This book describes Hereditary Spherocytosis, Diagnosis and Treatment and Related Diseases
Hereditary spherocytosis is a rare medical disorder of the surface layer of red blood cells.
It results in red blood cells that appear like spheres, and causes premature breakdown of red blood cells (hemolytic anemia).
It may manifest as a collection of inherited disorders which present as spherical-shaped erythrocytes (spherocytes) on the peripheral blood smear
Causes
This disorder is produced by a defective gene.
The defect leads to an abnormal red blood cell membrane.
The involved cells have a reduced surface area for their volume than normal red blood cells, and can rupture easily.
The anemia can range from mild to severe.
The medical severity differs (depending on the mutation), from asymptomatic to a life-threatening hemolytic anemia
All mutations change the cell membrane, producing loss of membrane surface area and decreased capability of the cell to change shape.
These abnormal red cells are then selectively kept and removed in the spleen, which decreases red cell life and causes the hemolytic anemia.
Defects in several membrane proteins may be present (e.g., alpha-spectrin, beta-spectrin, ankyrin, protein 4.2).
Symptoms
Infants may have jaundice (yellowing of the skin and eyes) and pallor (pale coloring).
Other symptoms may be:
1. Fatigue
2. Irritability
3. Shortness of breath
4. Weakness
Patients may manifest at any age with hemolytic anemia, jaundice (either from hemolysis or gallstones) and splenomegaly
Diagnosis
Most patients can be diagnosed based on a family history, characteristic medical features and laboratory investigations
1. Spherocytes,
2. Raised mean corpuscular hemoglobin concentration (MCHC), and
3. An increase in reticulocytes.
They do not require any additional tests
In most instances, the spleen is enlarged.
Tests may be:
1. Blood smear to show abnormally shaped cells
2. Bilirubin level
3. Full blood count to check for anemia
4. Coombs test
5. LDH level
6. Osmotic fragility or specialized testing to evaluate for the red blood cell defect
7. Reticulocyte count for hemlytic anemia
SDS-polyacrylamide gel electrophoresis of erythrocyte membrane proteins is done to confirm the diagnosis of atypical hereditary spherocytosis
Treatment
Surgery to remove the spleen (splenectomy) does not correct the abnormal cell shape but can cure the anemia.
Families with a history of spherocytosis should have their children evaluated for this disorder.
Children should wait until age 5 to have splenectomy because of the infection danger.
In mild cases diagnosed in adults, it may not be crucial to remove the spleen.
Children and adults should be given a pneumococcal vaccine before spleen removal surgery.
They also should take more folic acid supplements.
Once the diagnosis and baseline severity are ascertained, it is not essential to do repeated blood tests unless there is a further medical indication (e.g., infection, pallor, a rise in jaundice)
A routine annual review is normally adequate.
Mild cases do not normally need folate supplements or splenectomy
Steroid therapy may be successful in increasing hemoglobin levels during hemolytic crises in patients with moderate disease and will lead to the patient needing fewer transfusions
Moderate-to-severely involved patients are normally given folate supplementation and provided an offer of splenectomy:
Splenectomy removes anemia and hyper-bilirubinemia and reduces the high reticulocyte number...