[Recurring meningococcal meningitis in hereditary C 5 deficiency]

Area of Science:

• Immunology
• Genetics

Background:

• The complement system is crucial for innate immunity.
• Deficiencies in terminal complement components (C5-C8) impair bacteriolysis.
• Neisseria infections are associated with complement deficiencies.

Observation:

• A 20-year-old woman experienced recurrent meningococcal meningitis.
• Familial studies revealed an autosomal co-dominant inheritance pattern for C5 deficiency.

Findings:

• Inherited C5 deficiency was identified as the cause of recurrent meningococcal meningitis.
• Serum bacteriolytic activity is absent in deficiencies of C5 to C8.
• C5 deficiency specifically impacts chemotaxis in addition to bacteriolysis.

Implications:

• Recurrent Neisseria infections suggest terminal complement component deficiencies (C5-C8).
• Diagnosis of C5 deficiency is critical for managing recurrent meningococcal meningitis.
• Understanding complement pathways aids in predicting and treating Neisseria infections.