Spherocytosis (Hereditary, HS)

Spherocytosis produces of abnormal red blood cells.

Spherocytosis is the production of red blood cells (erythrocytes) that are in the shape of a sphere (spherocytes) instead of the concave disk shape that is normal for red blood cells. These spherocytes are abnormal, fragile, and possess a short lifespan as compared to normal red blood cells. The cells tax the ability of the spleen to clear out abnormal red cells and their products, and this can result in an enlargement of the spleen (splenomegaly) and gallbladder disease problems.

Spherocytosis can be found in hereditary spherocytosis (HS), and a few other diseases such as autoimmune hemolytic anemia. The emphasis of this article is on hereditary spherocytosis.

Hereditary spherocytosis is the predominant cause of spherocytosis and is caused by several genetic mutations that lead to membrane abnormalities of red blood cells. The disease usually is inherited as an autosomal dominant trait; although a few people with hereditary spherocytosis may develop it secondary to new mutations. In addition, there is an autosomal recessive mode of inheritance that also may occur in about 20%-25% of all individuals with hereditary spherocytosis.

Spherocytosis may be present in autoimmune hemolytic anemia in which autoantibodies react with red blood cells and cause alterations in their membranes that include lysis of red blood cells. Spherocytes may develop during this destruction of red blood cells.

The signs and symptoms of spherocytosis include:

• Anemia
• Paleness (pallor)
• Jaundice (especially in children)
• Intermittent jaundice (more often in adults)
• Enlarged spleen (splenomegaly; a majority of all patients with spherocytosis)
• Gallstone development (for example, bilirubin stones due to spherocyte lysis)
• Spherocytes have been seen in microscopic examination of red blood cells

Doctors that treat spherocytosis may include:

• Pediatricians
• Primary care physicians
• Internists
• Hematologists
• Hospitalists
• Possibly surgeons (to remove gallbladders and/or spleens)

Other doctors on the treatment team may include geneticists and/or immunologists.

After the doctor takes a history and does a physical exam, the diagnosis of spherocytosis is based upon identifying the abnormal red blood cells under a microscope.

Blood tests that often are ordered include:

• Complete blood cell count (CBC)
• Reticulocyte count
• Mean corpuscular hemoglobin concentration (MCHC)
• Peripheral blood smear (microscopic examination of red blood cells)
• Lactate dehydrogenase (LDH) level
• Fractionated bilirubin levels
• Osmotic fragility test
• Direct anti-globulin test

Other tests may be done to rule in or rule out other diseases (for example, a bone marrow biopsy) that may be a cause of abnormal red blood cells.

Treatment protocols vary; neonates may require phototherapy and/or exchange transfusions. Both adults and children are likely to require folic acid supplementation to sustain red blood cell production. Children may be candidates for partial or complete splenectomy (removal of the spleen) depending upon the severity of the disease.

The most common complication of all hereditary spherocytosis patients is the development of bilirubin gallstones which may require the removal of the gallbladder (cholecystectomy).

Each patient's condition should be discussed in detail with their treating physicians to help determine the individual's treatment plan and follow-up. For example, consideration of vaccination against Pneumococcus (pneumonia) and the Haemophilus influenzae bacteria before splenectomy should be discussed.

The prognosis for a person with spherocytosis is good to fair, and most individuals will have a normal life expectancy. Individuals that have the spleen and/or gallbladder removed may have fewer complications developed and have the abnormal red blood cells (spherocytes) survive and function longer, thus requiring fewer transfusions or other interventions.

One of the complications of spherocytosis is a megaloblastic crisis (the production of abnormally large immature and dysfunctional red blood cells). Appropriate folic acid supplementation may prevent this situation.

Occasionally the spleen (due to splenomegaly and destruction of partially functioning red blood cells) and the gallbladder (due to repeated gallstone development) may need to be removed as a complication of spherocytosis.

Anemia also is a complication of spherocytosis, and blood transfusions may be required.

A sudden increase in symptoms termed a crisis may occur due to viral infections or other problems that may influence the bone marrow production of red blood cells.

Folic acid or folate levels may need to be monitored.

In general, spherocytosis is usually modified by another word; consequently, spherocytosis may be written in the medical literature are:

• Hereditary spherocytosis
• Congenital hemolytic anemia
• Congenital hemolytic jaundice
• Chronic familial jaundice
• Spherocytic anemia
• Chronic acholuric jaundice