Prognostic value of kappa free light chains determination in first-ever multiple sclerosis relapse

Given its highly variable clinical course, an unmet need for objective prognostic assessment in Multiple Sclerosis (MS) persists. In this work, we suggest that CSF kappa free light chains (KFLC) determination at first relapse may provide insight into future disease activity and disability worsening. We quantified KFLC by nephelometry in paired CSF/serum samples of 28 patients, collected within one month of first-ever MS relapse, and explored correlations with clinical data on disease activity, retrospectively registered across a median follow-up time of 79 months. We documented KFLC ratio (CSF-FKLC/Serum-KFLC) as an independent predictor of second relapse occurrence and disability worsening at follow-up, in this cohort.