Deafness, complement deficiencies and immunoglobulin status in patients with meningococcal diseases due to uncommon serogroups.

The prevalence of deafness and complement deficiencies in association with meningococcal disease caused by uncommon serogroups of meningococci was studied in 30 patients (Group A) and 30 controls with Serogroup B disease (Group B). In Group A 8 patients (26.6%) had hearing impairment in contrast to only 1 patient (3.3%) in Group B (P < 0.01). Complement deficiency was detected in 8 patients (26.6%) of Group A whereas none of the Group B patients showed a defect in the complement system (P < 0.01). Association between complement deficiencies and meningococcal disease was detected for Serogroups Y (n = 5; 16.6%) and W135 (n = 3; 10.0%). Localization of the defects revealed only complement deficiencies of the classical pathway (C8-beta or C7 defects). The levels of Ig and IgG subclasses were found to be within the normal range for all patients. Our results suggest that meningococcal diseases caused by uncommon serogroups are more often associated with deafness and late complement component defects.