Bacterial DNA in synovial fluid cells of patients with juvenile onset spondyloarthropathies

Objective. To identify bacterial DNA in synovial fluid cells of patients wi th active juvenile onset spondyloarthropathy (SpA). Methods. The main group of study constituted 22 patients with juvenile onse t SpA. In addition, five patients with adult onset SpA and nine with rheuma toid arthritis (RA) were studied. Polymerase chain reaction (PCR) with eith er genus- or species-specific primers was performed on synovial fluid cells to detect DNA sequences of Chlamydia trachomatis, Yersinia enterocolitica. Salmonella sp., Shigella sp., Campylobacter sp. and Mycobacterium tubercul osis. The presence of antibacterial antibodies in sera and synovial fluid w as also determined by enzyme-linked immunoassay. Results. The synovial fluid of nine patients with juvenile onset SpA, three with adult onset SpA and one with RA contained bacterial DNA. Five juvenil e onset SpA samples had DNA of one single bacterium, two juvenile onset SpA and three adult onset SpA had DNA of two bacteria and two juvenile onset S pA had DNA of three bacteria. Overall. Salmonella sp. DNA was detected in s even synovial fluid samples, Shigella sp., Campylobacter sp. and M. tubercu losis were found in four samples each, and C. trachomatis was found in two. The bacterial DNA findings correlated with neither diagnosis nor disease d uration. One RA synovial fluid had DNA of Campylobacter sp. Neither serum n or synovial fluid antibacterial antibodies correlated with DNA findings or clinical diagnosis. Conclusion. In this study, single and several combinations of bacterial DNA were identified in the synovial fluid of patients with long-term undiffere ntiated and definite juvenile onset SpA and adult onset SpA. Of relevance i s that bacterial DNA corresponds to bacteria producing endemic disease in o ur population.