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Complement factor I deficiency with recurrent aseptic meningitis
A J Bonnin1, H J Zeitz, A Gewurz
1Department of Immunology/Microbiology, Rush-Presbyterian-St Luke's Medical Center, Chicago, Ill.
Abstract:
Patients with deficiency of the complement regulatory protein factor I typically present with systemic pyogenic bacterial infections, including meningitis. We report a novel case with total deficiency of factor I in serum and plasma; the patient experienced nine consecutive episodes of aseptic meningitis within a 2-year period. There was no history of previous bacterial sepsis. Aseptic meningitis recurred despite attempted penicillin prophylaxis. Each episode resolved rapidly without sequelae, with or without antibiotic treatment. Serum complement profiles showed persistently low levels of C3, factor B, and factor H and undetectable factor I protein. Family complement studies could not be performed. Except for a minimally increased titer of antinuclear antibody, no other immunologic abnormality was detected. Results of an oral ibuprofen challenge were negative. We conclude that deficiency of factor I may predispose to aseptic, as well as pyogenic bacterial, meningitis.
Insights
Total deficiency of factor I, a complement protein, can lead to recurrent aseptic meningitis, not just bacterial infections. This finding expands understanding of factor I
Area of Science:
- Immunology
- Infectious Diseases
Background:
- Factor I deficiency typically causes pyogenic bacterial infections.
- The complement system is crucial for immune defense.
Observation:
- A patient with total factor I deficiency presented with nine episodes of aseptic meningitis over two years.
- No history of bacterial sepsis was noted, and meningitis recurred despite antibiotic prophylaxis.
Findings:
- Serum complement levels were low for C3, factor B, and factor H, with undetectable factor I.
- The patient had a minimally elevated antinuclear antibody titer but no other immune defects.
Implications:
- Factor I deficiency may predispose individuals to aseptic meningitis.
- This expands the known clinical spectrum of complement deficiencies.
- Highlights the role of complement in non-bacterial meningitis pathogenesis.