Hematology and Immunology A concise update Adlette Inati MD Pediatric Hematology Oncology Lebanese American University and Rafik Hariri University Hospital Lebanese University Oct 25, 2013 Learning Objectives Concisely Review Anemia Hematopoietic and Stromal Cell Differentiation Erythropeisis Main players Pluripotent stem cells Chemical regulators Cytokines Erythroid specific growth factor Erythropoietin (EPO) Thyroid hormones, estrogens and androgens Nutritional requirements Proteins and amino acids Vitamin B12 and folic acid Vitamin B6 (pyridoxine) Iron Other nutrients (Vitamin C, cupper, cobalt) Anemia Diagnosis History Physical Examination Blood count Blood smear Reticulocyte count Medical History Sudden onset of pallor, fatigue or exercise intolerance? Blood loss, easy bruisability? Cold intolerance, constipation, lethargy, poor growth Recent drug or fava bean intake or viral infection? Neonatal jaundice or episodes of jaundice or dark urine in the past? The child’s diet? Any iron supplements? Any history of pica? Any history of recurrent bone or joint pain or diarrhea? Family History Anemia or low blood counts? Excessive bleeding, transfusion requirements ? Splenectomy ,cholecystectomy, hystereectomy at an early age? Autoimmune diseases ? Consanguinity? Ethnic / geographical origin? Physical Examination Is the child active and playful or fatigued? Look for pallor, signs of heart failure, icterus, jaundice, glossitis Look for petechiae, bruises, splenomegaly, pathologic lymphadenopathy, abdominal masses, skeletal abnormalities and abnormal facies Complete blood count (CBC) Automated counter Provides a panel of tests: Red Blood Cells (RBCs) Number of RBCs per volume of blood Hemoglobin (Hb) – amount of Hb in the blood Red cell Indices White Blood Count (WBCs) Number of white blood cells per volume of blood WBC differential - types of WBCs present Platelets (Plts) Number of platelets per volume of blood MPV Normal values are age and sex dependent Blood Smear Shows specific morphologic abnormalities Reveals polychromatophilia which is a reflection of reticulocytosis Recognizes abnormal cell morphology Reticulocyte Count An Underutilized Parameter Immature mononucleated RBCs indicating active erythropoiesis Elevated in blood loss or hemolysis Low to NL in bone marrow failure or ineffective erythropoiesis Oski FA, Brugnara C, Nathan DG: A diagnostic approach to the anemic patient. In: Nathan and Oski’s Hematology of Infancy and Childhood. 5th ed. Harcourt Health Sciences; 1998:375-384 Polycythemia Anemia Lymhocytes(Increased Hb) (Decreased Hb) Decreased blood volume (dehydration, burns, diuretics) Decreased production Increased RBC mass (polycythemia) Increased destruction - Chronic hypoxia (hemolysis) - Erythropoetin secreting Tumors - Primary (polycythemia vera) Blood loss - Sequestration Anemia Diagnostic Algorithm History, Physical exam Hb, WBC, Platelets Microcytic Red cell indices Macrocytic Reticulocyte count Blood film Iron deficiency Thalassemia Folic acid deficiency Lead poisoning Vit. B12 deficiency Sideroblastic anemia Normocytic Hypothyroidism Unstable hemoglobins Liver disease Anemia of chronic Drugs disease Low Reticulocyte count Nl reticulocyte count High reticulocyte count R/O Bone Marrow Chronic inflammation R/o hemorrhage Failure/Red Cell Aplasia Adlette Inati. Iron curriculum R/O hemolysis ESH, Webcast 2010 Iron-deficiency anemia (IDA) Thalassemias Inherited anemias characterized by decreased or absent globin chain synthesis • Homozygous disorder b-thalassemia • Significant imbalance of b a globin chains major • Severe transfusion dependent anemia presenting early in life • If untreated, leads to death usually in first decade • Various genetic interactions • Globin chain production moderately impaired b-thalassemia • Mild anemia, diagnosed usually in late childhood intermedia • Occasional blood transfusions may be required Severity of disease Severity • Heterozygous condition b-thalassemia • Asymptomatic minor • May require genetic counseling Thalassemia Diagnosis Beta thalassemia blood smear Normal blood smear Lab diagnosis Low Hb / Hct Low MCV / MCH High HbF / HbA2 β -Thalassemia Major Management Several ongoing thalassemia trials in Lebanon and the ME Macrocytic Anemias Large RBC s with high MCV > 100 Common in adults Hypersegmented neutrophils Megaloblastic: Impaired DNA synthesis and assembly resulting in delayed nuclear maturation with normal cytoplasmic development Vit B12 deficiency Folate deficiency Drug induced