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 C-6, 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 C-6 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 C-6 antibody titer of any magnitude and treatment or clinical outcome. Antibodies to C-6 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 C-6 antibody cannot be used to assess treatment outcome or the presence of active infection in this population.