Serum Contactin-1 in CIDP: a cross-sectional study by Wieske, L, Martín-Aguilar, L, Fehmi, J, Lleixà, C, Koel-Simmelink, MJA, Chatterjee, M, van Lierop, Z, Killestein, J, Verhamme, C, Querol, L, Rinaldi, S, Teunissen, CE, Eftimov, F