Red Blood Cells 2 Flashcards
define anaemia
Haemoglobin below normal for age and sex
factors influence haemoglobin normal range
Age Sex Ethnic origin Time of day sample taken Time to analysis
Haemoglobin Normal ranges
Male 12-70 (140-180g/l)
Female 12-70 (120-160)
Anaemia clinical features
Tiredness/ pallor Breathlessness Swelling of ankles Dizziness Chest pain
Anaemia clinical features
Evidence of bleeding:
- menorrhagia
- dyspepsia, PR bleeding
Symptoms of malabsorption:
- diarrhoea,
- weight loss
Jaundice
Splenomegaly/ lymphadenopathy
What are the main branch causes of anaemia
Bone marrow- cellularity, stoma, nutrients
Red cell- membrane, haemoglobin, enzymes
Destruction loss- blood loss, haemolysis, hypersplenism
What does MCH and MCV stand for?
MCH= Mean Cell Haemoglobin MCV= Mean Cell Volume
Anaemia morphological classes?
Hypochromic microcytic (pale and small)
Normochromic normocytic (normal looking)
Microcytic
Best investigation for hypochromic microcytic anaemia
Serum ferritin
Best investigation for normochromic normocytic
Reticulocyte count
Best investigation for macrocytic anaemia
B12/ folate
Bone marrow
In hypochromic microcytic anaemia what will the results of the serum ferritin show as the cause
Low= iron deficiency Normal= thalassaemia OR secondary anaemia OR sideroblastic anaemia
Role of ferroportin
Transporter for iron across basement membrane
Can also be transported bound to mucosal ferritin
THEN
Bound to transferrin in plasma
Role of hepcidin
Released from hepatocytes in response to
- increased iron levels
- inflammation
Regulates Fe transport by blocking ferroportin and thus further Fe absorption
History and examination to take from iron deficiency anaemia
Dyspepsia (?Gi bleed)
Other bleeding ? Eg menorrhagia
Diet
Increased requirement ? Eg pregnancy
Examination:
- signs of iron deficiency
- abdominal and rectal
Cells appearance in iron deficiency anaemia
Pencil/ rod cell
Hypochromic microcytic red cells
Clinical features of iron deficiency
Atrophic tongue
Angular stomatitis
Koilonychia
Causes of iron deficiency
GI blood loss
Menorrhagia
Malabsorption- gastrectomy, coeliac disease
For normochromic normocytic anaemia you do a reticulocyte count, what would the causes be depending on the results
Increased reticulocyte count - acute blood loss or haemolysis
Normal/ low reticulocyte count- secondary anaemia, hypoplasia, marrow infiltration
Secondary anaemia causes
Defective iron utilisation (increased hepcidin in inflammation)
Identifiable underlying disease (infection, inflammation and malignancy)
Describe haemolytic anaemia
Accelerated red cell destruction (decreased Hb)
Compensation by bone marrow (increased reticulocyte)
So balance between red cell production and destruction
What are the 2 types of haemolysis
Extravascular: -Auto-immune haemolytic anaemia Intravascular: -Mechanical eg artificial valve -Severe infection/ DIC -PET/HUS (haemolytic uraemia syndrome) /TTP )THrombotic Thrombocytopenic purpura)
What is a DAT test
Direct Antiglobulin Test
Detects antibody or complement on red cells
Reagents contains either:
- antihuman IgG
- anticomplement
Reagent then binds to Ab on red cell surface and causes agglutination in vitro
Implies immune basis for haemolysis
Results from DAT test meaning
Positive- immune mediated haemolysis
Negative- non-immune mediated haemolysis
Immune haemolysis causes
If:
Warm auto-antibody: auto-immune, drugs CLL
Cold auto-antibody: CHAD, infections, lymphoma
Alloantibody: transfusion reaction
How would immune haemolysis cells appear
Spherocytes on film
Agglutination (clumping) in cold AIHA
What do intravascular haemolysis cells appear like
Red cell fragments- “schistocytes”
Tests to do for haemolytic anaemia?
FBC Reticulocyte count Blood film Serum bilirubin LDH Serum haptoglobin
History and examination
Blood film
Direct Antiglobulin Test
Urine for haemosiderin/urobillinogen
Haemolytic anaemia management?
Folic acid If autoimmune- steroids Splenectomy Treat underlying cause Consider transfusion
What test would you do in macrocytic anaemia
B12/ folate assay
Blood film/ bone marrow
Causes of megaloblastic macrocytic anaemia
B12 deficiency
Folate deficiency
Causes of macrocytic non-megaloblastic anaemia
Myelodysplasia
Marrow infiltration
Drugs
Megaloblastic anaemia presentation
Due to B12/ folate deficiency
So presents:
-anaemia
-Neurological symptoms (B12)
-“lemon yellow” tinge
B12 and folate deficiency causes?
B12 deficiency:
Pernicious anaemia
Gastric/ileal disease
Folate deficiency: Dietary Increased requirements (eg haemolysis) GI pathology (eg Coeliac disease)
What is Pernicious anaemia
Autoimmune disease Autoantibodies against: -intrinsic factor -gastric parietal cells Malabsorption of dietary B12 (s/s take 1-2 years to develop)
Megaloblastic anaemia treatment
Replace vitamin:
B12 deficiency- im 3 monthly injections
Folate- oral folate replacement
Other causes of Macrocytosis
Alcohol Drugs (methotrexate, antiretrovirals, hydroxycarbamide) Disordered liver function Hypothyroidism Myelodysplasia
