marrow is the spongy tissue inside the center of some bones. It makes blood cells that carry oxygen to other parts of the body, fight infection and stop bleeding by clotting. Bone marrow disorders like aplastic anemia, leukemia and multiple myeloma cause a decreased ability to make healthy blood cells. This can lead to fatigue, increased risk of infections, easy bruising or bleeding, and anemia.
A bone marrow biopsy is usually done while you are asleep using a sedative. A doctor inserts a syringe into the center of your bone and withdraws marrow. They will send the marrow to a laboratory to be analyzed. It may take a few days for the results to be available.
The marrow is tested for several things including abnormal cell types, the number of blood cells and if there are any cancerous cells present. The blood cells are checked for their ability to carry oxygen to your tissues and the number of platelets that help clot blood. The marrow is also tested for plasma cells, which are white blood cells that produce antibodies to fight bacteria and viruses.
If you have bone marrow cancer, your doctor will use the results of your tests and other information to diagnose it. Depending on the type of cancer, your treatment options may include chemotherapy, radiation or surgery.
If you are diagnosed with bone marrow cancer, it is important to talk with your family members and friends about how this diagnosis affects them emotionally. You can also join a support group to learn how others are dealing with this disease. It is important to maintain open communication with your healthcare provider to ensure you get the best care for yourself and your family.
Fatigue or weakness is a common complaint of patients who have bone marrow disease. The patient feels tired, despite rest or reduced activity. Fatigue can be a result of many things, including illness, overwork, poor sleep, worry, or medical treatment such as chemotherapy. The key to diagnosing these symptoms is a precise understanding of what the patient is saying. Specifically, is the fatigue a general feeling of weakness or a specific lack of muscle strength? In addition, it is important to determine whether the fatigue or weakness is independent of, or accompanied by, exertion.
Bone marrow is the spongy tissue at the centre of some bones that produces blood cells. It is important that this marrow functions properly to make white blood cells, red blood cells and platelets. These blood cells fight infections, carry oxygen and help the blood to clot. Aplastic anemia, which is a condition where the marrow cannot make these blood cells, causes weakness and can increase a patient’s risk of infection, bleeding or bruising.
If you are diagnosed with a bone marrow disorder, you will need a blood and urine sample to be sent to a laboratory for analysis. These tests will help to diagnose the cause of your bone marrow problem and decide on the best treatment. The doctor may give you a sedative during the bone marrow test and numb the area with a local anesthetic. It is essential that you follow the instructions your doctor gives you to prevent any complications. This includes not showering, bathing or swimming for 24 hours after the test. You should also tell your doctor about any medications or supplements that you are taking, as these can affect the results of the test.
The blood cells that control infection, heal wounds and deliver oxygen to the rest of the body are produced in the soft spongy tissue at the center of bones called bone marrow. Cancer and other blood disorders can affect the function of these cells. The most common types of cancer that develop in the bone marrow are leukemia and lymphoma. Noncancerous (non-malignant) blood disorders that can cause problems with the marrow include sickle cell disease and aplastic anemia.
Bone marrow infections are often difficult to diagnose. They can develop as the result of an injury or surgery that exposes the marrow to bacteria, such as a fractured bone. They can also occur if bacteria enters the bone through a crack, and then grows over time. These infections are called osteomyelitis.
When a bone gets infected, the area over it becomes painful and swollen with pus. This type of infection is sometimes difficult to distinguish from other types of bone injuries, such as septic arthritis or stress fractures in the spine.
A doctor can diagnose bone marrow edema by doing a physical exam and asking about your symptoms and medical history. They can also use an MRI to see how much fluid is collecting in the bone marrow. MRI is usually done along with other tests, such as blood tests to look for inflammation and DEXA scans to check for osteoporosis.
To test your bone marrow, doctors can perform two types of tests — aspiration and biopsy. In aspiration testing, your doctor takes a sample of the fluid inside your bones with a needle. They then examine the sample under a microscope to see whether your marrow is making normal blood cells.
Bleeding that occurs more easily than usual; spotting or blood in your stool; vomiting or passing bright red blood in your vomit; bleeding from the mouth, nose or eyes; or bloody diarrhea may be signs of bone marrow problems. Your doctor will order blood tests that check for easy clotting, as well as other blood cells. These include red and white blood cell counts, platelet counts, liver function tests and a hemoglobin test.
