Bhalani Medicine Pg 112-121

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Questions and Answers

What is the common daily dose of oral iron therapy recommended for treating iron deficiency anemia?

9 mg/kg/day

6 mg/kg/day (correct)

12 mg/kg/day

3 mg/kg/day

Iron deficiency anemia can only be caused by a lack of iron in the diet.

False

Name one common preparation of oral iron therapy.

ferrous sulfate

One side effect of oral iron therapy can be __________.

constipation Signup and view all the answers

Match the oral iron preparations with their respective doses:

Ferrous sulfate = 200 mg three times daily Ferrous gluconate = 300 mg twice daily Ferrous fumarate = 325 mg two or three times daily Signup and view all the answers

What causes the red blood cells to take on a sickle shape in sickle cell disease?

Defective hemoglobin (HbS) Signup and view all the answers

Sickled cells can return to their normal shape when oxygenated.

False Signup and view all the answers

Name one consequence of sickling in sickle cell disease.

Microvascular occlusions or Hemolytic anemia Signup and view all the answers

In sickle cell disease, changes in the shape of HbS molecules cause the red blood cells to become ______.

rigid Signup and view all the answers

Match the following consequences of sickling with their descriptions:

Microvascular occlusions = Obstruction of small vessels leading to tissue ischemia-infarction Hemolytic anemia = Shortened survival of sickle cells due to destruction by the reticuloendothelial system Signup and view all the answers

Which of the following symptoms is specifically associated with iron deficiency anemia?

Pagophagia (craving for ice) Signup and view all the answers

Blue-tinged sclerae are a common clinical feature of iron deficiency anemia.

True Signup and view all the answers

What is the term for the unusual craving for non-nutritive substances often seen in iron deficiency anemia?

Pica Signup and view all the answers

In patients with iron deficiency anemia, _____ syndrome may develop, characterized by dysphagia for solids.

Plummer-Vinson Signup and view all the answers

Match the following clinical findings with their descriptions:

Cheilosis = Fissures at the corners of the mouth Atrophic glossitis = Loss of papillae on the tongue Koilonychia = Spoon-shaped fingernails Restless leg syndrome = An urge to move the legs that worsens at rest Signup and view all the answers

Which of the following is not a commonly associated symptom of folate deficiency?

Neurological features Signup and view all the answers

Pancytopenia refers to an increase in the counts of red blood cells, white blood cells, and platelets.

False Signup and view all the answers

What type of blood cells are characterized by having more than five nuclear lobes?

Hypersegmented neutrophils Signup and view all the answers

In megaloblastic anemia, the __________ count is typically normal or low.

reticulocyte Signup and view all the answers

Match the following laboratory findings with their descriptions:

Decreased WBC count = Leukopenia RBCs vary in size = Anisopoikilocytosis High serum homocysteine = Folate deficiency Normal or increased Megakaryopoiesis = Bone marrow findings Signup and view all the answers

What is a common factor observed in both Vitamin B12 and folic acid deficiencies?

Reduced hemoglobin and hematocrit Signup and view all the answers

Increased indirect bilirubin is typically observed in patients with megaloblastic anemia.

True Signup and view all the answers

What laboratory test is a sensitive measure of 5,10-methylene THF deficiency?

Deoxyuridine suppression test Signup and view all the answers

What is the first step in the Schilling test?

Give radioactive vitamin B12 orally Signup and view all the answers

Patients with pernicious anemia typically excrete more than 10% of the radioactive dose in the first stage of the Schilling test.

False Signup and view all the answers

What is the maintenance dose of vitamin B12 for life after initial treatment?

1000 µg intramuscularly every 3 months Signup and view all the answers

The addition of ________ to the Schilling test can indicate intrinsic factor deficiency if urinary excretion becomes normal.

oral intrinsic factor Signup and view all the answers

Match the following vitamin B12 deficiency treatments with their administration frequency:

Initial treatment = Daily for 7 days Maintenance treatment = Every 3 months Aggressive replacement = Weekly for 4 weeks Acute deficiency folate treatment = Daily for 21 days Signup and view all the answers

Which antibody is found in approximately 70% of patients with pernicious anemia?

Anti-intrinsic factor antibodies Signup and view all the answers

Folic acid can be safely given in large doses to treat megaloblastic anemia of pernicious anemia type.

False Signup and view all the answers

What is the initial injection frequency for vitamin B12 therapy?

Every 3-7 days for six injections Signup and view all the answers

Pregnant women are recommended to take ________ daily to prevent neural tube defects.

400 µg of folic acid Signup and view all the answers

What might indicate pancreatic insufficiency during the Schilling test?

