Disorders of Red Blood Cells PDF

DISORDERS OF RED BLOOD CELLS DR. Amal Ali Associate Professor of Oral medicine&Diagnosis Types of anemia: 1. Microcytic hypochromic anemia: a. Iron deficiency anemia. b. Thalassemia 2. Macrocytic normochromic anemia: a. Pernicious (Vitamin B12 deficiency)...

DISORDERS OF RED BLOOD CELLS DR. Amal Ali Associate Professor of Oral medicine&Diagnosis Types of anemia: 1. Microcytic hypochromic anemia: a. Iron deficiency anemia. b. Thalassemia 2. Macrocytic normochromic anemia: a. Pernicious (Vitamin B12 deficiency) anemia. b. Folate deficiency anemia. 3. Normocytic normochromic anemia: a. Aplastic anemia. b. Sickle-cell anemia. Vitamin B12 deficiency Anemia B12 is needed by the body for:  DNA synthesis and cell division  Nervous tissue metabolism Found in meat , specially liver Needs gastric intrinsic factor to be bound to and absorbed in the terminal ilium Vitamin B12 deficiency Anemia Causes: Nutritional deficiencies Pernicious anaemia PA (auto-immune disease): autoantibodies against parietal cells and intrinsic factor Gastrectomy Rarely ileal absorption defect due to disease or resection. Vitamin B12  II- Macrocytic anemia Pernicious anemia (Vitamin B12 deficiency Anaemia) Megaloblastic or pernicious anemia is an autoimmune disease resulting from autoantibodies directed against the intrinsic factor (needed to absorb vitamin B12 from the GIT) and gastric parietal cells. Vitamin B12 is necessary for the maturation of RBCs and the metabolism of nervous tissues. Clinical Manifestations  Degeneration of spinal cord leading to numbness of extremities, neuro-muscular incoordination, muscular weakness & ataxia.  Peripheral neuropathy, paraplegia & optic atrophy may occur  Impaired sense of smell  Irritability, personality changes  Mild memory impairment, depression and psychosis  N.B:Takes longer to develop (3 years ) (liver stores) Oral Manifestations Burning sensation in tongue, lips and buccal mucosa. Atrophic glossitis Recurrent aphthous stomatitis Dysphagia Taste alterations (due to disturbance in chorda tympani nerve). Diagnosis: A) The diagnosis of PA could be suspected if the patient complains of triad of symptoms: a) Sore, painful atrophic tongue. b) Generalized weakness c) Numbness or tingling in the extremities.  (B) Hematological findings: 1) Decrease RBC count less than 1,000,000/ml. 2) Increase in MCV and MCH, and normal MCHC. 3) Decreased leukocyte number and the polymorphs are hypersegmented with 6 or more lobes in the nucleus. 4) Abnormally large platelets. Platelets number may decrease. 5) Serum folate is normal. 6) Low serum Vit B12 level Use of Schilling test (which measure cyanocobalamin absorption ) Serological tests for parietal cells& IF Abs.  Treatment I.M injection of hydroxy-cobalamine N.B.: -Hematological changes of pernicious anemia may be improved by oral folic acid therapy but will not stop the progression of neurological symptoms. Folic Acid Deficiency Anemia Found in fresh green leafy vegetables Absorbed in the small intestine Small reserve so takes only 4 moths to develop Causes: Dietary deficiency Diseases of the small intestine Increased demand: infancy, pregnancy, increased hemolysis Drugs: phenytoin, oral contraceptive Clinical Manifestations  Pallor  Sore tongue & mouth  Recurrent aphthous stomatitis  Weakness, headaches, heart palpitations Risk of cleft lip and palate in the foetus Treatment Folic acid 5mg daily (orally Dental aspects : As B12 deficiency anemia but does not lead to neurological manifestations  III- Normocytic Normochromic Anemia Sickle cell Anemia It is caused by Hb gene mutation. Normal RBCs are biconcave discoid shape, becomes distorted, presenting a sickle-like shape. This will reduce both their plasticity and lifetime from the normal 120 days down to 14 days. This results in anemia and hypertrophic bone marrow. Pathogensis: The abnormal hemoglobin (HbS). Deoxygenated state or acidosis HbS molecules become insoluble and polymerize Flexibility of RBCs decrease (rigid) Sickle shaped This process is reversible initially. With repeated sickling, cells loose their membrane flexibility and remain deformed. Sickling is precipitated by: Infection Dehydration Cold Acidosis Hypoxia (high altitude, GA) 1)Hb S release its oxygen contents to the tissues more easily than Hb A. 2) Patients therefore feel well despite being anemic except during crisis or complication. Sickling can lead to: 1) Destruction of sickle cells (hemolysis) with features of anemia. 