Complement deficiencies in patients over ten years old with meningococcal disease due to uncommon serogroups.

46 patients in whom meningococcal disease due to serogroups X, Y, Z, W135, or 29E had developed after the age of 10 years were investigated retrospectively for complement deficiency. Complement deficiency was found in half of the patients: properdin deficiency in 9 patients, C3 deficiency syndromes in 5, and homozygous deficiency of a terminal component (C5, C6, C7, or C8) in 9. Meningococcal infections recurred in 5 of the 9 patients with terminal complement component deficiencies but not in the other complement-deficient patients. The findings show that meningococcal disease due to uncommon serogroups is often associated with complement deficiency.