Clinical and experimental evidence for persistent Yersinia infection in reactive arthritis

The findings of bacterial antigens in the joint and persistent triggering i nfection elsewhere in the body are thought to be important in the pathogene sis of reactive arthritis (ReA), We describe a patient with clinical and la boratory features consistent with this. The initial presentation with eryth ema nodosum and periarthritis due to infection with Yersinia pseudotubercul osis IV was followed 13 months later by recurrent erythema nodosum with joi nt effusion. At that time, synovial fluid was shown to contain Yersinia ant igens, and, surprisingly, Yersinia-specific 16S ribosomal RNA (rRNA) sequen ces were also identified by reverse transcriptase-polymerase chain reaction and sequencing. Since there was no serologic evidence of reinfection, we p ostulate that a silent persistent Yersinia infection was reactivated, leadi ng to dissemination of organisms to the joint, with consequent induction of ReA, Although the finding of synovial Yersinia antigens years after the or iginal infection in ReA has previously been reported, the presence of Yersi nia 16S rRNA indicates that viable organisms were also able to reach the jo int.