Cancer month: Leukaemia

Dr Frank Owusu-Sekyere Lifestyle Oct - 05 - 2022 , 12:51

Most blood cells develop from cells in the bone marrow called stem cells. The stem cells mature into the different kinds of blood cells, each specialised to perform a special function. White blood cells, red blood cells, and platelets are made from these stem cells in the marrow as the body needs them.

White blood cells help to fight infection and there are several types of them- neutrophils, lymphocytes, monocytes and eosinophils. Red blood cells carry oxygen to tissues throughout the body and platelets help to form blood clots that control bleeding. When these cells grow old or get damaged, they die, and new ones are produced to take their place.

The white blood cells are formed from two immature cell lines, myeloid (mature to form other white cells such as neutrophils) and lymphoid blasts (mature to form the lymphocytes). Those that form from myeloid blasts are different from the white blood cells that form from lymphoid blasts. In a person with leukemia, the bone marrow makes abnormal white blood cells. These abnormal cells are known as leukemic cells.

Unlike normal blood cells, leukemic cells don't die when they should. They may crowd out normal white blood cells, red blood cells, and platelets leading to reduced numbers of these normal cells and consequently limit the function of these normal cells. This makes it hard for normal blood cells to do their work.

Leukemia can be grouped based on how quickly the disease develops and worsens. Leukemia is either chronic (which usually gets worse slowly) or acute (which usually worsens quickly)

Chronic leukemia: Early in the disease, people with chronic leukemia may not have any symptoms at first and are usually picked up during routine checkups. This is because some of the leukemic cells can still do some of the work of normal white blood cells. Slowly, chronic leukemia gets worse. As the number of leukemia cells in the blood increases, symptoms, such as lymph node swellings or infections become manifest. When symptoms do appear, they are usually mild at first and get worse gradually.

Acute leukemia: Here the leukemic cells cannot do any of the work of normal white blood cells. The number of these leukaemic cells increases rapidly and usually worsens quickly. As a result, symptoms also develop rapidly.
Besides this classification, leukemia can also be grouped based on the type of white blood cell affected. Leukemia can start in lymphoid cells or myeloid cells. Leukemia that affects lymphoid cells is called lymphoid, lymphocytic, or lymphoblastic leukemia. When the myeloid cell line is affected, it is called myeloid, myelogenous, or myeloblastic leukemia.
Based on the appearance of the cells, there are four common types of leukemia:

Chronic lymphocytic leukemia (CLL) which affects lymphoid cells and usually grow slowly. Most often, people diagnosed with the disease are over age 55 years. It almost never affects children.
Chronic myeloid leukemia (CML) affects myeloid cells and usually grow slowly at first. It also mainly affects adults.
Acute lymphoblastic leukemia (ALL) affects lymphoid cells and grow quickly. ALL is the most common type of leukemia in young children. It can also affect adults as well.