1. 溶血性贫血 Hemolytic Anemia

2. HEMOLYTIC ANEMIA (reduced RBC life span)
Anemia of increased RBC destruction
Normochromic, normochromic anemia
Shortened RBC survival
Reticulocytosis--Response to increased RBC destruction
Increased indirect bilirubin
Increased LDH

3. Mechanisms and Causes membrane abnormalities
Inheritory: genetic defect
membrane abnormalities
metabolic abnormalities: enzyme defect
hemoglobinopathies
Acquired:
non-immune
immune

4. Membrane Defects - Hereditary spherocytosis
Microskeletal defects
- Hereditary spherocytosis
Increased sensitivity to complement
- Paroxysmal nocturnal hemoglobinuria

5. Enzymopathies - Glucose 6-Phosphate Dehydrogenase Deficiency - Pyruvate Kinase Deficiency Hemoglobinopathies - Hemoglobinopathy - Thalassemia

6. Extracorpuscular Hemolysis Nonimmune
Infectious
Chemical
Thermal
Osmotic

7. Extracorpuscular Hemolysis Immune
all require antigen-antibody reactions
- class of antibody
- number & spacing of antigenic sites on cell
- availability of complement
- temperature
- functional status of reticuloendothelial system

8. Extracorpuscular Hemolysis Immune
Antibodies combine with RBC, & either
- activate complement cascade, &/or
- opsonize RBC for immune system
If complement cascade is fixed to red cell, intravascular cell lysis occurs
&/or if complement is only partially fixed, macrophages recognize Fc receptor of Ig &/or C3b of complement & phagocytize RBC, causing extravascular RBC destruction

9. Classification
Intravascular
Extravascular

10. Clinical features Chronic pallor jaundice splenomegaly cholelithiasis
aplastic crisis
Acute
algor
hyperpyrexia
sore waist
hemoglobinuria
jaundice/anemia

11. Laboratory examination
- Increased RBC destruction
- Reduced RBC life span
- Indirect hyperbilirubinemia
- Erythroid hyperplasia
- Reticulocytosis
- Erythroblasts, anisopoikilocytosis, spherocytes
in blood smear
- Erythroid hyperplasia in bone marrow

12. Diagnosis and differential diagnosis
- hemolysis or not?
- type of hemolysis
- jaundice with other anemia?

13. Treatment - treatment targeting the causes - immunosupressive drug
- washed RBC transfusion
- splenectomy
- symptomatic treatment

14. Hereditary Spherocytosis
- defective or absent spectrin molecule
- leads to loss of RBC membrane, leading to spherocytosis
- decreased deformability of cell
- increased osmotic fragility
- extravascular hemolysis in spleen

15. Hereditary Spherocytosis
- Pathophysiology--RBC membrane protein defects (spectrin deficiency) resulting cytoskeleton instability
- Familly history
- Clinical features—splenomegaly

16. Hereditary Spherocytosis
Laboratory features - hemolytic anemia - blood smear-microspherocytes - abnormal osmotic fragility test - positive autohemolysis test - prevention of increased autohemolysis by
including glucose in incubation medium
Treatment--splenectomy

17. Hereditary Spherocytosis

18. Hereditary Spherocytosis Osmotic Fragility

19. Paroxysmal Nocturnal Hemoglobinuria (PNH)
PNH is an acquired chronic hemolytic anemia which arises from a somatic mutation in a hematopoietic stem cell.
Most hematopoitic cell lines may be affected by the intrinsic membrane defect. This defect renders the red cells highly susceptible to complement mediated lysis resulting in the characteristic hemolysis.

20. Paroxysmal Nocturnal Hemoglobinuria (PNH)
Pathogenesis - an acquired clonal disease, arising from a somatic mutation in a single abnormal stem cell - glycosyl-phosphatidyl- inositol (GPI) anchor abnormality - deficiency of the GPI anchored membrane proteins(CD55 and CD59) - red cells are more sensitive to the lytic effect of complement intravascular hemolysis

21. clinical manifestation
- Pancytopenia
- Passage of dark brown urine in the morning
- Venous thrombosis

22. Laboratory features - Pancytopenia - Chronic urinary iron loss
- Serum iron concentration decreased
- Hemoglobinuria
- Hemosiderinuria
- Positive Ham’s test (acid hemolysis test), sugar-water test
- Specific immunophenotype of blood cells(CD59, CD55)

23. Attention AA-PNH syndrome - AA→PNH - PNH→AA - PNH with AA
- AA with PNH

24. Treatment - avoid causes - washed RBC transfusion - iron therapy
- allogenic bone marrow transplantation

25. G-6-PD Deficiency - acute hemolytic anemia
- congenital nonspherocytic hemolytic anemia
- neonatal hyperbilirubinemia （kernicterus）
- favism

26. Level needed for protection vs ordinary oxidative stress

27. Autoimmune Hemolysis
- due to formation of autoantibodies that attack patient’s own RBC’s
- type characterized by ability of autoantibodies to fix complement & site of RBC destruction
- often associated with either lymphoproliferative disease or collagen vascular disease

28. Autoimmune Hemolytic Anemia
warm-reactive antibodies
- primary
- secondary
cold-reactive antibodies
- cold agglutinin
syndrome
- paroxysmal cold
hemoglubinuria

29. Autoimmune hematolysis Warm Type
- IgG+C3
- IgG
- C3

30. Autoimmune hematolysis Warm Type
- usually IgG antibodies
- fix complement only to level of C3,if at all
- immunoglobulin binding occurs at all temps
- Fc receptors/C3b recognized by macrophages
- hemolysis primarily extravascular
- 70% associated with other illnesses
- responsive to steroids/splenectomy

31. Clinical manifestation
- anemia、jaundice、splenohepatomegalia
- ITP+AIHA=Evens syndrome

32. Laboratory examination
- blood：anemia；Ret；erythroblasts, anisopoikilocytosis
- bone marrow：erythroid hyperplasia
- Coombs Test

33. Coombs Test - Direct
- looks for immunoglobulin &/or complement of surface of red blood cell (normally neither found on RBC surface)
- coomb’s reagent - combination of anti-human immunoglobulin & anti-human complement
- mixed with patient’s red cells; if immunoglobulin or complement are on surface, Coombs reagent will link cells together and cause agglutination of RBCs

34. Coombs Test - Indirect
- anti-red blood cell antibodies in the patient’s serum, using a panel of red cells with known surface antigens
- combine patient’s serum with cells from a panel of RBC’s with known antigens
- add Coombs’ reagent to this mixture
- if anti-RBC antigens are in serum, agglutination occurs

35. Treatment - Steroids - Splenectomy - Immunosupressive agents
- Transfusion

36. Autoimmune hematolysis Cold Type
- Most commonly IgM mediated
- Antibodies bind best at 30º or lower
- Fix entire complement cascade
- Leads to formation of membrane attack complex, which leads to RBC lysis in vasculature
- Typically only complement found on cells
- 90% associated with other illnesses
- Poorly responsive to steroids, splenectomy; responsive to plasmapheresis

37. Summary - Causes of increased RBC destruction
- Marrow function usually normal
- Requires extra folic acid to maintain hematopoiesis
- Anything that turns off the bone marrow can result in acute, life-threatening anemia