Numerous studies have shown the diagnostic interest of cerebrospinal fluid kappa free light chains and kappa index in multiple sclerosis. However, large cohort studies are lacking and little is known about the correlation between kappa and lambda indexes and multiple sclerosis evidence disease activity. Therefore, this study plan to validate the kappa and lambda free light chains and indexes as diagnostic biomarker in multiple sclerosis and to correlate the concentration of kappa and lambda free light chains with clinical and radiological activity in a large cohort of patients.
Study Type
OBSERVATIONAL
Enrollment
1,500
Collection of cerebrospinal fluid kappa and lambda free light chains and indexes
Centre Hospitalier Universitaire de Clermont-Ferrand
Clermont-Ferrand, France
Centre Hospitalier Universitaire de Dijon
Dijon, France
Centre Hospitalier Universitaire de Grenoble
Grenoble, France
Centre Hospitalier Universitaire de Lille
Lille, France
Assistance Publique des Hôpitaux de Marseille
Marseille, France
Centre Hospitalier Universitaire de Montpellier
Montpellier, France
Centre Hospitalier Universitaire de Nantes
Nantes, France
Centre Hospitalier Universitaire de Nice
Nice, France
Centre Hospitalier Universitaire de Nîmes
Nîmes, France
Assistance Publique des Hôpitaux de Paris
Paris, France
...and 4 more locations
Measurement of cerebrospinal fluid (CSF) and serum kappa and lambda free light chains (KFLC and LFLC)
1. Measurement of cerebrospinal fluid (CSF) and serum KFLC and LFLC by a turbilimetric analyzer (data in mg/L) 2. Quantification of QKFLC and QLFLC (CSF FLC/serum FLC) in each group of patients 3. Compare median of QKFLC and QLFLC between groups
Time frame: 1 day
Measurement of cerebrospinal fluid (CSF) and serum albumin
1. Measurement of cerebrospinal fluid (CSF) and serum albumin by the same turbilimetric analyzer (data in mg/L) 2. Quantification of albumin quotient (AQ) (CSF albumin/serum albumin) in each group of patients
Time frame: 1 day
Evaluation of the diagnostic performances of KFLC and LFLC intrathecal synthesis biomarkers (K/L FLC index and K/L FLC intrathecal fraction (IF)) for multiple sclerosis
1. Calculation of KFLC intrathecal synthesis biomarkers: KFLC index = (CSF KFLC/serum KFLC) / AQ KFLC IF = (KFLC(loc)/CSF KFLC) x 100 with: KFLC(loc) = ((CSF KFLC/serum KFLC) / Qk(lim)) x serum KFLC and Qk(lim) = 3.27 x (AQ\^2 + 33)\^0.5 - 8.2 2. Calculation of LFLC intrathecal synthesis biomarkers: LFLC index = (CSF LFLC/serum LFLC) / AQ) LFLC IF = (LFLC(loc)/CSF LFLC) x 100 with: LFLC(loc) = ((CSF LFLC/serum LFLC) / Ql(lim)) x serum LFLC and Ql(lim) = 2.1138 x AQ\^0.865 3. Determination of diagnostic performances by ROC curve analysis and best cut-off values with the Younden index to calculate sensitivity, specificity and predictive values for MS diagnosis
Time frame: 1 day
Comparison of diagnostic performances of K/L FLC intrathecal synthesis biomarkers to oligoclonal bands (OCB) for multiple sclerosis
1. Identification of OCB status for each patient 2. Calculation of diagnostic performances of OCB (sensitivity, specificity and predictive values) for MS diagnostic 3. Comparison of diagnostic performances (sensitivity, specificity and predictive values) of OCB and K/L FLC intrathecal synthesis biomarkers for multiple sclerosis
Time frame: 1 day
Evaluation of clinical data that can alter KFLC and LFLC values
Identification of data that can be independtly associated with high or low CSF KFLC or LFLC values as potential bias in K/L FLC intrathecal synthesis biomarkers interpretation: * Gender * Age * Type of clinical demyelinating event (i.e. myelitis, optic neuritis...) * Immune modifying drug treatment ongoing during sampling * Underlying disease activity (measured by the presence of subacute clinical symptoms ongoing at sampling or gadolinium enhanced lesions within the last MRI status)
Time frame: 1 day
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