Bone marrow is the soft, spongy tissue in the center of some bones where blood cells are produced. If cancerous plasma cells in the bone marrow crowd out healthy blood cells, it can cause anemia, infection risk and bruising or bleeding. This is called aplastic anemia.
The CBC and a special test for leukemia (cancer of the white blood cells) may also be ordered to help diagnose a bone marrow problem. Leukemia is a type of cancer that starts in the bone marrow and spreads to other parts of the body. There are three main types of leukemia: acute lymphocytic, chronic myelogenous and acute myeloid leukemia.
If a tumor is found, a bone marrow aspiration and biopsy may be done to find out how serious it is. In this test, a needle is inserted into the hip bone and a sample of the liquid bone marrow is withdrawn. You may feel a brief, sharp pain. If the liquid marrow isn’t enough, a larger needle will be used to remove a sample of solid bone marrow (called a core biopsy). This requires a more painful procedure.
After the exam, you’ll be asked to lie on your back for 10 to 15 minutes, and then to keep the area dry until it stops hurting, usually within 24 hours. You can take a pain reliever such as acetaminophen (Tylenol) to ease discomfort. The samples will be sent to a laboratory for testing. A specialist in analyzing biopsies (a pathologist or hematologist) will look at the samples to see if your bone marrow is making enough blood cells and to look for abnormal cells.
The spongy material in the center of your bones is called bone marrow. It produces blood cells that carry oxygen, fight infection and help the blood clot. Some blood cancers and noncancerous diseases of the bone marrow cause symptoms like easy bruising and loss of appetite. Blood cancers that start in the bone marrow are called leukemia and lymphoma. Noncancerous conditions that affect the bone marrow include aplastic anemia and sickle cell disease.
If you have symptoms of bone marrow problems, talk to your doctor. He or she will check your blood count and order a bone marrow aspiration and biopsy. This involves taking a sample of fluid or solid tissue from the hip bone (bone marrow aspiration) or from your belly button (bone marrow biopsy). Your doctor may give you medicine to relax you before the procedure, and he or she will use a needle to take the samples.
These tests can tell your doctor if the bone marrow is healthy or not, whether it’s making enough blood cells or if it’s producing abnormal blood cells. They can also determine if the symptoms are caused by chemotherapy or other health problems.
Some bone marrow problems are caused by genetic mutations, such as Fanconi anemia and Pearson syndrome. Others are due to a viral illness or exposure to certain chemicals.
If you have an inherited bone marrow failure disorder, such as Fanconi anemia, your doctor will closely monitor you for changes in your symptoms and signs. They will do blood tests, a bone marrow aspiration/biopsy and other diagnostic testing. The tests will look for a low number of blood cells, which can lead to anemia or other diseases.
If the transplant uses stem cells from a donor (allogeneic), doctors find one that matches your blood type and shares other genetic traits. This can be a family member or an unrelated person found through the British Bone Marrow Registry.
Up to 10 days before the transplant, you’ll come into the hospital for an evaluation and a long, thin tube (catheter) placed in a large vein in your chest or neck. The catheter will stay in place for the duration of your treatment.
Apheresis is a procedure in which blood is separated into its various components, such as red blood cells, white blood cells and platelets. Only the desired component is collected, while the rest of the blood is returned to the donor or patient. Apheresis can be used for a number of therapeutic and diagnostic purposes, including treating hematologic, neurologic and other diseases. Plasma, red blood cell exchange and clotting factor apheresis are types of apheresis.
Platelet apheresis is a type of apheresis in which a patient’s blood is sent to a machine that separates it into its four different components: red blood cells, platelets, white blood cells and plasma. A rotating centrifuge or a rotating belt separates the blood into these components based on density. The platelets are then removed from the blood and stored. They can be transfused to patients who need them. Cancer and leukemia patients who have a compromised immune system benefit particularly from single donor platelet transfusions because they are less likely to react to the platelets.
Donors undergoing apheresis experience a number of side effects, but the vast majority of donors are comfortable during the procedure. Some people feel a slight tingling sensation around the lips and nose during donation due to the anticoagulant used in the process. Donors should not take any ACE inhibitor drugs prior to the apheresis procedure because they increase the risk of vasovagal problems during apheresis.
