Intrathecal kappa free light chains as markers for multiple sclerosis.

Cerebrospinal fluid (CSF) kappa free light chain (KFLC) index has been described as a reliable marker of intrathecal IgG synthesis to diagnose multiple sclerosis (MS). Our aims were: (1) to compare the efficiency of KFLC through different interpretation approaches in diagnosing MS. (2) to evaluate the prognostic value of KFLC in radiologically and clinically isolated syndromes (RIS-CIS). We enrolled 133 MS patients and 240 with other neurological diseases (93 inflammatory including 18 RIS-CIS, 147 non-inflammatory). Albumin, lambda free light chain (LFLC) and KFLC were measured in the CSF and serum by nephelometry. We included two groups of markers: (a) corrected for blood-CSF barrier permeability: immunoglobulin G (IgG), KFLC and LFLC indexes. (b) CSF ratios (not including albumin and serum-correction): CSF KFLC/LFLC, CSF KFLC/IgG, CSF LFLC/IgG. KFLC were significantly higher in MS patients compared to those with other diseases (both inflammatory or not). KFLC index and CSF KFLC/IgG ratio showed high sensitivity (93% and 86.5%) and moderate specificity (85% and 88%) in diagnosing MS. RIS-CIS patients who converted to MS showed greater KFLC index and CSF KFLC/IgG. Despite OB are confirmed to be the gold-standard to detect intrathecal IgG synthesis, the KFLC confirmed their accuracy in MS diagnosis. A "kappa-oriented" response characterizes MS and has a prognostic impact in the RIS-CIS population.

Kappa free light chains could predict early disease course in multiple sclerosis.

BACKGROUND: Cerebrospinal fluid (CSF) kappa free light chains (KFLC) have been suggested as quantitative alternative to oligoclonal bands (OB) in multiple sclerosis (MS) diagnosis. Despite OB have been associated to poor disease prognosis, little is known on KFLC in predicting MS early progression. Our aim is to evaluate the prognostic value of KFLC in a cohort of Italian MS patients. METHODS: 100 patients (64 females) underwent CSF analysis during their diagnostic MS work-up. We collected clinical/paraclinical features (gender, age at onset, clinical course, early MS treatments (within 1 year), gadolinium-enhancing (Gd+) lesions), calculated K index (ratio CSF-serum KFLC and albumin), and MS severity score (MSSS) at last follow up (minimum 1 year). Statistical analysis included Mann-Whitney descriptive analysis, Spearman correlation for independent samples, and linear regression for significant predictors. RESULTS: K index resulted a significant predictor for disability over time being higher in patients who developed greater MSSS. Accordingly, K index was also significantly increased in patients undergoing early versus delayed treatment (N = 50/100, p = 0.046). A similar role in predicting MS disability was confirmed for age at onset. No other factors were retained in our regression model. Of note, K index was not associated to known MS prognostic markers such as gender, age at onset, and Gd+ lesions (N = 31/96). CONCLUSION: Our study suggests KFLC as a CSF quantitative marker to predict early disability in MS (despite not being a substitute for OB).

Assessing Serum Concentrations of 25-Hydroxy-Vitamin D in North-Western Italy.

OBJECTIVES: Backgound: Most of the published studies on vitamin D levels in Italy have been performed in specific age- or disease- subgroups. Few data are available on the status of vitamin D in the adult general population. OBJECTIVE: We report on vitamin D levels of a large sample of adults from North-Western Italy. Association with age, sex, and season is also evaluated. PARTICIPANTS: 13,110 cases (24% men, 76% women; median age 67 [interquartile range, IQR, 56-77] years old) were collected in the North-Eastern of Piedmont (Italy). MEASUREMENTS: 25-OH-vitamin D levels were measured by chemiluminescent immunoassay. RESULTS: Median total vitamin D level was 19.9 ng/ml (IQR 11.2-28.8 ng/ml) with up to 3,592 (27.4%) and 10,185 (77.7%) subjects respectively below 12 and 30 ng/ml. Vitamin D levels were significantly higher in women than in men (20.5 vs 18.1 ng/ml; p<0.001), in summer than in winter (21.4 vs 18.5 ng/ml; p<0.001), and in individuals aged ≤45years or 46-64 years than in those older than 65 years (20.3 and 21.3 vs 18.8 ng/ml). The lowest mean vitamin D levels were reported during the winter season by men aged ≥65 years (14.7 ng/ml) and 46-64 years (16.8 ng/ml). Multivariate analysis confirmed that age (p<0.001), sex (p=0.002), season (p<0.001) and their interaction (p=0.03) were independently associated to vitamin D concentrations. CONCLUSIONS: This study clearly shows that the majority of adult Italian population, living in a sunny and highly urbanized area of North-Western Italy, have an important deficiency in vitamin D. However, these data must be interpreted with caution if considering the lack of standardization of vitamin D assays.