Chlamydia-induced arthritis. Immunofluorescent antibody studies of the synovial fluid from 4 patients Clin Exp Rheumatol. 1992 Jul-Aug;10(4):

Using two monoclonal antibodies in direct immunofluorescence we found material which could be identified as elementary bodies and cytoplasmic inclusions of Chlamydia trachomatis (Ct) in the synovial fluid of 4 patients affected by acute seronegative oligoarthritis. The finding of Ct in synovial fluids is a well known occurrence and has been demonstrated during the last few years in patients affected by seronegative oligoarthritis. However the fact was impossible to culture viable Ct from synovial fluid led researchers to believe that the local immune responses might be triggered by bacterial antigens in the non viable form.The findings described in this work suggest that in our cases the bacteria was present in metabolically active vegetative form.