Pre-treatment and post-treatment assessment of the C6 test in patients with persistent symptoms and a history of Lyme borreliosis.

It was recently reported that antibody to C6, a peptide that reproduces an invariable region of the VlsE lipoprotein of Borrelia burgdorferi, declined in titer by a factor of four or more in a significant proportion of patients after successful antibiotic treatment of acute localized or disseminated Lyme borreliosis. The present study evaluated the C6 test as a predictor of therapy outcome in a population of patients with post-treatment Lyme disease syndrome. The serum specimens tested were from patients with well-documented, previously treated Lyme borreliosis who had persistent musculoskeletal or neurocognitive symptoms. All of the patients had participated in a recent double-blind, placebo-controlled antibiotic trial in which serum samples were collected at baseline and 6 months thereafter, i.show $132#e. 3 months following treatment termination. In this patient population no correlation was found between a decline of C6 antibody titer of any magnitude and treatment or clinical outcome. Antibodies to C6 persisted in these patients with post-treatment Lyme disease syndrome following treatment, albeit at a markedly lower prevalence and titer than in untreated patients with acute disseminated Lyme disease. The results indicate that C6 antibody cannot be used to assess treatment outcome or the presence of active infection in this population. [ABSTRACT FROM AUTHOR]