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Anemia . Premed 2 Pathophysiology. Normal blood smear. Anemia. Decrease in whole red cell mass Causes: 1.Excessive blood loss 2. decreased in RBC production 3. increased RBC loss. Anemia Caused by Blood Loss
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Anemia Premed 2 Pathophysiology
Anemia • Decrease in whole red cell mass • Causes: • 1.Excessive blood loss • 2. decreased in RBC production • 3. increased RBC loss
Anemia Caused by Blood Loss Red blood cells can be lost through bleeding, which can occur slowly over a long period of time, and can often go undetected. This kind of chronic bleeding commonly results from the following:
Gastrointestinal conditions such as ulcers, hemorrhoids, gastritis (inflammation of the stomach) and cancer Use of nonsteroidal anti-inflammatory drugs (NSAIDS) such as aspirin or Motrin Menstruation and childbirth in women, especially if menstrual bleeding is excessive and if there are multiple pregnancies
Anemia Caused by Decreased or Faulty Red Blood Cell Production The body may produce too few blood cells or the blood cells may not work properly. In either case, anemia can result. Red blood cells may be faulty or decreased due to abnormal red blood cells or the a lack of minerals and vitamins needed for red blood cells to work properly. Conditions associated with these causes of anemia include the following:
Sickle cell anemia Iron deficiency anemia Vitamin deficiency Bone marrow and stem cell problems Other health conditions
Sickle cell anemia is an inherited disorder that affects African-Americans. Red blood cells become crescent-shaped because of a genetic defect. They break down rapidly, so oxygen does not get to the body's organs, causing anemia. The crescent-shaped red blood cells also get stuck in tiny blood vessels, causing pain.
Iron-deficiency anemia • Major cause in adults: chronic blood loss menorrhagia ( heavy menses) bleeding from GIT • Dietary deficiency is common after 6 months of age in infants • Pallor, fatigue, dyspnea on exertion
Iron-deficiency anemia • Low hemoglobin • Low hematocrit • Low RBC count • Hypochromic, microcytic RBC on smear • Low serum iron • High total iron binding capacity(TIBC) • Low iron store; low ferritin
Vitamin deficiency anemia may occur when vitamin B-12 and folate are deficient. These two vitamins are needed to make red blood cells. Conditions leading to anemia caused by vitamin deficiency include the following:
Megaloblastic anemia • Presence of large, abnormal-looking erythroid precursor cells or MEGALOBLASTS in the bone marrow • Cause: low vitamin B12 or folic acid • Decrease DNA synthesis decrease DNA replication and nuclear division • Impaired RBC production
Megaloblastic anemia • Pancytopenia low RBC low platelets low WBC • Oval macrocytosis (“ big RBC”) • Hypersegmented neutrophils (more than 5 lobes) • Megaloblastic hyperplasia of the bone marrow
Vitamin B12 deficiency Pernicious anemia Lemon-yellow skin Stomatitis Glossitis Demyelination of the posterior and lateral columns of the spinal cord Ataxic gait, hyperreflexia, impaired position and vibration reflexes Labs: Antibodies against Intrinsic factor Abnormal Schilling test Megaloblastic anemia
Folate deficiency Seen in alcoholics Pregnancy Fad dieters Contraceptive pills Dilantin Chemotherapy agents Same presentation as B12 deficiency NO NEUROLOGIC DEFICITS Megaloblastic anemia
Anemia of Chronic disease • Second most common form • May be due to rheumatoid arthritis, kidney disease, chronic infection • Normochromic, normocytic • In chronic disease: it may be similar to IDA, but the TIBC is low
Aplastic anemia • Most common cause: toxic exposure radiation chemicals – benzene antibiotics – chloramphenicol cancer drugs viruses – hepatitis C and Parvovirus
Aplastic anemia • Hypocellular bone marrow • Loss of hematopoietic cells • Peripheral pancytopenia
Hemolytic anemias • Immune hemolytic anemias cold agglutinin disease Hemolytic disease of the newborn • Membrane skeletal protein abnormalities Hereditary spherocytosis • Enzyme deficiency HA G6PD deficiency Pyruvate kinase deficiency • Hemoglobinopathies Hemoglobin S disorder : Sickle cell anemia Thalassemias: alpha and beta
Hemolytic anemias • Shortened life span of RBC • Increased destruction • Increased unconjugated bilirubin • Pigment-containing stones • Increased urobilinogen • Hemoglobinemia, hemoglobinuria • Disappearance of serum haptoglobulins • Hemosiderosis • Increased erythropoiesis • reticulocytosis
IHA: Hemolytic disease of the newborn • Erythroblastosis fetalis • Maternal antibodies attack the D antigen of the Rh blood group Mom: Rh (-) or “ d” Baby: Rh (+) or “D” • Also seen in ABO incompatibility Mom O, Baby A or B Mom A, Baby B or AB Mom B, Baby A or AB
Hemolytic disease of the newborn • Kernicterus: unconjugated bilirubin accumulates in the basal ganglia and the CNS • Hydrops fetalis • stillbirth
Enzyme deficiency HA • Most common form • X-linked • Common in 10% of African Americans; Mediterrenean • Acute , self-limited • Hemoglobinemia, hemoglobinuria • Triggering factors: infections primaquine sulfonamides
Enzyme deficiency HA • Pyruvate kinase deficiency • Anemia is chronic and sustained • Autosomal recessive • No spherocytes seen
Hemoglobinopathies • Abnormal hemoglobin structure • Most commonly involved: Hemoglobin S • Point mutation in codon 6 of the beta-globin gene • Valine is substituted for glutamic acid
Hemoglobinopathies • Result: Hemoglobin S polymerizes at low oxygen tension sickle cells RBC membranes stiffen hemolysis/ obstruction of the blood vessels • Severe Hemolytic anemia • Chronic leg ulcers • Painful crises: limbs, back, chest, abdomen • Infarctions: lungs and spleen autosplenectomy • Aplastic crisis: fall in hemoglobin • Salmonella osteomyelitis
Thalassemia occurs when the red cells can't mature and grow properly. Thalassemia is an inherited condition that typically affects people of Mediterranean, African, Middle Eastern, and Southeast Asian descent. This condition can range in severity from mild to life-threatening; the most severe form is called Cooley's anemia
Thalasemias • Deficient production of either alpha or beta-globin chains • Beta-thalasemia: most common form; defect in the genes coding for Beta-globin gene
Decrease hgb synthesis Short rbc lifespan (due to insoluble, excess alpha-chains) Ineffective RBC production Enlarged spleen Skull, facial bones and long bones distortion Microcytosis, hypochromic anemia Hemosiderosis Increase Hgb F throughout life Beta-thalassemia major(Mediterrenean or Cooley anemia)
Beta-thalassemia minor Increase in Hgb A2 Alpha-thalassemia Most common in Southeast Asia May be asymptomatic or fatal. Other forms of thalassemias