Evidence map›Paper›PMID 41501321›Full record

ArticleAnnals of clinical and translational neurology2026

Real-World Performance of CSF Kappa Free Light Chains in the 2024 McDonald Criteria.

Maya M Leibowitz, Ryan Cooper, Stefania Kaninia, Kathryn I Challis, Will Greenway, Maria Bonello, Mahmoud Elbahnasawi, Deborah T Shode, Dominika Gajdasik, Victor Iliev and 2 more

Abstract read
In one paragraph

Article in Annals of clinical and translational neurology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Guideline
  2. Review
  3. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Maya M LeibowitzClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Ryan CooperClinical Biochemistry, University Hospitals Dorset NHS Foundation Trust, Bournemouth, UK.
Stefania KaniniaClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Kathryn I ChallisClinical Immunology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
Will GreenwayClinical Immunology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
Maria BonelloClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Mahmoud ElbahnasawiClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Deborah T ShodeClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.
Dominika GajdasikThe Binding Site (Part of Thermo Fisher Scientific), Birmingham, UK.
Victor IlievThe Binding Site (Part of Thermo Fisher Scientific), Birmingham, UK.
Alison M E WhiteleggClinical Immunology, University Hospital Southampton NHS Foundation Trust, Southampton, UK.
Ian GaleaClinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK.ORCID 0000-0002-1268-5102

Funding

National Institute for Health and Care ResearchThe Binding Site (Part of Thermo Fisher Scientific)
6 · The paper itself

Abstract

objectiveKappa free light chains (KFLCs) in the cerebrospinal fluid (CSF) have a similar performance to CSF-restricted oligoclonal bands (OCB) for multiple sclerosis (MS) diagnosis. To help with implementation, we set out to resolve several remaining uncertainties: (1) performance in a real-world cohort and the 2024 McDonald criteria; (2) equivalence to OCB in the specific clinical scenario when demonstration of intrathecal immunoglobulin synthesis is essential for MS diagnosis; (3) which KFLC metric has the best diagnostic performance.

methodsA retrospective study of 740 cases was conducted, categorised into three groups: MS (2024 McDonald criteria), other neuroinflammatory disorders and non-inflammatory groups. CSF and serum KFLC and albumin were assayed with immunoturbidimetry. OCB status was assessed using isoelectric focusing. Eight KFLC metrics were tested: CSF KFLC, KFLC index, three population-based models of the upper limit for the CSF/serum kappa quotient corrected for CSF/serum albumin quotient, and their corresponding intrathecal fractions.

resultsThe KFLC index and the KFLC intrathecal fraction performed as well as OCB; no cases were missed when KFLC was mandatory to achieve a MS diagnosis. Intrathecal fraction computation improved the performance of the population-based models.

interpretationIn the setting of the 2024 McDonald criteria, KFLC metrics correcting for the CSF/serum albumin quotient were equivalent to OCBs. The intrathecal fraction provided no advantage over the KFLC index, which is simpler to compute. Importantly, the KFLC index can replace OCB when CSF positivity is essential for diagnosis. We provide an explanation for KFLC's comparable diagnostic performance despite its inability to identify CSF-only clones.

Indexed as

Immunoglobulin kappa-ChainsMultiple SclerosisOligoclonal BandsAdultFemaleHumansMaleMiddle AgedRetrospective StudiesImmunoglobulin kappa-ChainsOligoclonal Bandskappa light chainsmultiple sclerosisoligoclonal bands

Identifiers

PMID41501321
PMCPMC13251450

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.