piotrzurek.net

Since my last post I’ve received a great deal of support from a lot of people but also a lot of questions about what’s exactly going on. How does CML (Chronic Myeloid Leukemia) work and how do you get it? Of course, it’s almost impossible to say what causes it but it seems like we know pretty well how it works, so below is a simple compilation of facts and pictures that I’ve found all around the internet.

Every cell in the body has a nucleus that contains chromosomes. To be more specific, 23 pairs of chromosomes.

The most important cause of CML is a translocation of two of them: chromosome 9 (the ABL gene) and chromosome 22 (the BCR gene).

During the division of the cells, these two chromosomes criss-cross, break, and fuse to each other. In doing so, they create so called Philadelphia chromosome.

Philadelphia chromosome is made up of two parts and is also called BCR-ABL.

This new gene produces a specific new protein called tyrosine kinase.

Tyrosine kinase stimulates uncontrolled production of abnormal blood cells by the bone marrow.

Normally, white blood cells grow and divide in an orderly and controlled way, but in leukemia the process gets out of control and the cells divide too quickly, and do not mature. In CML, too many myeloid cells (one of the main types of white blood cells) are produced. The myeloid cells are released into the blood when they are immature and unable to work properly. These immature white blood cells are known as blasts. The immature cells fill up the bone marrow and prevent it from making blood cells properly. As the leukemia cells do not mature, they can’t do the work of normal white blood cells, which leads to an increased risk of infection. Because the bone marrow is overcrowded with immature white cells it also can’t make enough healthy red cells and platelets.

As you can imagine that causes all sorts of problems but that is a story for completely different post…