Figure 1

Kappa free light chain (KFLC), expressed through different interpretation approaches, in patients with radiological or clinically isolated syndrome (RIS-CIS) according to conversion to multiple sclerosis (MS) after a minimum follow up of one year. Mean values were: CSF KFLC/IgG ratio 71.5 (± SD 45.9) in RIS-CIS converted to MS versus 26.0 (± 28.8) in non-converted (p = 0.003); KFLC index 38.2 (± 63.5) versus 5.9 (± 10.8) (p = 0.03). Mean values were: CSF KFLC/IgG ratio 71.5 (± SD 45.9) in RIS-CIS converted to MS versus 26.0 (± 28.8) in non-converted (p = 0.003); KFLC index 38.2 (± 63.5) versus 5.9 (± 10.8) (p = 0.03). No difference in LFLC was found between RIS-CIS patients with and without conversion to MS. CSF KFLC/IgG ratio resulted more informative in detecting whose patients were at risk of convert to MS. In fact, RIS-CIS patients with elevated CSF KFLC/IgG ratio had a higher risk to convert to MS (hazard ratio, HR 1.05; 95% CI 1.01–1,10; p = 0.02). Conversely, regression was not significant for KFLC index (HR 1.07; 95% CI 0.99–1.16; p = 0.09).