Common red blood cell disorders and aplastic anemia PDF

Common red blood cell disorders and aplastic anemia อ.นพ.ฐิติกร จันทรรวงทอง แพทยศาสตรบัณฑิต, วว. อายุรศาสตร, วว.อายุรศาสตรโรคเลือด หนวยโลหิตวิทยา สาขาวิชาอายุรศาสตร สํานักวิชาแพทยศาสตร มหาวิทยาลัยเทคโนโลยีสุรนารี...

Common red blood cell disorders and aplastic anemia อ.นพ.ฐิติกร จันทรรวงทอง แพทยศาสตรบัณฑิต, วว. อายุรศาสตร, วว.อายุรศาสตรโรคเลือด หนวยโลหิตวิทยา สาขาวิชาอายุรศาสตร สํานักวิชาแพทยศาสตร มหาวิทยาลัยเทคโนโลยีสุรนารี 1 Outline ตามเกณฑแพทยสภา - Nutritional anemia : Iron deficiency anemia (IDA), Megaloblastic anemia - Hemolytic anemia : - Immune : AIHA - Non-immune : Paroxysmal nocturnal hemoglobinuria (PNH), MAHA - Enzymatic deficiency : G6PD deficiency anemia - Common red blood cell membrane defect : HS - Thalassemia and hemoglobinopathies - Bone marrow disease : Aplastic anemia (AA) 2 RBC disorders approach by MCV - Microcytic anemia : IDA, Thalassemia, Sideroblastic anemia (Lead) - Normocytic anemia : Hemolytic disorder (AIHA, PNH, RBC membrane defect, G6PD deficiency anemia), anemia of chronic disease, AA - Macrocytic anemia : Megaloblastic anemia 3 Iron deficiency anemia (IDA) - The most common cause of anemia in the world especially women, children, and individuals living in under-resourced and middle-income countries. - Iron is an essential nutrient for RBC production - Iron is found in many foods 4 Iron deficiency anemia - 2 forms of iron - Ferrous (Fe2+) / heme iron : animal products - Ferric (Fe3+) / non-heme iron : plant-based food 5 https://sushantkumar-67353.medium.com/why-iron-rich-foods-should-be-part-of-your-diet-65800effb786 Healthy iron requirements and turnover 6 20–25 mg iron turnover/day for erythropoiesis1 1–2 mg daily dietary intake via intestinal absorption (esp. duodenum and proximal jejunum)2 Each mL of blood contains approximately 0.5 mg of iron1 1. Huch & Schaefer. Iron Deficiency and Iron Deficiency Anaemia. New York: Thieme Medical Publishers; 2006 2. Crichton et al. Iron therapy with special emphasis on intravenous administration. London: Uni-Med Verlag AG; 2008 Iron transport overview1-2 Heme iron Enterocyte life Fe(II) expectancy: 1-2 days Fe(III) DMT1 Enterocyt Elimination e via desquamation of dead intestinal cells LIP Ferritin Storage of iron into ferritin Ferroportin Hephaestin Hepcidin Hepcidi Transfe Ferroporti n rrin Fe(III) n Fe(II) Ferroportin = iron exporter Live r 7 21:S6–S20 1. Dev S and Babitt JL. Hemodialysis International. 2017; DMT1 = divalent metal transporter 1 2. Silva B and Faustino P. Biochimica et Biophysica Acta. 2015;1852:1347–1359 Iron Regulation Hepcidin regulates systemic iron homeostasis1 ENTEROCYTES MACROPHAGE (RES) HEPATOCYTE RB C Ferri tin Fe(II) Ferriti Ferro Ferrop n portin ortin Hepcidin Hep cidi Ferroporti Hepcidi n Tran n n sferr 8 Tran in sferri n Live Hepcidin function = Internalization and degradation of ferroportin r RBC = red blood cell; RES = reticuloendothelial system 1. Wallace DF. Clin Biochem Rev. 2016;37:51-62 Iron and erythropoietin: Vital for RBC production1-4 Iron incorporation into haem2,3 Erythropoietin Haem2,3 Pluripotent Burst-forming Colony-forming Proerythroblasts Erythroblasts Reticulocytes RBCs stem cell unit-erythroid cells unit-erythroid cells 9 About 1–2 days About 10–13 days About 21 days About 3–4 days 1. Besarab A et al. Oncologist. 2009;14(Suppl 1):22–33 2. Jankowska EA et al. Eur Heart J. 2013;34:816–826 RBC = red blood cell 3. Pittman RN. Regulation of Tissue Oxygenation. 2011. San Rafael (CA): Morgan & Claypool Life Sciences 4. Kalantar-Zadeh K et al. Adv Chronic Kidney Dis. 2009;16(2): 143-15 Various etiologies of iron deficiency anemia 10 GI = gastrointestinal; HMB = heavy menstrual bleeding 2019 The Association for the Publication of the Journal of Internal Medicine Journal of Internal Medicine, 2020, 287; 153–170 11 12  Iron Deficiency and Iron Deficiency Anemia BM iron > Plasma iron > MCV > Hb American Society of Hematology. www.hematology.org/Patients/Anemia/iron-Deficiency.aspx. (2018) MCV < 80 fl 13 NIH. www.nhlbi.nih.gov/health-topcis/iron-deficiency-anemia (2018)  Diagnostic criteria for iron deficiency depend on the level of inflammation. Iron storage Iron study - Ferritin - Serum iron - TIBC - %TF %TF = Serum iron/TIBC x 100 If serum ferritin is high, stored iron is present. However, it may not be available for use. Additional testing for iron deficiency is required. 