Lec-8. Hemolysis (PDF)

Red blood cell destruction Degradation of heme  Red blood cells are degraded by the cells of the reticuloendothelial system particularly in the spleen and liver after 120 days in the circulation (RBC life span)  Therefore, The principal sites of hemoglobin catabolism are the sp...

Red blood cell destruction Degradation of heme  Red blood cells are degraded by the cells of the reticuloendothelial system particularly in the spleen and liver after 120 days in the circulation (RBC life span)  Therefore, The principal sites of hemoglobin catabolism are the spleen & the liver  Bilirubin is the end product of hemoglobin catabolism: ◦ 85% from hemoglobin of old RBCs, ◦ the rest from hemoglobin of immature RBCs & from cytochromes from extra-erythroid tissues  Factor that contribute to hemolysis of normal RBC.s Aging factor of RBC,s Types of hemolysis Intravascular hemolysis May be  Physiological very little  Pathological Extravascular hemolysis May be  Physiological 85%----90%  Pathological  Pathway for haem degradation Hemoglobin catabolism is classified into 3 stages: 1. Formation of bilirubin in reticuloendothelial system (RES) 2. Uptake, conjugation and secretion of bilirubin by the liver 3. Catabolism of bilirubin in the gut Extravascular hemolysis  Occors in the  Spleen  Liver  Bone marrow Intravascular hemolysis Hemolysis within the vessels Negligible But if increases so then it is called pathological intravascualar hemolysis  Difference between intravascular and extravascular Substance Extravascular Intravascular Site Spleen, liver, bone Vessels marrow Hemoglobinemia Absent present Hemoglobinuria Absent Present Hemosidrinuria Absent present Haptoglubin Decrease Absent Hemofixin Decrease Absent Splenomegaly Present Absent Renal failure Absent Present Thank You