Testing for Lyme borreliosis: could serology tell more?

Abstract

Purpose: Remnant antibodies might be prevalent in the general population, thus recognizing relevant seropositivity might be challenging. The sequential nature of the anti-Borrelia antibody response might be diagnostically utilized. We aimed to specify details which might potentially be useful in orientating the diagnostic schedule. Methods: We processed the sera of 1304 patients using a recombinant antigen-based ELISA between Aprils of 2017 and 2019. Seroreactivity (when coherent with the anamnestic data) was confirmed with a line immunoassay (LIA). ELISA testing (IgG and/or IgM) was reactive in 539 cases. 107 patients with persistent symptoms tested positive or borderline with IgG ELISA. Results: A significant difference was observed (Mann-Whitney U-test p=0.003) between the LIA scores of patients with characteristic (arthritis, acrodermatitis, neuropathy, other objective neurologic disorder; n=83; median LIA score: 16) and non-specific symptoms (entirely subjective complaints, other known disease, lone subfebrility, uveitis; n=24; median LIA score: 6). 101 of the 107 patients tested positive for IgG against any specific protein by LIA. Those with a LIA score reaching the group median of 15 (n=51) displayed strong anti-VlsE IgG positivity or a typical late IgG antibody (against p100, p18 or p39) more often than those below (88,2% vs. 30% and 100% vs. 38% respectively, Χ2 p<0.0001). Conclusions: Weak LIA positivity (especially anti-VlsE IgG) in combination with the lack of late antibodies in patients with persistent symptoms might suggest the presence of remnant antibodies and prompt scrupulous differential diagnosis.