Complement levels in Brazilian children during and after meningococcal meningitis.

Abstract

PURPOSE:

To evaluate the functional activity of the classical and alternative pathways of the complement system and the levels of C3, C4, and factor B during the first episode of meningococcal infection and during the convalescence period.

PATIENTS AND METHODS:

Ten Brazilian children ranging in age from 8 months to 8 years, admitted from 1991 to 1993 with a clinical-laboratory diagnosis of meningococcal meningitis, were studied during acute infection (up to 7 days from diagnosis) and during the convalescence period (1 to 6 months after the acute episode). C3, C4, and Factor B were measured using nephelometry, and the lytic activity of classical and alternative pathways were evaluated by a kinetic method and expressed as the time needed to lyse 50% of an erythrocyte suspension (T1/2, expressed in seconds). Low T1/2 values for classical and alternative pathways correlate with high activities of the classical and alternative complement pathways, respectively.

RESULTS:

A significant difference was observed between the alternative pathway lytic activity during infection and the convalescence period (282 vs 238 seconds, respectively, P = .01). No differences were detected in the other complement parameters analyzed.

CONCLUSIONS:

In the presence of meningococcal meningitis, the alternative pathway is preferentially activated. This is probably due to the greater ability of the meningococcal endotoxin to activate this pathway in vivo.

• Authors: Pérsio Roxo Júnior, Virgínia Paes Leme Ferriani, José Eduardo Teixeira, José Elpídio Barbosa
• Journal: Clinics (Sao Paulo, Brazil) (Clinics (Sao Paulo)) Vol. 60 Issue 2 Pg. 127-30 (Apr 2005) ISSN: 1807-5932 [Print] United States
• PMID: 15880248 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Complement C3
• Complement C4
• Complement System Proteins
• Complement Factor B

Topics

• Acute Disease
• Brazil
• Child
• Child, Preschool
• Complement C3 (analysis)
• Complement C4 (analysis)
• Complement Factor B (analysis)
• Complement Pathway, Alternative (immunology)
• Complement Pathway, Classical (immunology)
• Complement System Proteins (analysis)
• Humans
• Infant
• Meningitis, Meningococcal (blood, immunology)
• Reference Values