ICD-11 Codes
for 4A00.12 - Immunodeficiency with factor B deficiency

Teodor Jurukovski January 1, 1970

Fact checked by: Teodor Jurukovski

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Understanding Immunodeficiency with Factor B Deficiency (ICD-11 Code 4A00.12)

Immunodeficiency with factor B deficiency, identified by the ICD-11 code 4A00.12, is a rare primary immunodeficiency disorder. It affects the body's complement system, a critical part of the immune response responsible for identifying and eliminating pathogens. A deficiency in complement factor B specifically impairs the alternative pathway of the complement system, significantly weakening the body's defence mechanisms against certain infections.

Causes and Genetic Factors

This condition is primarily genetic, typically inherited in an autosomal recessive pattern. It arises from mutations in the CFB gene, which provides instructions for making complement factor B. When these mutations occur, they lead to reduced levels of functional factor B in the blood, compromising the integrity of the alternative complement pathway. Individuals with this deficiency are born with the genetic predisposition.

Common Symptoms and Clinical Presentation

The hallmark of immunodeficiency with factor B deficiency is an increased susceptibility to recurrent, often severe, bacterial infections. These infections typically begin in infancy or early childhood. Encapsulated bacteria, such as Streptococcus pneumoniae and Neisseria meningitidis, pose a particular threat. Symptoms can include:

• Recurrent pneumonia
• Meningitis
• Sepsis
• Other severe bacterial infections

The severity and frequency of infections can vary among affected individuals.

Diagnostic Approaches

Diagnosing immunodeficiency with factor B deficiency involves a combination of clinical evaluation and laboratory testing. Healthcare providers will assess the patient's history of recurrent infections. Key diagnostic steps include:

• Complement Pathway Analysis: Laboratory tests to measure the levels and function of complement components, specifically identifying a deficiency or defect in factor B and the alternative pathway.
• Genetic Testing: DNA analysis to detect mutations in the CFB gene, confirming the genetic basis of the deficiency.

Treatment and Management Strategies

Management focuses on preventing and treating infections. While there is no cure for the genetic deficiency itself, proactive measures can significantly improve patient outcomes. Key management considerations include:

• Prophylactic Antibiotics: Long-term use of antibiotics to prevent bacterial infections.
• Vaccinations: Ensuring up-to-date immunisations, particularly against encapsulated bacteria like pneumococcus and meningococcus, although their effectiveness may be reduced in some individuals.
• Prompt Treatment of Infections: Immediate and aggressive treatment of any active infections.

Documentation and Coding Considerations

Accurate medical coding is essential for billing and record-keeping. The ICD-11 code for this condition is 4A00.12, officially termed 'Immunodeficiency with factor B deficiency'. This code falls under the broader category of Primary immunodeficiencies. When documenting patient care, healthcare professionals should use this specific ICD-11 code to accurately reflect the diagnosis. This ensures proper classification for statistical purposes, clinical management, and insurance claims. Common clinical synonyms include Factor B Deficiency and CFBD.