title: Bacterial components in the synovial tissue of patients with advanced rheumatoid arthritis or osteoarthritis: analysis with gas chromatography-mass spectrometry and pan-bacterial polymerase chain reaction.
abstract: OBJECTIVE
  To study the presence of bacterial components in the synovial tissue (ST) of patients with advanced rheumatoid arthritis (RA).
  
  
  METHODS
  ST was collected during joint surgery from 41 RA patients. Tissue from 39 patients with osteoarthritis (OA), 4 patients with undifferentiated inflammatory arthritis (UA), and 3 cases of accidental deaths served as controls. The pan-bacterial polymerase chain reaction (PCR) with primers for the 23S ribosomal RNA (rRNA) and 16S rRNA genes was used to detect bacterial DNA. In addition, synovial fluid (SF) samples from patients with chlamydial reactive arthritis (ReA) were also examined by the same method. The positive controls, bacterial DNA or ST spiked with different living bacteria, were analyzed alongside clinical samples. Most of the ST samples were also analyzed by gas chromatography-mass spectrometry (GC-MS) for determining the presence of bacteria-derived muramic acid. Strict precautions were followed in the clinics and the laboratory to prevent contamination.
  
  
  RESULTS
  In GC-MS analysis, muramic acid was observed in the ST from 4 of 35 RA patients and from 2 of 14 OA patients, but not in ST from 2 patients with UA and 3 cadavers. Bacterial DNA was not detected by either one of the PCR primers used in ST from 42 patients with RA and 39 patients with OA. However, 5 of 15 SF samples from ReA patients were PCR positive. The sensitivity of GC-MS to detect muramic acid was 2 pg/injected amount (227 pg muramic acid/mg ST), and that of the pan-bacterial PCR was 2-20 bacteria colony forming units/reaction.
  
  
  CONCLUSIONS
  These results indicate that a bacterial component, muramic acid, is detectable by GC-MS in ST from a few patients with advanced RA or OA. However, no bacterial DNA was detectable by PCR.
authors.affiliation: Department of Medical Microbiology, Turku University, Turku, Finland. tonche@utu.fi
authors.forename: Tong
authors.initials: T
authors.lastname: Chen
authors.forename: Marja
authors.initials: M
authors.lastname: Rimpiläinen
authors.forename: Reijo
authors.initials: R
authors.lastname: Luukkainen
authors.forename: Timö
authors.initials: T
authors.lastname: Möttönen
authors.forename: Tuomas
authors.initials: T
authors.lastname: Yli-Jama
authors.forename: Jari
authors.initials: J
authors.lastname: Jalava
authors.forename: Olli
authors.initials: O
authors.lastname: Vainio
authors.forename: Paavo
authors.initials: P
authors.lastname: Toivanen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001168:Arthritis / Q000378:metabolism; D016918:Arthritis, Reactive / Q000378:metabolism; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000503:physiopathology; D002689:Chlamydia / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008875:Middle Aged; D009112:Muramic Acids / Q000032:analysis*; D010003:Osteoarthritis / Q000378:metabolism* / Q000503:physiopathology; D016133:Polymerase Chain Reaction / Q000379:methods; D000091402:Prohibitins; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013583:Synovial Membrane / Q000737:chemistry*
chemical_list: D004269:DNA, Bacterial; D009112:Muramic Acids; C000717331:PHB2 protein, human; D000091402:Prohibitins