Normal excretion after adding pancreatic enzyme extracts Signup and view all the answers

What is the most common cause of anemia?

Iron Deficiency Anemia Signup and view all the answers

A decrease in circulating red blood cell mass is a criterion for defining anemia.

True Signup and view all the answers

List two types of hypoproliferative anemias.

Megaloblastic anemia and anemia of renal failure Signup and view all the answers

The normal adult hemoglobin level for males is ___ g/dL.

13-17 Signup and view all the answers

Match the types of anemia with their descriptions:

Megaloblastic Anemia = Deficiency or impaired utilization of vitamin B12 and folic acid Iron Deficiency Anemia = Caused by inadequate iron for hemoglobin synthesis Pernicious Anemia = Anemia due to vitamin B12 absorption issues Microcytic Hypochromic Anemia = Characterized by low MCV in red blood cells Signup and view all the answers

What is responsible for the defective heme synthesis in iron deficiency anemia?

Lack of iron Signup and view all the answers

Iron is poorly absorbed when obtained from cow's milk.

True Signup and view all the answers

What is the daily requirement of iron for adults?

10-15 mg Signup and view all the answers

Anemia can be classified into morphological classification and ___ classification.

etiological Signup and view all the answers

Which of the following is NOT a type of intrinsic hemolytic anemia?

Paroxysmal nocturnal hemoglobinuria Signup and view all the answers

What is the classic triad of symptoms associated with megaloblastic anemia?

Weakness, sore throat, and paresthesias Signup and view all the answers

Pernicious anemia is caused by a deficiency of intrinsic factor that affects the absorption of vitamin B12.

True Signup and view all the answers

What demographic is primarily affected by pernicious anemia?

Older adults, particularly females Signup and view all the answers

Megaloblastic anemias are characterized by defective _____ synthesis.

DNA Signup and view all the answers

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

Pernicious anemia Signup and view all the answers

Match the vitamin deficiency with its common causes:

Vitamin B12 = Prolonged use of proton-pump inhibitors Folic Acid = Malnutrition, chronic inflammatory diseases Both = Surgical resection of the ileum Signup and view all the answers

Increased pigmentation of the skin is due to decreased levels of reduced glutathione in cases of vitamin B12 deficiency.

True Signup and view all the answers

Deficiency in vitamin B12 can lead to _____ neuropathy.

peripheral Signup and view all the answers

What are the common clinical features seen in patients with megaloblastic anemia?

Weakness, sore throat, paresthesias, painful red tongue Signup and view all the answers

Which of the following is a known effect of folate deficiency?

Glossitis and atrophy of papillae Signup and view all the answers

Which type of hemolytic anemia results from intrinsic defects within the red blood cells?

Hereditary hemolytic anemia Signup and view all the answers

Intravascular hemolysis always results in splenomegaly.

False Signup and view all the answers

Name two causes of acquired hemolytic anemia.

Immunohemolytic anemias, fragmentation syndromes Signup and view all the answers

The normal lifespan of red blood cells is _____ days.

90-120 Signup and view all the answers

Match the following conditions with their associated features:

Sickle cell anemia = Chronic leg ulcers Hereditary spherocytosis = Splenomegaly Thalassemia = Skeletal abnormalities Acquired hemolytic anemia = Pigment gallstones Signup and view all the answers

Which of the following is NOT a physiological cause of macrocytic anemia?

Chronic liver disease Signup and view all the answers

The bone marrow can compensate for increased red cell destruction by producing more red blood cells.

True Signup and view all the answers

What is the typical color of urine during hemolytic anemia due to increased hemoglobinuria?

Dark or black Signup and view all the answers

The classification of hemolytic anemias includes intrinsic and _____ defects.

extrinsic Signup and view all the answers

Which of the following is a defect in red cell membrane associated with hereditary hemolytic anemias?

Hereditary spherocytosis Signup and view all the answers

Reticulocytosis indicates an increased production of red blood cells.

True Signup and view all the answers

What laboratory feature is commonly observed in extravascular hemolysis?

Splenomegaly Signup and view all the answers

Hemolytic anemia may lead to _____ hyperbilirubinemia.

unconjugated Signup and view all the answers

Match the following red cell enzyme deficiencies with the correct conditions:

Glucose-6-Phosphate dehydrogenase deficiency = Acquired hemolytic anemia Pyruvate kinase deficiency = Hereditary hemolytic anemia Hexokinase deficiency = Sickle cell anemia Fragmentation syndromes = Intravascular hemolysis Signup and view all the answers

What is the most common type of crisis associated with sickle cell disease?

Infarction (sickling) crisis Signup and view all the answers

Chronic hemolytic anemia in sickle cell disorder typically leads to increased levels of conjugated bilirubin.

