Work

Guidelines for Lyme borreliosis: Diagnostic strategies

Year: 2025

Type: article

Abstract: • Serologic testing is indicated only for suspected disseminated Lyme borreliosis; early localized disease (e.g., erythema migrans) remains a clinical diagnosis. • The recommended two-tiered strategy includes ELISA screening followed by immunoblot confirmation for positive or equivocal results. • Intrathecal antibody synthesis is essential for Lyme neuroborreliosis diagnosis, while isolated antibody index elevation without pleocytosis suggests alternative causes. • Serologic interpretation must consider clinical context: IgG may remain for years after recovery; isolated IgM beyond six weeks is likely false positive. • PCR, CXCL13, and novel molecular tools show promise but remain supplementary or experimental pending standardization. The diagnosis of Lyme borreliosis (LB) relies primarily on clinical evaluation supported by appropriate serologic testing in selected cases. Serology is recommended only in suspected disseminated LB, characterized by compatible clinical signs and history of tick exposure. In early localized disease such as erythema migrans, laboratory testing is unnecessary due to low sensitivity and the reliability of clinical diagnosis. A two-tiered testing algorithm remains the standard: enzyme-linked immunosorbent assay (ELISA) followed by immunoblot confirmation when ELISA results are positive or equivocal. For patients with symptoms lasting less than six weeks and negative initial results, serology should be repeated after three weeks. Only IgG are considered to confirm LB diagnosis. Intrathecal antibody synthesis is critical for diagnosing Lyme neuroborreliosis (LNB), achieving > 99 % sensitivity after 6–8 weeks, although isolated antibody index elevation without pleocytosis suggests alternative etiologies. Interpretation of serology must always consider clinical context: IgG may remain for years after recovery, and isolated IgM beyond six weeks typically represents a false positive. Serologic limitations include low sensitivity in early disease and cross-reactivity, particularly for IgM. PCR may aid diagnosis from synovial fluid or skin lesions but is rarely informative for cerebrospinal fluid. Emerging biomarkers such as CXCL13 and advanced molecular approaches remain experimental and require further validation.

Source: Infectious Diseases Now

DOI: 10.1016/j.idnow.2025.105203