Alterations of Erythrocyte Function Chapter 26 Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc.

2 Alterations in Erythrocytes  Too many cells  Polycythemias  Too few cells  Anemias  Normal number of cells with altered components

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 3 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

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 4 Anemia  Classifications  Etiology  Morphology Based on MCV, MCH, and MCHC values Based on MCV, MCH, and MCHC values Size Size  Identified by terms that end in “-cytic”  Macrocytic, microcytic, normocytic Hemoglobin content Hemoglobin content  Identified by terms that end in “-chromic”  Normochromic and hypochromic

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 5 Anemia  Anisocytosis  Red cells are present in various sizes  Poikilocytosis  Red cells are present in various shapes

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 6 Anemia  Physiologic manifestation  Reduced oxygen carrying capacity  Variable symptoms based on severity and the ability of the body to compensate  Classic anemia symptoms  Fatigue, weakness, dyspnea, and pallor  Other  Due to hypoxemia and tissue hypoxia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 7 Anemia  Cardiovascular function  Increased preload, heart rate, and stroke volume; reduced afterload  Respiratory function  Dyspnea  Nervous system function  Myelin degeneration  Gastrointestinal function  Pain, nausea, vomiting, anorexia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 8 Normochromic-Macrocytic Anemias  Also termed megaloblastic anemias  Defective DNA synthesis  Due to deficiencies in vitamin B 12 or folate Coenzymes for nuclear maturation and the DNA synthesis pathway Coenzymes for nuclear maturation and the DNA synthesis pathway  Ribonucleic acid (RNA) processes occur at a normal rate  Results in unequal growth of the nucleus and cytoplasm

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 9 Normochromic-Macrocytic Anemias  Pernicious anemia  Caused by a lack of intrinsic factor from the gastric parietal cells  Required for vitamin B 12 absorption  Results in vitamin B 12 deficiency

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 10 Normochromic-Macrocytic Anemias  Pernicious anemia  Typical anemia symptoms  Neurologic manifestations Nerve demyelination Nerve demyelination  Loss of appetite, abdominal pain, beefy red tongue (atrophic glossitis), icterus, splenic enlargement  Treatment Parenteral or high oral doses of vitamin B 12 Parenteral or high oral doses of vitamin B 12  Often unrecognized in older adults due to subtle, slow onset and presentation

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 11 Pernicious Anemia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 12 Normochromic-Macrocytic Anemias  Folate deficiency anemia  Absorption of folate occurs in the upper small intestine  Not dependent on any other facilitating factor  Similar to pernicious anemia except neurologic manifestations generally not seen  Treatment requires daily oral administration of folate

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 13 Hypochromic-Microcytic 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

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 14 Hypochromic-Microcytic 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, spoon-shaped nails Brittle, thin, coarsely ridged, spoon-shaped nails A red, sore, painful tongue A red, sore, painful tongue  Symptomtic Hgb 7-8 g/dl

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 15 Hypochromic-Microcytic 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 Sideroblasts are erythroblasts that contain iron granules that have not been synthesized into hemoglobin

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 16 Hypochromic-Microcytic Anemias  Sideroblastic anemia  Dimorphism  Myelodysplastic syndrome  Erythropoietic hemochromatosis

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 17 Normochromic-Normocytic Anemias  Characterized by red cells that are relatively normal in size and hemoglobin content but insufficient in number

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 18 Normochromic-Normocytic Anemias  Aplastic anemia  Pancytopenia  Pure red cell aplasia  Fanconi anemia  Posthemorrhagic anemia  Acute blood loss from the vascular space

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 19 Normochromic-Normocytic 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

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 20 Drug-Induced Hemolytic Anemia

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 21 Normochromic-Normocytic Anemias  Sickle cell anemia  Anemia of chronic inflammation  Mild to moderate anemia seen in: AIDS, rheumatoid arthritis, lupus erythematosus, hepatitis, renal failure, and malignancies AIDS, rheumatoid arthritis, lupus erythematosus, hepatitis, renal failure, and malignancies  Pathologic mechanisms Decreased erythrocyte life span Decreased erythrocyte life span Ineffective bone marrow response to erythropoietin Ineffective bone marrow response to erythropoietin Altered iron metabolism Altered iron metabolism

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 22 Anemia of Chronic Inflammation

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 23 Myeloproliferative RBC Disorders  Polycythemia  Overproduction of RBCs  Relative polycythemia  Result of dehydration  Fluid loss results in relative increases of red cell counts and Hb and Hct values

Mosby items and derived items © 2010, 2006 by Mosby, Inc., an affiliate of Elsevier Inc. 24 Polycythemia  Absolute polycythemia  Primary absolute Abnormality of stem cells in the bone marrow Abnormality of stem cells in the bone marrow Polycythemia vera (PV) Polycythemia vera (PV)  Secondary absolute Increase in erythropoietin as a normal response to chronic hypoxia or an inappropriate response to erythropoietin-secreting tumors Increase in erythropoietin as a normal response to chronic hypoxia or an inappropriate response to erythropoietin-secreting tumors