False Signup and view all the answers

What infection is known to cause aplastic crisis in patients with sickle cell disease?

Parvovirus B19 Signup and view all the answers

Patients with sickle cell disease usually experience ________ pain due to bone infarction.

severe Signup and view all the answers

Match the following complications of sickle cell anemia with their descriptions:

Impaired Growth/Development = Low weight and delayed sexual maturation. Leg Ulcers = Chronic leg ulcers. Neurological = Transient ischemic attacks and seizures. Cholelithiasis = Gallstones. Signup and view all the answers

Which of the following lab results is expected in patients experiencing hemolytic crisis?

Sudden drop in hemoglobin Signup and view all the answers

Sickle cells can form rouleaux, thus increasing the Erythrocyte Sedimentation Rate (ESR).

False Signup and view all the answers

What kind of acute chest condition can arise from lung involvement in sickle cell crises?

Acute chest syndrome Signup and view all the answers

In sickle cell disease, the peripheral smear typically shows ________ cells.

sickle Signup and view all the answers

Match each test with its purpose in diagnosing sickle cell disease:

Sickling Test = Identifies the presence of sickled cells Hemoglobin Electrophoresis = Measures different hemoglobin types Sickle Solubility Test = Tests for solubility of hemoglobin S Peripheral Smear = Visual examination of blood cells Signup and view all the answers

What is the most common long-term complication affecting the neurological system in sickle cell patients?

Cerebral infarction Signup and view all the answers

Sickle cell disease can result in prolonged, painful erections known as priapism.

True Signup and view all the answers

Name one preventive measure for sickle cell disease.

Folic acid supplementation Signup and view all the answers

Chronic liver dysfunction in sickle cell patients can lead to ________.

hepatomegaly Signup and view all the answers

What is the primary type of antibody involved in Warm Antibody Immunohemolytic Anemia?

IgG antibodies Signup and view all the answers

Cold agglutinin type anemia is caused by IgG antibodies.

False Signup and view all the answers

Name two underlying causes that should be excluded in patients presenting with symptoms of autoimmune hemolytic anemia.

Systemic lupus erythematosus and lymphoma Signup and view all the answers

The Coombs test detects the presence of _____ on the surface of red blood cells.

antibodies Signup and view all the answers

Match the treatment options with their indication:

Corticosteroids = Effective in about 80% of patients Danazol = Used alongside prednisone to reduce therapy duration Splenectomy = Necessary when steroids are ineffective Rituximab = Monoclonal antibody for refractory cases Signup and view all the answers

What is the most common age group affected by autoimmune hemolytic anemia?

Middle-aged females Signup and view all the answers

Direct antiglobulin test (DAT) uses the patient's serum to detect antibodies on red blood cells.

False Signup and view all the answers

What is the common temperature range for the activity of Cold agglutinin type antibodies?

4-18 °C Signup and view all the answers

The _____ test indicates the presence of antibodies in serum.

indirect Coombs Signup and view all the answers

Match the following autoimmune hemolytic anemia types with their respective antibodies:

Warm antibody type = IgG Cold agglutinin type = IgM Cold hemolysin type = Donath-Landsteiner antibodies Cold agglutinin type (chronic) = Chronic lymphomas Signup and view all the answers

What percentage of autoimmune hemolytic anemia cases are classified as idiopathic?

50% Signup and view all the answers

Rh blood group autoantibodies can have specificity in autoimmune hemolytic anemia.

True Signup and view all the answers

What is a common adverse effect of rituximab treatment?

Hypotension Signup and view all the answers

Avoiding blood transfusions is important because it may cause difficulty in _____ crossing.

cross-match Signup and view all the answers

Which immunosuppressive drug may be used if there is no response to steroids and other therapies?

Azathioprine Signup and view all the answers

Study Notes

Megaloblastic Anemia

Megaloblastic anemia is characterized by large, immature red blood cells (megaloblasts) due to impaired DNA synthesis.
It primarily arises from Vitamin B12 or folic acid deficiency.
Symptoms include fatigue, weakness, pallor, shortness of breath, palpitations, headache, tinnitus, and glossitis.
Neurological features are specific to Vitamin B12 deficiency and absent in folate deficiency.

Symptoms mirror Vitamin B12 deficiency, excluding neurological features.
Additional symptoms include:
- Prematurely gray hair.
- Atherosclerosis due to raised serum homocysteine levels.
- Hypochlorhydria caused by atrophic gastritis, leading to decreased hydrochloric acid and intrinsic factor production.