To ensure that apheresis procedures are being carried out safely and correctly, all clinical apheresis services should have a Quality Manager. This could be a full-time position dedicated to the apheresis service, or it may be an additional role in addition to other clinical duties. In either case, the Quality Manager should be able to demonstrate knowledge and competency of all critical aspects of the service. The Quality Manager should also have the authority to implement changes in the operation of the apheresis service to improve safety and efficacy. This includes reviewing SOPs, ensuring that staff understand them, and reporting incidents that occur (both those that result in harm to patients/donors and those that do not). In addition, all staff should have a written training record for each of the critical tasks relevant to their roles in the apheresis service.
The preparation regimen is a combination of chemical and physical agents that is given to the patient before transplantation. It is used to eliminate cancer cells (allogeneic HCT) or to allow engraftment of stem cells (autologous HCT). It can also be used to reduce the risk of complications from allogeneic HSCT, such as graft-versus-host disease. The intensity of the preparation regimen can vary depending on the condition being treated. The different levels of intensity are called myeloablative, reduced intensity, and non-myeloablative.
The choice of preparative regimen for a particular individual can be complex and is based on a number of factors including the underlying malignancy, the status of the person in remission (if a hematologic cancer), and the availability of syngeneic donors. Historically, most patients received a myeloablative conditioning regimen. Recently, improvements in preparative regimens have led to significant improvement in results with reduced intensity regimens and nonmyeloablative HSCTs.
It is important to be aware of potential long-term effects from the chemotherapy and radiation used for this procedure. These may include cataracts, delayed growth and development, sterility and second cancers. Your child’s doctors will explain these risks in detail to you.
A physical exam is done to make sure the body is healthy enough for the procedure. A small needle is inserted into the pelvic bone to get a sample of the bone marrow (see picture below). The marrow is then studied under a microscope by your doctor to determine if you are ready for the procedure.
If the doctor thinks you are a good candidate for the procedure, they will perform a bone marrow biopsy before starting the prep. The marrow is withdrawn from the pelvic bone with a needle and then sent to a lab to test for blood-forming cells, and to check for any signs of infection.
Before the marrow transplant, you will receive several days of radiation therapy to destroy any remaining cancer cells and to help your body accept the new bone marrow. This is usually performed at the Radiation Oncology Department. You will need to be very careful about what you eat and drink the day of the transplant. You should only drink CLEAR LIQUIDS: coffee, tea, water, carbonated beverages, white grape juice or white cranberry juice, Jell-O without fruit added, Gatorade and clear broth.
The hematopoietic stem cells that will be transplanted into the recipient need to grow and produce normal blood cells. To do this, the hematopoietic stem cell must survive the preparative regimen and the host’s immune system that would otherwise reject it. For leukemia, lymphoma and solid tumors that affect the bone marrow (or other organs), the goal is to control the cancer with the bone marrow/stem cell transplant and to achieve remission (i.e., no signs or symptoms of the disease).
The doctors may harvest stem cells from your bone marrow using a needle that they insert into your hip bone while you are under anesthesia. They can also obtain the stem cells from your blood by injecting drugs that stimulate the release of hematopoietic cells into the circulation. This is called apheresis.
If you are getting an allogeneic HSCT, your donor is someone else (typically a family member or close friend). Before giving the donated cells to the recipient, doctors give the donor several days of shots that help move stem cells out of the bone marrow into the bloodstream. This process is called leukapheresis.
On the day of your transplant, the hematopoietic marrow stem cells are given to you through a central line similar to a blood transfusion. The transplant is considered to be on the day of “Day 0,” but it may take weeks for the stem cells to grow and start producing healthy blood cells. Until this happens, you will need blood and platelet transfusions.
During this time, it’s important to follow a special diet and be extra careful to avoid infections as your immune system is not working. If the transplant is a success, your blood counts should start to rise and your cancer will stop growing or return to remission.
For patients with hematologic cancers, the most common outcome of an autologous hematopoietic stem cell transplant is remission, meaning that you do not have any signs or symptoms of your disease. A hematopoietic stem cell transplant may also cure certain types of cancers, including some leukemias and lymphomas.
Patients may require additional procedures after a transplant to ensure the organ is functioning properly. They may need blood work to be sure the transplanted kidney is receiving enough oxygen and nutrients to thrive. They must take anti-rejection (or immunosuppressant) drugs to prevent their bodies from rejecting the new kidney or other organs. These drugs weaken the body’s immune system, making infections more common. They also make the body more susceptible to certain diseases, such as skin cancer and heart disease. Patients will need to be monitored closely and frequently after transplantation for several weeks and should only travel to an approved transplant center.
