General Pathology Lecture 63: Erythrocytes

What is the normal range of hemoglobin amount in men?

13.6 - 17.2

What is the normal range of hemoglobin amount in women?

12 - 15

What is the normal range of hematocrit (%) in men?

39 - 49%

What is the normal range of hematocrit (%) in women?

33 - 43%

What is the normal range of RBC count in millions in men?

4.3 - 5.9 million

What is the normal range of RBC count in millions in women?

3.5 - 5 million

Why do women have slightly lower RBC indices than men?

Menstruation-related blood loss

What is the normal shape of RBCs?

Biconcave disks

What is the term for abnormalities in RBC size?

Anisocytosis

What is the term for abnormalities in RBC shape?

Poikilocytosis

What is the term for abnormalities in hemoglobin?

Chromia

What is the reduction of oxygen-carrying capacity of blood called?

Anemia

What are the three factors that may influence hematologic indices?

1. Dehydration

2. Chronic diarrhea/vomitting

3. Blood loss

What are the three mechanisms of anemia?

1. Blood loss

2. Increased RBC destruction

3. Decreased RBC production

What is caused by acute blood loss in anemia if the patient survives the shock?

Temporary dilution of blood

What is produced after acute blood loss in anemia for erythropoietin compensatory production?

Reticulocyte (immature RBC)

What kind of anemia is caused by chronic blood loss?

Iron-deficiency anemia

What is the most common anemia worldwide?

Iron-deficiency anemia

What are the three effects of hemolytic anemia?

1. Decreased RBC life span

2. Increased erythropoietin levels

3. Increased erythropoiesis

What is hemolytic anemia classified by?

Intrinsic/extrinsic abnormalities of RBCs

Is intravascular or extravascular hemolysis more common?

Extravascular hemolysis

What system does extravascular hemolysis occur within?

Mononuclear Phagocyte System

What is the function of the Mononuclear Phagocyte System?

Removes unhealthy RBCs

What appearance is hemolytic anemia associated with?

Heinz bodies

What do Heinz bodies result in?

Hemolysis

What are the two types of intrinsic hemolytic anemia?

1. Hereditary

2. Acquired

What are the three types of extrinsic hemolytic anemia?

1. Antibody-mediated

2. Mechanical trauma to RBCs

3. Infections

Where is the intrinsic defect found in hereditary spherocytosis?

RBC membrane components

What three things is diagnosis of hereditary spherocytosis based on?

1. Demonstration of spherocytosis

2. Increased osmotic fragility

3. Family history

What is the management method of hereditary spherocytosis?

Splenomegaly

What can deficiency of glucose-6-phosphate dehydrogenase (G6PD) result in?

Hemolytic anemia

What is the mode of inheritance for G6PD deficiency?

X-linked recessive

Protection from what is reduced with G6PD deficiency?

Oxidative stress

G6PD deficiency disease is not manifested until what occurs?

Oxidant injury to globin chains

How long after hemolytic episode should you test for G6PD deficiency?

6 weeks

What is the recovery response to G6PD deficiency?

Reticulocytosis

How many similar chains does normal hemoglobin have?

Two pairs (tetramer)

What is the most common inherited blood disorder in the US?

Sickle cell anemia

What change in beta globin gene causes sickle cell anemia?

Glutamic acid --> Valine

What is the mode of inheritance for sickle cell anemia?

Autosomal recessive

What disease does the prevalence of sickle cell trait protect from?

Malaria

What type of hemolysis is caused by sickle cell anemia?

Extravascular hemolysis

What bodies may be found in sickle cell anemia?

Heinz bodies

What is the main symptom of sickle cell anemia in children?

Splenomegaly

What occurs to children with sickle cell anemia suffering from splenomegaly in 2-3 years?

Non-functional spleen

What is the spleen symptom of sickle cell anemia in adults?

Autosplenectomy

What bodies are formed by autosplenectomy in adults?

Howell-Jolly bodies

What is the main effect of spleen issues in sickle cell anemia?

Susceptibility to infection

Which crisis caused in sickle cell anemia causes bone pain and acute chest syndrome?

Vaso-occlusive crisis

Which crisis caused in sickle cell anemia causes RBC sequestration in spleen?

Sequestration crisis

What is the radiographic presentation of sickle cell anemia?

Hair-on-end presentation

What is the main modality of sickle cell disease management?

Hydroxyuria

What is the group of genetic disorders of decreased hemoglobin synthesis called?

Thalassemia

What is beta thalassemia major (Cooley's) dependent on?

Transfusion

Is beta thalassemia major or minor more common?

Beta thalassemia minor

What is the radiographic presentation of beta thalassemia major?

Hair on end presentation

What does the severity of alpha thalassemia depend on?

How many alpha chains present

How many alpha chains do healthy patients have?

4

What are the two causes of immunohemolytic anemia?

1. Antibodies binding to RBCs

2. Medication binding to RBCs

What is promoted by affected heart valves in hemolytic anemia?

Turbulent blood flow

What causes stress that leads to microangiopathic hemolytic anemia?

Deposited microthrombi

What is the most common cause of anemias of diminished erythropoiesis?

Nutritional deficiencies

What morphological changes from impairment of DNA synthesis leads to megaloblastic anemia?

Macrocytic erythroid precursors

What are the two types of megaloblastic anemia?

1. Pernicious anemia

2. Folate deficiency anemia

What deficiency is pernicious anemia/

Vitamin B12 deficiency

What is another term for vitamin B12?

Cobalamin

Which four foods have high concentrations of vitamin B12?

1. Meat

2. Fish

3. Eggs

4. Milk

What does absorption of vitamin B12 require?

Intrinsic factor

What are the three functions of vitamin B12?

1. Formation of erythrocytes

2. DNA synthesis

3. Neural development

How does megaloblastic anemia affect the nervous system?

Subacute combined degeneration

What craving is common with iron deficiency anemia?

Chewing ice (Pica)

What oral syndrome is caused by iron deficiency anemia?

Plummer-Vinson syndrome

What are the three symptoms of Plummer-Vinson syndrome?

1. Esophageal webs

2. Microcytic hypochromic anemia

3. Atrophic glossitis

What cancer do esophageal webs predispose to?

Esophageal cancer

What is the most important cause of iron deficiency anemia?

Chronic blood loss

What body build is most common in iron deficiency anemia?

Thin

What must iron deficiency anemia be attributed to until proven otherwise?

GI bleeding

What anemia is a syndrome of chronic primary hematopoietic failure?

Aplastic anemia

What is the most common cause of aplastic anemia?

Idiopathic

What are the three features of aplastic anemia?

1. Anemia

2. Thrombocytopenia

3. Neutropenia

What is an abnormal elevated RBC count and hemoglobin levels called?

Polycythemia

What is relative polycythemia associated with?

Dehydration

What is the main cause of primary absolute polycythemia?

Polycythemia vera

What is the main cause of secondary absolute polycythemia?

Erythropoietin-secreting tumor

What is the main complication of polycythemia?

Thromboembolism