Multicentric evaluation of a specific intrathecal anti-Treponema pallidum IgG index as a diagnostic biomarker of neurosyphilis: results from a retro-prospective case-control study.

Details

Serval ID
serval:BIB_9F0E982EA4EF
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Multicentric evaluation of a specific intrathecal anti-Treponema pallidum IgG index as a diagnostic biomarker of neurosyphilis: results from a retro-prospective case-control study.
Journal
Sexually transmitted infections
Author(s)
Alberto C., Lambeng N., Deffert C., Breville G., Gayet-Ageron A., Lalive P., Calmy A., Coste A., Papadimitriou-Olivgeris M., Braun D., Lienhard R., Bosshard P.P., Fontao L., Toutous Trellu L.
ISSN
1472-3263 (Electronic)
ISSN-L
1368-4973
Publication state
Published
Issued date
19/02/2024
Peer-reviewed
Oui
Volume
100
Number
2
Pages
63-69
Language
english
Notes
Publication types: Journal Article
Publication Status: epublish
Abstract
The diagnosis of neurosyphilis (NS) lacks a true 'gold standard', making the diagnosis challenging while consequences of a misdiagnosis are potentially severe. The aim of this study was to evaluate the diagnostic performance of measuring an antibody index (AI) for the intrathecal synthesis of specific anti-Treponema pallidum (T. pallidum) IgG for the diagnosis of NS.
Specific anti-T. pallidum IgG were measured simultaneously in paired cerebrospinal fluid (CSF)-serum samples collected retrospectively and prospectively between 2007 and 2022, from patients suspected of NS, in Switzerland. An AI was calculated to account for blood-brain barrier integrity. Area under the receiver operating characteristic curve, sensitivity/specificity and positive/negative predictive values of AI test were estimated. Two NS definitions were used: NS1 included patients with NS suspicion presenting with neurological symptoms and/or acute neurosensory signs, and positive T. Pallidum Hemagglutinations Assay (TPHA)/T. pallidum particle agglutination assay (TPPA) serology and CSF-TPHA/TPPA ≥320, and either CSF-leucocytes >5 cells/mm <sup>3</sup> and/or CSF-protein >0.45 g/L and/or a reactive CSF-venereal disease research laboratory (VDRL)/rapid plasma reagin (RPR) test. NS2 included patients with suspected NS presenting with acute ocular and/or otologic symptoms, and positive TPHA/TPPA serology, and a favourable response to NS treatment. Controls were patients diagnosed with any other central nervous system (CNS) pathologies and with positive TPHA/TPPA serology.
The study included 71 NS (43 NS1 and 28 NS2) and 110 controls. With a threshold of ≥1.7, sensitivity and specificity of the specific AI test were 90.7% (CI 77.7 to 97.4) and 100% (CI 96.7 to 100.0), respectively, for NS1 and 14.3% (CI 4 to 32.7) and 100% (CI 96.7 to 100.0) for NS2. In patients suspected of NS with a CNS involvement (NS1 group), NS could be confirmed by the positivity of this specific AI.
Measurement of an intrathecal synthesis index of specific anti-T. pallidum IgG in patients with CSF inflammatory signs appears to be a valuable diagnostic test. However, in otic or ocular syphilis, presenting few CSF abnormalities, AI is not sufficient alone to confirm NS diagnosis.
Swiss Association of Research Ethics Committees number 2019-00232.
Keywords
Humans, Case-Control Studies, Retrospective Studies, Globus Pallidus, Neurosyphilis/cerebrospinal fluid, Syphilis, Immunoglobulin G, Antibodies, Bacterial, Biomarkers, Bacterial Infections, NEUROLOGY, SYPHILIS
Pubmed
Web of science
Create date
15/12/2023 15:29
Last modification date
27/02/2024 8:17
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