2) Increased viscosity & clumping of cells in the microcirculation: thrombosis &infarction.  Clogging sections of blood vessels leading to episodes of pain which can be severe. (hypoxia and necrosis) These episodes are called a sickle cell crisis (also known as a vaso- occlusive crisis). They can last from a few hours to few days and usually associated with low grade fever. Sickle cell disease is classified into: 1) Homozygous state " sickle cell anemia” -The patient receives two abnormal alleles- one from each parent (HbSS) 2) Heterozygous state "sickle cell trait” -The patient receives one abnormal allele from one parent and a normal one from the other (HbSA) The sickle cell trait is usually asymptomatic due to presence of some normal (HbA). The disease occur mainly in Africans (25% carry the gene). It is also found in middle east, India and southern Europe. SICKLE CELL ANEMIA (HbSS)  It is a serious disease since 80-90% of Hb is HbS and the remainder is HbF. Clinical feature: 1) Chronic anemia which may be mild asymptomatic to severe hemolytic anemia. -The affected patient shows underdevelopment with pallor and icteric tinge in the sclera. -The patient is weak, short of breath and easily fatigued. 2- Jaundice 3- Delayed growth 4- Sickle cell crisis (episodes of pain) A sickle cell crisis is triggered when the abnormal blood cells block the small blood vessels that supply the body tissues. This causes the cells in the affected tissue to be damaged, resulting in swelling (inflammation) which irritates nearby nerve endings. During a sickle cell crisis, younger children may develop painful swelling in their hands or feet. A sickle cell crisis also triggers: 1) Bone pain (commonest feature). 2) Pain: abdomen, chest, spleen, liver. 3) Cerebral damage: hemiparesis, fits. 4) leg ulcers. 5) Kidney infarcts causing hematuria.  Orally: Pallor or jaundice of the oral mucosa mainly seen on the soft palate and floor of the mouth. Delayed eruption and enamel hypoplasia may be seen. Maxillary overgrowth Radiographic changes: 1) The jaw bone shows both: -osteoporosis -areas of osteosclerosis. Resulting from 2 opposing mechanisms:  RBCs have short life span (30 days) -1/4 of the normal red cell life span hyperplastic bone marrow evident by osteoporosis.  Thrombosis in capillaries of bone marrow by sickled cells act as a nidus for calcification resulting in osteosclerosis. Osteoporosis and osteosclerosis affect: -mandible and maxilla -skull -vertebrae and long bones 2) The trabecular pattern of alveolar bone Ladder- like (runs horizontally between roots of teeth) -Lamina dura appears dense and distinct. 3) In skull films: -The diploe is thickened (due to bone marrow hyperplasia) -The trabeculae are coarse and run perpendicular to the inner and outer table giving Hair on end appearance -The frontal bossing is very prominent. Management & dental considerations: Avoid GA (low O2) Local aesthesia is the safest method Treat dental infections early and prophylactic AB should be given in any operation as any infection can precipitate crisis Risk of Hepatitis and HIV (blood transfusion) - Avoid elective surgery. - Non-steroidal anti-inflammatory analgesics for the painful bone infarcts. - Hospitalization in severe painful crises.  Aplastic Anemia A rare blood disorder characterized by peripheral blood pancytopenia (absence of RBCs, WBCs and Platelets), resulting from reduced or absent blood cell production in the bone marrow. Most cases are idiopathic or immune mediated.  Clinical Manifestations are due to: Anemia fatigue and malaise, chest pain, or shortness of breath. Thrombocytopenia bleeding manifested as increased bruising, evident by purpura and petechiae, and epistaxis or gingival bleeding. Leukopenia fever and infection. Oral Manifestations Pallor of the oral mucosa & Atrophy of filliform & fungiform papillae. Oral hemorrhage; petechiae, spontaneous gingival bleeding. Ulceration of the oral mucosa Candidiasis and viral infection. Laboratory Findings: 1. Pancytopenia. 