anemia etiology
TRANSCRIPT
Eti0logical Classification Of Anemia
OBJECTIVES
Definition
General Presentation
Classification
What is Anemia?
Anemia refers to a state in which the level of hemoglobin in the blood is below the normal range appropriate for that age and sex.
WHO Definition Male less than 13 g/dl Female less than 12 g/dl Pregnant less than 11 g/dl
Factors responsible forAnemic State
Volume lossReduced red cell massReduced hemoglobinRed cell / Hemoglobin defectImpaired red cell / hemoglobin
production
Ultimately, the oxygen-carrying capacity ofblood is reduced.
PALLORSites to look for:
Palpebral conjunctiva Skin Creases of palms and hands Nails Mucous membranes
Presentation
Usually non-specific symptoms:
Tiredness Lightheadedness Breathlessness Lassitude
Non-specific signs:
Pallor Tachypnoea Raised jugular venous pressure Postural hypotension Tachycardia Flow murmurs
Etiological Classification Of Anemia
3 major categories
1) Marrow production defects (Hypoproliferation)
2) Red cell maturation defects (Ineffective erythropoiesis)
3) Decreased red cell survival (Blood loss/Hemolysis)
Hypoproliferative Anemias
Marrow damage:• Infiltration (leukemia,lymphoma) /
fibrosis• Aplasia• Drugs (anti-retrovirals)
Fe def.
Disturbance of proliferation and differentiation of stem cells:
• Pure red cell aplasia
• Anemia of renal failure
• Anemia of endocrine disorders (hypoTH, DM)
Unknown / multiple mechanisms
• Anemia of chronic inflammations
1. Chr. Microbial infections (OM, bac endocarditis, lung abscess)
2. Chr. Immune disorders (RA, regional enteritis)
3. Neoplasms (HL, ca lung/breast)
• Myelophthisic anemias
Maturation Disorders
Cytoplasmic defects:
• Defecient heme synthesis fe def.
• Defective globin synthesis thalassemia
• Myelodysplastic syndromes sideroblastic anemia
Nuclear defects:
• Folate def.
• Vit. B12 def.
• Drug toxicity (mtx, alkylating agents)
• Refractory anemia (myelodysplasia)
Blood loss
Blood loss:
• Acute trauma
• Chronic lesions of g.i.t. gynaecologic disturbance
Hemolytic Anemia
Intrinsic abnormalities of red cells
1. Hereditary
a) Red cell membrane disorders
• Disorders of membrane cytoskeleton:Spherocytosis Elliptocytosis
• Disorders of lipid synthesis:selective increase in membrane
lecithin
b) Red cell enzyme deficiencies
• Glycolytic enzymes:PK def.Hexokinase def.
• Enzymes of HMP shunt:G6PD Glutathione synthetase
c) Disorders of hemoglobin synthesis
• Deficient globin synthesis:Thalassemia syndromes
• Hemoglobinopathies (str. abnormality):
Sickle cell anemiaUnstable hb
2. Acquired
a) Membrane defect:PNH
Extrinsic abnosmalities of red cells
1. Antibody mediated
• Isohemagglutinins:Transfusion reactionsErythroblastosis fetalis
• Autoantibodies:Idiopathic (primary)Drug-associatedSLEMalignant neoplasmsMycoplasmal infection
2. Mechanical trauma to red cells
• Microangiopathic Hemolytic Anemias (MAHA)
TTPDIC
• Cardiac traumatic hemolytic anemia
3. Infections: Malaria Hookworm
4. Chemical injury: Lead poisoning
5. Sequestration in Mononuclear PhagocyteSystem:
Hypersplenism