14 If the serum ferritin is considered inconclusive, the transferrin saturation (TSAT) or soluble transferrin receptor (sTfR) tests are useful. Gold standard diagnosis of IDA : BM study for Prussian blue stain Dignass AU et al. J Crohns Colitis. 2015;9:211–22. TYPES OF IRON DEFICIENCY AND DIAGNOSTIC THRESHOLDS IN ADULTS 15 Camaschella C. New Engl J Med 2015;372:1832–43 - Hypochromic - Microcytic - Anisopoikilocytosis - Pencil cell - Reactive thrombocytosis 16 Investigation - Gold standard diagnosis : prussian blue stain of bone marrow study 17 Principal of treatment in iron deficiency anemia 1. RBC transfusion : life threatening symptoms only !!! (CNS,CVS) 2. Iron supplement : Oral, IV, iron-rich diet 3. Correction of cause 18 Breymann C, et al. Geburtsh Frauenheilk. 2013;73:256-261. Sideroblastic anemia 19 Lead poisoning - Defect in heme synthesis (↓ferrochelatase) - Battery factory, Can factory 20 RBC disorders approach by MCV - Microcytic anemia : IDA - Normocytic anemia : Hemolytic disorder (AIHA, PNH, RBC membrane defect, G6PD deficiency anemia), anemia of chronic disease, AA - Macrocytic anemia : Megaloblastic anemia 21 Classification of hemolytic anemia 22 23  Hemolysis ↑Reti/Polychromasia ↑LDH/IDB/AST IVH EVH ↓Haptoglobin (due to Free Hb) Splenomegaly (chronic) ↓Hemopexin (due to Free heme) Hemoglobinemia Hemoglobinuria Urine hemosiderin (chronic) 24 Intravascular hemolysis Extravascular hemolysis G6PD deficiency anemia Thalassemia PNH RBC membrane defect disorder MAHA AIHA Transfusion hemolytic anemia Venom hematotoxin 25 Autoimmune hemolytic anemia (AIHA) 26 27 28 29 30 31 32 RBC membrane defect 33 Conditions Associated with Membrane Defects - Hereditary spherocytosis - Hereditary elliptocytosis - Hereditary pyropoikilocytosis - Hereditary stomatocytosis - Membrane lipid disorders - Paroxysmal nocturnal hemoglobinuria 34 35 Hereditary spherocytosis - Majority of cases are autosomal dominant (75%) with variable penetrance - Involves the RBC cell membrane, which has 3 main components - Lipid bilayer - Membrane proteins (band 3 is one of them) - Cytoskeleton network, of which spectrin is the most abundant protein - Spectrin/ankyrin deficiency - Spherocytes are prone to hemolysis - Abnormal RBC without cellular deformability >>> trapped by spleen >>> successively destroyed by macrophages 36 HS 37 Diagnosis of HS - CBC : decreased Hb, MCHC > 36, MCV can be mildly increased - Hemolysis marker : increased LDH/reticulocyte count/indirect bilirubin, decreased haptoglobin - OF test : increase - Eosin-5’-maleimide (EMA) binding test - Most reliable test - Eosin-based fluorescent dye binds to cell membrane protein (band 3) in RBC - Reduced fluorescence intensity in HS - Advantages: high specificity and sensitivity, short turnaround time, minimal amount of blood used (5 mcL) - Mild HS may come out false negative - Molecular analysis for gene mutations 38 39 40 Treatment of HS - Avoid precipitated cause of hemolysis - Blood transfusion - Supportive treatment : folic - Splenectomy 41 Paroxysmal nocturnal hemoglobinuria (PNH) - Acquired genetic disorder : increased susceptibility of RBCs to lysis by the complement system - PNH results from a mutation in the PIG-A gene on the X-chromosome, which encodes for the protein of the GPI anchor. - The condition results from an inability to synthesize some of the glycosyl phosphatidylinositol (GPI) anchor. - membrane inhibitor of reactive lysis (MIRL; CD59) - decay accelerating factor (DAF; CD55) - the homologous restriction factor (C8 binding protein) - which are all involved in the RBC defense against complement - Lacking these molecules, erythrocytes are unusually sensitive to lysis by complement and are unable to withstand the low level of complement activation that occurs normally. - This results in intravascular hemolysis - PNH frequently arises from, or transforms into, aplastic anemia. 