CSF kappa free light chains detection: comparison with oligoclonal bands in multiple sclerosis diagnosis
ECTRIMS Online Library. Sala A. 09/13/19; 278288; P1086
Arianna Sala
Arianna Sala
Contributions
Abstract

Abstract: P1086

Type: Poster Sessions

Abstract Category: Clinical aspects of MS - Diagnosis and differential diagnosis

A. Sala1, C. Nicolò2, M. Capobianco3, A. Balbo1, G. Viberti2, A. Bertolotto3

1SCDO Neurologia CRESM | Neurobiology Laboratory, Auo S. Luigi Hospital, Orbassano (TO), 2SCDO Laboratorio Analisi, Auo S. Luigi Hospital, Orbassano, 3SCDO Neurologia CRESM, Auo S. Luigi Hospital, Orbassano (TO), Italy

Objectives: To compare isoelectric focusing and immunoblotting (IEF) and Kappa free light chains (FLCk) INDEX (IFLCk) techniques for differential diagnosis in demyelinating diseases.
Background: Detection of CSF oligoclonal bands (OCB) by IEF is time consuming and operator dependent. Recently, CSF Kappa free light chains (FLCks) detection has been proposed as a replacement of IEF.
Design and Methods: FLCk, FLCl, IgG, albumin (turbidimetric assay) and OCB (IEF, 2 double blinded operators) were evaluated in 120 paired CSF and serum samples (65 demyelinating, 26 other neurological diseases (OND) and 28 other inflammatory neurological diseases (OIND)). The concurrence of results between two tests, i.e. (IEF +/) and (IEFLC +/-), the ratio between IFLCk and the number of OCB bands and their distribution were evaluated.
Results: The ROC curve for IFLCk with IEF has AUC = 0.96, whereas, AUC FLCl, was 0.84. IFLCk +/- and IEF +/- were significantly associated (p < 0.0001) with 10 exceptions: 4 IFLCk -/OCB+ (2 MS and 2 OIND) and 6 IFLCk +/OCB- (2 MS, 2 OIND, 2 OND) results. The IFLCk in the OCB- was lower (0.99 - 59.9) than in OCB+ (3-709) (p< 0.0001).
The number of OCB in the OCB+ samples was associated with IFLCk. In 53/65 demyelinating samples IFLCk was higher than OIND (n=9/28) and OND (n=5/26). 81% of MS samples have IFLCk+ (n=48/59) versus 83% with OCB+ (n=49/59).
Conclusions: The IFLCk results correlate with IEF in all groups and particularly in MS patients with automation and speed of handling as advantages. However, IEF is an irreplaceable diagnostic criterion of MS. Notably, 2/4 samples that were IFLCk-/ OCB+ in our study had a confirmed MS diagnosis. A stand-alone IFLCk determination would have prevented a correct diagnosis in these cases. Therefore, only IFLCk analysis maybe insufficient, rather it could be an additional evaluation for differential diagnosis in difficult cases.
Disclosure: Balbo: nothing to disclose
Sala: receiving funding from Biogen and Sanofi
Nicolò: nothing to disclose
Viberti: nothing to disclose
Capobianco: received personal honoraria for speaking or partecipating in advisory board from Almirall, Biogen, Novartis, Teva, Merck, Roche, Genzyme
Bertolotto: received personal honoraria for speaking or partecipating in advisory board from Almirall, Biogen, Novartis, Teva, Merck, Roche, Genzyme, Mylan.
Received research grant from Novartis, Biogen, Gemzyme

Abstract: P1086

Type: Poster Sessions

Abstract Category: Clinical aspects of MS - Diagnosis and differential diagnosis

A. Sala1, C. Nicolò2, M. Capobianco3, A. Balbo1, G. Viberti2, A. Bertolotto3

1SCDO Neurologia CRESM | Neurobiology Laboratory, Auo S. Luigi Hospital, Orbassano (TO), 2SCDO Laboratorio Analisi, Auo S. Luigi Hospital, Orbassano, 3SCDO Neurologia CRESM, Auo S. Luigi Hospital, Orbassano (TO), Italy

Objectives: To compare isoelectric focusing and immunoblotting (IEF) and Kappa free light chains (FLCk) INDEX (IFLCk) techniques for differential diagnosis in demyelinating diseases.
Background: Detection of CSF oligoclonal bands (OCB) by IEF is time consuming and operator dependent. Recently, CSF Kappa free light chains (FLCks) detection has been proposed as a replacement of IEF.
Design and Methods: FLCk, FLCl, IgG, albumin (turbidimetric assay) and OCB (IEF, 2 double blinded operators) were evaluated in 120 paired CSF and serum samples (65 demyelinating, 26 other neurological diseases (OND) and 28 other inflammatory neurological diseases (OIND)). The concurrence of results between two tests, i.e. (IEF +/) and (IEFLC +/-), the ratio between IFLCk and the number of OCB bands and their distribution were evaluated.
Results: The ROC curve for IFLCk with IEF has AUC = 0.96, whereas, AUC FLCl, was 0.84. IFLCk +/- and IEF +/- were significantly associated (p < 0.0001) with 10 exceptions: 4 IFLCk -/OCB+ (2 MS and 2 OIND) and 6 IFLCk +/OCB- (2 MS, 2 OIND, 2 OND) results. The IFLCk in the OCB- was lower (0.99 - 59.9) than in OCB+ (3-709) (p< 0.0001).
The number of OCB in the OCB+ samples was associated with IFLCk. In 53/65 demyelinating samples IFLCk was higher than OIND (n=9/28) and OND (n=5/26). 81% of MS samples have IFLCk+ (n=48/59) versus 83% with OCB+ (n=49/59).
Conclusions: The IFLCk results correlate with IEF in all groups and particularly in MS patients with automation and speed of handling as advantages. However, IEF is an irreplaceable diagnostic criterion of MS. Notably, 2/4 samples that were IFLCk-/ OCB+ in our study had a confirmed MS diagnosis. A stand-alone IFLCk determination would have prevented a correct diagnosis in these cases. Therefore, only IFLCk analysis maybe insufficient, rather it could be an additional evaluation for differential diagnosis in difficult cases.
Disclosure: Balbo: nothing to disclose
Sala: receiving funding from Biogen and Sanofi
Nicolò: nothing to disclose
Viberti: nothing to disclose
Capobianco: received personal honoraria for speaking or partecipating in advisory board from Almirall, Biogen, Novartis, Teva, Merck, Roche, Genzyme
Bertolotto: received personal honoraria for speaking or partecipating in advisory board from Almirall, Biogen, Novartis, Teva, Merck, Roche, Genzyme, Mylan.
Received research grant from Novartis, Biogen, Gemzyme

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