D58.0 Hereditary spherocytosis

Name of the Condition

• Hereditary spherocytosis

Summary

Hereditary spherocytosis is an inherited disorder characterized by the production of abnormal red blood cells (spherocytes) that are more fragile and prone to premature destruction (hemolysis). This leads to chronic hemolytic anemia, jaundice, and an enlarged spleen. The condition results from defects in red blood cell membrane proteins, which disrupt the cell's structural integrity and cause it to lose its normal biconcave shape.

Causes

Hereditary spherocytosis is caused by inherited genetic mutations that affect proteins in the red blood cell membrane, such as spectrin, ankyrin, band 3, or protein 4.2. These mutations impair the cell's ability to maintain its shape, leading to the formation of spherical cells that are less flexible and more likely to be destroyed in the spleen. The condition is typically inherited in an autosomal dominant pattern, though autosomal recessive forms exist.

Risk Factors

• Family history of hereditary spherocytosis
• Inherited genetic mutations in red blood cell membrane proteins
• Ethnic background (more common in individuals of Northern European descent)
• Triggers that exacerbate hemolysis (e.g., infections, certain medications, oxidative stress)

Symptoms

• Fatigue and weakness due to anemia
• Jaundice (yellowing of skin or eyes) from increased bilirubin
• Pale skin or mucous membranes
• Enlarged spleen (splenomegaly)
• Dark urine (hemoglobinuria) during hemolytic episodes
• Gallstones (cholelithiasis) from chronic bilirubin buildup

Diagnosis

Diagnosis involves a combination of clinical evaluation, laboratory tests, and imaging. Blood tests may show anemia, elevated reticulocyte count, and increased indirect bilirubin. A peripheral blood smear typically reveals spherocytes. Additional tests include the osmotic fragility test, which demonstrates increased red blood cell breakdown in hypotonic solutions, and direct antiglobulin test (Coombs test) to rule out autoimmune hemolytic anemia. Genetic testing may confirm the diagnosis in ambiguous cases.

Treatment Options

Treatment focuses on managing symptoms and complications. Mild cases may require folic acid supplementation to support red blood cell production. For moderate to severe anemia, blood transfusions may be necessary. Splenectomy (surgical removal of the spleen) is often curative for many patients, though it carries risks such as increased infection susceptibility. In some cases, partial splenectomy or splenic embolization may be considered to preserve immune function. Cholecystectomy (gallbladder removal) may be needed for symptomatic gallstones.

Prognosis and Follow-Up

With appropriate management, most individuals with hereditary spherocytosis have a good prognosis and can lead normal lives. Splenectomy significantly reduces hemolysis and anemia in many cases. Long-term follow-up includes monitoring for complications such as gallstones, iron overload from transfusions, and infection risk post-splenectomy. Regular blood tests and imaging may be recommended to assess disease activity and organ function.

Complications

• Severe anemia requiring transfusions
• Gallstones (cholelithiasis)
• Splenomegaly with risk of splenic rupture
• Iron overload from repeated transfusions
• Increased susceptibility to infections (especially post-splenectomy)
• Growth delays in children (rare)

Lifestyle & Prevention

• Avoid known triggers of hemolysis (e.g., certain medications, infections)
• Maintain a balanced diet rich in folic acid to support red blood cell production
• Stay hydrated to help manage jaundice
• Monitor for signs of infection, especially after splenectomy
• Regular medical follow-up to assess disease progression and complications

When to Seek Professional Help

Seek medical attention if you experience:

• Sudden worsening of fatigue or weakness
• Jaundice or dark urine
• Severe abdominal pain (possible gallstones or splenic rupture)
• Signs of infection (fever, chills) after splenectomy
• Unexplained weight loss or persistent symptoms

Tips for Medical Coders

When coding for hereditary spherocytosis (ICD10CM: D58.0), ensure documentation supports the diagnosis, including clinical findings (e.g., anemia, jaundice, splenomegaly), laboratory results (e.g., spherocytes on smear, osmotic fragility test), and genetic testing if performed. Note any complications (e.g., gallstones, splenectomy) as separate codes if applicable. Verify that the code aligns with the patient's specific presentation and exclude other hemolytic anemias unless coexisting.