Myelodysplasia Non-megaloblastic: abnormal RBC maturation Alcohol Liver disease Hypothryroidism chemotherapy/drugs Megaloblastic anemia Symptoms Folic Acid Vitamin B12 deficiency deficiency No neurologic symptoms Neurologic symptoms Pallor, lethargy, weakness Anorexia, diarrhea Light headedness Papitations, angina Macrocytic anemias Hemolytic anemias A group of inherited or acquired disorders characterized by premature RBC destruction and inability of the marrow to have sufficient erythrocyte production to keep up with accelerated RBC destruction, thus producing anemia Presentation ranges from an asymptomatic to a severe life threatening state with angina and cardiopulmonary decompensation in severe cases Usual symptoms and signs: pallor, lethargy, jaundice, icterus and dark urine, fever and sometimes back and abdominal pain Classification of Hemolytic Anemias Intra versus extra vascular hemolysis Intravascular Hemolysis Extravascular Hemolysis Severe clinical course Mild to moderate course ↑ Free plasma hemoglobin No free plasma hemoglobin ↑ Free urinary Hb / hemosiderin Absent urinary Hb / hemosiderin Schistocytes Spherocytes Decreased serum haptoglobin Normal serum heptaglobin ↑ Indirect bilirubin reticulocytosis Urobilinogen in stool and urine Intra versus extra corpuscular hemolysis INTRACORPUSCULAR EXTRACORPUSCULAR •Membrane abnormalities •Immune Hereditary spherocytosis •Allo immune •Autoimmune •Enzyme abnormalities •Non Immune G6PD deficiency •Microangiopathic (TTP) •Infection(malaria) •Chemical agents (spider venom •Hb abnormalities Sickle cell disease/ Thalassemia Membrane Abnormalities Hereditary Spherocytosis Enzyme abnormalities Favism Adlette Inati, et. J Med Screen. 2012;19 (2):103-4 Hemoglobinopathies Pathophysiology of SCD β-Globin Gene Glutamic acid HbS Valine (ɑ2βˢ2) Deoxygenated Hb polymers Low oxygen tension Sickle erythrocyte Haemolysis Vaso occlusion Pain, acute chest syndrome, joint necrosis, Anaemia, gallstones, priapism, stroke acute splenic sequestration, increased leg ulcers, pulmonary hypertension infections, multi-organ damage Adapted from Inati A, et al. Pediatr Ann. 2008;37:311-25. SCD diagnosis SCD blood smear Normal blood smear HPLC. Sickle Cell Disease Preventive strategies Neonatal Screening, Penicillin prophylaxis and Vaccination Disease Modifying Comprehensive Therapies Care and family (hydoxyurea, transfusions education and stem cell transplant) Transcranial Screening for doppler pulmonary hypertension screening for stroke risk Inati A etal. Pediatr Ann. 2008;37:311-25 Vichinsky et al. Pediatrics 1988; 81: 749-755 Sickle cell disease in Lebanon Evelyne Khoriaty etal. & Adlette Inati. EHA 2012, Abstract no. 2021 Hemoglobinopathies Treatment Options in Development Treatment Option Clinical Effect Arginine es production of nitric oxide a potent vasodilator Decitabine es HbF Butyrates short-chain FAs that inhibit histone deacetylase (HDAC), HbF production Clotrimazole Inhibits cation transport channels in RBC membranes thereby reducing cellular dehydration Gene Therapy Clinical evidence not yet available. Early promise shown in a transgenic mouse model Several ongoing trials in Lebanon on HbF modulation Bone marrow failure syndromes (BMFSs) Bone marrow failure syndromes Hereditary Acquired Diamond Blackfan anemia Idiopathic Fanconi’s anemia Drugs: chemotherapy, chloramphenicol, benzene, sulfas…. Dyskeratosis congenita Radiation, chemicals Schwackman – Diamond anemia Viruses: EBV, HIV, parvovirus, hepatitis Amegakaryocytic thrombocytopenia Malnutrition Thrombocytopenia with absent radius Paroxysmal nocturnal hemoglobinuria syndrome (PNH) Severe congenital neutropenia Disorders of immune system Myelodysplastic syndromes (MDS) Bone marrow failure syndromes Symptoms Bone marrow failure Treatment Options Hematopoetic growth Bone Marrow factors Transplant Immune Suppressive Supportive Care Therapy White blood cells disorders Benign disorders Proliferative disorders Quantitative Leukemia Leukopenia Leukocytosis Lymphoma Qualitative abnormalities Myeloma Leucocytosis Leucopenias Increased WBCs Decreased WBCs Infections Bone marrow failure Inflammations and or suppression Cancers Increased (leukemias….) destruction Shift of neutrophils Sequestration from marginating Shift of neutrophils pool to circulating from CP to MP pool (margination) Neutropenia Classification Neutrophil Count Mild 1.0- 2.0 x 10⁹/L Moderate 0.5-1.0x 10⁹/L Severe <0.5 x 10⁹/L Very severe <0.1 x 10⁹/L (agranulocytosis) Fever and Neutropenia.