title: Use of a peptide based enzyme immunoassay in diagnosis of Chlamydia trachomatis triggered reactive arthritis.
abstract: OBJECTIVE
  To assess the presence of circulating IgA and IgG antibodies to Chlamydia trachomatis in sera of patients with reactive arthritis (ReA) and other arthritides.
  
  
  METHODS
  A peptide based enzyme immunoassay (EIA) was used to study 132 patients divided into 5 groups: C. trachomatis triggered ReA, uroarthritis, enteroarthritis, oligoarthritis, and rheumatoid arthritis (RA). Followup sera were available from 19 patients.
  
  
  RESULTS
  An increased prevalence of C. trachomatis antibodies was observed in patients with ReA triggered by C. trachomatis; 18/23 (78%) had IgA and 19/23 (83%) had IgG antibodies. In patient groups with uroarthritis (n = 12), enteroarthritis (n = 56), oligoarthritis (n = 16), and RA (n = 25), C. trachomatis IgA/IgG antibodies were detected in 58%/75%, 27%/21%, 25%/31%, and 20%/32% of patients, respectively. Both the IgA and IgG antibodies were positive in 74%, 50%, 16%, 25%, and 12% of the patients with C. trachomatis triggered ReA, uroarthritis, enteroarthritis, oligoarthritis, and RA, respectively. Based on positivity of both isotypes the sensitivity of the assay was 74% and specificity 84%. In the followup sera, an association between circulating C. trachomatis-specific antibody concentrations and clinical disease outcome of the arthritis was seen in patients with culture-positive C. trachomatis triggered ReA.
  
  
  CONCLUSIONS
  C. trachomatis species-specific peptide EIA correlates well with conventional diagnosis of primary C. trachomatis infection in patients with ReA. This assay may be a valuable contribution to the diagnosis of C. trachomatis triggered ReA.
authors.affiliation: Division of Clinical Microbiology, Turku University Central Hospital, Finland. simo.nikkari@mobidiag.com
authors.forename: S
authors.initials: S
authors.lastname: Nikkari
authors.forename: M
authors.initials: M
authors.lastname: Puolakkainen
authors.forename: A
authors.initials: A
authors.lastname: Närvänen
authors.forename: O
authors.initials: O
authors.lastname: Aakre
authors.forename: P
authors.initials: P
authors.lastname: Toivanen
authors.forename: M
authors.initials: M
authors.lastname: Leirisalo-Repo
mesh_terms: D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000032:analysis / Q000276:immunology; D016918:Arthritis, Reactive / Q000175:diagnosis* / Q000209:etiology / Q000382:microbiology; D001425:Bacterial Outer Membrane Proteins; D002690:Chlamydia Infections / Q000150:complications / Q000175:diagnosis* / Q000276:immunology; D002692:Chlamydia trachomatis / Q000276:immunology* / Q000302:isolation & purification; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D008297:Male; D008565:Membrane Proteins / Q000276:immunology*; D008875:Middle Aged; D000091402:Prohibitins; D014552:Urinary Tract Infections / Q000150:complications / Q000175:diagnosis / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D008565:Membrane Proteins; C000717331:PHB2 protein, human; D000091402:Prohibitins