Validity of prior absorption of serum samples with Reiter's spirochetes inserological diagnosis of Borrelia burgdorferi infections

Evidence of Borrelia burgdorferi sensu late infection was sought in 230 pat ients with positive antibody titres in an indirect immunofluorescence test that became negative after serum samples were pre-absorbed with treponemal antigen. Infection could be excluded in 82.2% (189/230) of patients, was qu estionable in 6.9% (16/230), and was judged to have occurred in 10.9% (25/2 30), including four (1.7%) cases of early, acute disease that required trea tment. The preabsorption procedure clearly reduces the frequency of false-p ositive reactions; however, there is a definite risk of overlooking active infections with this technique.