Lecture 1 - Intro To anaemia Flashcards
1
Q
How do RBC make energy : glycolysis
A
- glycolysis is the first step in the breakdown of glucose to extract energy
- does not use oxygen, and can take place under anaerobic conditions
2
Q
Glycolysis two phases
A
1) Traps glucose molecule and uses energy to modify it: six carbon molecule splits into 2 times 3 carbon molecules
2) extracts energy from the molecules and stores it in the form of ATP and NADH using the pyruvate kinase enzyme
3
Q
Survival of RBC: dealing with reactive oxygen species
A
- ROS convert ferrous of haemoglobin to Ferric of methaemoglobin - doesnt transfer O2
- damages the lipid membrane - short life span
- glutathione scavenges ROS
- oxidized form of gluthatione is regenerated by glutathione reductase
- Hexose monophosphate shunt generates the necessary NADPH and uses G6PD
4
Q
Erythropoietin
A
- hormone which controls red cell production: works on red cell precursors in the bone marrow and promotes differentiation
- produced in kidney under hypoxic stress in adult
- produced in liver in the foetal and perinatal period
5
Q
Definition of Anaemia
A
- reduction in red cell number and haemoglobin concentration of blood
- hemoglobin is the oxygen carrying pigmented proteins in red cells
- results in a reduction in the oxygen carrying capacity of the blood
6
Q
Symptoms of anemia depend on:
A
- rapidity of onset
- general health
- severity of anemia
7
Q
Symptoms of anemia
A
- tiredness, headaches
- dizziness
- SOB
- palpitations
- chest pain
8
Q
Pallor
A
- conjunctivae
- palmar crease
9
Q
Cardiac decompression
A
- tachycardia
- postural hypotension
- congestive cardiac failure
10
Q
Signs of ane,ia
A
- angular stomatitis, glossitis, koilonychia
- jaundice
- underlying systematic illness
11
Q
Useful laboratory indices in anemia
A
- hemoglobin
- MCV
- blood film
- Reticulocyte count
12
Q
Automated counters
A
- haemoglobin measured by spectrophotometry at 540nm
- RBC count measured by particle counter
- MCV directly measured electronically
- MCHC calculated from haemoglobin and haematocrit
- heamatocrit calculated from red cell number and MCV
- white cells and platelets: measured optically via electrical impedence, light scatter, fluorescence and laser
13
Q
Haemoglobin normal range
A
- male: 130-170
- female: 120-150
- higher in newborn
- pregnancy: 10-20 lower due to disproportionate rise in plasma and red cell volumes
14
Q
- Mean corspuscular volume reference range
A
- 80-100 fl
15
Q
Principles of romanowsky stain on blood film
A
- basic cellular elements react with acidic dye (eosin) and stain red-orange. Eg: hemoglobin
- acidic cellular elements react wit basic dye (methylene) and stain blue (eg: DNA)
16
Q
Red cell development
A
- bone marrow proliferation and maturation is 3-5 days
- reticulocytes - bone marrow to blood: 3-4 days
- circulating mature red cell for 120 days
- vitamin B12 and folate are required for DNA synthesis and nuclear maturation
17
Q
Reticulocyte
A
- young and immature red cells
- have residual RNA
- therefore have a blue blush
- on a blood film is called polychromasia
18
Q
Reticulocyte count
A
- identified by staining residual RNA
- automated: residual RNA stained with flyuorescent dyes and enumerated by flow cytometry
- reference range: 50-100x10^9 g/L
19
Q
Possible causes of anemia
A
- decreased production: deficiencies or systemic illness
- increased loss: bleeding
- shortened life span or increased destruction: haemolytic anemias, either inherited or acquired
20
Q
When is anaemia due to primary bone marrow pathology
A
- when more than one cell line is abnormal: increased or decreased white cells and platelets
21
Q
If MCV
A
- iron deficiency due to chronic blood loss
- inherited Hb abnormality: thalassaemias
22
Q
If MCV normal
A
- acute blood loss
- systemic illness
- primary BM pathology
23
Q
If MCV > 100 fl
A
- B12 and folate deficiency
- haemolysis
- liver disease
24
Q
Hypochromic microcytic cells with anisopoikilocytosis
A
Iron deficiency anaemia
25
Target cells
- in liver disease
26
Macrocytes
- in B12 or folate deficiency
27
Spherocytes
- in haemolysis
28
Sickle cell
- sicle cell anaemia: an inherited abnormal Hemoglobin
29
Rouleaux
- in myeloma
30
- primitive white cells called blasts
- in acute leukaemia: a bone marrow disease
31
Increased reticulocytes means
- increased BM production
- acute hemorrhage
- reduced red cell life span: haemolysis
- response to replenished iron, B12 and folate
32
Normal or reduced reticulocytes means reduced BM production
- not enough iron, B12 or folate
- systemic illness
- bone marrow pathology
33
Further laboratory tests
- iron studies: transferrin saturation and ferritin
- B12 and folate levels
- heamollytic screen: bilirubin, LDH, haptoglobin, DCT
- tests of inherited causes of haemolysis
34
Systemic illness tests
- infection
- autoimmune disease: serology
- renal impairment: creatinine
- hepatic dysfunction: LFT
35
bone marrow biopsy
- aspirate vs trephine
- performed to confirm or exclude a suspected diagnosis
- site: posterior iliac crest or sternum, tibia in neonates
- aspirate: to assess cell number, maturation and morphology
- trephine: to assess cellularity, architecture and abnormal cellular infiltrate
36
Treatment of anemia
- transfusion in circulatory compromise
- replace missing iron, B12 or folate
- rectify shortened life span in case of haemolysis
- treat underlying condition
