title: Serovar D and E of serogroup B induce highest serological responses in urogenital Chlamydia trachomatis infections.
abstract: BACKGROUND
  Chlamydia trachomatis is the most prevalent bacterial sexually transmitted infection (STI) worldwide. A strong link between C. trachomatis serogroup/serovar and serological response has been suggested in a previous preliminary study. The aim of the current study was to confirm and strengthen those findings about serological IgG responses in relation to C. trachomatis serogroups and serovars.
  
  
  METHODS
  The study population (n = 718) consisted of two patient groups with similar characteristics of Dutch STI clinic visitors. We performed genotyping of serovars and used titre based and quantitative commercially available ELISA kits (medac Diagnostika) to determine specific serum IgG levels. Optical density (OD) values generated by both tests were used to calculate the IgG titres (cut-off 1:50). Analyses were conducted stratified by gender.
  
  
  RESULTS
  We observed very significant differences when comparing the median IgG titres of three serogroups, B, C and I: in women for B vs. C: p < 0.0001 (median titres B 200 vs. C <50); B vs. I: p < 0.0001 (200 vs. 50), and in men for B vs. C: p = 0.0006 (150 vs. <50); B vs. I: p = 0.0001 (150 vs. <50); C vs. I was not significant for both sexes. Serovars D and E of serogroup B had the highest median IgG titres compared to the other serovars in both men and women: 200 and 200 vs. ≤ 100 for women and 100 and 200 vs. ≤ 75 for men, respectively.
  
  
  CONCLUSIONS
  This study shows that B group serovars induce higher serological responses compared to the C and I group serovars in vivo in both men and women.
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Verweij
authors.forename: Esmée
authors.initials: E
authors.lastname: Lanjouw
authors.forename: Caroline J
authors.initials: CJ
authors.lastname: Bax
authors.forename: Koen D
authors.initials: KD
authors.lastname: Quint
authors.forename: Paul M
authors.initials: PM
authors.lastname: Oostvogel
authors.forename: P Joep
authors.initials: PJ
authors.lastname: Dörr
authors.forename: Jolein
authors.initials: J
authors.lastname: Pleijster
authors.forename: Henry J C
authors.initials: HJ
authors.lastname: de Vries
authors.forename: Remco P H
authors.initials: RP
authors.lastname: Peters
authors.forename: Sander
authors.initials: S
authors.lastname: Ouburg
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Microbiology and Infection Control, VU University Medical Center, De Boelelaan 1117, 1081, HV, Amsterdam, The Netherlands. samorretravel@yahoo.co.uk.
authors.forename: Servaas A
authors.initials: SA
authors.lastname: Morré
mesh_terms: D002690:Chlamydia Infections / Q000453:epidemiology / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D052776:Female Urogenital Diseases / Q000382:microbiology; D005838:Genotype; D006801:Humans; D008297:Male; D052801:Male Urogenital Diseases / Q000382:microbiology; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D065288:Serogroup