Red blood cell disorders Anemias

1. Red blood cell disorders ''Anemias''

2. Red blood cell disorders Anemia Polycythemia increase in the total number of red blood cells Primary polycythemia (Vera) (Often associated with excess white blood cells and platlets) Secondary polycythemia Pancytopenia a combination of anemia, thrombocytopenia, and neutropenia

3. Definition of Anemia Anemia is a reduction in the number or volume of erythrocytes with a corresponding decrease in the hemoglobin and thereby ? O2 carrying capacity. There are a number of different types of anemia (~ 400 ), but many of them are rare. Some have mild health problems, while others are much more severe.

4. Normal erythrocytes

5. The Three Primary Measures Measurement Normal Range RBC count 5 (1012/L) 4 to 5.7 Hemoglobin 15 g/dl 12 to 17 Hematocrit 45 % 38 to 50 A x 3 = B x 3 = C - This is the rule of thumb Check whether this holds good in a given result If not -indicates micro or macrocytosis or hypochro.

6. The Three Derived Indicies Measurement Normal Range RBC 5 (1012/L) 4 to 5.7 Hemoglobin 15 g/dl 12 to 17 Hematocrit 45 % 38 to 50 MCV mean RBc volume in femtoliters (fl = 10-15 L) = 90 fl MCH = Hb ÷ RBC count = 30 pg MCHC = Hb ÷ hematocrit = 33g/dl

7. The Three Derived Indicies Measurement Normal Range RBC 5 (1012/L) 4 to 5.7 Hemoglobin 15 g/dl 12 to 17 Hematocrit 45 % 38 to 50 MCV C ÷ A x 10 = 90 fl MCH B ÷ A x 10 = 30 pg MCHC B ÷ C x 100 = 33g/dl

8. Anemia Anemia is a value of Hb or Hct which are more than two standard deviations (SD) below the normal mean level. Cut off marks for Hb WHO < 12.5 g US < 13.5 g Low levels are common in Patients living at high altitude The elderly Smokers 

9. Symptoms Symptoms of anemia often go unrecognized. The first signs are loss of appetite Constipation Headaches noises in the ears Irritability difficulty in concentrating Established anemia may present as Weakness Fatigue coldness of the extremeties Depression Dizziness overall pallor (pale complexion) pale and brittle nails soreness in the mouth Glossitis restless leg syndrome cessation of menstruation and/or a loss of libido

10. Clinical Signs to be looked for Skin / mucosal pallor Skin dryness, palmar creases Bald tongue, Glossitis Mouth ulcers Jaundice, Purpura Lymph adenopathy Hepato-splenomegaly Breathlessness Tachycardia, CHF Bleeding, Occult Blood

11. Causes of Anemia Anemia can be caused by one or more of three mechanisms: Decreased production of Red Cells - Hypo proliferative, marrow failure Increased destruction of Red Cells - Hemolysis (decreased survival of RBC) Loss of Red Cells due to bleeding - Acute / chronic blood loss (hemorrhagic)

12. Causes of Anemia Decreased production of Red Cells Disturbance of proliferation and differentiation of stem cells (aplastic anemia, tumor infiltration) Disturbance of proliferation and maturation of erythroblasts Defective DNA synthesis (megaloblastic anemia) Defective hemoglobin synthesis Deficient in heme synthesis (iron deficency anemia) Deficient in globin synthesis (thalasimia) Bone marrow suppression (drugs, chemotherapy, irradiation). Low levels of trophic hormones which stimulate RBC production, such as erythropoeitin (anemia due to renal failure).