Diagnosis/Laboratory Findings of Megaloblastic Anemia

Hemoglobin and Hematocrit (PCV): Reduced in both Vitamin B12 and folic acid deficiencies.
Red Blood Cell Indices (MCV): Elevated above 100 fL (normal 82-98 fL) indicating macrocytic anemia.
Red Blood Cell, White Blood Cell and Platelet Count: All are reduced, resulting in pancytopenia.
Peripheral Smear: Exhibits pancytopenia with the following characteristics:
- Red Blood Cells: Macrocytic and oval-shaped (macro-ovalocytes) with significant variation in size and shape (anisopoikilocytosis). Evidence of dyserythropoiesis: basophilic stippling, Cabot ring, Howell-Jolly bodies.
- White Blood Cells: Reduced count (leukopenia) with hypersegmented neutrophils (more than five nuclear lobes).
- Platelets: Decreased count.
Reticulocyte Count: Typically normal or low. Reticulocytosis occurs in response to negligible doses of parenteral vitamin B12.
Bone Marrow:
- Markedly hypercellular.
- Hallmark of megaloblastic erythropoiesis.
- Granulocytic precursors display nuclear-cytoplasmic asynchrony.
- Megakaryopoiesis (platelet production) is normal or increased.
- Bone marrow iron: Moderately increased.
Deoxyuridine suppression test: Sensitive measure of 5,10-methylene THF deficiency, elevated in both deficiencies.
Serum homocysteine: Elevated in both deficiencies.
Serum bilirubin: Mildly increased indirect bilirubin due to increased red blood cell breakdown.
Serum iron and ferritin: Raised. Iron binding capacity is reduced.
Plasma lactate dehydrogenase (LDH): Significantly increased.
Serum vitamin B12/folate: Decreased levels.

Diagnostic/Specific Tests for Vitamin B12 Deficiency

Serum vitamin B12 levels: Reduced, very low.
Schilling Test: A series of stages used to diagnose vitamin B12 malabsorption.
- Stage 1: Normal individuals excrete more than 10% of the ingested radioactive vitamin B12 in 24 hours. Patients with pernicious anemia excrete less than 5%.
- Stage 2: If Stage 1 is abnormal, it's repeated with intrinsic factor added. Normal excretion indicates intrinsic factor deficiency (likely due to pernicious anemia or gastrectomy).
- Stage 3: If Stage 2 is abnormal, pancreatic enzyme extracts are added. If this corrects the abnormality, it suggests pancreatic insufficiency.
- Stage 4: If Stage 3 remains abnormal, the issue lies in the terminal ileum or there's bacterial overgrowth. A 7-day course of oral tetracycline/antibiotics may rectify this. If excretion normalizes after antibiotics, it confirms bacterial overgrowth as the cause.

Specific Diagnostic Tests for Pernicious Anemia

Serological tests:
- Anti-intrinsic factor antibodies: present in approximately 70% of patients; highly specific for pernicious anemia.
- Antiparietal cell antibodies: present in 85-90% of patients; less specific than anti-intrinsic factor antibodies.
Achlorhydria with histamine stimulation: Indicative of decreased stomach acid production.
Severe deficiency of intrinsic factor: Characteristic feature of pernicious anemia.

Management of Megaloblastic Macrocytic Anemias

General Management: Treatment of the underlying cause (vitamin B12 or folate deficiency) whenever possible.
Specific Therapy:
- Vitamin B12 deficiency: Treat with vitamin B12 injections (cyanocobalamin, hydroxocobalamin, or methylcobalamin). Typically, six intramuscular injections of hydroxycobalamin (1000 µg) are given at 3-7 day intervals, followed by a maintenance dose of 1000 µg every 3 months for life. Methylcobalamin can also be used. An aggressive, rapid dose replacement scheme involves 1 mg intramuscular cyanocobalamin per day (week 1); 1 mg twice weekly (week 2); 1 mg/week for 4 weeks; 1 mg/month for life.
- Response: Improvement often occurs within 48 hours. Reticulocytosis peaks within 3-4 days. Anemia resolves within 4-6 weeks.
- Dimorphic Anemia: If combined iron deficiency exists, ferrous sulfate (200 mg thrice daily) should be commenced concurrently with Vitamin B12 treatment.

Folate Deficiency

Dosage:
- Acute deficiency: Oral dose of 5 mg folate (folic acid) daily for 3 weeks.
- Maintenance therapy: 5 mg once weekly.
- Folinic acid: Can bypass dihydrofolate reductase blockage caused by medications like methotrexate and trimethoprim-sulfamethoxazole.
- Congenital Folate Malabsorption: Response to high-dose parenteral leucovorin is similar to that observed with pernicious anemia.
Precautions: High doses of folic acid should not be administered for megaloblastic anemia associated with pernicious anemia or other Vitamin B12 deficiency anemias unless the serum Vitamin B12 level is normal. If Vitamin B12 deficiency is present, treat that first, as cobalamin neuropathy may worsen.
Pregnancy: Prophylactic folic acid (400 µg daily) is recommended for all women planning pregnancy to prevent neural tube defects.

