Background and aim: For the laboratory diagnosis of Lyme borreliosis it is sometimes considered useful to obtain two or more blood samples to detect a change in specific IgG or IgM antibodies, either a rise suggesting a recent or ongoing infection or a decline suggestive of a previous infection. It is not easy to decide, whether a difference between two consecutive measurements of antibody reactivity suggests a clinically significant change in reactivity.
Methods: Register study of routine results using the quantitative results, for Borrelia IgG in Denmark and Sweden. In both laboratories the same VlsE-based assay was used (Liaison XL, Diasorin, Italy).
In the DK dataset there were 807 cases with only low values (negative <10 AU) in 1767 samples. 450 cases with 1132 samples, with at least 10 AU/ml were analysed to determine antibody reactivity over time.
In both DK and SE IgG changes occur 10 days or later after the first sample. A relative change in IgG antibody concentration >2 was considered significant. Cases with initially high AU/ml values rarely displayed subsequent increases in IgG reactivity. In cases with high IgG in the first sample the average concentration started to decline slowly after about 100 days. Some patients had more sharp declines, possibly suggesting some kind of down-regulation.
Graphical presentations of antibody dynamics will be shown.
Conclusion: Subpopulations with different initial antibody reactivity displayed different serological patterns over time. Cases with initially high IgG concentrations rarely displayed subsequent increases
|Periode||15. jun. 2022|