13. Causes of Anemia Increased RBC destruction Inherited hemolytic anemias (eg, hereditary spherocytosis, sickle cell disease, thalassemia major) Acquired hemolytic anemias (autoimmune hemolytic anemia, thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, malaria) Blood loss Acute / chronic blood loss (hemorrhagic) Obvious bleeding (trauma, melena, hematemesis, menometrorrhagia) Occult bleeding (slowly bleeding ulcer or carcinoma). Induced bleeding (repeated diagnostic testing, hemodialysis losses, excessive blood donation)

14. Classification of anemia Anemia can be classified as: Nutritional: iron, vitamin B12, or folic acid. Non-nutritional: due to decreased development of RBC precursors, blood loss, decreased formation, or increased destruction of RBCs. Also Anemia can be classified by using two basic approaches: Etiology (mechanism): the causes of erythrocyte and hemoglobin depletion (with more details on important types later) Morphology: the characteristic changes (size, shape, and color) in the erythrocytes

15. Morphological changes of RBCs and Hb

16. Mean Cell Volume (MCV) RBC size is measured indirectly by The Mean Cell Volume (MCV) and RDW

17. Mean Cell Volume (MCV)

18. Morphological classification of anemia Macrocytic-normochromic anemia erythrocytes are large and abnormally shaped but hemoglobin is normal (megaloblastic anemia) Microcytic-hypochromic anemia erythrocytes are small and hemoglobin is reduced. results from irregular iron metabolism, porphryin, and globin synthesis (iron-deficiency, sideroblastic, thalassemia, chronic disease anemia) Normocytic-normochromic anemia both the erythrocytes size and the hemoglobin content are normal (aplastic, posthemorrhagic, hemolytic, chronic disease anemias, sickle cell)

19. Macrocytic Anemias A. Megaloblastic Macrocytic – B12 and Folate? B. Non Megaloblastic Macrocytic alcohol abuse Liver disease/alcohol Hemoglobinopathies Hypothyroidism Postspleenoctomy Reticulocytosis Drugs (cytotoxics, immuno suppressants, AZT, anticonvulsants)

20. Megaloblastic anemia Caused by deficiencies of vitamin B12 and /or folate that lead to defective DNA synthesis and, consequently, ineffective erythropoiesis (cell formation). The unusually large stem cells (megaloblasts) in the bone marrow mature into abnormally large erythrocytes (macrocytes) in the circulation. Produces large, abnormally shaped erythrocytes (MCV > 100 fl) with normal Hb concentrations. Megaloblastic stem cells are larger at all maturational stages than normal stem cells (normoblasts). The nucleus of the megaloblast is unusually small in relation to the size of the cell. Other common causes of macrocytic anemia include alcohol abuse, liver disease, and hypothyroidism.

21. Megaloblastic anemia Pathological features:- RBC: macrocytic with anisocytosis (?RDW) and poikilocytosis. Polymorphonuclear neutrophils (PMN): nuclear hypersegmented. Mild to moderate leucopenia and thrombocytopenia. Bone marrow: hypercellularity with abnormality of the three major hematopoietic cell lines.

22. Macrocytic anemia

23. Anisocytosis - Macrocytic Anemia (different size)

24. Poikilocytosis - Macrocytic Anemia (different shapes)

25. Megaloblastic anemia Clinical presentation Anemia Neuropsychatric disorders (B12) Hyperhomocysteinemia Premature gray hair Bald red beefy tongue Macrocytic anemias may be asymptomatic until the Hb is as low as 6 g.

26. Pernicious Anemia - Tongue

27. Microcytic-hypochromic anemia Small RBCs (MCV < 80 fL) and low Hb content (low MCH). Caused by Disorders of iron metabolism Disorders of heme synthesis Disorders of globin synthesis The most common types are iron deficiency thalassemia Sideroblastic anemia anemia of chronic diseases lead poisoning

28. Microcytic-hypochromic anemiaDifferential diagnosis Iron deficiency anemia: low serum ferritin, elevated total iron binding capacity (TIBC, transferrin), and low serum iron. Alpha or beta thalassemia: increased levels of Hb-A2 Anemia of chronic disease: low serum iron, low TIBC, and increased serum ferritin concentration. Sideroblastic anemia: The diagnosis is established by the demonstration of ringed sideroblasts on Prussian Blue stain of the bone marrow

29. Microcytic Anemias

30. Microcytic HypochromicIron Deficiency Anemia

31. Hypochromia

32. Sideroblastic anemia

33. Normocytic-normochromic anemia Characterized by destruction or depletion of normal or mature erythrocytes. Does not share any common cause, pathologic mechanism, or morphologic characteristics. The most common types are: Aplastic anemia (depressed stem cell proliferation resulting in bone marrow aplasia) Posthemorrhagic anemia (any blood loss) Anemia of chronic disease Hemolytic anemia Sickle cell anemia

