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Recurrent meningitis in a black man
1Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN.
Abstract:
A 43-year-old black man had recurrence of acute bacterial meningitis caused by Neisseria meningitidis. He had had three previous episodes of acute meningitis, starting at age 27 years. The patient's serum was found to have an undetectable level of the sixth component of complement. Congenital absence of one of the terminal proteins in the complement system impairs a patient's ability to eradicate bacteria, and increases susceptibility to recurring infections caused by meningococci and other Neisseria species. Though the serum of complement-deficient patients promotes normal opsonization of bacteria, it is unable to kill meningococci directly. The currently available meningococcal vaccine may augment type-specific antibody, but it does not correct the underlying complement deficiency. The role of self-administered antibiotics in preventing recurrent Neisseria infection remains uncertain.
Insights
Recurrent Neisseria meningitidis meningitis in a patient with a complement component 6 deficiency highlights impaired bacterial killing. This deficiency increases susceptibility to Neisseria infections despite normal opsonization.
Area of Science:
- Immunology
- Infectious Diseases
- Genetics
Background:
- Recurrent bacterial meningitis poses significant health challenges.
- Neisseria meningitidis is a common cause of bacterial meningitis.
- Complement system deficiencies are associated with increased infection susceptibility.
Observation:
- A 43-year-old male experienced recurrent acute bacterial meningitis caused by Neisseria meningitidis.
- The patient presented with a history of four meningitis episodes since age 27.
- Serum analysis revealed undetectable levels of the sixth complement component (C6).
Findings:
- Congenital absence of C6 impairs the direct killing of Neisseria species.
- Complement deficiency affects the terminal pathway of the complement system.
- While opsonization is normal, direct bacterial lysis by serum is compromised in C6 deficiency.
Implications:
- Patients with C6 deficiency are at high risk for recurrent Neisseria infections.
- Current meningococcal vaccines may not fully address the underlying complement defect.
- Further research is needed on prophylactic strategies, including the role of antibiotics, for complement-deficient individuals.