Anemia
Transcript of Anemia
Anemia
Objectives
What is anemia? Diagnostic basis of classification Types and Classification Etiology or Causes of disease Compare and contrast different types of
anemias Polycythemia Why polycythemia occurs
Anemias Diagnostic Classification
1. Kinetic Approach Production vs. destruction or loss
Reticulocyte Production Index (RPI)
2. Morphological Approach Red blood cell size
Microcytic (Cells Smaller than normal size i.e. MCV< 80 fl) Normocytic (Cells Normal sized i.e. MCV = 80-100 fl) Macrocytic (Cells bigger than normal size i.e. > 100 fl)
Concentration of Hb Hyperchromic (Increased Hb Concentration) Normochromic (Normal Hb Concentration) Hypochromic (Decreased Hb Concentration- cells paler
than normal)
Anemia Anemia means deficiency of hemoglobin in the blood
Cause Too few red blood cells or Too little hemoglobin in the cells.
Classification1. Aplastic or Hypoplastic Anemia2. Nutritional Anemia3. Hemolytic Anemia
1. Aplastic or Hypoplastic Anemia Aplastic Loss of bone marrow function Hypoplastic Reduced bone marrow function Anemia due to lack of functioning of Bone Marrow or bone
marrow aplasia. Aplastic anemia patients have lower counts of all three blood cell types: termed pancytopenia.
Characterstics: Decreased Red blood cells Diminished immunity Tendency to bleed
Aplastic Anemia– Causes
– Drugs e.g. (Cytotoxic drugs, some anti convulscent drugs etc)– Radiations (X-Rays)– Chemicals (Benzene and its derivatives)– Viral diseases– Invasion of bone marrow (fibrosis or Leukemia)
Hereditary Congenital hypoplastic anemia (or constitutional aplastic anemia) a
type of aplastic anemia which is primarily due to a congenital disorder (defects or damage to a developing fetus). Examples include:
Fanconi anemia (Caused by short Stature, Skeletal Abnormalities)
Diamond-Blackfan anemia (Congenital Erythroid Aplasia- Characterized by anemia with decreased erythroid progenitors in bone marrow)
Acquired Pure Red cell Aplasia (PRCA) Sideroblastic anemia (Sideroachrestic anemia)1 The body has iron available, but
cannot incorporate it into hemoglobin Myelophthisic anemia2 (Normal marrow space is replaced by nonhematopoietic or
abnormal cells). Cause e.g. tumors
Nutritional Anemia2. Nutritional Anemia
Type of anemia that can be directly attributed to nutritional disorders
Iron Deficiency Anemia (Microcytic) Megaloblastic Anemia (Macrocytic)
Iron Deficiency Anemia (Microcytic) Sideropenic Anemia, cells are smaller in size and paler in colour
Causes: Parasitic Infections
e.g. Hook worms Normal Requirement, Deficient intake
Weight reducing diets, Vegetarian diets High Requirements, Normal or deficient intake
Pregnancy Chronic blood loss (peptic ulcers, menorrhagia,
haemorrhoids, GI carcinoma) Low iron absorption or malabsorption
GI abnormalities Increase in pH (removal of part of stomach) Loss of absorbing surface area (intestine removal)
Nutritional Anemia
Megaloblastic Anemia (Macrocytic) Inhibition of DNA synthesis during erythropoiesis Large, immature RBCs (Megaloblasts)
Characterstics: Immature, fragile cells, Life span b/w 40-50 days Size larger than normal cells, Might contain nucleus
Causes: Hypovitminosis (B12, B9) Antimetabolites that inhibit DNA synthesis e.g.
Purine & Pyrimidine Antagonists (6-Mercaptopurine, Cytosine)
Nutritional Anemia Vitamin B12 deficiency Anemias
Deficient intake in diet (vegetarians) Deficient intrinsic factor (Gestractomy & Pernicious Anemia) Selective B-12 malabsorption (removal of Terminal ileum) Increased needs: pregnancy, infant, rapid cellular proliferation.
Pernicious Anemia Most common form of Vitamin B12 deficiency Anemias Occurs more often in females Cause:
Autoimmune disease results in production of antibodies directed against Intrinsic Factor (IF)* and parietal cells in stomach.
Impaired absorption of vitamin B-12 due to the absence of intrinsic factor as a result of loss of gastric parietal cells.
Treatment IV injections of Vitamin B-12
Complications of B-12 deficiency anemia Appear before the signs of anemia Includes Irreversible neurological damage commonly in spinal
cord (B-12 needed for formation and maintenance of Myelin by schwann cells)
Nutritional Anemia
Vitamin B9 (Folic Acid) deficiency Anemias Deficiency causes megaloblastic anemia but not
associated with neurological damage Causes
Dietary Deficiency e.g. in infants absence or delay of establishing mix diets.
Alcoholism Anorexia (Loss of appetite) Pregnancy (Raised requirement) Malabsorption from jejunum (tropical sprue) Interference with Folate metabolism
Folic acid Antagonists (Methotrexate) Trimethoprim (Antimicrobial agent)
Deficiency Causes neural tube defects during pregnancy*
Folic acid Metabolism
Hemolytic Anemias3. Hemolytic Anemias
Occur when RBCs are destroyed in circulation or removed prematurely from circulation because of abnormal cells or overactive spleen
Hereditary or Congenital hemolytic AnemiasHereditary or Congenital hemolytic Anemias Hemolytic anemia which is primarily due to congenital
disorders Types include:
Genetic conditions of RBC Membrane Hereditary spherocytosis (Sphere shaped RBCs) Hereditary elliptocytosis (Elliptical RBCs) (Also known as ovalocytosis)
Genetic conditions of RBC metabolism (enzyme defects) Glucose-6-phosphate dehydrogenase deficiency (G-6-PD) 1
Pyruvate kinase deficiency (No energy) Hemoglobinopathies / genetic conditions of hemoglobin
Sickle cell anemia Thalassaemia
Hemolytic Anemias Acquired hemolytic anemia
No familial or racial factors have been identified Causes:
Chemical Agents: These agents may cause excessive or early hemolysis
Some Drugs, if taken for long time & in large doses e.g. Sulphonamides
Chemicals faced in general or work environment e.g. lead, arsenic compounds
Toxins produced by certain microbes. e.g. streptococcus pyogenes
Autoimmunity Production of antibodies against self antigens
Blood transfusion Reactions Parasitic Disease e.g. malaria Physical damage to cells by e.g. artificial heart valves, dialysis
machines.
Polycythemia An increase in RBCs number or hematocrit. (65%)
1. Absolute Polycythemia The overproduction of red blood cells in the bone marrow Causes:
Myeloproliferative syndrome, (MPDs)1
Reaction to chronically low oxygen levels Rarely, a malignancy.
Types:1. Primary Polycythemia (Polycythemia vera)
Excess red blood cells are produced as a result of an abnormality of the bone marrow e.g. (Malignancy), (Mutations in JAK2)2
2. Secondary Polycythemia Secondary polycythemia is caused by either natural or artificial increases
in the production of erythropoietin, hence an increased production of erythrocytes.
3. Chuvash Polycythemia (patients from Chuvashia- C598T mutations in (VHL) gene.
Polycythemia
2. Relative Polycythemia Relative Polycythemia is an apparent rise of the erythrocyte level
in the blood Cause: The underlying cause is reduced blood plasma. caused by
loss of body fluids, e.g. in burns, dehydration stress
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