title: Reactive arthritis: urogenital swab culture is the only useful diagnostic method for the detection of the arthritogenic infection in extra-articularly asymptomatic patients with undifferentiated oligoarthritis.
abstract: Reactive arthritis (ReA) is a seronegative oligoarthritis triggered by a preceding extra-articular infection. While evidence of a microbial infection is mandatory for establishing the diagnosis of ReA, the sensitivity of bacteriological and serological tests has not been determined in patients without symptoms of infection. In a retrospective study, we evaluated the usefulness of urogenital swab cultures, serology and stool culture to identify infections in 234 patients with undifferentiated oligoarthritis. One hundred and forty-four patients complaining about joint pain who had no sign or history of inflammatory arthritis served as controls. Urogenital swab cultures showed a microbial infection in 44% of the patients with oligoarthritis (15% Chlamydia, 14% Mycoplasma, 28% Ureaplasma), whereas in the control group only 26% had a positive result (4% Chlamydia, 7% Mycoplasma, 21% Ureaplasma) (P < 0.001). A Chlamydia IgG-antibody titre > or = 1:256 was found in 22% of the patients in the oligoarthritis group and in 9% of the controls (P < 0.01). However, for only half of Chlamydia IgG-positive patients could a Chlamydia infection be confirmed by urogenital swab culture. Twenty-one per cent of patients with oligoarthritis vs 23% of the controls had positive antibody titres for Salmonella (not significant), 15% vs 5% for Yersinia (P < 0.05) and 17% vs 3% for Borrelia IgG (P < 0.01). In two patients, stool cultures were positive for Campylobacter. Urogenital swab culture is a sensitive diagnostic method to identify the triggering infection in ReA. A single determination of antibodies against Chlamydia trachomatis is of limited value because of the high prevalence of positive results in the control group.
authors.affiliation: Department of Internal Medicine III, University of Vienna, Austria.
authors.forename: L
authors.initials: L
authors.lastname: Erlacher
authors.forename: W
authors.initials: W
authors.lastname: Wintersberger
authors.forename: M
authors.initials: M
authors.lastname: Menschik
authors.forename: A
authors.initials: A
authors.lastname: Benke-Studnicka
authors.forename: K
authors.initials: K
authors.lastname: Machold
authors.forename: G
authors.initials: G
authors.lastname: Stanek
authors.forename: J
authors.initials: J
authors.lastname: Söltz-Szöts
authors.forename: J
authors.initials: J
authors.lastname: Smolen
authors.forename: W
authors.initials: W
authors.lastname: Graninger
mesh_terms: D000328:Adult; D016918:Arthritis, Reactive / Q000175:diagnosis* / Q000276:immunology; D003581:Cytodiagnosis; D005243:Feces / Q000382:microbiology; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D000091402:Prohibitins; D012698:Serologic Tests; D014521:Urethra / Q000382:microbiology; D014566:Urogenital System / Q000382:microbiology*; D014626:Vaginal Smears
chemical_list: D015796:HLA-B27 Antigen; C000717331:PHB2 protein, human; D000091402:Prohibitins