Chlamydia pneumoniae as a causative factor of ankylosing spondylitis / 中华临床感染病杂志

ABSTRACT

Objective To investigate the association of chlamydia pneumoniae infection with ankylosing spondylitis (AS).MethodsSerum samples were obtained from 33 AS patients and 22 healthy controls.Enzyme-linked immunosorbent assay (ELISA) was applied to mearsure serum anti-Chlamydia pneumoniae antibodies (IgM/IgG),while immunofluorescence assay (IFA) was used to detect Chlamydia pneumoniae LPS antigen,and polymerase chain reaction (PCR) was used to amplify Chlamydia pneumoniae DNA in peripheral blood cells. Immunohistochemistical technique was applied to examine Chlamydia pneumoniae LPS antigen in synovial tissue from another 9 AS patients who received total hip replacement and 13 patients with comminuted femoral fractures.ResultsThe positive rates of Chlamydia pneumoniae IgM,LPS antigen and chlamydia pneumoniae DNA were higher in AS patients than those in healthy controls (78.8％ vs 22.7％,x2 =16.867,P =0.000; 66.7％ vs 31.8％,x2 =6.431,P =0.011; 33.3％ vs 9.1％,x2 =4.298,P =0.038).Chlamydia pneumoniae DNA positive rate was correlated with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels (Z =-2.774 and -2.829,P =0.004).In synovial tissues,chlamydial LPS-containing inflammatory cells were observed in 77.8％(7/9) AS patients,while those in fracture patients was 30.8％ ( 4/13 ) ( P =0.08 ).Conclusion Chlamydia pneumoniae infection is common in blood circulation and joint cavity of AS patients and may be associated with the pathogenesis of AS.