Anemia, Microcytic Hypochromic and Macrocytic anemia
- 1. Anemia , its classification, Microcytic Hypochromic and Macrocytic anemia Dr. Mehdi Ashik Chowdhury M.B.B.S. MD. (BSMMU) Assistant Professor & Head of the Department of Pathology Tairunnessa Memorial Medical College
- 19. Deficiency anaemia Iron deficiency anaemia
- 27. Cause of Iron deficiency anaemia • A) Increased physiological demand 1) During period of growth of children. 2) During reproductive life of female- Menstruation, Pregnancy, Parturation, lactation. • B) Nutritional deficiency : Deficient diet. • C) Pathological blood loss : Adult male and Postmenopausal female D) Impaired absorption : Coeliac disease, Tropical sprue.
- 28. Total body iron content is about 3 to 5 gram. The distribution of body iron is as follows : Haemoglobin 2.3 gm. Storage (available) tissue 1.0 gm. iron (Ferritin and haemosiderin) Essential (Non-available) tissue 0.5 gm. Iron (myoglobin and enzyme of Cellular respiration) Plasma (transport) iron 3-5 mg Total 3.8 gm.
- 29. • Clinical feature of Iron deficiency anaemia: • Symptoms : • Fatigue and weakness, Dyspnoea on exertion, Palpitation, Headache. In older subject Angina pectoris and symptoms of cardiac failure. Signs : Pallor of mucous membrane and conjunctiva. Tachycardia, systolic flow murmur. Koilonychia (Brittle, spoon shaped nail) Plummer-vinson syndrome : Glossitis, Dysphagia due to constriction at the entrance of oesophagus and chronic iron deficiency.
- 30. Diagnosis of Iron deficiency anaemia • Hb% : Reduced • MCV, MCH and MCHC all are reduced. • Blood film : • RBC : Microcytic hypochromic with anisopoikilocytosis including a few eliptical cells and pencil form cells with occasional target cell. • WBC : Mature with normal count and distribution. • Platelets are adequate in number with normal morphology. • Comment : Microcytic hypochromic anaemia suggestive of iron deficiency anaemia.
- 32. Biochemical test Serum iron profile : Serum iron : Reduced Serum ferritin : Reduced Total iron binding capacity : Increased Percentage saturation of iron binding protein :Decreased Red cell protoporphyrin level is increased. Protoporphyrin accumulate in the free form as there is insufficient iron to bind with it to form haem.
- 33. Bone marrow examination. • Bone marrow examination is not needed in iron deficiency anaemia unless there is unusual difficulties in the differentiation of iron deficiency anaemia from other cause of hypochromic anaemia. If it is done the marrow picuture will be as follows : • Cellularity : Hypercellular. • Myeloid erythroid ratio : Reduced • Erythropoiesis : Hyperplastic and micronormoblastic. • Granulopoiesis : Active and maturing to segmented form. • Megakaryocytes are normal in number and morphology. • Lymphocytes and plasma cells are normal in number and morphology. • Perl’s prussian blue stain: No stainable iron.
- 34. • Causes of microcytic hypochromic anaemia: • Iron deficiency anaemia • Thalassaemia • Anaemia of chronic disease. • Sideroblastic anaemia. • Lead poisoning.
