Haemotology Flashcards
Anaemia defenition
- Low RBC mass
- Increase plasma volume
eg: Pregnancy
What does reticulocyte count indicate
Low - production issue
High - removal issue
MCV classification
MCV <80 - Microcytic
MCV 80-100 - Normocytic
MCV >100 - Macrocytic
Microcytic anaemia causes
Iron deficiency
- hypochromic
Chronic disease
Thalassaemia
Normocytic anaemia causes
Acute blood loss
Chronic disease
Combined haemanitic def
- Querey malabsorption
Macrocytic anaemia causes
Vit B12 def
Alcohol/liver disease
Hyperthyroidism
Folic acid def
Reticulocytosis
FAT RBC MD
D- drugs
AZT/Phenytoin
Serum ferritin
Major iron storage protein in the body
- directly measure iron levels in the body
- Acute phase reactant so can be raised falsley in inflammand malignancy
Anaemia general presentation
Sx
- fatigue
- lethargy
- dyspnoea
- palpitations
- headache
Signs
- pale skin
- pale mucous membranes
- tachycardia (compensatory)
Iron deficiency causes
Poor diet - low iron Blood loss - Menorrhagia - GI bleeding - Hookworm Malabsorption - coeliac Pregnancy - increased requirements
Where is iron absorbed
Duodenum
*Coelaic disease - Inflamm and duodenal cell destruction
Iron deficiency anaemia signs
- Brittle hair and nails
- Atrophic glossitis
- Kolionychia
- Angular stomatitis
Iron deficiency anaemia investigations
- Serum ferritin
- Low serum ferritin confirms dx
- Acute phase reactant
- FBC
Hypochromic microcytic anaemia - Reticulocyte count
- Reduced
- Transferrin saturation
- LOW = Iron deficiency
HIGH = Iron overload - Coeliac serology
Iron deficiency anaemia tx
Ferrous sulphate S/E: - Black stools - Nausea - Constipation - Diarrhoea - GI upset - Abdo discomfort
*Take with OJ
Why should you take ferrous sulphate with OJ
Increases acidity - helps with absorption
What are the promoting factors for intestinal iron absorption
- Gastric acid
- Iron def
- Increase Erythropoeitc -activity
Anaemia of chronic disease
- Shortening of RBC
- RBC reduced cell production
CKD
RA
SLE
Cancer
Investigations for new iron def anaemia in an adult withhout a clear underlying cause
GI cancer investigations
- Oesophago-gastroduodenoscopy (OGD)
- Colonoscopy
What is the normal rise in iron levels for a pt recieving iron def anaemia tx
10 grams/ litre / week
Megaloblastic anaemia
B12 and folate
- Inhibition of DNA synthesis
- Continued growth without division
- Macrocytosis
What are megaloblasts
Erythroblasts with delayed nuclear maturation due to delayed DNA synthesis
Folate deficiency
- Anaemia
- Neural tube malformation
Folate sources
Green leafy veg - Spinach - Brocolli Liver Kidney
How long is the folate store in the body + where is it basorbed
4 months
Jejunum
Causes of folate def anaemia
- Poor folate diet
Alcohol
Poverty - Malabsorption
Coeliac
IBD - Crohns - Pregnancy
- Anti flolate drug
Methotrexate
Phenytoin - Haemolysis
- Malabsorption
Folate deficiency anaemia presentation
Anaemia sx - Headache Pallour Lethargy Fatigue
Signs -
Glossitis
NO neuropathy
Folate deficiency anaemia investigations
Blood film -
Macrocytic anaemia
Hypersegmented neutrophil polymorphs
Red cell folate levels - LOW
*Indicates low body stores
SB biopsy only if hx does not suggest dietary deficiency - Looking for small bowel disease
Folate deficiency anaemia tx
- Oral folic acid tablets
Sources of B12
Animal meats
Dairy
Milk
Length of B12 bodily stores
2-4 years
B12 deficiency anaemia
Prenicious anaemia
- Megaloblastic
- Low reticulocyte count
Where is B12 absorbed
- Terminal ileum
- Binds to Intrinsic factor and absobed by enterocytes
What is prenicious anaemia
AI disease
- Ab against parietal cells or Intrinsic factor
- Prevents B12 absorption due to lack of Intrinsic factor
Prenicious anaemia causes
Atrophic gastritis
Gastrectomy
Crohns
Coeliac
Causes of B12 deficiency anaemia
Prenicious anaemia Ileal resection Crohns disease Gastric bypass - Food passes quickly (Pepsin can't act to release B12) - Tapeworm
B12 def anaemia presentation
Sx of anaemia Glossitis Angular stomatitis Neurological sx Lemon - Yellow tinge *pallour + mild jaundice *Excessive Hb breakdown as body tries to remove defective large RBC
Specific neurological sx of B12 def anaemia
Peripheral neuropathy
- w/ numbness or paraesthesia
- Weakness
- Ataxia
- Dementia
- Hallucinations
- Loss of vibration sense/propioception
- Depression
- Irritabilty
B12 deficiency anaemia investigations
Blood film
- Macrocytic RBC
- Hypersegmented neutrophils
Serum Ab screen
- Inrinsic factor Ab
Serum B12 Low
