Chronic myeloid leukemia (CML) is a malignant disease of the hematopoietic system and belongs to the group of myeloproliferative neoplasias. There is an unrestrained proliferation of myeloid cells, especially granulocytes.
The disease typically runs in three phases. Mostly the disease is diagnosed in the chronic phase. This is associated with a leukocytosis with pathological left shift and nonspecific symptoms and may persist for many years.
In the acceleration phase, the general condition of the patients worsens and is characterized by symptoms that result from the displacement of the other cell lines (coagulation disorders, anemia, susceptibility to infection).
The blast crisis resembles the picture of acute leukemia and represents the final stage of CML. The massive overproduction of dysfunctional blasts in the bone marrow and their flushing into the peripheral blood lead to death within a few weeks if left untreated.
More than 90% of CML patients have a specific chromosome aberration, the so-called Philadelphia chromosome. This is a reciprocal translocation between chromosomes 9 and 22. The translocation leads to the formation of a fusion protein (BCR-ABL). which leads to an excessive tyrosine kinase activity and thus proliferates proliferating.
Imatinib, the selective BCR-ABL tyrosine kinase inhibitor, represents the most important therapeutic approach. This therapeutic option has revolutionized the treatment of CML and greatly improved the prognosis of patients.