Anemia Review Flashcards
What is microcytosis?
A condition defined as a mean corpuscular volume of less than 80 µm³ (80 fL) in adults, often associated with anemia.
How is microcytosis usually discovered?
Incidentally during a complete blood count (CBC).
What is the normal mean corpuscular volume in adults?
Greater than 80 µm³ (80 fL).
What factors can affect normal hemoglobin levels?
Ethnicity, tobacco use, and altitude.
What is the most common cause of microcytosis in the United States?
Iron deficiency anemia.
Name other causes of microcytosis besides iron deficiency anemia.
Anemia of chronic disease, lead toxicity, sideroblastic anemia, and thalassemia trait.
Are most patients with microcytosis symptomatic or asymptomatic?
Asymptomatic.
What happens to serum iron levels in iron deficiency anemia?
They decrease.
How do serum iron levels vary throughout the day?
They have diurnal variations with higher concentrations later in the day.
What physical findings may be present as the severity of anemia increases?
Systolic murmur, pallor of the mucous membranes, nail beds, and palmar creases.
What can cause transient increases in serum iron levels?
Meat ingestion or iron supplementation.
What do transient increases in serum iron levels not represent?
An increase in true iron stores.
What are useful in differentiating iron deficiency anemia and anemia of chronic disease when serum iron is decreased?
Ferritin, transferrin saturation levels, and TIBC.
What laboratory tests help differentiate the cause of microcytosis?
Red blood cell distribution width, serum iron levels, serum ferritin levels, total iron-binding capacity (TIBC), transferrin saturation, hemoglobin electrophoresis, reticulocyte blood count, and peripheral blood smears.
What does red blood cell distribution width measure?
The variation in red blood cell size.
What does TIBC refer to?
The ability of unsaturated transferrin to bind to iron.
How is TIBC usually affected in iron deficiency?
It is increased.
How does red blood cell distribution width differ in iron deficiency anemia and anemia of chronic disease?
Increased in iron deficiency, normal in anemia of chronic disease.
How is TIBC usually affected in anemia of chronic disease?
It is decreased.
How is TIBC usually affected in less severe thalassemias?
It is normal.
What is transferrin saturation?
A percentage calculated as serum iron concentration/TIBC x 100.
Is red blood cell distribution width sensitive or specific enough to differentiate iron deficiency and beta-thalassemia trait?
No.
How can the red blood cell count help differentiate iron deficiency anemia and beta-thalassemia trait?
It is often high to normal in beta-thalassemia trait.
What happens to serum iron levels in iron deficiency anemia?
They are decreased.
What does a transferrin saturation level less than 16 percent indicate?
Iron deficiency anemia.
What is ferritin?
A complex of iron and the binding protein apoferritin.
What does ferritin reflect?
True iron stores.
What can cause transient increases in serum iron levels?
Meat ingestion or iron supplementation.
What can cause ferritin to be elevated?
Liver disease, malignancy, and chronic renal disease.
What ferritin level indicates iron deficiency anemia in a healthy person?
Less than 15 ng per mL (15 mcg per L).
What are the main categories of etiologies for increased red blood cell loss or destruction?
Acute blood loss, hypersplenism, hemolytic disorders, congenital conditions, acquired conditions.
What ferritin level indicates iron deficiency anemia in a person with chronic inflammation?
Less than 50 ng per mL (50 mcg per L).
Name two congenital conditions that can lead to increased red blood cell loss.
red cell membrane disorders (e.g. hereditary spherocytosis) hemoglobinopathies (e.g. sickle cell disease and thalassemia) hemolytic anemia
What ferritin level usually excludes iron deficiency?
Greater than 100 ng per mL (100 mcg per L).
What is TIBC?
Total iron-binding capacity, the ability of unsaturated transferrin to bind to iron.
What are hemoglobinopathies?
Disorders related to abnormal hemoglobin, such as sickle cell disease.
How does TIBC differ in iron deficiency anemia and anemia of chronic disease?
Increased in iron deficiency, decreased in anemia of chronic disease.
What are the etiologies of microcytic anemia?
Iron deficiency anemia, thalassemia, anemia of chronic disease.
What is homozygous sickle cell disease also known as?
Hemoglobin SS disease.
What affects TIBC besides the type of anemia?
Diurnal variations.
What is heterozygous sickle hemoglobin C disease also known as?
Hemoglobin SC disease.
What are the etiologies of normocytic anemia?
Decreased production of normal-sized red blood cells, increased destruction or loss of red blood cells, uncompensated increase in plasma volume, mixture of conditions producing microcytic and macrocytic anemias.
Name two disorders of red blood cell membranes.
Hereditary spherocytosis and hereditary elliptocytosis.
What happens in the initial stage of nearly all anemias?
They are normocytic.
What are the causes of increased red blood cell loss or destruction?
Acute blood loss, hypersplenism, hemolytic disorders, congenital conditions, acquired conditions.
What enzyme deficiency is associated with hemolytic anemia?
Glucose-6-phosphate dehydrogenase deficiency.
What is another enzyme deficiency that can cause hemolytic anemia?
Pyruvate kinase deficiency.
What are some congenital conditions causing increased red blood cell loss?
Hemoglobinopathies, disorders of red blood cell membranes, red blood cell enzyme deficiencies.
What are some acquired conditions causing increased red blood cell loss?
Mechanical hemolysis, macrovascular disorders, microangiopathic disorders, autoimmune hemolytic anemias, drug-induced anemias, paroxysmal nocturnal hemoglobinuria.
What are some acquired conditions that can lead to increased red blood cell destruction?