2. Absence (Zero) of reticulocytes no activity of bone marrow. Differential Diagnosis of aplastic anemia: Treatment General:  Supportive treatment: RBCs & platelet transfusion.  Bone marrow transplantation. Dental Management of aplastic anemia: I. The main clinical problems are: 1. Increased bleeding tendency. 2. Marked susceptibility to infection. 3. Presence of severe anemia. 4. Graft versus host diseases consequent to bone marrow transplant Lichenoid lesions.  II. General rules: 1. Conservative therapy is better to avoid infection and bleeding. 2. Maintain good oral hygiene to avoid oral infection by using Chlorhexidine M.W. 3. Prophylactic antifungal, antiviral & antibiotic drugs.  III. Management: 1. Avoid dental surgery except in emergencies to avoid: a. Risk of hemorrhage. b. Risk of infection (osteomyelitis and septicemia). 2. If dental surgery is essential hospitalization (platelets or blood transfusion). 3. Patients with acute signs and symptoms: a. Symptomatic treatment for painful oral ulcers. b. Analgesic for pain. c. Antibiotic, anti-fungal and anti-viral drugs for infection. d. Drainage of the pulp in acute dental pain.  4.If spontaneous bleeding occur Antifibrinolytic drugs & local hemostatic measures to control bleeding. 5.Avoid nerve block injection. Intra-ligamentary technique is more suitable. 6. Dental procedures should be atraumatic. 7. Patient with bone marrow transplant is under cortisone treatment which leads to atrophy of adrenal gland before surgery adjusts cortisol level. Glucose 6 Phosphate Dehydrogenase Deficiency An erythrocyte metabolic defect, in the absence of G6PD, the RBC cannot withstand oxidant compound and hemolysis occur due to denaturing the hemoglobin. The life span of RBC is reduced to about 2/3 normal Infection, diabetes and oxidant drugs may cause an acute acceleration of RBC hemolysis. Dental infection should be treated without delay Avoid:. a. Analgesics: e.g Aspirin c. Antibacterial : e.g Sulphonamide Blood transfusion may be life saving.  Polycythaemia Polycythaemia is the over-production of red blood cells. Can be either : Primary (idiopathic)Polycythemia Rubra Vera Secondary  1ry or idiopathic (POLYCYTHEMIA RUBRA VERA ) Mainly in old, smokers , more in males, there is: 1) Increased number of RBCs (may reach 18million/mm3 ). 2) Increased hemoglobin (18-24 g/dl). Increase blood cells  hyperviscosity  risk of thrombus Clinical Features: 1) Purplish - red skin color 2) Bone pain, 2ry to bone marrow hyperplasia. 4) Headache, tennitus and nervousness. 5) Bleeding - bruising (petechiae & ecchymosis) or thrombosis Platelets dysfunction and increased blood viscosity. Oral Features and Dental Aspects: 1. Oral mucosal surfaces are purplish red in color. 2. Petechiae and ecchymosis. 3. Gingival enlargement with gingival bleeding. 4. Prominent varicositis in ventral surface of tongue. 5. Infarcts in smaller vessels (increased viscosity of blood) multiple ulcers in the mucosa. Dental management problems : Tendency to bleeding and thrombosis, sometimes may by fatal. 1) CBC should be ordered before dental treatment. 2) Hypertension may be associated. 3) Patient's physician should be consulted.  Blood Indices used in Anemia Assessment: Index Definition Increased in Decreased in Packed cell It is the ratio of spun RBCs Polycythemia Anemia volume to plasma, reflecting the (Hematocrit) volume of packed RBCs Hct relative to the total blood volume. Mean MCV represents the average -Macrocytic anemias -Iron deficiency corpuscular measurement of RBC -Myelodysplastic anemias volume (MCV) volume and calculated as Hct syndromes -Thalassemia divided by RBC count -Alcoholism -Liver diseases Index Definition Increased in Decreased in Mean corpuscular MCH is the Hb Macrocytic anemias Microcytic anemias Hemoglobin concentration in a single (MCH) RBC Mean Corpuscular MCHC is the Hb conc. Hereditary -Microcytic anemias Hemoglobin divided by Hct spherocytosis concentration (MCHC) Total Iron binding TIBC measures the blood’s -Iron deficiency -Thalassemia capacity capacity to bind iron with -Acute and chronic -Anemias of infection transferrin blood loss and chronic diseases 1- Enumerate hemolytic anemia? 2-Enumerate types of anemia due to hemoglobinopathies? 3- Dose the pernicious anemia develop rapidly ?Why?