Systemic immune responses in patients with early localized or early disseminated Borrelia afzelii lyme borreliosis.

Introduction: The role of host immune responses in the pathogenesis of borrelial dissemination in early Lyme borreliosis (LB) in the form of multiple erythema migrans (MEM) or LB-associated symptoms is incompletely understood.

Methods: In this study, fifteen cytokine or chemokine levels, representative of innate, Th1, and Th17 immune responses, were assessed using a bead-based Luminex multiplex assay in acute sera from 76 adult patients with skin culture-positive Borrelia afzelii solitary erythema migrans (SEM) and 58 patients with MEM at a single-center university hospital. Differences between the groups were tested by modeling each cytokine or chemokine concentration by means of left-censored regression using the classic Tobit model.

Results: Mean serum cytokine or chemokine levels were low. When taking into account the proportion of patients with cytokine or chemokine concentrations below the lowest detectable limit, only levels of CXCL10 (p = .03) and CCL19 (p = .02), representatives of the Th1 immune response, differed between patients with SEM and those with MEM; however, the differences did not reach statistical significance when adjusted for multiple comparisons. In addition, we did not find differences in systemic inflammatory responses when comparing patients with and those without LB-associated constitutional symptoms.

Conclusion: No significant differences in systemic immune responses represented by selected cytokines or chemokines in serum samples of patients with EM infected with B. afzelii suggest that systemic mediators are not pivotal in the pathogenesis of dissemination of early infection in the form of MEM or LB-associated symptoms. Localized immune responses in the skin or other pathogenetic mechanisms may be more important in this regard.