- 35. Anemia of Chronic Disease • EPO production inadequate for the degree of anemia observed or erythroid marrow responds inadequately to stimulation • Causes: inflammation, infection, tissue injury, cancer • Low serum iron, increased red cell porphyrin, transferrin 15-20%, normal to increased ferritin
- 36. Pathophysiology
- 37. AICD vs. Iron Deficiency • TIBC: elevated in cases of iron deficiency • Ferritin: elevated in anemia of chronic disease • If all else fails, Bone Marrow Biopsy – In anemia of chronic disease: macrophages contain normal/ increased iron & erythroid precursors show decreased/absent amounts of iron
- 38. Treatment • Treat the underlying cause • Treat the underlying cause • And Treat the Underlying Cause! • Consider co-existent iron deficiency as well • If underlying disease state requires it, consider EPO injection
- 39. Iron deficieny anaemia Anaemia of chronic Diasease Thalassa- emia trait. Siderobl- astic anaemia MCV MCH Reduced in relation with sev- erity of anaemia Normal or mild reduction Reduced; very low for degree of anaemia. Usually low but may be high* Serum iron Reduced Reduced Normal Raised TIBC Raised Reduced** Normal Normal
- 40. *Normal in congenital type but MCV often raised in acquired type. ** Iron deficieny anaemia Anaemia of chronic Diasease Thalassa- emia trait. Siderobl- astic anaemia Serum transferin receptor Raised Normal/ Low Variable Normal Serum ferritin Reduced Normal or raised Normal Raised Bone marrow iron stores Absent Present Present Present
- 41. Iron deficieny anaemia Anaemia of chronic Diasease Thalassa- emia trait. Siderobl- astic anaemia Erythrob- last iron Absent Absent Present Ring form Haemogl- obin Elect- rophoresis Normal Normal HbA2 raised in β form. Raised
- 42. • A characteristic finding of ACD (Anaemia of chronic disease) is low serum iron with adequate reticuloendothelial iron but with reduction of iron in marrow erythroblast. The fall in serum iron results from impaired flow of iron from cells (Including intestinal mucosal cells, hepatocytes and macrophages ) to plasma. The inflammatory cytokines TNF, IL-1 and IFN-γ all have shown to cause reduced serum iron and increased serum ferritin. Increased lactoferrin , occuring in response to inflammatory cytokines competes with transferrin for iron and form a complex, which is taken up by macrophages in liver and spleen. Increased intracellular apoferritin synthesis occurs in response to inflammation and malignancy and this too also bind iron. All of these mechanism reduce the amount of available iron for binding to serum transferrin and thus serum iron is reduced. • ** A rise in serum ferritin and fall in serum transferrin occur as part of acute phase response. • *MCV and MCH are low in congenital sideroblastic anaemia but they are higher in acquired sideroblastic anaemia. • In iron deficiency anaemia microcytosis appear first then hypochromia • In anaemia of chronic disorder hypochromia appear first and then microcytosis. In anaemia of chronic disorder haemoglobin seldom become lower than 9 gm /dl, In iron deficiency anaemia haemoglobin may be much lower.
- 43. • Iron deficiency :The earliest changes in iron deficiency are a fall in bone marrow iron and a concomitant fall in serum ferritin. This is followed by a fall in serum ferritin and rise in RBC free erythrocyte protoporphyrin. The MCV then falls and finally Hb falls with hypochromia of red cells. • Lead poisoning : Microcytosis may be seen in lead poisoning but is not uniformly present, while a rise in free erythrocyte protoporphyrin is almost invariably present. Free erythrocyte protoporphyrin tends to be much higher in lead poisoning than in iron deficiency anaemia. • Thalassemia Minor : A low MCV is the hallmark of thalassemia minor and the MCV may be used as a screening test in the detection of beta thalassemia minor . A very simple calculation may be used to distinguish iron deficiency and lead poisoning from thalassemia minor . The test is done on MCV and RBC count . If MCV is divided by RBC count, a discriminate index is obtained : • MCV/RBC if < 12 = Thalassaemia minor • MCV/RBC if > 14 = Iron deficiency or lead poisoning.
- 44. • Pathogenesis of iron deficiency anaemia : • Three pathogenetic factor are implicated in iron deficiency anaemia. • The first is reduced haemoglobin synthesis. • The second is generalized defect in cellular proliferation. • The third is reduced RBC survival especially in severe iron deficiency. So in severe iron deficiency fragmented RBC may be seen in peripheral blood, • When transferrin saturation falls below 16% , the supply of iron to the marrow is inadequate to meet the basal requirement of haemoglobin synthesis. The synthesis of heam is reduced and there is accumulation of more free protoporphyrin. Each cell produced less haemoglobin, resulting in microcytosis and hypochromia. • Cellular proliferation is restricted in iron deficiency and red cell count falls. Although there is relative erythroid hyperplasia in the bone marrow , both the degree of erythroid hyperplasia and the reticulocyte count are low for the degree of anaemia. There is significant component of “ineffective erythropoiesis” in iron deficiency and a proportion of immature erythroid cells are so defective that they are rapidly destroyed.
