Macrocytic Anemias: Types and Diagnosis

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following is a common cause of iron deficiency anemia?

Excessive water intake

High protein diet

Rapid growth (correct)

Frequent exercise

What symptom is associated with a deficiency of tissue enzymes requiring iron?

Improved digestion

Hyperactivity

Fatigue (correct)

Weight gain

Which lab finding is indicative of iron deficiency anemia?

Low Hb (correct)

Normal RDW

High MCH

High MCV

Which of the following is NOT a typical blood smear finding in iron deficiency anemia?

Macrocystosis Signup and view all the answers

What would the serum ferritin levels typically be in a patient with iron deficiency anemia?

Low Signup and view all the answers

Which of the following is a characteristic of megaloblastic anemia?

Vit B12 Deficiency Signup and view all the answers

Which condition is a cause of non-megaloblastic macrocytic anemia?

Liver disease Signup and view all the answers

Which of the following is part of the investigation process for diagnosing anemia?

Assessing Hb level Signup and view all the answers

Which type of anemia would a folic acid deficiency most likely cause?

Megaloblastic Signup and view all the answers

Which of these measures is not part of the initial steps in diagnosing the type of anemia?

Blood glucose levels Signup and view all the answers

Which of the following is a clinical feature of pernicious anemia?

Dementia Signup and view all the answers

Which laboratory finding is specific for pernicious anemia?

Anti-intrinsic factor antibodies Signup and view all the answers

What is typically observed in the bone marrow examination of patients with vitamin B12 deficiency?

Erythroid hyperplasia and presence of megaloblasts Signup and view all the answers

Which of the following is elevated in the serum of patients with pernicious anemia?

Serum methylmalonic acid Signup and view all the answers

Which of the following investigations would show increased values in both folate deficiency and vitamin B12 deficiency?

Serum/plasma homocysteine Signup and view all the answers

In pernicious anemia, which of the following is a characteristic finding from gastric analysis?

Achlorhydria Signup and view all the answers

According to WHO, what is the hemoglobin (Hb) threshold for diagnosing anemia in women?

12 g/dL Signup and view all the answers

What effect does a reduction in plasma volume due to dehydration have on Hb concentration?

Apparent increase in Hb level Signup and view all the answers

Which of the following is NOT a symptom or sign of anemia?

Increased concentration ability Signup and view all the answers

Which of the following factors does NOT affect the definition of anemia?

Skin color Signup and view all the answers

What can an increase in plasma volume during pregnancy cause?

Wrong diagnosis of anemia Signup and view all the answers

Which of the following symptoms of anemia is due to compensatory attempts of the body?

Palpitation Signup and view all the answers

Which of the following is a characteristic feature of the peripheral blood film in megaloblastic anemia?

Oval macrocytes with hypersegmented neutrophils Signup and view all the answers

What is the primary cause of pernicious anemia?

Intrinsic factor deficiency Signup and view all the answers

Which population is most commonly affected by pernicious anemia?

Females over 60 years old Signup and view all the answers

Which autoimmune diseases are associated with pernicious anemia?

Thyroid disease, Addison's disease, and Vitiligo Signup and view all the answers

Which neurological feature is associated with pernicious anemia?

Symmetrical paresthesia in the fingers and toes Signup and view all the answers

Which clinical feature is indicative of severe anemia in the context of megaloblastic anemia?

Pancytopenia Signup and view all the answers

Which of the following is a general clinical feature of hemolytic anemias?

Splenomegaly Signup and view all the answers

Which virus is associated with aplastic crises in hemolytic anemia patients?

Parvovirus B19 Signup and view all the answers

Which of the following lab findings supports increased red cell production in the blood?

Elevated reticulocyte count Signup and view all the answers

Which symptom is part of the triad of hemolytic anemia?

Pallor Signup and view all the answers

What is a common biochemical finding in hemolytic anemia patients?

Elevated LDH levels Signup and view all the answers

What morphologic evidence on a peripheral smear indicates red cell damage in hemolytic anemia?

Reduced red cell lifespan Signup and view all the answers

What characterizes megaloblastic anemia?

Delayed nuclear maturation due to defective DNA synthesis Signup and view all the answers

Which vitamin deficiency is a common cause of megaloblastic anemia?

Vitamin B12 Signup and view all the answers

Which of the following is NOT a known cause of folate deficiency?

Hypertension Signup and view all the answers

What is the most common cause of vitamin B12 deficiency?

Pernicious anemia Signup and view all the answers

Which drug category is associated with folate deficiency?

Antifolate drugs Signup and view all the answers

What role does vitamin B12 play in the body related to macrocytic anemia?

Involved in DNA synthesis Signup and view all the answers

Which of the following is impaired in megaloblastic anemia?

DNA synthesis Signup and view all the answers

Which condition is NOT related to vitamin B12 deficiency?

Hypertension Signup and view all the answers

Which of the following is a symptom of anemia?

Yellowish skin Signup and view all the answers

What is a characteristic feature of microcytic anemia?

MCV < 80 FL Signup and view all the answers

Which of the following is NOT a classification for normocytic anemia?

Iron deficiency anemia Signup and view all the answers

What is the underlying mechanism for blood loss causing anemia?

Bleeding Signup and view all the answers

Which of the following factors does NOT influence the presence or absence of anemia symptoms?

Type of anemia Signup and view all the answers

What classification would be given to an anemia with an MCV = 85 FL?

Normocytic Signup and view all the answers

Which process results in erythroid hyperplasia?

Expansion of erythroid lineage Signup and view all the answers

What occurs during intravascular hemolysis?

Free hemoglobin is released into the circulation Signup and view all the answers

Which of the following is NOT associated with intravascular hemolysis?

