T-cell acute lymphoblastic leukaemia (T-ALL) is a type of acute leukaemia that is aggressive and progresses quickly. It affects the lymphoid cell-producing stem cells, in particular a type of white blood cell called T lymphocytes, as opposed to acute lymphoblastic leukaemia (ALL), which commonly affects B lymphocytes. A lymphoid stem cell becomes a lymphoblast cell and then one of three types of lymphocytes (white blood cells):
- B lymphocytes that make antibodies to help fight infection.
- T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
- Natural killer cells that attack cancer cells and viruses.
There are no specific signs or symptoms that would allow a T-ALL diagnosis to be made. The most common signs and symptoms are caused by the bone marrow being unable to produce enough normal blood cells. T-ALL often causes swollen lymph nodes in the middle part of the chest (mediastinum) which may affect breathing and circulation. The results of a simple blood count will usually indicate leukaemia, although in rare cases a blood count may be normal even though leukaemia is present. Virtually all patients with T-ALL will have bone marrow samples taken to confirm the diagnosis and to help to determine exactly what type of leukaemia is present.
The main ways in which leukaemia is treated are:
- Chemotherapy – Cell-killing drugs. Steroids are normally used along with chemotherapy for T-ALL
- Radiation therapy – Usually only given in conjunction with a stem cell transplant in T-ALL
- Stem cell transplant – Younger/fitter patients may be given a stem cell transplant (bone marrow transplant). This is done using healthy stem cells from a donor. This is also done for T-ALL if chemotherapy does not cure the disease