- 45. • In iron deficiency, survival of circulating erythrocyte is normal or somewhat reduced. There is strong correlation between the degree to which red cell survival is shortened and the proportion of morphologically abnormal cells. • With haemorrhagic anaemia, in contrast to haemolytic anaemia, the rate of red cell production may be restricted by the availability of iron, even in the absence of iron deficiency. Iron must be drawn from ferritin and haemosiderin stored in macrophages, a slow process compared to mobilization of iron from destroyed red cells. Marrow production after hemorrhage may be limited to approximately three times the normal level, compared with five or even times the normal level in chronic haemolytic states. If there is concurrent inflammation, iron supply may also further restricted.
- 46. Pathogenesis of anaemia of chronic disease. • A mild decrease of red cell lifespan occurs in ACD, but it is at a level that could be compensated by a normal marrow. The major cause of ACD is disturbance of erythropoiesis due to reduced sensitivity to physiological erythropoietic activity, relative lack of erythropoietin and reduced iron utilization. • Relative lack of erythropoietin : Normally with reduction of haemoglobin there is increase of erythropoietin. In ACD there is also increase in erythropoietin but the increase is relatively low compared with other type of anaemia. • Inhibition of erythropoiesis : TNF and IL-1 may cause inhibition of erythropoiesis.
- 47. • Reduced Iron Utilisation : • A characteristic finding of ACD (Anaemia of chronic disease) is low serum iron with adequate reticuloendothelial iron but with reduction of iron in marrow erythroblast. The fall in serum iron results from impaired flow of iron from cells (Including intestinal mucosal cells, hepatocytes and macrophages ) to plasma. The inflammatory cytokines TNF, IL-1 and IFN-γ all have shown to cause reduced serum iron and increased serum ferritin. Increased lactoferrin , occuring in response to inflammatory cytokines competes with transferrin for iron and form a complex, which is taken up by macrophages in liver and spleen. Increased intracellular apoferritin synthesis occurs in response to inflammation and malignancy and this too also bind iron. All of these mechanism reduce the amount of available iron for binding to serum transferrin and thus serum iron is reduced.
- 49. • Megaloblastic anemia is an anemia that results from inhibition of DNA synthesis in red blood cell production. When DNA synthesis is impaired, the cell cycle cannot progress from the G2 growth stage to the mitosis (M) stage. The cells have a prolonged intermitotic resting phase and a block early in mitosis. This leads to continuing cell growth without division, which presents as macrocytosis. Cytoplasmic maturation and growth continue accounting for enlargement of cytoplasm as well as nucleus of cells. Due to block early in mitosis there is also increased number of mitotic figure. Nuclear chromatin is open, delicate and stippled ( Granular chromatin or salt and pepper chromatin). Stippled nuclei can be observed even in the orthochromatic stage. There is increased number of promegaloblast and basophilic megaloblast in the bone marrow than in normal erythropoiesis. This has termed as maturation arrest.
- 50. • Megaloblastic anaemia are anaemia resulting from impaired DNA synthesis characterized by presence of megaloblast in the bone marrow and macrocyte (macro-ovalocyte) in the peripheral blood. They usually result from deficiency of Vitamin B12 and folic acid.
- 51. Causes of megaloblastic anaemia due to vitamin B12 deficiency : 1) Decreased intake : Nutritional deficiency 2) Impaired absorption Gastric cause : Pernicious anaemia Gastrectomy 3) Intestinal cause : Coeliac disease Tropical sprue Fish tapeworm infestation
- 52. Clinical manifestation of megaloblastic anaemia due to vitamin B12 deficiency : 1) Sign symptoms of anaemia 2) Glossitis. 3) Peripheral neuropathy and subacute combined degeneration of spinal cord. Neurological manifestation occur more frequently in pernicious anaemia than other cause of vitamin B12 deficiency.