Supportive Therapy

Blood transfusions: Generally not required; reserved for severely symptomatic individuals with severe deficiency, angina, or heart failure.
Other measures: Treatment of infections and physiotherapy for neurological involvement.

Follow Up

Clinical and hematological evaluation: Every 6 months.
Crucial considerations: Patients with pernicious anemia may have a higher risk of gastric carcinoma and/or gastric carcinoids. Early detection is critical.

Hemolytic Anemias - Classification, Management and Pathophysiology

Definition: Hemolytic anemias occur due to accelerated red blood cell destruction. Normally, red blood cells have a lifespan of 90-120 days.
Compensated Hemolytic Disease: Increased red blood cell destruction may not always lead to anemia because the bone marrow can compensate by augmenting red blood cell production by six to eight times.

Classification of Hemolytic Anemias

Location of Hemolysis:
- Intravascular Hemolysis: Red blood cell destruction occurs within blood vessels.
- Extravascular Hemolysis: Red blood cell destruction takes place outside of blood vessels, usually in the spleen.
Source of Defect Causing Hemolysis:
- Intrinsic Red Blood Cell Defect: Abnormalities within the red blood cell itself.
- Extrinsic Abnormalities: Defects outside of the red blood cell that lead to its destruction.
Mode of Onset:
- Hereditary: Inherited disorders.
- Acquired: Develop later in life.
Clinical Point of View:
- Acute: Sudden onset.
- Chronic: Gradual onset.

Causes of Non-Megaloblastic Macrocytic Anemia

Physiological causes:
- Pregnancy.
- Newborn.
Pathological causes:
- Alcohol excess.
- Chronic liver disease.
- Reticulocytosis.
- Hypothyroidism.
- Postsplenectomy.
- Myeloproliferative disorders.
- Hematological disorders (aplastic anemia, sideroblastic anemia, pure red cell aplasia).
- Drugs (azathioprine, hydroxycarbamide, metformin, zidovudine, leflunomide).

Classification and Causes of Hemolytic Anemia

Category	Hereditary Hemolytic Anemia	Acquired Hemolytic Anemia
A. Defects in Red Cell Membrane	Hereditary spherocytosis	Immunohemolytic Anemia:
	Hereditary elliptocytosis	Warm antibodies (idiopathic,
	Stomatocytosis	secondary)
	Abetalipoproteinemia (acantho-	Cold antibodies (cold agglutinin
	cytosis)	disease, paroxysmal cold hemoglobinuria,
		hemolytic disease of the newborn)
B. Red Cell Enzyme Deficiencies	Pyruvate kinase deficiency	Fragmentation syndromes
	Hexokinase deficiency	Hemolytic uremic syndrome,
	Glucose-6-Phosphate dehydro-	Thrombotic thrombocytopenic purpura,
	genase deficiency (G-6-PD)	Disseminated intravascular coagulation,
		Prosthetic cardiac valves
C. Defects in Globin Synthesis	Thalassemia-quantitative	Paroxysmal nocturnal hemoglobinuria
	hemoglobinopathies
	Sickle cell hemoglobinopathies	Drugs and chemicals (primaquine, dapsone,
	Alpha thalassemia	naphthalene, nitrite, nitrates, oxidizing
	Unstable hemoglobin disease	chemicals),
		Thermal injury (burns)

Clinical Features of Hemolytic Anemia

Symptoms/History:
- Mild jaundice.
- Symptoms due to anemia.
- Urine color (normal, darkens on standing, or black with hemoglobinuria).
- Infections.
Physical Findings/Signs:
- Anemia.
- Mild jaundice.
- Splenomegaly (in some cases, especially in thalassemia or hereditary spherocytosis).
- Chronic leg ulcers (in some cases, e.g., sickle cell anemia).
- Skeletal abnormalities (expansion of bone marrow, maxillary bone enlargement, frontal bossing, malocclusion of teeth - thalassemic facies).
- Signs of systemic diseases
- Signs of cholelithiasis (gallstones): Cholecystitis.
Hemolytic Anemia - Investigations:
- Splenic pain (due to enlargement, or infarction of spleen).
- Acute crisis (due to sudden drop in hemoglobin, sometimes fever, joint and abdominal pain).
- Symptoms due to pigment gallstones (as complication of chronic hemolysis).
- Leg ulcers (manifest in adult males especially in patients with hereditary spherocytosis and sickle cell anemia).
- Family history of congenital hemolytic anemias.

