Week 4- Blood Cell Abnormalities

Question 1

What is anaemia?

Answer 1

A reduction in the volume of total haemoglobin in a given volume of blood leading to reduced haemoglobin concentration, reduced RBC and Hct/PCV

Question 2

What are some mechanisms by which anaemia arises?

Answer 2

Loss of blood from body
Reduced RBC synthesis in bone marrow
Reduced survival of RBCs in circulation
Pooling of RBCs in spleen

Question 3

What is the cause of anaemia?

Answer 3

Iron deficiency

Question 4

What is the name of the inherited condition that leads to reduced globin synthesis?

Answer 4

Thalassemia

Question 5

What are the 2 main types of anaemia?

Answer 5

Microcytic and macrocytic

Question 6

What are the causes of microcytic anaemia?

Answer 6

Reduced iron intake, heavy periods, haemorrage

Question 7

What are the causes of macrocyctic anaemia and how is this visible in blood films?

Answer 7

Due to over production of haemoglobin but failure of the nucleus to develop/divide properly

Main cause is megaloblastic erythropoiesis caused by B12/folate defiency, other causes include drugs that interfere w DNA synthesis, liver disease etc

Visible in blood films as tear drop shaped cells, hyper-segmented nuclei and oval macrocytes

Question 8

What is polycythemia? Describe the 2 types

Answer 8

Over production of RBCs leading to higher volume of RBCs in circulation

Pseudo: when total plasma volume falls
True: higher actual volume of RBCs

Question 9

What are the mechanisms of polycythaemia?

Answer 9

1. Unnatural increase in erythropoietin eg doping/drugs
2. Natural increase in erythropoietin eg living at high altitude
3. Indépendant of erythropoietin: polycythaemia Vera

Question 10

What is polycythemia vera?

Answer 10

A myloproliferative neoplasm where there is excessive production of RBCs leading to viscous blood that increases risk of obstruction and thrombosis

Question 11

What is leukemia?

Answer 11

Bone marrow disease- not everyone has abnormal cells

Due to mutations in lymphoid or myeloid cells

Question 12

Why is leukemia different from other cancers?

Answer 12

Haemopoeitic and lymphoid stem cells can circulate in blood so it would be incorrect to use ‘benign’ or ‘metastatic’ as all cells can enter other tissues

Question 13

How are leukaemia classed and what are the 2 lineages and 4 different types?

Answer 13

‘Benign’ leukaemias are known as chronic: they persist for a long time
‘Metastatic’ leukaemias are known as acute: they are very aggressive and cannot be left untreated

Lineages are either from lymphoid cells (B/T/NK cells) or myeloid (granulocytic, megakaryocytic, erythroid or monocytic)

Therefore the 4 types are 
Acute lymphoblastic
Acute myeloid
Chronic lymphocytic 
Chronic myeloid

Question 14

How might people get leukaemia?

Answer 14

Loss of tumor suppressor gene, mutation in protooncogene, gene brought under the influence of an active promoter during translocation

Question 15

What happens in acute myeloid leukaemia?

Answer 15

Cells proliferate but don’t mature

Reduced production of neutrophils, monocytes, platelets etc

Question 16

What happens to the blood in acute lymphoblastic leukaemia?

Answer 16

Increase in number of very immature cells (lymphoblasts)

Leucopenia, anaemia, thrombocytopenia

Question 17

What happens in chronic lymphocytic leukaemia?

Answer 17

Mature cells that are abnormal are present (B/T/NK cells)

Question 18

What happens genetically in chronic myeloid leukaemia?

Answer 18

Translocation between chromosomes 9 and 22 leading to the formation of gene BCR-ABL1 (involved with communicating between cell surface and nucleus)

Question 19

What happens to the blood and in the body in chronic myeloid leukaemia?

Answer 19

Anaemia, increase in all granulocytes, spleen is enlarged

Question 20

How is chronic myeloid leukaemia treated?

Answer 20

By tyrosine kinase inhibitors

Question 21

Amongst what age is acute lymphoblastic leukaemia most common? What are some visible symptoms?

Answer 21

Young children- they may have pale skin, bruises and enlarged testes

Question 22

What happens genetically in acute lymphoblastic leukaemia?

Answer 22

Formation of a fusion gene

Point mutation in a proto oncogene

Question 23

How is acute lymphoblastic leukaemia treated?

Answer 23

Supportive red cells, platelets, antibiotics

Systemic chemo therapy and intrathecal chemo (can get to CSF)