Mechanical hemolysis, macrovascular disorders, microangiopathic disorders, disseminated intravascular coagulopathy, hemolytic-uremic syndrome, thrombotic thrombocytopenic purpura, autoimmune hemolytic anemias, drug-induced anemias, paroxysmal nocturnal hemoglobinuria.
What are examples of hemoglobinopathies?
Homozygous sickle cell disease, heterozygous sickle hemoglobin C disease.
What is mechanical hemolysis?
Destruction of red blood cells due to physical damage.
What are macrovascular disorders?
Conditions affecting large blood vessels that can lead to hemolysis.
What are examples of disorders of red blood cell membranes?
Hereditary spherocytosis, hereditary elliptocytosis.
What are examples of red blood cell enzyme deficiencies?
Glucose-6-phosphate dehydrogenase deficiency, pyruvate kinase deficiency.
What are microangiopathic disorders?
Conditions affecting small blood vessels that can lead to hemolysis.
What are examples of autoimmune hemolytic anemias?
Warm-reactive anemias, cold-reactive anemias.
What is paroxysmal nocturnal hemoglobinuria?
An acquired condition causing increased red blood cell loss.
What is disseminated intravascular coagulopathy?
A condition where blood clots form throughout the body’s small blood vessels.
Where is Vitamin B12 absorbed in the body?
Ileum
What is hemolytic-uremic syndrome?
A condition characterized by hemolysis, kidney failure, and low platelet count.
What is necessary for Vitamin B12 absorption?
Intrinsic factor
What condition results from the loss of parietal cells?
Pernicious anemia
What is the most common cause of pernicious anemia?
Autoimmune atrophic gastritis
What is thrombotic thrombocytopenic purpura?
A rare blood disorder causing blood clots in small vessels, leading to low platelet count and hemolysis.
What are autoimmune hemolytic anemias?
Conditions where the immune system attacks and destroys red blood cells.
What are warm-reactive anemias?
Autoimmune hemolytic anemias where antibodies react at body temperature.
What are cold-reactive anemias?
Autoimmune hemolytic anemias where antibodies react at cold temperatures.
What are drug-induced anemias?
Hemolytic anemias caused by medications.
What are less common causes of pernicious anemia?
Nonautoimmune gastritis secondary to H. pylori infections and Zollinger-Ellison syndrome
What is paroxysmal nocturnal hemoglobinuria?
A rare, acquired, life-threatening disease of the blood characterized by destruction of red blood cells.
Why are serum folate levels not useful?
They fluctuate rapidly with dietary intake and are not cost effective.
What are the primary causes of decreased red blood cell production?
Marrow hypoplasia or aplasia, myelopathies, myeloproliferative diseases, pure red blood cell aplasia.
What test more accurately correlates with folate stores?
RBC folate levels
What are the secondary causes of decreased red blood cell production?
Chronic renal failure, liver disease, endocrine deficiency states, anemia of chronic disease, sideroblastic anemias, overexpansion of plasma volume.
What is anemia of chronic disease?
A type of anemia associated with chronic disorders, characterized by hypo-activity of the bone marrow and inadequate production or response to erythropoietin.
What does a normal methylmalonic acid level indicate in the context of megaloblastic anemia?
Folate deficiency
What can cause anemia of chronic disease?
Inflammatory conditions, infections, neoplasms, and various systemic diseases.
What is the second most common form of anemia worldwide?
Anemia of chronic disease.
Who can be contacted for questions?
Clay W. Walker, PA-C
What will be elevated with both vitamin B12 and folate deficiencies?
Homocysteine levels
What is the pathogenesis of anemia of chronic disease?
It is multifactorial, involving hypo-activity of the bone marrow, inadequate production of erythropoietin, poor response to erythropoietin, and slightly shortened red blood cell survival.
What are some chronic disorders associated with anemia of chronic disease?
Inflammatory conditions, infections, neoplasms, and various systemic diseases.
What is the email address provided for inquiries?
clay_walker@rush.edu
What effect do reverse transcriptase inhibitors have on patients with HIV?
Cause macrocytosis
What is the professional title of Clay W. Walker?
PA-C
What are some conditions that can lead to decreased red blood cell production due to endocrine and renal pathology?
Chronic renal failure and endocrine deficiency states.
What does macrocytosis indicate in patients treated with reverse transcriptase inhibitors?
Medication compliance
Which institution is associated with the email address provided?
Rush University
What is uncompensated blood loss?
Blood loss that the body cannot adequately replace.
What is hypersplenism?
An overactive spleen that destroys blood cells too quickly.
What are the two most sensitive tests for detecting alcohol misuse in patients with macrocytosis?
Michigan Alcoholism Screening test and Gamma-glutamyltransferase levels
What are some etiologies of macrocytic anemia?
Alcohol misuse, B12 deficiency, medications, folate deficiency, hypothyroidism, bone marrow dysplasias, liver disease, reticulocytotic, miscellaneous not established.
What physical findings are consistent with alcohol misuse?
Gynecomastia, caput medusae, and jaundice
What is macrocytosis?
The presence of abnormally large red blood cells in the blood.
What can cause B12 deficiency?
Poor dietary intake, malabsorption, pernicious anemia.
How does alcohol use more commonly cause macrocytosis?
Through its toxic effect
What can cause folate deficiency?
Poor dietary intake, malabsorption, increased demand.
What is the role of the American Academy of Family Physicians in the context of this text?
They provided the source material for the information on anemia.
What is the mean corpuscular volume generally less than with chronic alcohol use?
110 fL
What rapidly corrects the elevated mean corpuscular volume caused by alcohol use?
Abstinence from alcohol
What is required to establish a diagnosis of myeloproliferative disorders?
Bone marrow biopsy
Who will likely be necessary for the work-up and management of myeloproliferative disorders?
Hematology referral