Diagnosis of Hemolytic Anemias

Laboratory Investigations/Features of Hemolysis/Hemolytic Anemia:
- Features/Consequences of Increased Red Blood Cell Destruction/Breakdown:
  - Anemia.
  - Unconjugated hyperbilirubinemia (jaundice).
  - Increased urobilinogen in urine (high-colored urine).
  - Shortened red cell lifespan (51Cr-labeled RBCs).
  - In extravascular hemolysis—Splenomegaly Usual.
  - In intravascular hemolysis: Decreased plasma haptoglobin, Increased plasma lactic dehydrogenase (LDH), Hemoglobinemia, Hemoglobinuria, Hemosiderinuria, Methemoglobinemia.
- Consequences of Increased Red Blood Cell Production:
  - Peripheral Blood Smear: Reticulocytosis.
  - Bone Marrow: Erythroid hyperplasia.
- Morphological Features of Damaged Red Blood Cells:
  - Peripheral Smear: Microspherocytes, Elliptocytes, Red Cell Fragments.
- Features of Increased Red Blood Cell Production: (compensatory mechanism to hemolysis)
  - Bone Marrow erythroid hyperplasia.
  - Peripheral smear shows increased reticulocytes, nucleated RBCs, and polychromasia.
- ** Recognition of Cause of Hemolysis**:
  - Peripheral Smear Examination: Red Cell Morphology (spherocyte, sickle cell, target cell, acanthocyte, schistocyte, triangular cells), provides clues to underlying hemolytic disorders.

Hematology and Transfusion Medicine

Anemia Classification:
- Megaloblastic Anemia.
- Iron Deficiency Anemia.
- Pernicious Anemia.
- Microcytic Hypochromic Anemia.

Vitamin B12 Deficiency

Definition of Anemia: Anemia is a decrease in the circulating red blood cell mass, marked by a lower than normal hemoglobin concentration (Hb), red blood cell count, or hematocrit (PCV) for the patient's age, sex, and altitude of residence. Normal adult hemoglobin levels: 13-17 g/dL in males and 12-15 g/dL in females.

Classification of Anemia

Morphological Classification:
- Normocytic normochromic (normal MCV)
- Microcytic hypochromic (low MCV)
- Macrocytic (high MCV)
- Etiological Classification:

Cause	Details
1. BLOOD LOSS	Acute: Loss of large volume over a short period (Trauma, postpartum bleeding). Chronic: Small volume over a long period (lesions of gastrointestinal tract e.g., peptic ulcers, hemorrroids, carcinoma colon, hookworms, excessive menstrual loss, urinary blood loss).
2. IMPAIRED RED CELL PRODUCTION (HYPOPROLIFERATIVE ANEMIAS)	Disturbed Proliferation and Maturation of Erythroblasts: a. Defective DNA synthesis: Megaloblastic anemias due to deficiency or impaired utilization of vitamin B12 and folic acid, Anemia of renal failure due to deficiency of erythropoietin, Anemia of chronic disease due to iron sequestration and relative erythropoietin deficiency, Anemias of endocrine disorders. b. Defective hemoglobin synthesis: Defective heme synthesis: Iron deficiency, sideroblastic anemia. Defective globin synthesis: Thalassemias.
3. INCREASED RED CELL DESTRUCTION (HEMOLYTIC ANEMIAS)	* Intrinsic (Intracorpuscular) Abnormalities: Hereditary: Membrane abnormalities (Spherocytosis, elliptocytosis), Enzyme deficiencies (Glucose-6-phosphate dehydrogenase, pyruvate kinase), Disorders of hemoglobin synthesis (Deficient globin synthesis: Thalassemia syndromes, Structurally abnormal globin synthesis (hemoglobinopathies): Sickle cell anemia). Acquired: Membrane defects (Paroxysmal nocturnal hemoglobinuria). * Extrinsic (Extracorpuscular) Abnormalities: Antibody-mediated.