Our transplant team will teach you how to take your medications properly and when to come in for checkups. We will help you set up appointments with your doctor and nurse, as well as a social worker and psychiatrist. We are available 24 hours a day, seven days a week to help you and answer your questions.
Patient-reported measures of treatment burden can help identify individuals at risk for nonadherence, which is associated with poorer clinical outcomes and higher health care costs. In addition, the measure can be used as a research tool to assess the impact of different approaches to post-transplant medication management.
A common problem after transplant is a type of rejection called chronic rejection. It can develop in a few days or weeks and can be very serious. It is most often caused by not taking your medications as prescribed. It is more likely to happen after a year of transplant, but can occur at any time.
If you experience signs of rejection, your transplant team can help you resolve it by increasing the dose or switching medications. The most important thing is to stay in contact with your doctor and keep your appointments.
Regular exercise can help you feel better after transplant. Walking, bicycling and swimming are good options. Talk to your doctor before starting an exercise program and be sure to check in with your team if you have questions or concerns.
Bone marrow is the soft, spongy tissue in the center of bones. It contains blood-forming stem cells that make red and white blood cells, and platelets.
There are 2 types of bone marrow transplants: Autologous and allogeneic. The marrow or stem cells come from another person, called a donor. A donor can be a sibling, parent or other relative, or someone who is not related and found through national bone marrow registries.
Bone marrow is the soft, spongy tissue inside most of our bones. It makes blood cells that carry oxygen to all parts of our bodies and help protect us from infection. Bone marrow contains stem cells that mature into blood and immune system cells.
The hematopoietic stem cells in bone marrow develop into red blood cells, white blood cells and platelets. The red blood cells bring oxygen to the tissues, and the white blood cells destroy bacteria and other foreign invaders to prevent infections. The platelets form clots in damaged blood vessels to stop bleeding. Bone marrow also produces granulocytes, which are specialized white blood cells that produce antibodies to fight disease.
Stem cells in bone marrow can be transplanted to other people through blood transfusions or to treat some diseases by injecting them into the body. When transplanted, the stem cells grow into healthy blood cells in a procedure called hematopoietic cell infusion. The hematopoietic stem cell transplants can then be used to replace or supplement the blood supply in patients with certain types of leukemia and other diseases.
Blood stem cells also can be donated to other people through a process called peripheral blood stem cell transplantation, or PBSCT. A person who wishes to donate his or her blood stem cells must be tested for compatibility with potential recipients. The testing involves checking the human leukocyte antigen (HLA) tissue in the blood. The HLA tissue determines the genetic makeup of a person’s immune system and is what doctors use to match donors with recipients.
When donating blood stem cells, the donor must be at least 18 years old and in good health. The donor’s doctor will review the medical history and perform a physical exam to determine whether the person is a good candidate for the procedure. The donor is required to sign a consent form and undergo laboratory tests, including a complete blood count and a bone marrow biopsy.
Before the test, the patient puts on a hospital gown and lies down on a table. The skin over the area that will be needled is cleaned with an antiseptic solution. The patient may receive a sedative, a mild medication that will make the patient relaxed and sleepy. The sedative may be administered through an IV or in pill form. The sample is taken from the back of the hip bone, called the ilium, or the sternum in adults.
Bone marrow is the soft, gelatinous tissue that fills the medullary cavities (the centers) of most bones. It contains two types of tissue: red bone marrow, which produces blood cells, and yellow bone marrow, which stores fatty tissue. Each type of marrow plays an important role in the body. Healthy bone marrow and blood cells are essential for life, but diseases that affect the function of the marrow can deprive the body of these vital substances.
The marrow is separated into vascular and non-vascular sections by a fibro-osseous meshwork of bone-forming cells, called stromal cells. The vascular section of the bone marrow contains a delicate, highly vascular network of tubes called sinusoids. These sinusoids communicate with arteries that enter the bone marrow through nutrient canals. These arteries connect to significantly larger veins that form the nutrient veins of the bone marrow. The sinusoids also communicate with the vascular system of the bone marrow through capillaries and blood vessels.
Hematopoietic stem cells in the red marrow produce red blood cells, white blood cells and platelets. Blood cells carry oxygen to the tissues of the body and help stop bleeding by clotting when a wound opens. White blood cells destroy bacteria and other foreign invaders in the body. Platelets help blood clot and prevent uncontrolled bleeding from damaged blood vessels.
