Comparative analysis of albumin quotient and total CSF protein in immune-mediated neuropathies: a multicenter study on diagnostic implications

Tabea Seeliger; Stefan Gingele; Yunus Emre Güzeloglu; Lena Heitmann; Benjamin Lüling; Felix Kohle; Hannah Preßler; Frauke Stascheit; Jeremias Motte; Anna Lena Fisse; Thomas Grüter; Kalliopi Pitarokoili; Thomas Skripuletz

doi:10.3389/fneur.2023.1330484

Comparative analysis of albumin quotient and total CSF protein in immune-mediated neuropathies: a multicenter study on diagnostic implications

Front Neurol. 2024 Jan 9:14:1330484. doi: 10.3389/fneur.2023.1330484. eCollection 2023.

Authors

Affiliations

¹ Department of Neurology, Hannover Medical School, Hannover, Germany.
² Department of Neurology, St Josef Hospital, Ruhr University Bochum, Bochum, Germany.
³ Department of Neurology, Faculty of Medicine and University Hospital of Cologne, University of Cologne, Cologne, Germany.
⁴ Department of Neurology with Experimental Neurology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt Universität, Berlin, Germany.
⁵ Neuroscience Clinical Research Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.

Abstract

Introduction: Blood-cerebrospinal fluid (CSF) barrier dysfunction is pivotal for diagnosing immune-mediated neuropathies, especially in spinal nerve root inflammation. Typically, either total CSF protein or the CSF to serum albumin ratio (Q_Alb) is measured. Total CSF protein measurements have limitations, notably its fixed reference value regardless of age, in contrast to the age-dependent reference for Q_Alb. Our goal was to evaluate both markers in patients with immune-mediated neuropathies.

Methods: In our multicenter research, we collected retrospective CSF data from patients suffering from immune-mediated neuropathies across four German research centers. These parameters were analyzed in relation to their clinical characteristics.

Results: Out of 419 samples, 36 (8.6%) displayed a notable variation between total CSF protein and Q_Alb values. A detailed analysis revealed that patients displaying elevated Q_Alb but normal total CSF protein levels were significantly younger at disease onset (p = 0.01), at the time of diagnosis (p = 0.005), and when undergoing lumbar puncture (p = 0.001) compared to patients with elevated CSF protein and normal Q_Alb levels. These effects were especially evident for the subgroup of samples derived by female patients.

Discussion: Our work confirms the crucial role of Q_Alb in diagnosing immune-mediated neuropathies and particularly its efficacy as a marker for evaluating the blood-CSF barrier in patients with an earlier disease onset. Considering the significance of the albumin quotient, its assessment is especially advisable in younger patients of female sex to avoid missing a potential barrier dysfunction that might be falsely negative when using total protein.

Keywords: CSF; QAlb; barrier-dysfunction; blood-cerebrospinal fluid-barrier; immune-mediated neuropathies.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. TSe was funded by the Ellen-Schmidt-Scholarship of the Hannover Medical School. FK is supported by the Cologne Clinician Scientist Program (CCSP) / Faculty of Medicine / University of Cologne funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation; Project no. 413543196).