Podcast
Questions and Answers
What is the result of a single amino acid substitution in the beta-polypeptide chain of hemoglobin?
What is the result of a single amino acid substitution in the beta-polypeptide chain of hemoglobin?
What is the reason for the delayed manifestations of sickle cell anemia in infants?
What is the reason for the delayed manifestations of sickle cell anemia in infants?
What type of crisis is precipitated by infection, dehydration, hypoxia, and acidosis?
What type of crisis is precipitated by infection, dehydration, hypoxia, and acidosis?
What is a common manifestation of vaso-occlusive or symptomatic crisis?
What is a common manifestation of vaso-occlusive or symptomatic crisis?
Signup and view all the answers
What is a complication of vaso-occlusive or symptomatic crisis?
What is a complication of vaso-occlusive or symptomatic crisis?
Signup and view all the answers
What is a CNS manifestation of vaso-occlusive or symptomatic crisis?
What is a CNS manifestation of vaso-occlusive or symptomatic crisis?
Signup and view all the answers
What is a respiratory manifestation of vaso-occlusive or symptomatic crisis?
What is a respiratory manifestation of vaso-occlusive or symptomatic crisis?
Signup and view all the answers
What is a renal manifestation of sickle cell anemia?
What is a renal manifestation of sickle cell anemia?
Signup and view all the answers
What type of crisis is characterized by the sudden onset of severe anemia?
What type of crisis is characterized by the sudden onset of severe anemia?
Signup and view all the answers
What is a common age range for the manifestation of hand-foot syndrome?
What is a common age range for the manifestation of hand-foot syndrome?
Signup and view all the answers
Study Notes
Splenic Infarction and Complications
- Splenic infarction leads to an initially enlarged spleen, which becomes small and fibrotic with repeated infarctions, resulting in functional hyposplenism and increased susceptibility to infection.
- Ischemic damage can cause retinopathy, delayed puberty, avascular necrosis of the femoral head and humerus.
- Priapism can occur.
Sequestration Crisis
- A large amount of blood becomes acutely pooled in the liver and spleen, causing massive enlargement of these organs and signs of collapse.
- This crisis is a frequent cause of death in young infants.
Aplastic Crisis
- Parvovirus B19 infection can cause red cell aplasia, fever, pain, splenic sequestration, acute chest syndrome, glomerulonephritis, and strokes.
Hyperhemolytic Crisis
- Severe hemolysis, particularly with concomitant G6PD deficiency, can be precipitated by ingestion of an oxidant.
General Manifestations
- Chronic hemolytic anemia
- Liver impairment
- Spleen initially enlarged, then becomes small and fibrotic
- Increased susceptibility to infection (e.g., Salmonella osteomyelitis and H. influenzae meningitis)
Diagnosis
- Moderate to severe normochromic, normocytic anemia with reticulocytosis
- Indirect evidence of hemolysis
- Blood smear: sickle cells, nucleated red cells
- α-globin tetramers form, leading to red cell damage and hemolysis
Clinical Manifestations
- Onset usually in the 2nd half of the first year
- General features of chronic hemolytic anemia
- Failure to thrive in early childhood
- Pallor, jaundice, and gallstones
- Hepatosplenomegaly and hypersplenism
- Abnormal facies: prominence of malar eminence, frontal bossing, depression of bridge of nose, and exposure of upper central teeth
- Manifestation of hemosiderosis
Pathophysiology
- Single amino acid substitution: valine for glutamic acid in the beta-polypeptide chain
- HbS is less soluble than HbA
- Sickle cells are prematurely destroyed, causing hemolytic anemia
- Sickle cells result in increased blood viscosity and impaired blood flow, leading to thrombi
Crisis Types
- Vaso-occlusive or symptomatic crisis
- Sequestration crisis
- Aplastic crisis
- Hyperhemolytic crisis
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
