Evidence map›Paper›PMID 41921124›Full record

ArticleNeurology2026

Diagnostic Value of the Kappa Free Light Chain Index to Distinguish MOGAD, NMOSD, and MS.

Apolline Tournier, Antoine Gavoille, Julie Pique, Michael Levraut, Eléonore Micoud, Elisabeth Maillart, Bertrand Audoin, Sarah Demortiere, Clemence Boutiere, Xavier Ayrignac and 22 more

Abstract readMulticenter Study
In one paragraph

Article in Neurology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

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2 · The registry

The trial behind it

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

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5 · Who and what money

Authors and funding

32 authors.

Apolline TournierService de Neurologie, Sclérose en Plaques, Pathologies de la Myéline et Neuro-inflammation, Hospices Civils de Lyon, Bron, France.
Antoine GavoilleService de Neurologie, Sclérose en Plaques, Pathologies de la Myéline et Neuro-inflammation, Hospices Civils de Lyon, Bron, France.ORCID 0000-0002-9118-0849
Julie PiqueService de Neurologie, Sclérose en Plaques, Pathologies de la Myéline et Neuro-inflammation, Hospices Civils de Lyon, Bron, France.ORCID 0000-0002-1986-7945
Michael LevrautUnité de Recherche Clinique Cote d'Azur-UR2CA URRIS, Centre Hospitalier Universitaire de Nice, France.ORCID 0000-0002-5611-212X
Eléonore MicoudLaboratoire d'Immunologie, Hôpital E. Herriot, Hospices Civils de Lyon, France.ORCID 0009-0007-9106-1085
Elisabeth MaillartDepartment of Neurology, Centre de référence des maladies inflammatoires rares du cerveau et de la moelle (MIRCEM), Assistance Publique Hôpitaux de Paris, Hôpitaux Universitaires La Pitié Salpêtrière-Sorbonne, France.ORCID 0000-0001-7699-0328
Bertrand AudoinNeurology Department MICeME (Maladie Inflammatoire du Cerveau et de la Moelle Epinière), University Hospital of Marseille, AP-HM, France.ORCID 0000-0002-9860-7657
Sarah DemortiereNeurology Department MICeME (Maladie Inflammatoire du Cerveau et de la Moelle Epinière), University Hospital of Marseille, AP-HM, France.ORCID 0000-0002-8513-5443
Clemence BoutiereNeurology Department MICeME (Maladie Inflammatoire du Cerveau et de la Moelle Epinière), University Hospital of Marseille, AP-HM, France.ORCID 0009-0001-3119-8203
Xavier AyrignacDepartment of Neurology, Hôpital Gui de Chauliac, CHU de Montpellier, France.ORCID 0000-0003-3834-2981
José BoucrautCentre de Recherche en Neurobiologie-Neurophysiologie de Marseille (UMR 7286 CRN2M), France.ORCID 0000-0002-3471-7769
Alexandre JentzerDepartment of Immunology, CHU Montpellier, France.ORCID 0000-0002-0223-4359
Jonathan CironDepartment of Neurology, Centre de Ressources et Compétences Sclérose en Plaques, Toulouse University Hospital, France.ORCID 0000-0002-3386-6308
Chloe BostImmunology Laboratory, Centre Hospitalier Universitaire de Toulouse, France.
Nicolas CollonguesDepartment of Neurology, Strasbourg University Hospital, France.ORCID 0000-0002-3683-5582
Romain DeschampsDepartment of Neurology, Fondation A. De Rothschild, Paris, France.ORCID 0000-0001-6291-8771
Mikael CohenCRCSEP Neurologie Pasteur 2, CHU de Nice, Université Cote d'Azur, UMR2CA (URRIS), France.ORCID 0000-0002-3985-1297
Barbara Seitz-PolskiLaboratoire d'Immunologie, CHU de Nice, Université Côte d'Azur, France.ORCID 0000-0002-8913-5969
Eric ThouvenotDepartment of Neurology, Centre Hospitalier Universitaire Carémeau, Nîmes cedex 9, France.ORCID 0000-0001-8671-7747
Sanae SqualliLaboratoire de Biochimie (S.S.), Centre Hospitalier Universitaire de Nîmes, France.
Denis MaréchalService de Neurologie, CHRU Brest Site Hôpital la Cavale Blanche, Brest.
Pierre BrangerNeurology Department, Caen University Hospital, France.ORCID 0000-0002-4183-9502
Guido AhleService de Neurologie, Hôpital Pasteur, Hôpitaux civils de Colmar, France.ORCID 0000-0002-0877-2289
Helene ZephirUniversité de Lille, Inserm U1172, CHU de Lille, France.ORCID 0000-0003-4029-2012
Sandra VukusicService de Neurologie, Sclérose en Plaques, Pathologies de la Myéline et Neuro-inflammation, Hospices Civils de Lyon, Bron, France.ORCID 0000-0001-7337-7122
Frederic KlapczynskiService de Neurologie, CH de Meaux site Saint Faron, France.ORCID 0009-0003-8235-6667
David Axel LaplaudCHU de Nantes, Service de Neurologie, Inserm CR1064, Nantes cedex, France.ORCID 0000-0001-6113-6938
Claire GiannesiniDépartement de Neurologie, Paris.ORCID 0009-0007-3962-0337
Nicolas MéléINSERM U1266, Department of Neurology, GHU Paris Psychiatrie et Neurosciences, Sainte-Anne Hospital, Université Paris, France.ORCID 0000-0001-5390-401X
Thomas DrouetGHRE - Site Saint Malo Broussais, France.ORCID 0009-0003-3596-2701
Delphine SterlinDepartment of Immunology, Assistance Publique-Hôpitaux de Paris (AP-HP), Hôpital Pitié-Salpêtrière, France; and.ORCID 0000-0002-5993-687X
Romain MarignierService de Neurologie, Sclérose en Plaques, Pathologies de la Myéline et Neuro-inflammation, Hospices Civils de Lyon, Bron, France.ORCID 0000-0002-5967-2800

