Kappa free light chains is a valid tool in the diagnostics of MS: A large multicenter study. (July 2020)

• Record Type: Journal Article
• Authors: Leurs, CE; Twaalfhoven, HAM; Lissenberg-Witte, BI; van Pesch, V; Dujmovic, I; Drulovic, J; Castellazzi, M; Bellini, T; Pugliatti, M; Kuhle, J; Villar, LM; Alvarez-Cermeño, JC; Alvarez-Lafuente, R; Hegen, H; Deisenhammer, F; Walchhofer, LM; Thouvenot, E; Comabella, M; Montalban, X; Vécsei, L; Rajda, C; Galimberti, D; Scarpini, E; Altintas, A; Rejdak, K; Frederiksen, JL; Pihl-Jensen, G; Jensen, PEH; Khalil, M; Voortman, MM; Fazekas, F; Saiz, A; La Puma, D; Vercammen, M; Vanopdenbosch, L; Uitdehaag, BMJ; Killestein, J; Bridel, C; Teunissen, C;
• Is Part Of: Multiple sclerosis. Volume 26:Number 8(2020)
• Page Start: 912
• Page End: 923
• Publication Date: 2020-07
• Subjects: Multiple sclerosis -- KFLC -- OCB -- CSF -- biomarkers; Central nervous system -- Diseases -- Periodicals; Myelin sheath -- Diseases -- Periodicals; Inflammation -- Periodicals; Multiple sclerosis -- Periodicals; Central Nervous System Diseases -- Periodicals; Demyelinating Diseases -- Periodicals; Inflammation -- Periodicals; Multiple Sclerosis -- Periodicals; Système nerveux central -- Maladies -- Périodiques; Gaine de myéline -- Maladies -- Périodiques; Inflammation (Pathologie) -- Périodiques; Sclérose en plaques -- Périodiques; Electronic journals; 616.834005
• DOI: 10.1177/1352458519845844
• Languages: English
• ISSNs: 1352-4585

Abstract

Objective: To validate kappa free light chain (KFLC) and lambda free light chain (LFLC) indices as a diagnostic biomarker in multiple sclerosis (MS). Methods: We performed a multicenter study including 745 patients from 18 centers (219 controls and 526 clinically isolated syndrome (CIS)/MS patients) with a known oligoclonal IgG band (OCB) status. KFLC and LFLC were measured in paired cerebrospinal fluid (CSF) and serum samples. Gaussian mixture modeling was used to define a cut-off for KFLC and LFLC indexes. Results: The cut-off for the KFLC index was 6.6 (95% confidence interval (CI) = 5.2–138.1). The cut-off for the LFLC index was 6.9 (95% CI = 4.5–22.2). For CIS/MS patients, sensitivity of the KFLC index (0.88; 95% CI = 0.85–0.90) was higher than OCB (0.82; 95%CI = 0.79–0.85; p < 0.001), but specificity (0.83; 95% CI = 0.78–0.88) was lower (OCB = 0.92; 95% CI = 0.89–0.96; p < 0.001). Both sensitivity and specificity for the LFLC index were lower than OCB. Conclusion: Compared with OCB, the KFLC index is more sensitive but less specific for diagnosing CIS/MS. Lacking an elevated KFLC index is more powerful for excluding MS compared with OCB but the latter is more important for ruling in a diagnosis of CIS/MS.