B12 def anaemia tx
Hydroxyxobalamin - B12
- Tablets
- Injections
B12 def anaemia complications
HF
Angina
Neuropathy
What is sickle cell disease
Disorder of Hb quality
- Autosomal Recessive
- Point mutation of the Beta globin gene resulting in a HbS variant
Whta is the codon chnage in sickle ell disease
Glutamic acid –> Valine
When does SCD manifest
After HbF levels decrease
- Approx 6 months
How does HbS affect oxygenation
HbS can carry O2 normally
- changes shape when deoxygenated
- allows aggregation with other HbS proteins
- Insoluble and polymerises
- polymerisation distorts RBC into a crescent shape
- RBC fragile and easily haemolysed
Factors promoting sickling in SCD
Acidosis Low flow vessels Infection Dehydration Hypoxia Cold Stress
What does repeated sickling do to RBCs
Promotes premature destruction
- Intravascular haemolysis
- Anaemia
- Hb spillage –> Jaundice
Impaired passage of RBCs in microcirculation due to sickling
- Small vessel obstruction
- Tissue infarction
PAIN
Sickle cell trait presentation
Sx free with no disability unless in extreme conditions: *Vaso-occlusive events - High altitude - Dehydration - Hypoxia Unpressured aircraft Anasthesia
Benefit of sickle cell trait
Selective advantage of protection against Falciparum malaria
Sickle cell disease presentation
Vaso-occlusion - Dactylitis - Avascular necrosis - Pain in long bones spine/ribs/pelvis - stroke - seizures
Anaemia
Splenic sequestriasation
Mesenteric ischaemia
Long term SCD complications
CKD
Pulmonary HTN
Poor growth
- avascular necrosis of bones results in shortened deformed bones in kids
Vaso-occlusive crisis
- Sickled RBCs clog up capillaries
- Distal ischaemia
- Assosc with:
dehydration
Riased haematocrit
*PRIAPISM
trapping blood in penis causing painful and persistent erection
- UROLOGICAL EMERGENCY
Splenic sequestrian crisis
- Sickled cells block blood flow to the spleen
- Acute enlarged and painful spleen
- leads to:
- Severe anaemia
- Hypovolemic shock
Aplastic crisis
- Temp loss of new blood ell production
- Triggered by parvovirus B19 infection
- Leads to severe anaemia
Acute chest syndrome Sx and causes
Sx:
- Fever / resp sx
- New infiltrates seen on X-ray
Causes:
- Infection (pneumonia)
- Non infective cause
(pulmonary vaso-occlusion or fat emboli)
Acute sickle cell disease complications
Sickle cell crisis
Acute chest syndrome
Haemolytic
Mesenteric ischaemia
Sickle cell disease investigations
Screen neonates - Blood/Heel prick test
FBC -
Hb
Reticulocyte
Blood film -
Sickled erythrocytes
Hb electropharesis
- HbSS present
- HbA absent
Sickle cell disease management
- Analgesia
- Tx underlying cause: Abx
- Fluids
- Folic acid
- Tranfuse when falling Hb
Disease modifying tx SCD
Hydroxycarbamide
- Increase gamma and foetal globin
- HbS cannot polymerise as HbF gets in its way so prevents sickling
Stem cell transplant
Blood transfusion
*Beware iron overload
Alpha - Thalassaemia
Deficiency in alpha chain synthesis in red cell precursors
- Caused by gene deletions found on chromosome 16
- Protection from falciparum malaria
Thalassaemia
- Hb quantity disease
- AR disease
- Precipitation of globin chains on:
- RBC precursors –> ineffective erythropoesis
*Mature RBC –> Haemolysis
Faulty production and premature destruction
Thalassaemia
- Spleen
- Bone marow
Splenomegaly
- filters blood to collect destroyed RBCs causing swelling
BM expansion
- Compensate for chronic anaemia
- Susceptibility to fractures
- Prominent features:
- Pronounced forehead
- Malae eminences
Thalassaemia presentation
Sx:
- Fatigue
- Poor growth and development
- Pronounced forehead and malar eminences
Signs:
- Splenomegaly
- Gallstones
- Jaundice
- Pallor
- Microcytic anaemia
What is HbH disease
3 deleted alpha genes
- Low HbA
- Severe haemolyticanaemia
- Splenomegaly
What disease is caused by 4 deleted alpha globin chain genes
- Hb Barts Hydrops Fetalis
- Cannot carry oxygen
- Not compatible with life
- Baby is:
Pale
Oedematous
Big Liver
Big spleen
Alpha thalassaemia investigations
Bloods - Microcytic
Blood smear:
- Microcytic + Hypochromic
- Target cells
Hb Electrophoresis
Genetic testing:
- Amniocentisis
Iron overload
- Monitoring
- Management
Serum ferritin
Chelating agents
- Deferiprone
Beta - Thalassaemia
Deficiency in Beta globin chain synthesis
- Results in excess alpha chains which combine with gamma and delta chains
- Increase HbA2 and HbF
- Ineffective erythropoesis and haemolysis
HbF chains
2 x alpha
2 x gamma
HbA2 chains
2 x aplha
2 x delta