Red Blood Cell Disorders DR.Leni Lismayanti, SpPK-K Dept of Clinical Pathology RSHS/FKUP Bandung
Reference book: • Denise M Harmening. Clinical Hematology and Fundamental of Hemostasis. 5th edition. Philadelphia: FA Davis Co, 2009.
RBC Structure & Function • Areas of RBC metabolism important in normal RBC survival and function: • RBC membrane • Hb structure & function • RBC metabolic pathway
RBC Membrane • RBC membran proteins: • Deformability • Permeability • RBC membran lipids: • Phospholipd • Glycolipid • cholesterol
Hb Structure & Function Hb function: delivery and release of oxygen to the tissue and facilitation of CO2 excretion. • Hb synhesis • depends on 3 prs: • Adequate Iron delivery & supply • Adequate synthesis of protophorphyrin • Adequate globin synthesis
RBC Metabolic Pathway ATP needs for: • Hb function • Membrane integrity & deformability • RBC volume • Adequate amounts of reduced pyridine nucleotides • Protection of metabolic enzymes
RBC Senescence & Hemolysis • RBC traveles 200-300 miles during 120 day life span undergo the process of senescence (aging) metabolic & physical changes. • 1% RBC taken out (removed) from circulation by RES/MPS process: • Extravascular hemolysis (90%) • Intravascular hemolysis (5-10%)
RBC Disorders: • Numbers: • Decreased (Anemia) • Increased (Polycythemia) • Structure and function: • Hemoglobin • RBC membrane • Abnormal erythropoiesis nutritional RBC disorders morphologic changes
Anemia • Inability of the circulating blood pool to supply the tissue with adequate oxygen for proper metabolic function. • Clinically d/ based on: HT, SS, PE, Lab. • Caused by or associated with underlying disease. • Usually associated with decrease Hb & Hct (Lab: + RBC count). • Consideration by age, sex and other fact
Classification of Anemia • Based on Hb level: • Moderate (7-10), severe (<7). • BM dynamic: • Hypoproliferative • Accelerated destruction • combination • Clinically (caused): • RBC indices (normochromic normocytic)
Categories of anemia by causes • Blood loss • Accelerated destruction • Nutritional deficiency • BM replacement • Infection • Toxicity • Hematopoietic SC arrest/damage • Hereditary/acquired defect • idiopathic
Significance of Anemia and Compensatory Mechanism • N: 1% of RBC loss daily BM produce (measured by reticulocyte count 0.5-2.0%). • Replacement RBC requires: • Adequate functioning SC in BM • Normal RBC maturation process • Ability to release mature RBC from BM
Proper HB & RBC production requires: • Variety of nutritional factors • Normal pathway of Bh synthesis • In severe anemias symptoms of functional impairment of several organs (+). • Compensatory mechanism increase 2,3-DPG levels
2,3-DPG • Physiologic regulator of: • Normal Hb oxygen-carrying capacity • Tissue oxygen delivery • 2,3-DPG (+) Hb more readily released oxygen to tissues depend on: pH & Oxygen level of arterial blood. • N individual responds to anemia elevated EPO Recombinant EPO Th/ certain anemia.
Lab Tests in Diagnosis of Anemia • Hb • Hct • (RBC Count) • RBC indices • Peripheral Blood Smear • Reticulocyte Count • BM smear/biopsy Treatment of anemia: depends on etiology
Polycythemia • Polycythemia Vera (Myeloproliferative disorders). • Secondary Hypoxic Polycythemia (Secondary Erythrocytosis). • Relative Erythrocytosis.
Thank You Very Much for Your Attention