Leukemia is a cancer of the blood cells, it starts when normal healthy blood cells change and grow uncontrollably.
About Blood Cells
Blood cells form in the bone marrow, the red, spongy tissue inside the long bones in the body. Changes in the bone marrow cells can result in too few or too many specific blood cells. There are different types of blood cells –
- White blood cells that fight infection
- Red blood cells that carry oxygen throughout the body
- Platelets that help the blood to clot
Types of leukemia get their name after specific blood cells that become cancerous, like the myeloid or lymphoid cells. Lymphoid cells are the type of white blood cell (WBC), and myeloid cells are bone marrow cells that turn into cells fighting bacterial infections.
A T-cell is a white blood cell that directly helps the body’s immune system fight infection.
Subtypes of T-cell leukemia
The subtypes of T-cell leukemia include –
- Large granular lymphocytic leukemia (LGLL) – LGLL is slow-growing T-cell leukemia. It is more common in women than in men and the cause of LGLL is not known. However, around 30% of people having LGLL also have rheumatoid arthritis, it is a chronic disease causing swelling in the feet, hands, knees, wrists, hips, or shoulders. Also, nearly 50% of patients with LGLL have a genetic change in either a gene called STAT3 or another called STAT5B.
- T-cell prolymphocytic leukemia (T-PLL) – T-PLL is an aggressive subtype of CLL. It is the most common mature T-cell leukemia in adults, it is more common in older men, but women can also develop T-PLL. It can affect the skin, but differently than Sezary syndrome. Patients with T-PLL mostly have genetic changes to their T-cells called a T-cell receptor rearrangement linked to abnormal T-cell growth, this type of gene change happens due to damage to the genes during a person’s life, it is not inherited from parent to child.
- Adult T-cell leukemia/lymphoma (ATLL) – ATLL has four subtypes. The different features are subclassified as smoldering, acute, chronic, or adult T-cell lymphoma. Lymphoma is the cancer of the lymph system. The adult and the acute T-cell lymphoma subtypes proliferate. The main cause of ATLL is a retrovirus which is the human T-cell leukemia virus (HTLV1).
Sezary syndrome – Sezary syndrome is a type of mycosis fungoides, T-cell lymphoma that happens only on the skin. This syndrome is typically slow-growing and takes several years to develop from mycosis fungoides, sezary syndrome is usually diagnosed when there are large numbers of lymphoma cells in the blood, often together with reddening of the skin. This is erythroderma.