[Diagnostic and prognostic significance of serologic studies in Yersinia arthritis].

Commonly-used serological methods for the determination of Yersinia antibodies are based on the presence of agglutinins, which are frequently absent or of low titer when arthritis begins. Stool cultures are usually negative at that time, so many Yersinia infections are underdiagnosed. On the other hand, significant agglutinin titers, of diagnostic value, become frequently minimised because of cross reactivity with Yersinia and other gram-negative bacteria. With the immunoblot-technique, using specific virulence-associated antigens and the detection of class-specific antibodies, clear statements are possible about whether there is a recent or an old Yersinia infection. As Yersinia arthritis may have an acute start and a protracted course over months, an exact diagnosis is essential for therapy and prognosis, as well as for answering the question of whether there is acute exacerbation of a preexisting rheumatoid illness of an additional infectious arthritis.