Lyme neuroborreliosis. Pathophysiological and diagnosis aspects

Abstract

Lyme neuroborreliosis is the neurological complication of Borrelia burgdorferi infection. The main mechanism involved is acute inflammation (direct infectious or indirect autoimmune) leading to degeneration of the central and peripheral nervous system structures. Several cell populations are involved in mediating the inflammatory response: endothelial cells modify the function of the blood-brain barrier; the microglia and the astrocytes act as immune cells as they present antigens to T cells and secrete prostaglandins, and the dendritic cells which can determine disease relapse or transformation into a chronic condition. All these cells secrete cytokines (interleukins, interferons, TNF), prostaglandins and complement components. The permeabilization of the blood-brain barrier through inflammation leads to cerebral edema, associated with characteristic CSF modifications which can be detected by specific laboratory tests. Serologic analysis and CSF analysis are the most useful tests for Lyme disease diagnosis. CSF analysis is mandatory in patients with neurological symptoms in the absence of skin manifestations and involves detection of intrathecal antibodies and pro-inflammatory cytokines by ELISA, FIA and Western Blotting. PCR for detecting Borrelia burgdorferi, DNA and Flow Cytometry are important in the later, chronic stages of the disease. Lyme neuroborreliosis is a disease with complex manifestations which can induce difficulties in diagnosis, especially in the early stages. False positive diagnosis can occur in patients considered to be at high risk for this disease (endemic zones, certain professions). Therefore collaboration between neurologist, infectionist and laboratory doctor is essential for an early and correct diagnosis; it allows for effective treatment of the disease, with a favourable prognostic.

Keywords

• inflammation
• cns
• lyme disease
• csf
• serologic analysis