Iron Deficiency Anemia (IDA)

Etiology:
- 1.Decreased iron intake: Milk-fed infants, Elderly with improper diet and poor dentition, Low socioeconomic sections, Vegetarians (contains poorly absorbable inorganic iron).
- 2.Decreased absorption of iron: Total/partial gastrectomy, Intestinal absorption is impaired in sprue, other causes of intestinal steatorrhea and chronic diarrhea, Specific items in the diet (e.g., phytates, tannins, carbonates, oxalates, phosphates), drugs.
- 3.Increased demand/requirement for iron: Rapid growth in infancy or adolescents, Pregnancy, and lactation.
- 4.Increased iron loss: Chronic blood loss due to bleeding from the gastrointestinal tract (e.g., peptic ulcers, gastric carcinoma, colonic carcinoma, hemorrhoids, hookworm infestation), Urinary tract (e.g., renal or bladder tumors, schistosomiasis), Genital tract (e.g., menorrhagia, uterine cancer).
Additional Notes: IDA is caused by iron deficiency. It is the most common type of anemia. The daily iron requirement is 10-15 mg. Children who consume large amounts of cow's milk may develop IDA because the iron in cow's milk is poorly absorbed and calcium in the milk inhibits iron absorption.

Iron Deficiency Anemia Management

Three primary approaches are used to manage IDA:
- Oral iron therapy:
  - The preferred treatment for most patients.
  - Dose: 6 mg/kg/day. Typical preparations: ferrous sulfate (200 mg three times daily), ferrous gluconate (300 mg twice daily), ferrous fumarate (325 mg two or three times daily), and others.
  - Side effects: Metallic taste, nausea, dyspepsia, constipation, black tarry stools, or diarrhea. Side effects may be minimized by taking with food, reducing the dose, or using controlled-release or liquid preparations.
  - Response: Improvement typically seen within 7-10 days, marked by an increased reticulocyte count (typically no more than 10%, normal 0.5-2.5%).
- Parenteral Iron Therapy:
  - Used for situations like malabsorption, poor compliance with oral iron, or if oral iron is not tolerated.
  - Dosage: Initially 100 mg iron per injection, repeated weekly until the total iron dose is reached (1000 mg).
- Red Blood Cell Transfusion:
  - Reserved for severe symptoms, particularly if the patient has a cardiac condition.
  - May be required in cases of severe symptomatic anemia, particularly when rapid elevation in red blood cell mass is needed, or if the patient has a cardiac condition.

Sickle Cell Disease

Introduction: Sickle cell disease (SCD) is a group of autosomal recessive hereditary disorders characterized by the production of defective hemoglobin (HbS). HbS causes red blood cells (RBCs) to assume a sickle or crescent shape when exposed to low oxygen tension or deoxygenation.
Pathogenesis: Dehydration leads to potassium leaving the red blood cells through calcium-activated potassium channels (Gárdos channel). This causes changes in the shape of HbS molecules, making them insoluble and prone to polymerization. These structures are called "tactoids" and cause the red blood cells to become rigid, deformed, and sickle-shaped. Repeated episodes of sickling cause irreversible sickling of RBCs. Factors influencing sickling include other hemoglobins, transit time in microvasculature, mean corpuscular hemoglobin concentration (MCHC), intracellular pH, and oxygen tension.
Consequences of Sickling:
- Microvascular occlusions: Sickled cells are unable to pass smoothly through small blood vessels, leading to obstruction and tissue ischemia-infarction.
- Hemolytic anemia: Sickle cells have a shortened survival time and are destroyed by the reticuloendothelial system.
Clinical Features (Children):
- Asymptomatic (infants < 6 months): Infants are protected because they have high levels of fetal hemoglobin (HbF), which does not sickle.
- Symptomatic (6 months onwards): Symptoms appear when levels of HbF decline.
- Dactylitis (hand-foot syndrome): Occurs in infants and young children. Swelling of hands and feet due to bone marrow infarction.
Signs and Symptoms (Adults):
- Acute pain episodes (sickle cell crisis): Occur due to vaso-occlusion.
- Hemolytic anemia: Causes pallor, fatigue, jaundice, and splenomegaly.
- Chronic organ damage: Can occur in the spleen (autosplenectomy), liver, kidneys, heart, lungs, and brain.
- Complications:
  - Stroke
  - Acute chest syndrome: A serious lung condition due to a combination of infection, infarction, and pulmonary hypertension.
  - Priapism: Difficult to treat.
  - Chronic leg ulcers.
  - Osteonecrosis (avascular necrosis).
Management of Sickle Cell Disease:
- Pain management: Opioids are commonly used to manage pain during sickle cell crises.
- Blood transfusions: May be used to increase the number of non-sickle red blood cells in the blood.
- Hydroxyurea: A medication that can increase levels of HbF, reducing sickling.
- Prevention: Prophylactic penicillin is given to children to prevent infections. Avoiding exposure to high altitude and cold temperatures is also important.
- Bone marrow transplantation: Can cure SCD but is not an option for many people.