Removal of antibody-coated red blood cells by macrophages Signup and view all the answers

Which organ is primarily involved in extravascular hemolysis?

Spleen Signup and view all the answers

What is one possible result of intravascular hemolysis?

Red plasma Signup and view all the answers

What type of anemia is usually found in blood films for hemolytic anemia?

Normocytic or macrocytic anemia Signup and view all the answers

What classification is based on the inheritance of hemolytic anemia?

Acquired versus congenital Signup and view all the answers

Which finding is typically seen in the urine with intravascular hemolysis?

Hemosiderinuria Signup and view all the answers

What is the normal mean corpuscular volume (MCV) for red blood cells?

MCV = 80-100 fL Signup and view all the answers

Which of the following conditions is NOT associated with microcytosis (MCV < 80 fL)?

Vitamin B12 Deficiency Signup and view all the answers

Which of the following thalassemia types is associated with elevated MCHC?

Beta Thalassemia Signup and view all the answers

Which iron-containing component is found in muscle tissue?

Myoglobin Signup and view all the answers

Where are ferritin and hemosiderin primarily stored in the body?

Bone marrow, liver, and spleen Signup and view all the answers

Which of the following is the most common cause of anemia?

Iron deficiency Signup and view all the answers

Total iron binding capacity (TIBC) is a laboratory test that measures what?

Capacity of transferrin to bind iron Signup and view all the answers

Which of these is NOT a stage of iron depletion and iron deficiency?

Iron sufficiency Signup and view all the answers

Study Notes

Macrocytic Anemias

Subdivided into megaloblastic and non-megaloblastic anemias based on erythroblast morphology in bone marrow.

Megaloblastic Anemia

Characterized by presence of erythroblasts in BM with delayed nuclear maturation due to defective DNA synthesis.
Causes: Vitamin B12 deficiency or abnormal B12 metabolism, folic acid deficiency or abnormal folate metabolism, and other defects of DNA synthesis.

Non-Megaloblastic Anemia

Causes: Liver disease, alcoholism, hypothyroidism, aplastic anemia, anemia of acute bleeding, and hemolytic anemias.

Diagnosis and Investigations

Determine if patient is anemic, type of anemia, and cause of anemia.
Investigations: Hb level, RBC count, Hct, red cell indices (MCV, MCH, MCHC), red cell morphology (peripheral smear), and iron studies (serum iron, TIBC, serum ferritin).

Iron Deficiency Anemia

Causes: rapid growth, pregnancy, lactation, inadequate intake, inadequate absorption, chronic blood loss (menstrual flow, gastrointestinal bleeding), and decreased iron stores.
Clinical features: fatigue, pallor, glossitis, angular stomatitis, nail changes, hair loss, and developmental problems.
Laboratory features: low Hb, Hct, RBC, MCV, MCH, MCHC, RDW, and high platelet count.

Anemia

Definition: reduction in hemoglobin concentration below reference values for age and sex.
Factors affecting diagnosis: plasma volume, age, sex, race, and altitude.

Clinical Features of Anemia

Symptoms and signs: fatigue, weakness, tiredness, palpitation, dyspnea, and pale mucous membranes.
Tissue hypoxia and compensatory attempts: fatigue, tachycardia, and hyperventilation.

Classification of Anemia

Morphologic: microcytic, normocytic, and macrocytic.
Pathogenic (underlying mechanism): blood loss, decreased RBC production, and increased RBC destruction (hemolytic anemia).

Microcytic Anemias

Iron deficiency anemia, thalassemia, lead poisoning, and anemia of chronic diseases.

Microcytosis

Iron deficiency, thalassemia, hemoglobinopathies, inflammation, and rare causes (sideroblastic anemia, lead poisoning, hyperthyroidism).

Body Iron

Total amount: 3-5 gm.
Distribution: Hb (1.5-2 gm), myoglobin, iron-containing enzymes, and storage forms (ferritin and hemosiderin).

Total Iron Binding Capacity (TIBC)

Measures transferrin's capacity to bind iron.
Calculated as: serum iron/TIBC %.

Pernicious Anemia

Autoimmune disorder characterized by destruction of parietal cells, leading to intrinsic factor deficiency and vitamin B12 deficiency.
More common in elderly females, associated with other autoimmune diseases (thyroid disease, Addison's disease, and vitiligo).
Increased risk of gastric carcinoma.

Hemolytic Anemias

Definition: group of disorders characterized by decreased RBC lifespan.
Clinical features: splenomegaly, increased incidence of pigmented gallstones, dark urine, and chronic ankle ulcers.
Laboratory findings: evidence of increased RBC destruction and production.

Macrocytic Anemia

Megaloblastic anemia: defective DNA synthesis, characterized by large immature erythroblasts (megaloblasts).
Causes: vitamin B12 deficiency, folic acid deficiency, and other defects of DNA synthesis.

Hemolytic Anemia Triad

Pallor, jaundice, and splenomegaly.

Laboratory Evidence of Hemolysis

Biochemical findings: elevated LDH, bilirubin, and decreased haptoglobin.
Morphologic evidence: red cell damage on peripheral smear.

Bone Marrow Examination

Evidence of increased RBC production: reticulocytosis, nucleated RBCs, and normoblasts.
Evidence of megaloblastic anemia: megaloblasts, delayed nuclear maturation.

Folate Deficiency

Causes: poor intake, malabsorption, pregnancy, lactation, and antifolate drugs.

Vitamin B12 Deficiency

Causes: pernicious anemia, low dietary intake, gastrectomy, ileal disease, and Crohn's disease.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the different types of macrocytic anemias, including megaloblastic and non-megaloblastic, and the diagnosis and investigation of these conditions. It also touches on the causes and characteristics of each type.