Approach to Childhood Anemia H. Tamary Hematology, Schneider Children’s Medical Center of Israel Normal Hemoglobin and MCV Values in Term Infant Day 1 12 weeks Hb (g/dL) MCV (fl) 19.0±2.2 11.3 ±0.9 119 ±9.4 88 ±7.9 Regulation of Erythropoiesis Hemoglobin ConcentrationDifferent Gestational Age Globin Synthesis in Embryo, Fetus and Adult Decline in Fetal Hemoglobin Criteria for Identifying Children with Low Hemoglobin Values Age 6ms –11 years >11 male >11 female Hemoglobin (g/dL) <11 <13 <12 Etilogical Classification of Anemia (I) A. Blood loss B. Excessive blood destruction 1. Intrinsic factors a. Defects of membrane: spherocytosis, elliptocytosis b. Defects of hemoglobin – Structural anomaly: HbS – Synthesis anomaly: thalassemia Etilogical Classification of Anemia (II) c. Enzymatic defect: G6PD deficiency, pyruvate kinase 2. Extrinsic factors a. Immune mechanisms: Rh, ABO incompatibility, autoimmune hemolytic anemia b. non-immune mechanisms: infections Etilogical Classification of Anemia (III) C. Decreased production 1. Deficiency of substance: iron, Vit B12, folic acid 2. Mechanical interference: malignant replacement 3. BM failure a. Primary: aplastic anemia b. Secondary: renal, liver disease Etiological Classification of Neonatal Anemia • A. Blood loss-fetal to fetal, feto-maternal, traumatic delivery • B. Increased blood destruction-Rh, ABO or minor blood group incompatibility, enzymopathy, hemoglobinopathy athalassemia • C. Decreased production-pure red cell aplasia Anemia Historical Factors • Age-Neonatal period initial manifestation of hemolytic disease, 6 m-iron deficiency, bthalassemia • Ethnic group-Thalassemia syndromes, G6PD def • Diet- documented sources of iron • Drugs- oxidant-induced hemolytic anemia, drug induced aplastic anemia • Inheritance-family history of anemia, jaundice, gall stones Anemia Physical Findings Skin Facies Eyes Hands Spleen Hyperpigmentation Fanconi Anemia (FA) Frontal bossing Thalassemia Prominence malar Major &maxillary bone Microphthalmia FA Abnormal thumb FA Enlargement Hemolytic anemia, infection, leukemia Features of Ineffective Erythropoiesis FA Congenital Anomalies Complete Blood Count • • • • • • Hemoglobin MCV WBC and differential count PLT RDW- red cell distribution width CHr - hemoglobin concentration in reticulocytes Microcytic Anemias MCV<80fl • • • • • Iron deficiency anemia Thalassemia syndromes Chronic inflammation Siderblastic anemias Lead poisoning Normocytic Anemias MCV 80-90fl • • • • • Congenital hemolytic anemia Acquired hemolytic anemia Acute blood loss Splenic pooling Chronic disease Macrocytic Anemias MCV>90fl With megaloblastic bone marrow • Vitamin B12 deficiency • Folic acid deficiency • Hereditary orotic aciduria Without meglaoblastic bone marrow • Aplastic anemia • Pure red cell aplasia • Liver disease • Congenital Dyserythropoietic Anemia Direct antiglobulin test (Coombs’) Bone Marrow Aspiration Acute Lymphoblastic Leukemia Bone Marrow Biopsy Normal Aplastic anemia Erythroid BM Colonies Iron Deficiency Anemia in Children Human Hemoglobin Distribution of Iron in Man Cytochromes Myoglobin 3% 10% Ferritin & Hemosiderin 22% Hemoglobin 65% Nutritional Iron Deficiency Increment of RBC Mass as Function of Age Stages of Iron Depletion Absorption of Food Iron Iron Absorption in Infants Mental &Psychomotor Development According to Hb Concentration Prevention of Nutritional Iron Deficiency Anemia • Encourage breast feeding for the first 6 months • Avoid cow’s milk at least for the first year of life • Iron fortified formula (12mg/l) • Solid food: cereals, meat • Oral iron 2mg/kg 4-12months • CBC: 9-12 months and 15-18 months Iron Doses for Low Birth Weight Infants Starting at 1 Month of Age Iron mg/kg/day Birth weight (g) 4 3 2 1000 1000-1500 1500-2500 “The tragedy of iron deficiency during infancy and early childhood” • Brain injury as a result of iron deficiency caused by improper nutrition • Iron deficiency affects mental development and motor functioning • Reduced activity of iron-containing enzymes in CNS, appear to be irreversible Buchanan G, J of Ped 135:413, 1999 Nutritional Iron Deficiency • No iron prophylaxis • No introduction of meat products • Increased tea consumption Stages of Iron Depletion Iron Depletion • Hb, MCV, RDW, CHr-Normal • SI, TIBC-Normal • Serum Ferritin- Low Iron Deficiency – No Anemia • • • • • • Hb, MCV- Normal RDW- High CHr- Low Serum Ferritin- Low Serum Iron – Low TIBC- High Iron Deficiency Anemia • • • • • • • Hb-Low MCV- Low RDW- High CHr –Low Serum Iron –Low TIBC – High Serum Ferritin - Low Iron Deficiency-Biochemical Markers • Serum iron concentrationInfluenced by iron absorption from meals, infection, inflammation and diurnal variation • Total iron-binding