Format

Send to

Choose Destination
J Infect Dis. 1999 Jul;180(1):133-40.

Correlation of opsonophagocytosis and passive protection assays using human anticapsular antibodies in an infant mouse model of bacteremia for Streptococcus pneumoniae.

Author information

1
Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, 30333. sej2@cdc.gov

Abstract

An infant mouse assay system for assessment of protective concentrations of human serum pneumococcal anticapsular antibodies is described. Passive immunization of anticapsular antibodies was evaluated for protection of infant mice challenged with Streptococcus pneumoniae serotypes 1, 4, 5, 6B, 18C, and 23A, with bacteremia as an end point. Protection was defined as no detectable bacteremia in 70% of mice 48 h after challenge. Type-specific anticapsular concentrations required for protection varied with serotype (</=0.05 to >0.4 microg/mL). Across serotypes, there was no significant correlation between human IgG concentration in mouse serum and protection from bacteremia or between IgG concentration and opsonophagocytic titer. Significant correlation (r=.84, P<.001) was observed between opsonophagocytic titer of human IgG antibody in mouse sera and protection from bacteremia. Thus, protective concentrations of anticapsular antibodies against bacteremia are serotype dependent. Opsonophagocytosis is a better predictor of in vivo protective capacity of pneumococcal anticapsular antibodies than are ELISA IgG antibody concentrations.

PMID:
10353871
DOI:
10.1086/314845
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center