20.500.12556/RUL-187891 Dynamics of borrelial antibodies in European Lyme borreliosis patients with erythema migrans Background/Objectives: The diagnosis of typical erythema migrans (EM) is clinical, and serological testing for Borrelia-specific antibodies is not required. However, characterization of the immune response in patients with a reliable clinical diagnosis may improve the interpretation of serological findings in early Lyme borreliosis (LB) without characteristic skin lesions. Methods: Serum IgM and IgG antibodies to Borrelia burgdorferi sensu lato were evaluated in 1356 Slovenian adults with EM at baseline and at a follow-up visit approximately two months after treatment initiation, using a chemiluminescence immunoassay based on recombinant borrelial antigens. Results: At baseline, 41.5% of patients were IgMseropositive, 55.5% IgG-seropositive, and 70.1% positive for either IgM or IgG. Patients with multiple EM were significantly more often seropositive than those with solitary EM. In previously untreated patients, baseline IgG seropositivity showed a clearer positive association with longer lesion duration and larger lesion diameter, whereas the corresponding IgM patterns were less consistent. Multiple EM remained strongly associated with both IgM and IgG seropositivity in adjusted analyses. Seroconversion at follow-up was uncommon, occurring in 8.0% of initially IgM-negative and 8.2% of initially IgG-negative patients. Conclusions: The low frequency of newly detectable antibody responses indicates that repeat qualitative serologic testing approximately two months after treatment initiation provides limited additional diagnostic information in European adults with EM. Lyme borreliosis erythema migrans Borrelia burgdorferi sensu lato humoral immune response IgM antibodies IgG antibodies Lyme serology lymska borelioza erythema migrans Borrelia burgdorferi sensu lato protitelesa IgM protitelesa IgG true false true Angleški jezik Slovenski jezik Članek v reviji 2026-09-16 07:58:34 2026-10-01 10:04:29 2026-10-02 04:26:45 0000-00-00 00:00:00 2026 0 0 16 str. iss. 5, art. 563 Vol. 14 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 616.9 2076-3271 10.3390/medsci14050563 290967811 RAZ_Bogovic_Petra_2026.pdf RAZ_Bogovic_Petra_2026.pdf 1 DED85D3F3837FFFB3D8508B90A9E16B6 9536d575fbde0e02e0c893e78de8761934fe8ce6fb9e8e7d7aad51db184b4cc2 3dd17470-b335-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=248110 https://www.mdpi.com/2076-3271/14/5/563 1 a0e41d81-b193-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=247719 Medicinska fakulteta 0 0 0