1 / 23

Alterations of Erythrocyte Function

Alterations of Erythrocyte Function. Chapter 26. Anemia. Reduction in the total number of erythrocytes in the circulating blood or in the quality or quantity of hemoglobin Impaired erythrocyte production Acute or chronic blood loss Increased erythrocyte destruction Combination of the above.

dwiles
Télécharger la présentation

Alterations of Erythrocyte Function

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Alterations of Erythrocyte Function Chapter 26

  2. Anemia • Reduction in the total number of erythrocytes in the circulating blood or in the quality or quantity of hemoglobin • Impaired erythrocyte production • Acute or chronic blood loss • Increased erythrocyte destruction • Combination of the above

  3. Anemia • Classifications • Etiology • Morphology • Based on MCV, MCH, and MCHC values • Size • Identified by terms that end in -cytic • Macrocytic, microcytic, normocytic • Hemoglobin content • Identified by terms that end in -chromic • Normochromic and hypochromic

  4. Anemia • Anisocytosis • Red cells are present in various sizes • Poikilocytosis • Red cells are present in various shapes

  5. Anemia • Physiologic manifestation • Reduced oxygen carrying capacity • Variable symptoms based on severity and the ability for the body to compensate • Classic anemia symptoms • Fatigue, weakness, dyspnea, and pallor

  6. Macrocytic-Normochromic Anemias • Also termed megaloblastic anemias • Characterized by defective DNA synthesis • Due to deficiencies in vitamin B12 or folate • Coenzymes for nuclear maturation and the DNA synthesis pathway • Ribonucleic acid (RNA) processes occur at a normal rate • Results in the unequal growth of the nucleus and cytoplasm

  7. Macrocytic-Normochromic Anemias • Pernicious anemia • Caused by a lack of intrinsic factor from the gastric parietal cells • Required for vitamin B12 absorption • Results in vitamin B12 deficiency

  8. Macrocytic-Normochromic Anemias • Pernicious anemia • Typical anemia symptoms • Neurologic manifestations • Nerve demyelination • Others • Loss of appetite, abdominal pain, beefy red tongue (atrophic glossitis), icterus, and splenic enlargement • Treatment • Parenteral or high oral doses of vitamin B12

  9. Pernicious Anemia

  10. Macrocytic-Normochromic Anemias • Folate deficiency anemia • Absorption of folate occurs in the upper small intestine • Not dependent on any other facilitating factor • Similar symptoms to pernicious anemia except neurologic manifestations are generally not seen • Treatment requires daily oral administration of folate

  11. Microcytic-Hypochromic Anemias • Characterized by red cells that are abnormally small and contain reduced amounts of hemoglobin. • Related to: • Disorders of iron metabolism • Disorders of porphyrin and heme synthesis • Disorders of globin synthesis

  12. Microcytic-Hypochromic Anemias • Iron deficiency anemia • Most common type of anemia worldwide • Nutritional iron deficiency • Metabolic or functional deficiency • Progression of iron deficiency causes: • Brittle, thin, coarsely ridged, and spoon-shaped nails • A red, sore, and painful tongue

  13. Iron Deficiency Anemia

  14. Microcytic-Hypochromic Anemias • Sideroblastic anemia • Group of disorders characterized by anemia • Altered mitochondrial metabolism causing ineffective iron uptake and resulting in dysfunctional hemoglobin synthesis • Ringed sideroblasts within the bone marrow are diagnostic • Sideroblasts are erythroblasts that contain iron granules that have not been synthesized into hemoglobin

  15. Microcytic-Hypochromic Anemias • Sideroblastic anemia • Dimorphism • Myelodysplastic syndrome • Erythropoietic hemochromatosis

  16. Normocytic-Normochromic Anemias • Characterized by red cells that are relatively normal in size and hemoglobin content but insufficient in number

  17. Normocytic-Normochromic Anemias • Aplastic anemia • Pancytopenia • Pure red cell aplasia • Fanconi anemia • Posthemorrhagic anemia • Acute blood loss from the vascular space

  18. Normocytic-Normochromic Anemias • Hemolytic anemia • Accelerated destruction of red blood cells • Autoimmune hemolytic anemias • Immunohemolytic anemia • Warm antibody immunohemolytic anemia • Drug-induced hemolytic anemia • Cold agglutinin immunohemolytic anemia • Cold hemolysin hemolytic anemia

  19. Drug-Induced Hemolytic Anemia

  20. Normocytic-Normochromic Anemias • Sickle cell anemia • Anemia of chronic inflammation • Mild to moderate anemia seen in: • AIDS, rheumatoid arthritis, lupus erythematosus, hepatitis, renal failure, and malignancies • Pathologic mechanisms • Decreased erythrocyte life span • Ineffective bone marrow response to erythropoietin • Altered iron metabolism

  21. Anemia of Chronic Inflammation

  22. Myeloproliferative RBC Disorders • Polycythemia • Overproduction of red blood cells • Relative polycythemia • Result of dehydration • Fluid loss results in relative increases of red cell counts and Hgb and Hct values

  23. Polycythemia • Absolute polycythemia • Primary absolute • Abnormality of stem cells in the bone marrow • Polycythemia vera (PV) • Secondary absolute • Increase in erythropoietin as a normal response to chronic hypoxia or an inappropriate response to erythropoietin-secreting tumors

More Related