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND AND

objectivesThe differential diagnosis between aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD), myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), and multiple sclerosis (MS) can be complex. Kappa free light chain index (KFLC-Index) emerged as an effective biomarker for distinguishing patients with MS from patients with other conditions. The main aim of this study was to assess the diagnostic performance of KFLC-Index in differentiating MOGAD, AQP4-NMOSD, and MS and to compare it with CSF-restricted oligoclonal bands (OCB) performance.

methodsWe conducted a retrospective case-control study involving 18 French centers through our national NOMADMUS database. Patients were eligible if they received MOGAD or AQP4-NMOSD diagnosis and if OCB status and KFLC-Index levels were available or could be measured retrospectively. As a comparator, we included a group of patients with MS from the Lyon center.

resultsWe included 303 patients with 140 MOGAD, 37 AQP4-NMOSD, and 126 MS. The sex ratio F/M was 1/1 in the MOGAD group, 5/1 in the NMOSD group, and 4/1 in the MS group. The median age was 38 years in the MOGAD group, 52 in the NMOSD group, and 32 in the MS group. The median KFLC-Index (interquartile range) was the lowest in the MOGAD group (0.60 [0.33-2.09]) with 71% of undetectable CSF-KFLC, intermediate in the NMOSD group (8.85 [3.04-16.78]), and the highest in the MS group (49.90 [16.31-113.39]). KFLC-Index had very good diagnostic performance in differentiating MOGAD from MS (area under the curve [AUC] 0.93, 95% CI 0.9-0.96) with an optimal threshold of 5.7 (95% CI 4.74-6.85), a sensitivity of 0.89 (0.83-0.94), and a specificity of 0.89 (0.83-0.94). KFLC-Index had good performance in differentiating NMOSD from MS (AUC 0.82, 95% CI 0.74-0.88) and MOGAD from NMOSD (AUC 0.77, 95% CI 0.69-0.86). KFLC-Index did not significantly outperformed OCB in separating MOGAD from MS and NMOSD from MS; however, the combination of the 2 tests was more performant than used separately. DISCUSSION: KFLC-Index is a valuable tool in distinguishing MS from AQP4-NMOSD and MOGAD and provides additional information to that given by OCB. We suggest that KFLC-Index as an additional supporting criterion for the differential diagnosis between MOGAD and MS.

Indexed as

Immunoglobulin kappa-ChainsMultiple SclerosisMyelin Oligodendrocyte Glycoprotein Antibody-Associated DiseaseNeuromyelitis OpticaAdultAquaporin 4BiomarkersCase-Control StudiesDiagnosis, DifferentialFemaleHumansMaleMiddle AgedMyelin-Oligodendrocyte GlycoproteinOligoclonal BandsRetrospective StudiesAQP4 protein, humanAquaporin 4BiomarkersImmunoglobulin kappa-ChainsMyelin-Oligodendrocyte GlycoproteinOligoclonal Bands

Identifiers

PMID41921124
PMCPMC13051478

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