title: A rapid and sensitive chemiluminescence assay for evaluation of functional opsonic activity of Haemophilus influenzae type b-specific antibodies.
abstract: Luminol-enhanced chemiluminescence (CL) of heterologous neutrophils was used to assess the capacity of a 1-ng/ml concentration of Haemophilus influenzae type b (Hib)-specific antibodies to induce opsonization of Hib with autologous heat-inactivated sera from children immunized with Hib capsular polysaccharide-polyribosylribitolphosphate (Hib-PRP) conjugate vaccine. Serum samples from 15 of 36 children (42%) vaccinated with Hib-PRP conjugate vaccine had protective levels of Hib-specific antibodies of > or = 1,000 ng/ml. Ten of these 15 (67%) had poor or nonfunctional opsonic activity. Of the 10 children whose sera lacked opsonic activity, 5 (50%) presented with recurrent Hib infection. In contrast, none of the sera of 20 healthy adults lacked opsonic capability. CL intensity was proportional to the concentration of anti-Hib antibodies used for opsonization. Furthermore, the titers of Hib-PRP-specific antibody in children and adults did not correlate with opsonic activity. These results suggest that luminol-enhanced CL as described here with minute concentrations of antibody for opsonization can be used to assess functional capacity of anti-Hib antibodies after vaccination or natural infection in the evaluation of patients with recurrent infections.
authors.affiliation: Specialty Laboratories, Inc., Santa Monica, California 90404-3900, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Ojo-Amaize
authors.forename: J A
authors.initials: JA
authors.lastname: Church
authors.forename: N E
authors.initials: NE
authors.lastname: Barka
authors.forename: M S
authors.initials: MS
authors.lastname: Agopian
authors.forename: J B
authors.initials: JB
authors.lastname: Peter
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000918:Antibody Specificity; D016667:Bacterial Capsules / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000097:blood / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006192:Haemophilus Infections / Q000097:blood* / Q000276:immunology; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007118:Immunoassay / Q000379:methods* / Q000592:standards; D007074:Immunoglobulin G / Q000145:classification / Q000276:immunology; D007223:Infant; D008163:Luminescent Measurements; D008297:Male; D009504:Neutrophils / Q000382:microbiology; D009895:Opsonin Proteins / Q000276:immunology*; D010587:Phagocytosis / Q000502:physiology*; D011135:Polysaccharides, Bacterial / Q000276:immunology; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D009895:Opsonin Proteins; D011135:Polysaccharides, Bacterial