capacity (TIBC)-Increases in iron deficiency. Decrease in malnutrition, chromic infection and cancer. • Ferritin-Correlates with total iron stores. Acute phase reactant Iron Deficiency- Serum Transferrin Receptor • Serum transferrin receptor- in iron deficiency there is increased number of receptors Unlike ferritin, increases in iron deficiency but not in chronic infection Iron Deficiency-Treatment • Elemental iron 5-6mg/Kg/d • Reticulocytosis in one week • After 1 month the Hb should increase by at least 1gr% • Iron therapy continued 2-3 months after Hb returned to normal • No improvement after a month other cause for iron deficiency Etiologic Factors in Iron Deficiency (1) Increased physiologic requirements • Rapid growth • Menstruation Decreased iron assimilation • Iron-poor diet • Iron malabsorption: Celiac disease Etiologic Factors in Iron Deficiency (2) Blood loss • Gastrointestinal bleeding • Milk induced enteropathy • Peptic disease • Inflammatory bowel disease • Parasite bowel infection Hemoglobinuria due to prosthetic valve Idiopathic pulmonary hemosiderosis Intense exercise Thalassemia Syndromes & Hemoglobinopathies • a-thalassemia • b-thalassemia • Sickle cell anemia b-thalassemia Geographical Distribution of Thalassemia and Hemoglobin Disorders Globin Synthesis in Embryo, Fetus and Adult b-thalassemia -Location and Type of Mutations Clinical Classification of b-thalassemia b-thalassemia trait • Homozygous b-thalassemia Thalassemia Major Thalassemia Intermedia b-thalassemia minor Differential Diagnosis of Microcytosis Iron deficiency Anemia Serum Iron Transferrin Ferritin Hemoglobin electrophoresis Low High Low Normal Carriers of b Thalassemia Normal Normal Normal High A2 b-thalassemia Minor – HPLC Hb Electrophoresis Hb A b-thalassemia Carrier Detection • • • Microcytic anemia MVC <78fl, MCH<27pg HbA2>3.5% b-thalassemia Major Thalassemia Major at Diagnosis Peripheral Blood Smear Normal Beta-thalassemia Homozygote Homozygous b-thalassemia Hb Electrophoresis Hb F Decline in Fetal Hemoglobin Pathogenesis of b-thalassemia Major Free excess of a-globin chains Hemolysis Ineffective erythropoiesis Severe anemia Skeletal deformities Increased iron absorption Transfusion Program-Suppression of Ineffective Erythropoiesis Clinical Manifestations of Iron Overload • Cardiac: arrhythmias, CHF • Endocrine: growth failure, delayed sexual maturation, hypoparathyroidism, hypothyroidism, DM • Skin: bronze discoloration • Liver: cirrhosis Important studies of Deferoxamine Therapy in Thalassemia Year 1974 1978 1981 1985 1989 Finding IM therapy stabilize hepatic iron 12h portable infusion for iron balance Therapy reduces hepatic iron Reduction of cardiac disease in compliant patients Extended survival in young patients Compliance with DFO Treatment and Survival Combination of L1and DFO • L1 not as powerful as DFO • Two chelators given on the same day have additive affect on urine iron loss BMT in Thalassemia Prognostic Criteria • Hepatomegaly • Liver fibrosis • Quality of iron chelation Prognostic Categories • Class I-none of the above • Class II One of the above • Class III two or three of the above BTM Class I Prevention of b-thalassemia • Carrier screening • Prenatal diagnosis CVS and DNA analysis Pre-implantation diagnosis (PGD) DNA extracted form fetal erythroblasts in maternal circulation a-thalassemia a-globin Cluster a-thalassemia-Abnormal Hbs 2 2 Hb Bart’s b b b2b2 Hb H Gene Deletion in a-thalassemia Hydrops Fetalis Syndrome • Most Hb- Hb Barts, unable to deliver O2 to tissues • Tissue hypoxia & anemia Massively enlarged palcenta Heart failure, edema anasarca Interferes with organogenesis, -congenital malformations Extramedullay erythropoiesis Hydrops Fetalis Syndrome Hemoglobin H Disease • Genotype --/-a • On cord blood: 10-20% Bart’s hemoglobin • Moderate microcytic anemia • Hb electrophoresis 5-30% Hb H a-thalassemina Trait • Genotype: - -/aa,-a/-a • Hb electrophoresis on cord blood: 2-10% Hb Bart’s • On adult blood: microcytic, with or without anemia • Diagnosis by exclusion of b-thalassemia minor & iron deficiency a-thalassemia Silent Carrier -a/aa • Hb electrophoresis on cord blood: traces to 2% Hb Bart’s • No anemia or microcytosis on adult blood Deletions in the a-globin Gene Cluster Categories of a-thalassemia Mutations Non-deletion a-thalassemia Mutations a2 aNco aHph aTSaudi a-thalassemia Genotype-Spectrum a-thal Trait • --/aa • -a/-a aTa/aa aTa/-a Hb H Disease • --/-a aTa/aTa aTa/-- Strategy for a-thalassemia Multiplex PCR Analysis Anemia of Chronic Infection Anemia of Chronic Infection • • • • Serum Iron- Low TIBC- Low Serum ferritin- High Reduced release of iron form macrophages and reduced intestinal iron absorption Anemia of Chronic Disease