Iron Deficiency Anemia

Clinical Features:
- Usual anemia symptoms (fatigue, weakness, pallor, shortness of breath, palpitations, headache, tinnitus, and glossitis).
- Advanced iron deficiency:
  - Cheilosis (fissures at the corners of the mouth)/angular stomatitis
  - Atrophic glossitis
  - Brittle fingernails, platonychia and koilonychia (spooning of the fingernails), brittle hair
  - Blue-tinged sclerae, alopecia
  - Pica (unusual craving for substances with a "crunching" sound, no nutritional value, like clay or chalk). Craving for ice (pagophagia). Pagophagia is the most specific to iron deficiency.
  - Restless leg syndrome, observed in approximately 25% of patients.
  - Plummer-Vinson syndrome or Patterson-Brown-Kelly or sideropenic dysphagia, occurring in long-standing cases.
  - Esophageal/post-cricoid webs resulting in dysphagia for solids (rather than liquids), which can be identified by endoscopy or barium swallow.### Iron Deficiency Anemia
Increased risk of squamous cell carcinoma of the pharynx and esophagus.
Beeturia (urine turns red after beet ingestion) is increased in iron deficiency, affecting 49-80% of individuals with this deficiency.

Autoimmune Hemolytic Anemia (AIHA)

Autoimmune hemolytic anemias are a group of acquired disorders resulting from increased red cell destruction due to red cell autoantibodies.
Classified based on antibody type (warm or cold) and etiology.

Warm Antibody Type (IgG antibodies active at 37°C)

Most common type (50-70%).
Antibodies combine with red cell antigen at 37°C.
Primary (Idiopathic) and Secondary types.
- Secondary types include autoimmune disorders (systemic lupus erythematosus, others), drugs (e.g., methyldopa, penicillins, quinidine), and Lymphomas (Hodgkin's lymphoma, Chronic lymphatic leukemia).

Cold Agglutinin Type (IgM antibodies active at 4-18°C)

Acute and Chronic types.
- Acute types include Mycoplasmal infection and Infectious mononucleosis.
- Chronic types include Idiopathic and Lymphomas.

Cold Hemolysin Type (Donath-Landsteiner antibodies)

Rare; seen mainly in children; usually postviral.

Warm Antibody Immunohemolytic Anemia

Most common type (50-70%).
Antibodies are mainly of IgG type.
May occur at all ages and in both sexes, but most frequent in middle-aged females.
May present with anemia, jaundice, hepatosplenomegaly, and potential underlying disease manifestations.

Coombs Test

Detects antibodies on red blood cells.
Direct Coombs test (DAT): Detects antibodies directly on red blood cells in the patient's blood.
Indirect Coombs test (IAT): Detects antibodies in the patient's serum.

Sickle Cell Crises

Can be severe in adults, including anemia, crises, and long-term complications.
Anemia: Severe hemolytic anemia, often exacerbated by secondary folate deficiency.
Crises: Episodes that rapidly worsen the condition.
- Infarction (sickling) crisis (vaso-occlusive crisis): Most common and hallmark of sickle cell disease, characterized by pain due to microcirculation blockage.
- Aplastic crisis: Temporary suppression of bone marrow erythropoiesis due to parvovirus B19 infection of erythroid progenitor cells.
- Hemolytic crisis: Increased destruction of red blood cells, marked by decreased hemoglobin and enlarged liver/spleen.
- Sequestration crisis: Increased red blood cell sequestration and destruction in the spleen.
Long-term complications include impaired growth and development, bone infections, leg ulcers, cardiac issues, neurological problems, cholelithiasis, liver issues, priapism, eye problems, and pregnancy complications.

Megaloblastic Anemia

Characterized by defective DNA synthesis, leading to megaloblasts in the bone marrow and macrocytes in the peripheral blood.
Commonly caused by vitamin B12 or folate deficiencies.
Genetic or acquired abnormalities in the metabolism of these vitamins can also lead to the condition.
Causes of B12 deficiency: decreased intake, impaired absorption (gastric or intestinal), increased demand, and abnormal cobalamin transport.
Causes of folate deficiency: decreased intake, impaired absorption, increased loss, increased demand, and impaired utilization.

Pernicious Anemia

Chronic autoimmune disorder characterized by gastric atrophy and lack of intrinsic factor, leading to impaired B12 absorption.
Microscopically, the stomach shows chronic atrophic gastritis with damage to gastric parietal cells.
Primarily affects older adults, more common in females.
Classic triad of symptoms: weakness, sore throat, and paresthesias.
Tongue: Smooth, red, and painful due to glossitis and atrophy of papillae.
Pigmentation: Pigmentation of knuckles and creases.
Neurological features: Peripheral neuropathy (numbness or paresthesia in hands and feet), loss of ankle reflexes.

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Hematology