Leukaemia - Chronic Myeloid Leukaemia

Question 1

Cytogenetic Change in CML (3).

Answer 1

1. Philadelphia Chromosome - Translocation of Genes Between 9 and 22 (95% of cases).
2. ABL Proto-Oncogene (9) fuses with BCR gene (22).
3. Fusion Protein with Excessive Tyrosine Kinase Activity.

Question 2

Phases of Chronic Myeloid Leukaemia (3).

Answer 2

1. Chronic Phase (up to 5 years).
2. Accelerated Phase.
3. Blast Phase.

Question 3

What happens in the Chronic Phase (2)?

Answer 3

1. Asymptomatic.
2. Diagnosis with a Raised WCC.

Question 4

What happens in the Accelerated Phase (2)?

Answer 4

1. Abnormal Blast cells take up a high proportion of cells in the bone marrow and blood (10-20%).
2. Symptomatic e.g. Anaemia, Thrombocytopenia, Immunocompromise.

Question 5

What happens in the Blast Phase? (2)

Answer 5

1. Even higher proportion of blast cells in blood (>30%).
2. Severe Symptoms and Pancytopenia.

Question 6

Unique Clinical Features of CML (5).

Answer 6

1. Massive Splenomegaly.
2. Increase in Granulocytes at Different Stages of Maturation.
3. Thrombocytosis.
4. Decreased Leukocyte ALP.
5. Gout.

Question 7

Investigations in CML.

Answer 7

Bloods : Leukocytosis (Raised Myeloid Cells).

Question 8

Management of CML.

Answer 8

1. 1st Line - Imatinib.
2. Hydroxyurea.
3. INF-a.
4. Allogenic Bone Marrow Transplant.

Question 9

What is Imatinib?

Answer 9

An inhibitor of the Tyrosine Kinase associated with the BCR-ABL defect.