42 43 44 Clinical manifestation of PNH - PNH occurs at all ages from childhood to old age but is most commonly diagnosed in the fourth and fifth decades. - The course is highly variable, from clinically benign to chronic disabling disorder. - The name PNH derived from patients who experienced episodes of dark urine on awakening from sleep (occurs in only about one-fourth of patients). - The majority of patients have an insidious onset of fatigue, intermittent abdominal pain, weakness, and jaundice. - Many have period exacerbations of hemolysis. - In most cases, there is no obvious cause for the exacerbations, but some attacks may be precipitated by infections, menstruation, transfusions, surgery, ingestion of iron salts, or vaccinations. The attacks are not precipitated by exposure to cold, distinguishing PNH from paroxysmal cold hemoglobinuria 45 Complications of PNH - Venous thromboembolism (VTE) - Infection - IDA - Transformation to AA, AML 46 Diagnosis of PNH - The traditional diagnosis tests are the acidified serum (Ham’s) test and the sucrose hemolysis test. Both tests depend on activating the complement system and demonstrating increased sensitivity of the cells to complement lysis. - Demonstration of a decreased expression MIRL (CD59) and DAF (CD55), FLAER (a bacterial channel-forming toxin (proaerolysin) which binds specifically to the GPI anchor) on the RBCs or leukocytes by flow cytometry has been shown to be more sensitive than either of these tests 47 Treatment of PNH - Steroid - Androgen - Blood transfusion - Complement inhibitor : Eculizumab (C5), Pegcetacoplan (C3) - Iron supplement - Anticoagulant if VTE - BMT 48 G6PD deficiency anemia - Most common RBC enzyme disorders - X-linked recessive - Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited disorder caused by a genetic defect in the red blood cell (RBC) enzyme G6PD 49 50 51 52 Function of G6PD enzyme - The main function of the HMP shunt is to protect red blood cells against oxidative injury via the production of NADPH - Red blood cells contain relatively high concentrations of reduced glutathione (GSH), a sulfhydryl-containing tripeptide that functions as an intracellular reducing agent, thereby protecting against oxidant injury - Oxidants, such as superoxide anion (O2-) and hydrogen peroxide, are formed within red cells via reactions of hemoglobin with oxygen and can also be produced by exogenous factors such as drugs and infection - If these oxidants accumulate within red cells, hemoglobin and other proteins are oxidized, leading to loss of function and cell death - G6PD deficiency : ↓NADPH,reduced glutathione 53 WHO classification 54 Investigations of G6PD deficiency anemia - Anemia - Decreased haptoglobin - Increased reticulocyte, LDH - Hemoglobinuria - AKI - Indirect hyperbilirubinemia - False low HbA1C - Fluorescent spot test (FST) : screening test - NADPH generation is determined by monitoring a florescent spot under ultraviolet light - Confirmatory tests recommended by WHO : G6PD activity assays, Molecular analysis for G6PD enzyme 55 56 Treatment of G6PD deficiency anemia - Precipitating cause eradication - Aggressive hydration - Blood transfusion - Folic supplement - Genetic counseling 57 Microangiopathic hemolytic anemia (MAHA) - Schistocyte + Hemolytic blood picture - Disseminated intravascular coagulopathy (DIC) - TTP (Thrombotic thrombocytopenic purpura) - HUS (Hemolytic uremic syndrome) 58 MAHA - Microvascular - DIC/TTP/HUS/TMA - APS - Malignant HT - PIH/Preeclampsia/HELLP - Vasculitis/GN - SSC with renal crisis - Severe burn - Macrovascular - Vascular malformation : AVM/OWRS/Hemangioma/KMS - Valve : Prosthetic valve/IE - Great vessel : aortic dissection/Aneurysm 59 DIC - DIC ISTH score ≥ 5 - Lab - MAHA (20-30%), ↓Plt, ↓Fibrinogen, ↑D-dimer, ↑PT(early)/APTT(late) - Tx - Transfusion when indicated - Correction of cause 60 61 62 63 64 TTP - ADAMTS13 deficiency : acquired (autoAb), congenital - Pentad : - Fever, renal insufficiency, NS - Thrombocytopenia , MAHA : mostly present - Plasmic score > 5 : high probability - Lab : ↑↑↑LDH, ↑Reticulocyte, ↓Hb/Plt, normal coagulogram, ADAMTS Lv ( 150,000 x 2 days) - Immunosuppressive : IVMP, rituximab - Caplacizumab (inhibitor of VWF-plt string formation) - Avoid platelet transfusion except major bleeding 65 66 67 HUS - Triad : MAHA, thrombocytopenia, AKI - Setting : Childhood, GI prodrome (bloody diarrhea, abdominal pain, N/V) - Cause - Hereditary : complement gene mutation - Acquired - Infection (MC 90%) : ETEC/EHEC, Shigella, HIV, S. pneumoniae - AutoAb ti complement factor - Drug - Autoimmune : SLE - Clinical diagnosis - Tx : supportive treatment 68 RBC disorders approach by MCV - Microcytic anemia : IDA, Thalassemia - Normocytic anemia : Hemolytic disorder (AIHA, PNH, RBC membrane defect, G6PD deficiency anemia), anemia of chronic disease, AA - Macrocytic anemia : Megaloblastic anemia 69 Anemia of chronic disease 70 71 Various etiologies of iron deficiency anemia 72 GI = gastrointestinal; HMB = heavy menstrual bleeding 2019 The Association for the Publication of the Journal of Internal Medicine Journal of Internal Medicine, 2020, 287; 153–170 73 RBC disorders approach by MCV - Microcytic anemia : IDA, Thalassemia - Normocytic anemia : Hemolytic disorder (AIHA, PNH, RBC membrane defect, G6PD deficiency anemia), anemia of chronic disease, BM disease (AA) - Macrocytic anemia : Megaloblastic anemia 74 Aplastic anemia (AA) - Loss of hematopoietic stem cells (HSC) - AA refers to pancytopenia in association with bone marrow hypoplasia/aplasia - Life-threatening form of bone marrow failure - Cause - Congenital AA - Acquired AA - Diagnosis : BM study 75 76 77 78 Treatment of AA - Specific treatment - Allogeneic bone marrow transplantation - Immunosuppressive drug : ATG,cyclosporine - TPO receptor agonist - Anabolic hormone - Supportive treatment - Blood transfusion 79 RBC disorders approach by MCV - Microcytic anemia : IDA, Thalassemia - Normocytic anemia : Hemolytic disorder (AIHA, PNH, RBC membrane defect, G6PD deficiency anemia), anemia of chronic disease, AA - Macrocytic anemia : Megaloblastic anemia 80 81 Megaloblastic anemia - Most common causes: cobalamin (vitamin B12) and folate deficiency - Findings: macrocytosis (often macro-ovalocytes), anisopoikilocytosis, hypersegmented neutrophils, megaloblastic changes in BM, ± pancytopenia - Impaired DNA synthesis in hematopoietic cells - Dyssynchrony between nuclear and cytoplasmic maturation - Hypercellular marrow with an erythroid predominance + presence of giant pronormoblasts and giant band forms, giant metamyelocytes - Ineffective erythropoiesis: elevated LDH and unconjugated bilirubin 82 83 84 85 86 87 88 Clinical manifestation - Hematologic : anemia, leukopenia, thrombocytopenia - GI : glossitis - Skin : jaundice, vitiligo, early grey hair, hyperpigmentation esp knuckle - Neurologic (B12 deficiency) : symmetric paresthesias or numbness and gait problems, cognitive impairment - The classic neurologic finding in vitamin B12 deficiency is subacute combined degeneration of the dorsal (posterior) and lateral columns (white matter) of the spinal cord due to demyelination 89 90 Investigations of megaloblastic anemia - Macrocytic anemia, anisocytosis, ↑RDW, pancytopenia (advanced cases) - Ineffective erythropoiesis (↑LDH, ↑indirect hyperbilirubinemia) - PBS: macrocyte/macroovalocyte, hypersegmented neutrophils (≥1 6+- lobed neutrophils or ≥5% 5-lobed neutrophils) - Laboratory test of deficiency - RBC folate level - Vitamin B12 level 91 92 Treatment of megaloblastic anemia - Vitamin B12 deficiency - Intramuscular vitamin B12 (1000 μg) in pernicious anemia Everyday for 1 week, followed by every week for 1 month, and then every month continuously - High dose oral cobalamin (1-2 mg/day) → passively absorbed at high dose - Vegetarians: daily oral cobalamin 5-10 mcg (in multivitamin tablets) - Folate deficiency - Oral folic acid 1-5 mg/day - Folinic acid in rescue protocols involving antifolates (eg, MTX) 93 94