34. Hemolytic Anemia Anemia of increased RBC destruction – Normochromic, normocytic anemia – Shortened RBC survival – Reticulocytosis – due to ? RBC destruction

35. Classification of Hemolytic anemias I. Red cell abnormality (Intracorpuscular factors) A. Hereditary  1. Membrane disorders spherocytosis, elliptocytosis 2. Metabolic defect Glucoze-6-Phosphate-Dehydrogenaze deficiency, Pyruvate kinase (PK) deficiency  3. Hemoglobinopathies unstable hemoglobins, thalassemias, sickle cell anemiaB. Acquired Membrane abnormality paroxysmal nocturnal hemoglobinuria (PNH)

36. Classification of Hemolytic anemias II. Extracorpuscular factors A. Immune hemolytic anemias  1. Autoimmune hemolytic anemia  - caused by warm-reactive antibodies  - caused by cold-reactive antibodies  2. Transfusion of incompatible blood B. Nonimmune hemolytic anemias  1. Chemicals  2. Bacterial infections, parasitic infections (malaria), venons 3. Hemolysis due to physical trauma  - hemolytic -uremic syndrome (HUS) - thrombotic thrombocytopenic purpura (TTP) - prosthetic heart valves 4. Hypersplenism

37. Hemolytic anemias Mechanisms of hemolysis: - Intravascular - Extravascular

38. Classification of Hemolytic anemias Intravascular hemolysis (1):- red cells destruction occurs in vascular space - clinical states associated with intravascular hemolysis: acute hemolytic transfusion reactions  severe and extensive burns  paroxysmal nocturnal hemoglobinuria severe microangiopathic hemolysis  physical trauma  bacterial infections and parasitic infections (sepsis)

39. Hemolytic anemia Inravascular hemolysis (2): - laboratory signs of intravascular hemolysis:  indirect hyperbilirubinemia  erythroid hyperplasia  hemoglobinemia methemoalbuminemia hemoglobinuria absence or reduced of free serum haptoglobin  hemosiderynuria

40. Extravascular hemolysis :- red cells destruction occurs in reticuloendothelial system - clinical states associated with extravascular hemolysis : autoimmune hemolysis delayed hemolytic transfusion reactions  hemoglobinopathies hereditary spherocytosis  hypersplenism hemolysis with liver disease - laboratory signs of extravascular hemolysis: indirect hyperbilirubinemia  increased excretion of bilirubin by bile erythroid hyperplasia  hemosiderosis

41. Diagnosis of hemolytic syndrome: 1. Anemia 2. Reticulocytosis 3. Indirect bilirubinemia

42. Tests Used to Diagnose Hemolysis Reticulocyte count Combined with serial Hb Hemoglobin electrophotesis Serum LDH Serum bilirubin Haptoglobin Urine hemosiderin Hemoglobinuria

43. General laboratory findings in Hemolytic Anemia

45. sickle cell anemia Definition: chronic hemolytic anemia characterized by sickle-shaped red cells caused by homozygous inheritance of Hb-S

46. sickle cell anemia

47. sickle cell anemia -pathogenesis In Hb S, valine is substituted for glutamic acid at the 6th amino acid position of the ß-globin chain. The alpha chain is normal. In homozygotes (sickle-cell anemia, SS gentotype) all Hb A is replaced by Hb S. In homozygotes (sickle-cell trait, AS gentotype) only half of Hb A is replaced by Hb S. - Deoxygenated Hb S is much less soluble than deoxygenated Hb A; it forms a gelatinous network of fibrous polymers that cause RBCs to sickle at sites of low O2 tension. - Hemolysis occurs because sickle RBCs are too fragile to withstand the mechanical trauma of circulation - Occlusion in microvascular circulation caused by distorted, inflexible RBCs adhering to vascular endothelium

