Myeloid cells are immature precursor cells of blood cells other than lymphocytes that are present in the bone marrow. They mature into various blood cells – red blood cells, platelets and myeloblasts (immature white blood cells except lymphocytes). Acute myeloid leukaemia is an aggressive cancer in which there are too many immature white blood cells (myeloblasts) in the blood. The accumulation of myeloblasts in the bone marrow also leads to a drop in red blood cells, platelets and normal white blood cells. Acute myeloid leukaemia is the most common type of acute leukaemia in adults.
Risk factors are some genetic problems, exposure to high levels of radiation, chemotherapy drugs, smoking, exposure to certain chemicals such as benzene and pre-existing blood disorders. The cancer usually does not present with any symptoms at first and may be found by chance during a blood test. Symptoms usually begin slowly. But as the immature white blood cells increase in the blood the symptoms quickly get severe. Susceptibility to infection increases because the white blood cells are less effective at fighting bacteria and viruses. Also, a decrease in red blood cells or platelets can cause anaemia and chances of excessive bleeding.
It is diagnosed by blood test and bone marrow biopsy. Lymph node biopsy establishes how far the leukaemia has spread. Once diagnosed, it requires immediate treatment because it progresses rapidly and aggressively. Patients go into ‘remission’ or periods of no symptoms with treatment. Regular blood transfusions and radiotherapy may also be needed. Scientists have discovered a Brg1 gene that can turn off leukaemia stem cells – making it a promising therapeutic target in leukaemia treatment.