Leukemia is a group of blood cancers that start in the bone marrow. The bone marrow is a soft spongy tissue found in the centre of bone. Bone marrow normally manufactures and contain hematopoietic stem cells which produce white and red blood cells. Red cells are important for transporting oxygen around the body and the different types of white cells make up our immune system and help us fight off infections.

In leukemia, the stem cells produced are abnormal; called leukemia cells or leukemia blasts, they are not fully developed and can not fight off infection.

The type of leukemia depends on both the type of blood cells that become cancerous, and the speed at which the cells multiply, If they multiply slowly, the disease is known as chronic. If they multiply quickly, the disease is know as acute. Furthermore, the types of cells that are cancerous also defines the subtype of leukemia. Abnormal growth of stem cells that become immune cells, known as lymphocytes, is called Lymphocytic leukemia. Whereas, abnormal growth of cells that would have become red blood cells, other white blood cells and platelets is known as myelogenus (myeloid) leukemia.

Together, these abnormalities give rise to four types of leukemia:

• Acute Lymphocytic Leukemia (ALL)
• Acute Myeloid Leukemia (AML)
• Chronic Lymphocytic Leukemia (CLL)
• Chronic Myeloid Leukemia (CML)

Jibraan was diagnosed with Acute Myeloid Leukemia (AML) in August 2024.

When the abnormal hematopoietic stem cells multiply rapid, they effectively fill up the available space in the bone marrow. When fully occupied, the bone marrow’s manufacturing process is suppressed, which means that the signals that the bone marrow send to healthy stem cells to mature into a specific type of blood cell stops. This means that no healthy blood cells are produced, yet the leukemia blasts continue to multiply.

Chemotherapy treatment for leukemia is designed to kill all the hematopoietic stem cells and mature blood cells in the bone marrow, creating space, and allowing the bone marrow to produce new blood cells. Since the original mutated cells are also killed, the treatment relies on the bone marrow producing the correct, functional, non-mutated blood cells. However, whilst the treatment works to kill the mutated cells, it also kills any healthy white blood cells. This means between the time of receiving the chemotherapy and the bone marrow producing new cells (around 21-28 days), the patient has no infection fighting capabilities at all – a condition known as leukopenia (having no white blood cells). When considering the ability to fight off bacterial infections, the lack of a specific type of white blood cell called neutrophils is called neutropenia.