L26: Anaemia Flashcards
Anaemia is a condition in which a patient has decreased haemoglobin.
What is the numerical value in:
a) Females
b) Males
a) Females < 11.5 g/dL
b) Males < 13 g/dL
What does hypochromic mean? (in regards to anaemia)
less Hb present in the RBCs
List some of the possible causes of anaemia
- failure to make RBCs
- lack of haematinics
- – from diet
- – autoimmune
- – malabsorption
- increased loss of RBCs
- reduced bone marrow function
- increased haemolysis
Where is intravascular and extravascular haemolysis done?
Intravascular = in peripheral blood
Extravascular = in spleen
Where in the GIT is iron absorbed?
stomach + duodenum
Where in the GIT is folate absorbed?
duodenum + upper jejunum
Where in the GIT is B12 absorbed?
terminal ileum
What is pernicious anaemia?
- autoimmune disorder affecting GIT (antibodies present)
- causes malabsorption of B12
- can lead to macrocytic megaloblastic anaemia
Give 2 examples of hypochromic microcytic anaemia
- Iron Deficiency Anaemia
2. Thalassaemia
List some of the possible causes of IRON-DEFICIENCY anaemia
- lack of iron dietary intake
- loss of iron in GIT
- malabsorption
- — partial gastrectomy
- — coeliac disease
- — crohn’s disease
- any cause of long-standing severe diarrhea
List some of the common clinical features/presentations of IRON-DEFICIENCY anaemia
- mucosal pallor
- angular cheilitis
- atrophic glossitis (smooth tongue)
- brittle nails
- koilonychia (spoon nails)
- ice pica
If there is a patient over the age of 50 with iron deficiency anaemia, what MUST be done?
- duodenal biopsy
- upper and lower GI endoscopy
What is the treatment of iron deficiency anaemia?
oral Iron (IV if they can’t tolerate it)
Give 2 main causes of megaloblastic anaemia
- B12 Deficiency
2. Folate Deficiency
What are megaloblasts?
- enlarged RBCs due to retarded RBC synthesis
- nucleus is enlarged compared to cytoplasm
What vitamin is Cobalamin?
Vitamin B12
Explain the process by which vitamin B12 is absorbed
- intrinsic factor released from gastric parietal cells
- B12 from diet combines with IF
- B12-IF complex formed
- complex absorbed in terminal ileum
Pernicious anaemia can cause vitamin B12 deficiency. Which 2 antibodies may be present?
- Antibody to IF
2. Antibody to Gastric Parietal Cells
List some of the possible causes of B12 DEFICIENCY anaemia
- lack of IF
- – pernicious anaemia
- – atrophic gastritis
- – partial gastrectomy
- malabsorption
- – Crohn’s disease
- – loss of terminal ileum
- blind loop bacteria (compete for B12)
List some of the clinical features/complications of B12 deficiency
- peripheral neuropathy
- subacute combined degeneration of the cord
- optic atrophy
- psychiatric disorder
- atrophic glossitis
If a chronic alcoholic presents with a confusion disorder, which anaemia is the most likely cause?
B12 Deficiency Anaemia
What is the treatment for B12 deficiency anaemia?
- Parenteral B12 (intramuscular injection)
2. Folate given at same time`
List some of the causes of folate deficiency which would cause anaemia
Malabsorption:
- Coeliac disease
- Crohn’s disease
- pregnancy*
- resection of small bowel
- blind loop syndrome
When looking at the histology of a patient with Coeliac disease - what can be seen in their intestines?
- blunting of villi
- closing off of crypts
impaired villi = decreased absorption
List some of the possible causes of “anaemia of chronic disease”
anything that causes long-standing inflammation
- Inflammatory Diseases of the GIT (e.g. Crohn’s Disease)
- RA
- SLE
- Sarcoid
- Renal Failure
- Malignant Disease (carcinoma, lymphoma, sarcoma)
What is the pathophysiology of “anaemia of chronic disease”?
- inflammation will trigger liver to produce hepcidin
- hepcidin causes:
a) decreased iron absorption
b) decreased release of iron from macrophages
What are the 2 effects of hepcidin? What is it associated with?
- decreases iron absorption
- decreases release of iron from macrophages
a/w anaemia of chronic disease
List ALL the causes of macrocytic anaemia
- B12 Deficiency
- Folate Deficiency
- Alcohol
- Liver Disease
- Reticulocytosis
- Hypothyroidism
What is vitamin B12 and folate necessary for?
DNA synthesis
List the investigations/tests that may be done when investigating anaemia
- FBC
- Blood Film
- Bone Marrow Aspirate/Trephine (to see bone marrow activity)
- Coombs Test (antibodies against RBCs?)
- Upper and Lower GIT Endoscopy ± Biopsies
- TTG Antibodies?
- Gastric Parietal Cell Antibodies?
What is Coombs test and what is it used for?
- direct antiglobulin test (DAT)
- used to detect antibodies against RBCs
- indicative of an immune haemolytic anaemia
What are tTG antibodies? What disease are they linked to?
tTG antibodies = tissue transglutaminase antibodies
detected in Coeliac disease
If gastric parietal cell antibodies are present, what type of anaemia is present?
pernicious anaemia
What do upper and lower GIT endoscopies look for in an anaemic patient?
cause of blood loss or malabsorption
