Blood cell abnormalities Flashcards
What is anaemia?
Anaemia concerns the reduction in the amount of haemoglobin present in a given volume of blood, below the expected range in comparison to a healthy adult of same age & gender
Reduction and absolute deficiency of haemoglobin in circulation
What parameters does anaemia reduce?
Red blood cell count
HCT/PCV (Hematocrit)
What is the primary cause of anaemia in a healthy individual?
Increased plasma volume
What are the mechanisms of anaemia?
Reduced production of erythrocyte/haemoglobin in the bone marrow
Removal of blood
Reduced lifespan of circulating erythrocytes
Pooling of erythrocytes in spleen (Splenomegaly)
Iron deficiency, reduced synthesis of haem/globin
What is thalassemia?
An inherited genetic condition resulting in reduced globin synthesis, resulting in malformed erythrocytes
What type of microcytic anaemia is common?
Hypochromia
What is hypochromia?
Low mean corpuscular hemoglobin concentration (MCHC), haemoglobin content within an individual cell is reduced
What are the two examples of hypochromic erythrocytes?
Target cells
Elliptocytes
What is microcytic anaemia?
Hypochromic, relatively smaller erythrocyte; larger area of central pallor as a result of reduced haemoglobin content. Concerns a reduction in erythrocyte count, cells have reduced size
What are the causes of microcytic anaemia (3)?
Iron deficiency (haemoglobin synthesis is reduced, ferrous iron is required for haem group) insufficient ferritin
Anaemia of chronic disease
Thalassemia
An insufficiency of what molecule contributes towards microcytic anemia?
Ferritin
Why does ferritin insufficiency contribute towards microcytic anaemia?
Ferritin insufficiency causes reduced iron storage capacity
What is thalassemia?
Defect in alpha and beta chain synthesis (Dysfunctional and malformed RBCs are haemolysed)
What are the causes of iron deficiency?
Hookworm infection (primary cause)
Menorrhagia
Insufficient intake- Vegans, coeliac disease (Malabsorption)
Increased requirements: Physiological (pregnancy)
Why does Hookwork infection cause iron deficiency?
Adult hookworms rupture erythrocytes through ingestion of blood, contributing towards hemoglobin degradation
Why does menorrhagia cause iron deficiency?
Reduces the number of circulating RBCs, thereby hemoglobin concentration and content declines, iron deficiency is attributed towards the increased synthesis of haemoglobin since hemosiderin and ferritin is used to combat blood loss = DEPLETES iron storage molecules = iron levels decline
What are the two types of iron storage molecules?
Hemosiderin and ferritin
What are the signs and symptoms of iron deficiency?
Pale skin
Weakness & fatigue
What is the primary female risk factor for iron deficiency?
Heavy menstrual periods
Which two diets contribute to iron deficiency?
Vegan & Vegetarian
Why does coeliac disease cause iron deficiency?
Gluten-induced enteropathy
Gluten-derived peptides bind to HLA-DQ2 molecules (Intestinal CD4 T cells); causes a cytotoxic response, damages enterocytes and reduces absorption ability
Which bacteria cause chronic malabsorption?
H pyloric gastritis
How does H pyloric gastritis cause malabsorption?
Mucinase enzymes secreted, hydrolyzes mucosal epithelium.
What is macrocytic anemia?
Concerns that of which the average erythrocyte size has increased.
Macrocytic anaemia result from abnormal hemopoiesis whereby red cell precursors (reticulocytes and proerythroblasts) continue to synthesise haemoglobin and cellular proteins, however aberrantly deivide. Red cells result in larger morphology
What is the main cause of macrocytic anaemia?
Megaloblastic erythropoiesis
What is megaloblastic erythropoiesis?
Delayed maturation of the nucleus whilst the cytoplasm continues to grow and mature (nucleocytoplasmic dissociation).
Defect in DNA synthesis interferes with cellular prolifeation and maturation
What causes megaloblast anaemia?
Abnormal none marrow erythroblast
B12 or foalte deficiency, inhibition of homocysteine conversion to methionine.
Liver disease and ethanol toxicity
Blood loss
Haemolytic anaemia (reticulocytes increased)
Which anaemia concerns the deficiency in erythrocytes, presence of normal-sized RBCs?
Normocytic
What are the mechanisms of normocytic anaemia?
Recent blood loss
Failure of erythrocyte production
Splenic sequestration -Hypersplenism in liver cirrhosis, and SCA
What is polycythemia?
Abnormally increased concentration of haemoglobin in blood, either through reduced plasma volume or increase in circulating erythrocyte number
What RBC parameters increase during polycythemia?
Red blood cell count
Haematocrit
What is pseudo polycythemia?
Reduced plasma volume
What is true polycythemia?
Increase in total volume of red blood cells in circulation
What are the causations of polycythemia (4)?
1) Blood doping/ over transfusion
2) Appropriately increased erythropoietin
3) Inappropriate erythropoietin synthesis or use
4) Independent of erythropoietin