title: Optimized testing for C. trachomatis DNA in synovial fluid samples in clinical practice.
abstract: OBJECTIVE
  No standardized polymerase chain reaction (PCR) assay is available for detection of Chlamydia trachomatis (C. tr.) in synovial fluid (SF) for diagnostic use in clinical practice. This study tested the performance of two optimized molecular biology methods, to determine which is best suited for detecting C. tr. in SF clinical samples from patients with various rheumatologic diseases.
  
  
  METHODS
  Two DNA extraction methods, i.e., (1) alkaline lysis and (2) QIAEX II Gel Extraction Kit® + cetyltrimethylammonium bromide (CTAB; Qiagen, Hilden, Germany), and C. tr.-omp1-152 bp PCR were tested in SF samples from a total of 329 patients with the following diagnoses: reactive arthritis (ReA; n = 10, 4 patients had posturethritic ReA), undifferentiated arthritis (UA; n = 66), rheumatoid arthritis (RA; n = 169), psoriatic arthritis (PSA; n = 12), and osteoarthritis (OA) n = 72.
  
  
  RESULTS
  In SF samples, C. tr.-omp1-152 bp PCR in combination with alkaline lysis DNA extraction allowed detection of more C. tr.-positive samples: 3/10 (30%) ReA patients (all with posturethritic ReA) and 20/66 (38%) UA patients were positive, compared to the 0/10 (0%) patients with ReA and 1/66 (2%) with UA detected using the QIAEX II Gel Extraction Kit® + CTAB. Moreover, 2/12 (17%) SF samples from PSA patients tested positive with alkaline lysis. All samples from patients with OA and RA tested negative.
  
  
  CONCLUSIONS
  Alkaline lysis in combination with C. tr.-omp1-152 bp PCR emerged as the most sensitive method for identification of C. tr. in clinical SF samples.
authors.affiliation: Clinic of Pneumology, Medical School Hannover, Hannover, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Freise
authors.affiliation: Klinikum Bremen Mitte, Bremen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Bernau
authors.affiliation: Clinic of Immunology and Rheumatology, Medical School Hannover, Hannover, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Meier
authors.affiliation: Emeritus, Medical School Hannover, Hannover, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Zeidler
authors.affiliation: Div. of Rheumatology, Rotes Kreuz Krankenhaus, St. Pauli Deich 24, 28199, Bremen, Germany. kuipers.j@roteskreuzkrankenhaus.de.
authors.forename: J G
authors.initials: JG
authors.lastname: Kuipers
mesh_terms: D000328:Adult; D001168:Arthritis / Q000175:diagnosis* / Q000382:microbiology; D002690:Chlamydia Infections / Q000175:diagnosis* / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000235:genetics* / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics*; D005260:Female; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D000091402:Prohibitins; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000592:standards*; D013582:Synovial Fluid / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; C000717331:PHB2 protein, human; D000091402:Prohibitins
keywords: Arthritis, psoriatic; Arthritis, reactive; Diagnosis; Joints; Polymerase chain reaction