Chlamydia trachomatiselementary bodies in synovial fluid of patients with reactive arthritis and undifferentiated spondyloarthropathy in India

Abstract

Reportedly, there is little information on the magnitude of genitourinary-induced reactive arthritis (gReA) from India. Genital infection with Chlamydia trachomatis is a major health problem in India because of its high prevalence; therefore, this study was conducted with the aim to screen ReA/undifferentiated spondyloarthropathy (uSpA) patients (n=20) attending a major city hospital in New Delhi, for investigating the presence of intra-articular chlamydial antigen in knee joints. Patients with rheumatoid arthritis (RA) and osteoarthritis (OA) served as controls (n=20). Synovial fluid samples were screened for chlamydial elementary bodies (EBs) using a commercial kit (MicroTrak C.trachomatis Direct Specimen Test; Trinity Biotech, USA) for performing direct fluorescence assay (DFA). Chlamydia trachomatis EBs were detected in the synovial fluid cell deposits of six patients in Group I, namely, 33.3% (4/12) ReA and 25% (2/8) uSpA. All C.trachomatis positive patients exhibited an oligoarticular clinical picture with knee joint involvement. In the synovial fluid cell deposits of control patients, namely, RA/OA, no chlamydial EBs could be detected. This is the first study reporting the presence of C.trachomatis EBs in the synovial fluid of spondyloarthropathy patients, namely, ReA/uSpA from our country and it can be concluded that the prevalence of C.trachomatis-induced ReA is underestimated. Although our study had limitations in terms of sample size and lower sensitivity of DFA, yet this test can be used as an initial diagnostic tool for screening and patients with positive results may undergo specific tests for validation.