[Synovial cellular immune response to bacterial pathogens in patients with chronic juvenile arthritis]

Juvenile chronic arthritis is a heterogenous disease with an ill-defined pathogenesis. In our study, synovial fluid (SF) and peripheral blood (PB) of 70 children with oligoarthritis were investigated; bacteria-specific lymphocyte proliferation and antibodies to arthritogenic bacteria were determined. Specific cellular immune responses in SF but not in PB were found in 4/7 patients with either Lyme- or reactive arthritis (60%). In comparison, in subgroup JCA II (n = 45) encompassing mainly elder HLA B27 positive boys, a specific response in SF but again not in PB was detected in 10 children to Yersinia enterocolitica (YE), in four children either to Borrelia burgdorferi (BB) and Chlamydia trachomatis (CT), and in one child to Campylobacter jejuni (CJ). In contrast, in subgroup JCA I (n = 17) encompassing mainly young ANA-positive girls with chronic iridocyclitis, no specific response was found. The correlation of the synovial cellular and the humoral immune responses was 100% in the case of BB and 50% for YE; no antibodies against CT or CJ were detectable. Neither specific cellular nor humoral immune responses were detected against Salmonella or Shigella. We conclude that, in the pathogenesis of some patients with JCA, bacterial microbes have a triggering role. Mainly YE, but also BB and CT are responsible for cases of JCA in which no symptomatic infection preceded.