Blood Cell Abnormalities Flashcards

1
Q

What is anaemia?

A

A reduction in the amount of haemaglobin in a given volume of blood, below what would be expected in comparison with a healthy subject of the same age and gender

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2
Q

What are the four mechanisms of anaemia?

A

Production - reduced production of RBC
Pooling - RBC may pool in the spleen
Loss - RBCs may be lost due to blood loss
Survival - reduced survival of RBCs

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3
Q

What is meant by microcytic RBCs

A

Smaller than usual - normally hypochromic and can therefore be identified by their larger area of central pallor

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4
Q

What causes microcytic anaemia?

A

Occurs either due to a loss of HAEM or GLOBIN
HAEM loss = due to iron deficiency
GLOBIN loss = thalassemia

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5
Q

What causes an iron deficiency?

A

Heavy menstruation, diet, malabsorption,

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6
Q

What is macrocytic anaemia?

A

When the red blood cells are larger than normal

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7
Q

What causes megaloblastic anaemia?

A

Deficiency of folate or B12 - cells are continuing to divide by cannot synthesize the DNA therefore just keep growing

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8
Q

What causes macrocytosis?

A

Abnormal haematopoiesis - red cell precursors continue to make Hb and other proteins but do not divide properly

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9
Q

How to diagnose megaloblastic anaemia?

A

Bone marrow examination

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10
Q

Causes of normocytic anaemia?

A

Recent blood loss - trauma, gastrointestinal bleed
Failure of production
Pooling of RBC in spleen

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11
Q

What is splenic sequestration?

A

When sickle cells get trapped in the spleen, leading to hyposplenism and the spleen not functioning properly

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12
Q

What is polycythemia?

A

Too many red cells in circulation

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13
Q

What causes polycythemia?

A

Blood doping or transfusions

Increased EPO - can be appropriate or inappropriate

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14
Q

What is pseudo polycythemia?

A

When you have a reduced plasma volume, so it looks like the RBCs take up a larger proportion of the blood colume

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15
Q

What causes a reduced plasma volume?

A

Dehydration

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16
Q

What is leukemia?

A

A cancer arising as a result of a mutation in a precursor of myeloid or lymphocyte cells

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17
Q

How is leukemia different to other cancer?

A

The cells involved circulate in the blood so invasion / metastasis doesn’t apply here

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18
Q

What are the four types of leukemia?

A

Acute Lymphoblastic Leukemia
Chronic Lymphocytic Leukemia
Acute Myeloid Leukemia
Chronic Myeloid Leukemia

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19
Q

What does acute mean in the context of leukemia?

A

Profound pathological affects, fatal in days

20
Q

What does chronic mean in the context of leukemia?

A

Takes years to be fatal

21
Q

What genes are mutations in to cause leukemia?

A

Proto-oncogenes and tumour suppressor genes

22
Q

What are the three I’s of leukemic clones?

A

Immortal, independent and immature

23
Q

What does the abnormal behavior of leukemia clones include?

A

growth without the need for growth factors
Proliferation without maturation
Failure to undergo normal cell death

24
Q

What are some causes of leukemogenic mutations?

A

Irradiation eg X Rays
Chemicals eg Benzene
Anti cancer drugs
Cigarette smoke

25
Q

What is the difference between AML and CML?

A

In AML - there is failure of production of end cells

In CML - there is too much production of end cells

26
Q

What happens in AML?

A

There is too many immature myeloblasts in the bone marrow - cells continue to divide but cannot nature. Failure of production of end cells like neutrophils, basophils etc

27
Q

What happens in CML?

A

Too many mature cells end cells - reduced apoptosis so end cells do no die

28
Q

What is hepatomegaly?

A

Increased liver size

29
Q

What disease characteristics does leukemia lead to?

A

Enlarged liver, enlarged spleen (splenomegaly), lymphomegaly (enlarged lymph nodes), thymic enlargement (if lymphoid leukemia)

30
Q

What is thrombocytopenia?

A

Lack of platelets - can arise from leukemia

31
Q

What mutation causes CML?

A

Translocation between chromosome 9 and chromosome 22, forming the BCR-ABL1 gene which gives the cell a growth and survival advantage

32
Q

What happens in CML?

A

Increase in ALL GRANULOCYTES and their precursors = splenomegaly

33
Q

What can CML be inhibited by?

A

Specific tyrosine kinase inhibitors - inhibits the tyrosine kinase which the BCR-ABL1 protein makes which stops the bone marrow from making abnormal cells

34
Q

What is ALL?

A

Acute lymphoblastic anaemia - replacement of normal bone marrow cells with lymphoblasts

35
Q

What can ALL cause?

A

Thrombocytopenia, anaemia

36
Q

Which leukemia occurs more commonly in children?

A

ALL

37
Q

How to treat ALL?

A

Supportive - give them the cells they are missing

Chemithearoy

38
Q

An aspiring bodybuilder repeatedly takes steroid injections during his training for a competition. What could occur as a result? And why?

A

Polycythaemia - repeated steroid injections increase testosterone levels which acts on the kidney to increase erythrocyte production, leading to polycythaemia

39
Q

What can increase the risk of leukaemia?

A

Increased chromosomal breaks, inability to repair DNA normally

40
Q

What are some identifyable causes of leukaemogenic mutations?

A

Irradiation
Anti-cancer drugs
Cigarette Smoke
Chemicals eg benzene

41
Q

In Chronic Myeloid Leukaemia, cells become independant of external signals. What affect does this have?

A

There are changes seen in the interactions with the stroma and reduced apoptosis

42
Q

What types of genes are affected to cause chronic myeloid leukaemia?

A

Genes encoding proteins in signalling pathways between a cell surface receptor and the nucleus eg membrane receptor

43
Q

Why is there a build up of immature cells (myeloblasts) in the bone marrow and in the blood?

A

Cells continue to proliferate but no longer mature

44
Q

Mutations in what genes usually cause Acute Myeloid Leukaemia?

A

Mutations in transcription factors for multiple genes causing profoundly disturbed cell behaviour

45
Q

What are the haematological features of Acute lymphoblastic Leukaemia?

A

Thrombocytopenia, replacement of normal bone marrow cells by lymphoblasts, neutropenia, normochromic and normocytic anaemia

46
Q

What are five supportive treatments for acute lymphoblastic leukaemia?

A

red cells, platelets, antibiotics, intrathecal chemotherapy, systematic chemotherapy