title: Chlamydia pneumoniae antibody levels before coronary events in the Helsinki Heart Study as measured by different methods.
abstract: The lack of specific tests for the diagnosis of chronic Chlamydia pneumoniae infection has led to the use of enzyme immunoassay (EIA) instead of the gold standard, that is, microimmunofluorescence (MIF), in the measurement of C. pneumoniae antibodies. We assessed the predictive values of C. pneumoniae antibody levels and seroconversions measured by MIF and EIA for coronary events in the prospective Helsinki Heart Study. Sera from 239 cases with coronary events and 239 controls were available at the baseline and data from 210 cases and 211 controls before and after the event. The agreement between MIF and EIA antibody levels was best in high antibody titers. In conditional logistic regression analysis, only high IgA MIF titers (>/=40) at the baseline predicted future coronary events, and the participants with MIF seroconversion between consecutive sera had a higher (nonsignificant) risk for coronary events than the controls. The difference in the kinetics of EIA and MIF antibodies demonstrated that MIF should remain the gold standard.
authors.affiliation: National Public Health Institute, P.O. Box 310, FIN-90101 Oulu, Finland. mika.paldanius@ktl.fi
authors.forename: Mika
authors.initials: M
authors.lastname: Paldanius
authors.forename: Maija
authors.initials: M
authors.lastname: Leinonen
authors.forename: Hanna
authors.initials: H
authors.lastname: Virkkunen
authors.forename: Leena
authors.initials: L
authors.lastname: Tenkanen
authors.forename: Tiina
authors.initials: T
authors.lastname: Sävykoski
authors.forename: Matti
authors.initials: M
authors.lastname: Mänttäri
authors.forename: Pekka
authors.initials: P
authors.lastname: Saikku
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000936:Antigen-Antibody Complex / Q000097:blood / Q000737:chemistry; D002318:Cardiovascular Diseases / Q000097:blood / Q000382:microbiology*; D002690:Chlamydia Infections / Q000276:immunology* / Q000382:microbiology; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D004311:Double-Blind Method; D005455:Fluorescent Antibody Technique; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000097:blood*; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012044:Regression Analysis
chemical_list: D000907:Antibodies, Bacterial; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G