Yellow bone marrow is home to mesenchymal stem cells, which are not blood-forming cells but can transform into cell types that form the body’s connective tissues like fat, cartilage and muscle. These cells are also known as marrow stromal cells or hematopoietic stromal cells.
In humans, the yellow marrow also produces lymphocytes that are part of the immune system and can destroy infectious microorganisms in the body. The lymphocytes mature in other lymphoid organs, including the thymus and the spleen.
During infancy, red bone marrow occupies the entire ossified skeleton except for the epiphyses and apophyses of long bones. As the body grows, it gradually converts the peripheral red marrow into yellow bone marrow, which is confined to the axial skeleton by 25 years of age.
The bone marrow is soft, spongy tissue that resides in the inner cavities (medulla) of the bones. The marrow produces blood cells and fat cells. It contains vascular and non-vascular sections. It is also divided into two types of cellular tissue: red and yellow.
The hematopoietic stem cells in red bone marrow produce red blood cells, platelets and early white blood cells. They also help obliterate old red blood cells and destroy foreign substances like parasites. Early white blood cells, called leukocytes or lymphocytes, begin formation in the bone marrow but mature into their final form in other parts of the immune system including the thymus and spleen.
Yellow bone marrow is fattier and contains mesenchymal stem cells or marrow stromal cell which are the stem cells that produce the body’s connective tissues such as cartilage, muscle and bone cells. They also store the body’s fats for energy. Yellow marrow is less vascular than red marrow.
Both types of marrow can be affected by disease which deprives other parts of the body of their life-giving blood cells. This includes diseases like leukemia which develop when the marrow is not producing normal blood cells. It may also be impacted by other diseases which impact the blood’s ability to carry oxygen and nutrients to other organs and tissues.
A diagnosis of a disease that affects the bone marrow may be determined by tests such as bone marrow aspiration and biopsy. In bone marrow aspiration, a hollow needle is inserted into the hip or sternum of an adult to extract liquid marrow that can then be examined under a microscope for abnormalities. A bone marrow biopsy uses a different type of needle to remove a solid core of bone tissue which is then fixed and thinly sliced to be examined under a microscope.
Individuals who have been diagnosed with a disease that is impacting the marrow are often looking for a matched donor to donate bone marrow. Those interested in volunteering can do so by signing up with several national and international registries that pair donors with recipients. It takes many thousands of people on a registry to find a match for an individual who needs bone marrow.
Bone is a natural composite material containing mineral and organic matrix components. The mineral component of bone is predominantly a highly compressed non-stoichiometric form of carbonated hydroxyapatite, Ca10(PO4)6(OH)2, which has compositional similarities to synthetic stoichiometric hydroxyapatite (HA) powder. Bone matrix is a complex polymer of collagen fibrils, proteoglycans and other biomacromolecules.
During bone remodeling, a constant balance between bone resorption and formation maintains bone density and strength. Osteoclasts break down a section of bone and osteoblasts enter the resulting space to secrete new mineral and protein. The process of breaking down and building up is coordinated so that the overall skeletal architecture adapts to changing loads, the concentration of calcium in extracellular fluids is maintained within a certain range, and reserves of phosphorus are replenished (1).
More than half the mass of bone is made up of a highly mineralized substance called hydroxyapatite crystals. This material gives bones their hardness and compressive strength. Most of the remainder of bone is a porous network of channels called Haversian canals. These channels provide pathways for blood vessels and nerves, and allow materials to be moved into and out of bone cells.
The organic part of bone is composed of a protein matrix woven together by collagen fibers. The most prevalent type of collagen in bone is type I collagen, which forms the inner scaffolding upon which the mineralized hydroxyapatite particles are deposited (1, 2). The remaining 10% of the organic matrix is composed of non-collagenous proteins, including members of the vitamin K-dependent gamma-carboxyglutamic acid (Gla)-containing protein family (2, 3).
Because the mineralization of bone depends on local phosphorus concentrations, a deficiency of this element results in impaired mineralization and an increased risk for osteoporosis (4, 5). However, because the normal dietary intake of phosphorus is much higher than the requirements, high dietary phosphorus levels do not appear to be associated with osteoporosis risk (6, 7).
Bone mineral density (BMD) refers to the amount of bone mineral per unit area of a defined section of bone. BMD is commonly measured in the spine and hip using dual-energy X-ray absorptiometry (DXA). It also can be measured by quantitative computed tomography, magnetic resonance imaging and ultrasound. Unlike DXA, QCT and ultrasound do not involve radiation and can be performed on patients of any age.