SICKLE CELL DISEASE Dr. MUBARAK ABDELRAHMAN MD PEDIATRICS AND CHILD HEALTH Assistant Professor FACULTY OF MEDICINE -JAZAN
Objective: The student should be able: To identify the presentation, diagnosis, management and long term complications of Sickle Cell Disorder and Thalassemia.
Hemoglobin Synthesis Adult hemoglobin - 96% HgA (a 2 B 2 ) a 2 B2 a 2 B2
Hemoglobinopathies Abnormal Hb Structure (Qualitative) Hereditary Disorders >300 Types Abnormal Hemoglobin Hemoglobin S Disorders - Most Prevalent - Sickle Cell Disease - Homozygous (SS) - Sickle Cell Trait - Heterozygous
Hemoglobin S Disorders 6th GLU VAL HbA HbS Point Mutation of B Globin Gene Hb S Gene occurs in Africa and middle east.
Sickle Cell Disease Sickle cell Deoxygenation (or H 2 0, ph) Ca K, O 2 O 2 Polymerization of Hgb S
Sickle Cells
Clinical presentation Depends on severity of condition and age of the child. Hand foot syndrome in infants Pallor, jaundice, splenomegaly in young children Pallor, jaundice and no spleen in older children
Clinical presentation cont. Sickled cells are hemolyzed in the Spleen (young children- Splenomegaly) Micro vascular occlusion: - Tissue Infarcts and Pain - Auto-splenectomy (older children) - Infections - Salmonella Osteomyelitis
COMPLICATIONS Infections Vaso-occlusive effects (Acute chest syndrome) Cholecystitis Renal failure is common Neurological complications Leg ulcers
COMPLICATIONS cont. Crisis: Hemolytic Aplastic - Usually Parvovirus Infectious crisis Vaso-occlusive crisis Sequestration crisis
Diagnosis Sickling test In vitro sickling after adding Reducing Agent Hb electrophoresis to detect Hb S DNA Analysis - Prenatal Testing
TREATMENT Emergency Department Care: Administer oral hydration if the patient can tolerate oral fluids. Administer IV fluids Medications involved in treatment of sickle cell anemia include analgesics for pain and antibiotics for infections.
TREATMENT cont. In/Out Patient Meds: Folic acid. Discharge patient on oral analgesics for a week. Antibiotics when an infection is suspected. Hydroxyurea: Increases hemoglobin F. Hematopoietic stem cell transplantation
TREATMENT cont. Simple blood transfusion Aplastic crisis and acute sequestration crisis. Exchange blood transfusion Cerebrovascular accidents (CVA), acute chest syndrome. And occasionally in cases of priapism. ## Exchange transfusion consists of replacing the patient's RBCs by normal donor RBCs, decreasing HbS to less than 30%.
TREATMENT cont. Consultations: Ophthalmologist, if retinopathy is suspected and visual symptoms are present. Urologist in case of priapism that does not resolve after 6 hours. Orthopedist, if avascular necrosis of the hip or osteomyelitis is suspected. Surgery.
Thalassemia Absent or â Synthesis of Globin Chains (Quantitative) Most Frequent in Mediterranean, African and Asian Populations
Thalassemia β - Thalassemia - â β Chain Synthesis (Gene Mutations) α - Thalassemia - â α Chain Synthesis (1-3 of 4 Genes Deleted
Chromosome 16 α α α Silent carrier HbH disease α - Thalassemia α α α α α α - thalassemia trait (+/- anemia) (severe anemia) Hydrops fetalis (lethal in utero) Hb Bart
β - Thalassemia Minor β β β o β â β chain synthesis β β β + β â β chain synthesis Mild or no anemia
β - Thalassemia Major β β Chromosome 11 β β β o β o β + β + No β Chain Synthesis â β Chain Synthesis Severe Anemia
Clinical Presentation Anemia, jaundice, splenomegaly, prominent maxillary and frontal bones
Diagnosis Peripheral Blood Smear: - Target cells and basophilic stippled RBCs - Severe Hypochromic Microcytic Anaemia ( Hb A MCHC) Bone Marrow: - Erythroid Hyperplasia - Skeletal deformities Extra medullary Hematopoiesis - Splenomegaly and Hepatomegaly
Complications Growth Retardation Systemic Iron Overload (due to chronic blood transfusions) = Cirrhosis, Cardiomyopathy (Cardiac Failure), Death (2nd-3rd Decade)