Myelosuppression

Question 1

What is myelosuppression?

Answer 1

Bone marrow suppression causing a decrease leukocytes, erythrocytes, and thrombocytes (platelets). It can caused by the disease or by the treatment.

Question 2

What biological therapies also cause myelosuppression?

Answer 2

Interferon and interleukin-2

Question 3

How can some malignancies cause myelosuppression?

Answer 3

1. Bone marrow infiltration - Malignancy infiltrates the bone marrow and replaces it, this can produce pancytopaenia (decrease in WBC, RBC and platelets).
2. Para-neoplastic syndromes - can result in pancytopaenia or single haemotopoiectic lineages

Question 4

What malignancies are associated with bone marrow infiltration?

Answer 4

Haemotological malignancies and certain solid cancers (breast, lung, prostate)
Successful anti-tumour therapy will lead to an improvement in the pancytopaenia

Question 5

What type of anaemia occurs in response to repeated chemotherapy treatment?

Answer 5

Macrocytic, but not megaloblastic

Question 6

What is a full investigation for myelosuppression?

Answer 6

Blood film, measurement of haematinics, bone marrow aspirate and trephine

Question 7

What happens when a patients haemoglobin falls below 10gldl?

Answer 7

Impaired QoL

Would benefit from a blood transfusion, or EPO injections

Question 8

What are the clinical signs of thrombocytopenia?

Answer 8

Petechial haemorrhage, spontaneous nosebleeds, corneal haemorrhage and haematuria

Question 9

What are the risks and treatment for a platelet count less than 10x109/L?

Answer 9

Significant risk of spontaneous bleeding, intra-cerebral haemorrhage, with irreversible disability.
Indication for urgent platelet transfusion

Question 10

A man has a platelet count between 10 and 20 and an infection, treatment?

Answer 10

Platelet transfusion still indicated, especially because of concurrent infection

Question 11

A man has a platelet count >20 and no spontaneous bleeding, treatment?

Answer 11

No - do not routinely need platelet transfusion

Question 12

Discuss the complications associated with repeated platelet/ blood product transfusions

Answer 12

Associated with the development of specific antibodies to blood cells, including platelets
Manifests as a failure to increase platelet counts immediately after transfusion
Suggests need for single donor or HLA matched platelets

Question 13

Describe some current research in myelosuppression

Answer 13

The role of colony-stimulating growth factors and EPO is investigated for a role in the prevention of myelosuppression
Thrombopoietic (a platelet growth factor) is being assessed