48. Pathological changes Hemolysis ? anemia ? reticulocytosis Increased break down of Hb ? bilirubin formation Capillary stasis ? ischemia, infarction, congestion and thrombosis in any organ

49. Sickle cell anemia-clinical features In Homozygotes 1. Clinical complications due to severe hemolytic anaemia - slowed growth and development in children - bilirubins stones - aplastic crises (sudden cesation of erythroopiesis) - congestive heart failure from chronic anemias and cardiac overload compensation - autosplenectomy (fibrosis and shrunken) 2. Consequences of vaso-occlusion of the microcirculations (tissue ischemia and infarction (infarction crises) ) - infarction of spleen, brain, bone marrow, kidney, lung, central nervous system and ophtalmic vascular lesions

50. Sickle cell anemia-Laboratory findings Severe anemia (normocytic or slightly macrocytic) HCT 18-30% Reticulocytosis Biliruninemia Peripheral smear: sickle shaped red cells, Howell-Jolly bodies (splenic function) Hb -electrophoresis

51. Howell-Jolly Bodies

52. Sickle cell anemia-Therapy Preventive measures: prevention or remedy of: infections(penicillin prophylaxis and pneumococcal vaccination) fever, dehydratation, acidosis, hypoxemia, cold exposure Blood transfusions for very severe anemia New approaches to therapy; 1. Activation of Hb F synthesis -5-azacytidine 2. Antisickling agents acting on hemoglobin or membrane 3. Bone marrow transplantation

54. Autoimmune hemolytic anemia Warm antibodies autoimmune hemolytic anemiaMediated by IgG antibodies that react with red cell surface antigen. the natibodies optimally active at 370C (warm) I. Primary II. Secondary 1. acute - viral infections - drugs ( ?-Methyldopa, Penicillin, Quinine, Quinidine) 2. chronic  - rheumatoid arthritis, systemic lupus erythematosus - lymphoproliferative disorders (chronic lymphocytic leukemia, lymphomas,  WaldenstrÖm’s macroglobulinemia) - miscellaneous (thyroid disease, malignancy )

55. Autoimmune hemolytic anemia Cold antibodies autoimmune hemolytic anemia Mediated by IgM. Optimally active below 300C (cold). I. Primary cold agglutinin disease II. Secondary hemolysis: - mycoplasma infections  - viral infections  - lymphoproliferative disorders  III. Paroxysmal cold hemoglobinuria

56. Autoimmune hemolytic anemia Diagnosis:  - positive Coombs’ test Treatment: - steroids - splenectomy - immunosupressive agents  - blood transfusion

57. Hereditary spherocytosis 1. Pathophysiology - red cell membrane protein defects (spectrin deficiency)  resulting cytoskeleton instability2. Familly history3. Clinical features - anemia, splenomegaly and jaundice4. Laboratory features - hemolytic anemia - blood smear-spherocytes  - abnormal osmotic fragility test 5. Treatment  - splenectomy

58. Hereditary spherocytosis

59. Paroxysmal nocturnal hemoglobinuria (PNH) 1. Pathogenesis - an acquired clonal disease, arising from a somatic mutation in a single stem cell gene (PIG-A)- red cells are more sensitive to the lytic effect of complement - intravascular hemolysis  2. clinical features. - passage of dark brown urine in the morning - Intravascular hemolytic anemia - Pancytopenia - Venous thrombosis

60. Paroxysmal nocturnal hemoglobinuria (PNH) 3. laboratory features: - pancytopenia - decreased serum iron - hemoglobinuria - hemosiderinuria - positive Ham’s test (acid hemolysis test) - Flow cytometry: specific immunophenotype of erytrocytes (CD59, CD55)4. Treatment: - washed RBC transfusion - iron therapy  - allogenic bone marrow transplantation

62. Tests to define the cause of hemolysis Hemoglobin electrophoresis Hemoglobin A2 (ßeta-Thalassemia trait) RBC enzymes (G6PD, PK, etc) Direct & indirect antiglobulin tests (immune) Cold agglutinins Osmotic fragility (spherocytosis) Acid hemolysis test (PNH) Clotting profile (DIC)

63. Leukoplakia - Aplastic Anemia