Introduction to hematology and normal hemopoiesis

Question 1

Define polycythaemia:

Answer 1

too many red cells

Question 2

Define leukemia:

Answer 2

excess of white cells in the blood

Question 3

Define lymphoma:

Answer 3

accumulation of malignant cells in lymph nodes

Question 4

Define neutropenia:

Answer 4

leads to susceptibility to infection

Question 5

Define lymphopenia:

Answer 5

immunodeficiency - effect depends on specific type of lymphocyte affected

Question 6

What are some different clotting disorders?

Answer 6

inherited disorders of poor clotting = hemophilia
acquired disorders of poor clotting = DIC (disseminated intravascular coagulation), aspirin

Increased tendency to clot

• inherited thrombophilia
• acquired disorders - stasis, endothelial damage

Question 7

What are the normal Hb ranges (g/dl) for cord blood, newborn, children (6m-6 years, 6-14 years), males, females and pregnant females?

Answer 7

cord blood = 13.5-20.5
Newborn = 15 - 23.5 
Children (6m-6 years) = 11 -14.5
Children 6-14 years) = 12 -15.5
males = 13-17
females = 12-15.5
pregnant females = 11-14= lower due to consumption of Fe2+ by fetus

Question 8

What is anaemia and how is it classified?

Answer 8

reduced hemoglobin for age and sex
Classified:
- microcytic = iron deficiency, thalassemia
- normocytic = bone marrow failure, aplastic anaemia, chronic disorders, renal disease
- macrocytic = vitamin B12 or folate deficiency

Question 9

What is the commonest cause of anaemia worldwide and what are the causes of it?

Answer 9

iron deficiency (hypo chromic, microcytic RBCs (low color))
causes:
- chronic blood loss = menstruation, GI blood loss
- poor diet = mainly in children (developing world)
- malabsorption = a minor cause (often also don't absorb folic acid

Question 10

What are the treatments for iron deficiency anaemia?

Answer 10

1) treat underlying cause where needed

2) iron tablets (ferrous sulphate 200mg/day)

Question 11

What are haemoglobinopathies?

Answer 11

inherited disorders of hemoglobin structure

- thalassemia, sickle cell disease

Question 12

What are the causes of hemolytic anaemia?

Answer 12

inherited: membrane, enzyme or hemoglobin
acquired: immune or non-immune = more common in UK

Question 13

What is aplastic anaemia?

Answer 13

rare syndrome characterized by loss of haemopoiesis in the marrow

• causes: idiopathic, post-viral, drugs, radiation
• treatment: immunosuppression, bone marrow transplant

Question 14

Define pancytopenia:

Answer 14

low rbcs, platelets and WBCs in bone marrow

Question 15

What are the large red blood cells known in macrocytic anaemia?

Answer 15

vitamin B12 deficiency and folate deficiency are associated with very large erythroblasts in the bone marrow = megaloblastic anaemia

Question 16

What is folate important for and what can a deficiency in it lead to?

Answer 16

important for DNA synthesis = can lead to CNS problems - subacute degeneration of spinal cord
cause spina bifida in newborns

Question 17

What are neutrophils characteristically like in vitamin b12 deficiency?

Answer 17

neutrophils have too many segments = hypersegmented

Question 18

What is the blood count and function of neutrophils?

Answer 18

2 x 10^9 L - Protection against bacteria

Question 19

What is the blood count and function of eosinophils?

Answer 19

0.4 x 10^9L - Protection against parasites

Question 20

What is the blood count and function of basophils?

Answer 20

0.2 x 10^9 L - Unknown

Question 21

What is the blood count and function of lymphocytes?

Answer 21

4 x 10^9L - Cellular immunity

Question 22

What is the blood count and function of monocytes ?

Answer 22

0.2 x 10^9L - Phagocytosis

Question 23

What are the characteristics of acute leukemia?

Answer 23

due to rapidly dividing primitive (blast) cells
packs the bone marrow and leads to anaemia, infection and bleeding
is fatal within weeks or months if untreated
can often be cured by chemotherapy

Question 24

What are the characteristics of chronic leukemia?

Answer 24

less rapidly growing - less aggressive than acute
consists of recognizable cells types e.g. neutrophils or lymphocytes
is harder to cure by chemotherapy

Question 25

Other than acute and chronic how else can leukemia’s been classified?

Answer 25

lymphoid - tumor of B or T lymphocytes

Myeloid - affects cells of all other lineage e.g. neutrophils, red cell, monocytes, or platelets

Question 26

What are lymphomas and how can they be classified?

Answer 26

tumors of cells that accumulate in lymph nodes
presents as lymphadenopathy
divided into:
- hodgkins lymphoma
-non-hodgkins lymphoma - many different variants

Question 27

What defines hodgkins lymphoma?

Answer 27

reed-sternberg cells = large with abundant pale cytoplasm and 2 oval lobulated nuclei prominent “owl eye” eosinophilic nucleoli
- only 5-10% of the “owl eyes” are malignant

Question 28

What is myeloma?

Answer 28

malignancy of plasma cells that produce monoclonal immunoglobin called paraprotein

• presents with renal failure, bone pain and anaemia (commonest characteristic)
• incurable

Question 29

What are myeloproliferative disorders?

Answer 29

clonal proliferations of stem cells which lead to a hyper cellular bone marrow with increased:

• red cells = polycythaemia
• platelets = essential thrombocythaemia
• white cells = chronic myeloid leukemia
• reactive fibrosis = myelofibrosis

Question 30

What does effective blood clotting depend on?

Answer 30

interaction between endothelium, platelets and coagulation factors

Question 31

What are the different patterns of bleeding?

Answer 31

vascular or platelet abnormalities tend to lead to mucosal or skin bleeding

• purpura or bruising
• oral or gastrointestinal bruising

Coagulation disorders tend to lead to bleeding into joints and muscles

Question 32

What is thrombosis?

Answer 32

tendency to increased thrombosis can be inherited or acquired

• inherited: factor V, antithrombin, protein C or protein S abnormalities
• acquired: vessel damage, stasis, change in blood composition = virchows triad

Question 33

What are the different types of cells that can be replaced in a blood transfusion and what are the major issues associated with it?

Answer 33

replacement of:

• red cells
• platelets
• coagulation factors
• white cells - difficult

Major issues

• indications
• safety of products

Question 34

How can bone marrow be examined?

Answer 34

aspirate = involves removal of liquid marrow prior to examination on a slide
- inser needle through the posterior superior iliac crest
trephine = a solid histology section which allows study of marrow cellularity

Question 35

When is a trephine biopsy particularly used?

Answer 35

in lymphoma