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. 2023 Jun 13;10(4):e200129.
doi: 10.1212/NXI.0000000000200129. Print 2023 Jul.

Frequency and Referral Patterns of Neural Antibody Studies During the COVID-19 Pandemic: Experience From an Autoimmune Neurology Center

Helena Ariño  1 , Raquel Ruiz García  1 , Beatriz Rioseras  1 , Laura Naranjo  1 , Eugenia Martinez-Hernandez  1 , Albert Saiz  1 , Francesc Graus  1 , Josep Dalmau  2
Affiliations

Frequency and Referral Patterns of Neural Antibody Studies During the COVID-19 Pandemic: Experience From an Autoimmune Neurology Center

Helena Ariño et al. Neurol Neuroimmunol Neuroinflamm. .

Erratum in

  • Missing Full Disclosures.
    [No authors listed] [No authors listed] Neurol Neuroimmunol Neuroinflamm. 2025 Jan;12(1):e200342. doi: 10.1212/NXI.0000000000200342. Epub 2024 Oct 30. Neurol Neuroimmunol Neuroinflamm. 2025. PMID: 39475708 Free PMC article. No abstract available.

Abstract

Objective: To determine whether the frequency of paraneoplastic or autoimmune encephalitis antibodies examined in a referral center changed during the COVID-19 pandemic.

Methods: The number of patients who tested positive for neuronal or glial (neural) antibodies during pre-COVID-19 (2017-2019) and COVID-19 (2020-2021) periods was compared. The techniques used for antibody testing did not change during these periods and included a comprehensive evaluation of cell-surface and intracellular neural antibodies. The chi-square test, Spearman correlation, and Python programming language v3 were used for statistical analysis.

Results: Serum or CSF from 15,390 patients with suspected autoimmune or paraneoplastic encephalitis was examined. The overall positivity rate for antibodies against neural-surface antigens was similar in the prepandemic and pandemic periods (neuronal 3.2% vs 3.5%; glial 6.1 vs 5.2) with a mild single-disease increase in the pandemic period (anti-NMDAR encephalitis). By contrast, the positivity rate for antibodies against intracellular antigens was significantly increased during the pandemic period (2.8% vs 3.9%, p = 0.01), particularly Hu and GFAP.

Discussion: Our findings do not support that the COVID-19 pandemic led to a substantial increase of known or novel encephalitis mediated by antibodies against neural-surface antigens. The increase in Hu and GFAP antibodies likely reflects the progressive increased recognition of the corresponding disorders.

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Conflict of interest statement

J. Dalmau holds patents for the use of NMDAR, GABAaR, GABAbR, and DPPX, as autoantibody tests. Drs. Dalmau and Graus hold a patent for the use of IgLON5 as an autoantibody test. The rest of the authors have no conflict of interest. Go to Neurology.org/NN for full disclosure.

Figures

Figure 1
Figure 1. Antibody Findings During the Study Period (2017–2022)
Donut pie chart illustrating the distribution of specific antigenic reactivities among 801 positive results. Numbers indicate the percentage of particular antigenic specificities among patients with neural antibodies.
Figure 2
Figure 2. Distribution of Antibody Categories Studied During Pre-COVID and COVID-19 Periods
Bar charts comparing the number of unique patients screened for NSA, ICA, and GSA antibodies during the pre-COVID (3 years) and COVID-19 (2 years) periods, showing also the number with positive results and the positivity rates. *p = 0.01. GSA = glial surface antigens; ICA = intracellular antigens; ns = not significant; NSA = neuronal surface antigens.
See this image and copyright information in PMC

References

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