General public

What is Multiple Myeloma?

Multiple Myeloma is a white blood cells type of cancer. A tumor arises when cells divide and growth out of any control. A tumor is benign when cells do not invade other tissues. In general, benign tumors are not life threatening. If the tumor cells spread into the body and invade other tissues, then the tumor is called malign and can threat the life of the patient. The cells usually spread via the blood circulation or the lymph channels. The organ of origin of a cancer is usually known but the exact causes leading to uncontrolled growth is not always defined for a single patient. Cells contain chromosomes, their genetic material, localized in the nucleus. Changes (mutations) appearing into the chromosomes and consequently into the individual’s genes may lead to abnormal growth of the cells. These mutations may be inherited or induced by external factors (sun light, chemicals, cigarette, etc…).

Multiple Myeloma affects plasma cells that belong to the immune system. The immune system is composed of several types of cells that work together to fight infections and other diseases. Lymphocytes are the main cell type of the immune system. There are 2 major types of lymphocytes: T cells and B cells. When B cells respond to an infection, they mature and change into plasma cells. Plasma cells produce antibodies that help the body attack and kill germs. T Cells mediate the cellular response against infection: when a cell is infected by a virus, the T cell will recognize the infected cell and kill it via apoptosis. Lymphocytes can be found in many areas of the body, such as lymph nodes, the bone marrow, and the bloodstream. Plasma cells, however, are mainly found in the bone marrow. Bone marrow is the soft tissue inside some hollow bones.

When plasma cells become cancerous and grow out of control, they can produce a tumor called a plasmacytoma. These tumors generally develop in a bone, but they are also rarely found in other tissues. If there is only a single plasma cell tumor, it is called an isolated plasmacytoma. When there is more than one plasma cell tumor, it is called multiple myeloma. The accumulation of one type of plasma cells and the over production of a single antibody, lead to serious medical problems. Myeloma cells interfere with cells that help keep the bones strong. The cells that lay down new bone are called osteoblasts. The cells that break down old bone are called osteoclasts. Myeloma cells make a substance that tells the osteoclasts to speed up dissolving the bone. Since the osteoblasts do not get a signal to put down new bone, old bone is broken down without new bone to replace it. This makes the bones weak and they break easily. Fractured bones are a major problem in people with myeloma. Another consequence of damaged bones is the release of calcium into the blood leading to hypocalcaemia. This lead to appetite lost, nausea, thirst, fatigue, muscle weakness, restlessness and confusion. Myeloma cells may also prevent other plasma cells to develop leading to an increase of infections. They also may prevent erythrocytes to be produced leading to patient’s anemia. Multiple myeloma can also cause the level of platelets in the blood to become low (called thrombocytopenia). This can lead to increased bleeding and bruising. Moreover, the high quantity of calcium and antibodies into the blood affect the good functioning of the kidney having serious consequences on the health of the patient.

Multiple Myeloma is quite hard to cure. But the treatments can improve the quality of life of the patients by controlling the symptoms and the complications of the disease.


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