Red Cells 2 Flashcards
What factors cause variability in Hb normal range?
Age
Sex
Ethnicity
Time of day/analysis
Clinical features of anaemia?
Tiredness Pallor Breathlessness Swollen ankles Dizziness Chest pain May also see: Bleeding, malabsorption, jaundice, splenomegaly
What are the general symptoms of malabsorption?
Diarrhoea
Weight loss
What are the causes of anaemia?
Bone marrow abnormality
Red cell abnormality
Destruction/loss
What are the main indices of anaemia diagnosis?
MCH - meal cell haemoglobin
MCV - mean cell volume
What are the 3 descriptions of RBC?
Hypochromic microcytic
Normochromic normocytic
Macrocytic
What is the commonest cause of hypochromic microcytic anaemia? What should you check?
Iron deficiency
Check: serum ferritin
What should be checked in normocytic/normochromic anaemia?
Reticulocyte count (immature RBC)
When is reticulocyte count low in anaemia?
Suppressed bone marrow activity
When is reticulocyte high?
Haemolytic anaemia - bone marrow activity increased
What should be checked in macrocytic anaemia?
B12
Folate
Bone marrow
Hypochromic microcytic anaemia with low serum ferritin means what?
Iron deficiency
Hypochromic microcytic anaemia with normal/increased serum ferritin?
Thalassaemia
Secondary anaemia
(sideroblastic anaemia)
How can ferritin vary in inflammation?
Ferritin is an acute reactant, it will increase in normal inflammation
Outline the pathway of iron metabolism?
Bound by mucosal ferritin
-or-
Transported across basement membrane by ferroportin
Bound to transferrin in plasma
Stored as ferritin
What is the role of Hepcidin?
Made in liver
Regulate Iron storage
Made in response to ↑iron levels, inflammation
Blocks ferroportin
What is the role of ferroportin?
Regulates the passage of iron across membranes (uptake)
What stimulates the synthesis of hepsidin?
Inflammation
↑ Iron levels
What are the causes of iron deficiency anaemia?
GI bleed Other bleed Diet Increased requirement (pregnancy) Malabosorption (gastrectomy, coeliac, carcinoma)
What are the physical signs on examination of Fe deficiency?
Tongue atrophy
Angular cheilitis
Koilonychia
How is iron deficiency managed?
Correct deficiency
Correct the cause
What is the cause of Normochromic normocytic anaemia with increased reticulocyte count?
Acute blood loss
Haemolysis
What is the cause of Normochromic normocytic anaemia with Normal/low reticulocyte count?
Secondary anaemia++
Hypoplasia
How does Secondary anaemia present?
70% Normochromic normocytic
30% hypo/micro
What are the causes of secondary anaemia?
(chronic disease)
Defective iron utilisation
Infection, inflammation, malignancy
What the classes of haemolytic anaemia?
Congenital
Acquired
Immune- Extravascular
Non-immune- Intravascular
How does the Direct antiglobulin test work?
Detect antibody or complement on red cell membrane
Implies immune basis for haemolysis
DAGT positive Haemolytic anaemia suggests what?
Immune mediated Haemolytic anaemia
DAGT negative Haemolytic anaemia suggests what?
Non-immune mediated haemolytic anaemia
What are the main types of immune Haemolytic anaemia?
Warm autoantibody Cold autoantibody (only in cold) Alloantibody
What are the causes of alloantibody immune haemolytic anaemia?
Transfusion reaction
What investigations should be used in suspected haemolytic anaemia?
FBC Reticulocyte count (will be increased) Blood film (sphero/schistocytes, fragments?) Serum bilirubin Haptoglobin Coomb's/DAGT
How is haemolytic anaemia managed?
Folic acid
Correct cause
Consider transfusion
How is Macrocytic anaemia diagnosed?
B12/folate assay
Blood film/bone marrow
What is megaloblastic anaemia?
Macrocyctic anaemia caused by B12 or Folate deficiency
What is non-megaloblastic anaemia?
Macrocytic anaemia NOT caused by B12/Folate deficiency
What is the cause of non-megaloblastic anaemia?
Myelodysplasia
Marrow infiltration
Drugs
How does B12/Folate deficiency present?
Anaemia
Peripheral neuropathy
What causes B12 deficiency?
Pernicious anaemia (AntiB vs IF) Gastric/ileal disease
What causes folate deficiency?
Diet
Haemolysis
GI pathology
How does Megaloblastic anaemia present?
“lemon yellow” tinge
Elevated bilirubin, LDH
Red cells friable
?Neurological symptoms (Peripheral neuropathy)
What is the cause of Pernicious anaemia?
Autoantibodies vs Intrinsic factor -or- gastric parietal cells
How is megaloblastic anaemia treated?
Replace vitamins (both until assay returns)