- 53. Megaloblastic anaemia due to folate deficiency : 1) Decreased intake : Nutritional deficiency 2) Impaired absorption : Coeliac disease Tropical sprue 3) Increased demand : Pregnancy Haemolytic anaemia Myeloproliferative disorder. Leukaemia and lymphoma Inflammatory disorder. Hyperthyroidism. 4) Drugs : Anticonvulsant drugs Oral contraceptive Methotrexate, Trimethoprim.
- 54. Clinical manifestation of megaloblastic anaemia due to folate deficiency : • 1) Symptoms and signs of anaemia. • 2) Glossitis.
- 55. Diagnosis of megaloblastic anaemia • Blood picture : • Hb : Reduced. • MCV : Increased. Commonly 110 to 140 fl. • MCHC : Normal • MCH : Increased. • Blood film : Macrocytic RBC many of which are macro-ovalocyte. WBC count may be reduced with increased number of hypersegmented neutrophil (Five or more lobes). Platelets are normal or reduced.
- 57. • Bone marrow examination : • Cellularity : Hypercellular. • Myeloid erythroid ratio : Reduced. • Erythropoiesis: Hyperactive and megaloblastic. Megaloblastic changes are seen at all stages of development. Megaloblasts are larger than erythroblast with an increase in cytoplasm and nuclear size. The chromatin is more open being arranged in fine reticular fashion to give a stippled appearance. The predominant cells are promegaloblast and basophilic megaloblast indicating maturation arrest. • Granulopoiesis : Granulopoiesis is active and show giant metamyelocyte. • Megakaryocytes are usually normal. • Lymphocytes and plasma cells are normal.
- 58. • Biochemical test : Serum Vitamin B12 and serum and red cell folate assay. • Pernicious Anaemia : Pernicious anaemia are vitamin-B12 deficiency anaemia caused by lack of intrinsic factor resulting from atrophic gastritis. • Blood and bone marrow picture are similar to above. • The schilling test is done to diagnose pernicious anaemia.
- 59. • Causes of Macrocytosis : • Macrocytosis with megaloblastic bone marrow: • Vitamin B12 deficiency • Folic acid deficiency. • Macrocytosis with normoblastic or macronormoblastic bone marrow: • Macrocytosis common : • Haemolytic anaemia • Posthaemorrhagic anaemia.
- 60. • Macrocytosis Occasional : • Alcoholism • Liver disease • Aplastic anaemia • Sideroblastic anaemia. • Myelodysplastic syndrome. • Scurvy • Hypothyroidism.
- 61. • Macronormoblast are large normoblast i.e cells that are larger than their normal counterpart of a similar stage of development, which they resemble in all other respect, including their nuclear structure. Megaloblast have more cytoplasm with respect to macronormoblast and their nucleus have fine reticular chromatin than their normal counterpart macronormoblast. In megaloblast nuclear maturation lag behind than cytoplasmic maturation. There is delay in intermitotic phase in megaloblastic erythropoiesis but in macronormoblastic erythropoiesis there is such rapid mitosis that there may be skip mitosis in any stage of macronormoblastic development which may give rise to giant erythrocyte. • Megaloblastic anaemia also seen in condition where there is retarded DNA synthesis. Such condition are seen in neoplastic disorder of haematopoietic stem cell where there is DNA mutation in stem cell which give rise to both myeloid and erythroid series. Such disorder include erythroleukaemia and myelodysplastic syndrome.
- 62. • So macrocytic anaemia can be seen in following condition : • 1) Condition associated with megaloblatic erythropoiesis : Such as : Vitamin B12 or folate deficiency. Erythroleukaemia. Myelodysplastic syndrome. 2) Condition associated with macronormoblastic erythropoiesis without increase of reticuloyte count : Liver disease, Aplastic anaemia. Due to direct toxic effect Alchohol. Sometimes in Hypothyroidism 3) Condition associated with macronormoblastic erythropoiesis with increase reticulocyte count: Posthaemorrhagic anaemia Haemolytic anaemia. This condition also known as stress erythropoiesis. In this condition high level of erythropoietin are released. High level of erythropoietin may cause macronormoblastic erythropoisis with increase production of reticulocyte and other young red cell. There may be skip mitosis which may cause formation of giant RBC.