Intrathecal K free light chain synthesis in multiple sclerosis at clinical onset associates with local IgG production and improves the diagnostic value of cerebrospinal fluid examination.

BACKGROUND: The pathological significance and the diagnostic usefulness of intrathecal κ and λ free light chain (FLC) synthesis in Multiple Sclerosis (MS) are debated. METHODS: Paired cerebrospinal fluid (CSF) and serum specimens from 70 relapsing remitting MS (RRMS), 40 with and 30 without CSF restricted IgG Oligoclonal Band (IgGOB), and 37 from healthy controls (HC) were analyzed. IgG, IgM, κFLC and λFLC concentrations and indexes were evaluated. All RRMS performed MRI to estimate white and grey matter (WM) pathology. RESULTS: In HC, no intrathecal κ or λ FLC synthesis was found, and κFLC and λFLC Indexes were reciprocally correlated (r = 0.67, p < 0.001). In RRMS, intrathecal κFLC or λFLC synthesis was demonstrated in respectively 66% and 43% of the cases, the Qκ/λ ratio was significantly higher compared to HC (17.0 ±â€¯31.3 vs 0.79 ±â€¯0.20, p < 0.001) and the correlation between κFLC Index and λFLC Index was weak (r:0.38, p < 0.05). Intrathecal IgG synthesis was associated with κFLC Index (IgG Index: r2 = 0.53, ß = 0.73, p < 0.001; IgGLOC: r2 = 0.37, ß = 0.61, p < 0.001; IgGIF: r2 = 0.69, ß = 0.83, p < 0.001), but not with λFLC Index, while intrathecal IgM synthesis correlated with λFLC Index (IgM Index: r = 0.41, p < 0.001; IgMLOC: r = 0.34, p < 0.005; IgMIF: r = 0.45, p < 0.001), but not with κFLC Index. 26% of RRMS patients without CSF-restricted IgGOB had increased κFLCLOC. Finally, no associations were observed between any CSF and MRI parameters. CONCLUSIONS: The demonstration of intrathecal κFLC synthesis may further improve the diagnostic usefulness of CSF examination in RRMS. The marked increased in Qκ/λ further suggests a deregulated B-cell activation in MS pathology.

Short-course cefuroxime axetil therapy in the treatment of acute exacerbations of chronic bronchitis.

The efficacy and safety of a five-day course of cefuroxime axetil (250 mg b.d.) and a seven-day course of clarithromycin (250 mg b.d.) were compared in a large double-blind, randomised, multinational study involving 684 patients with acute exacerbations of chronic bronchitis. In an intent-to-treat analysis, the post-treatment clinical responses to each treatment were comparable (82%) and rates at follow-up were similar: 64% on cefuroxime axetil and 61% on clarithromycin. Pre-treatment pathogens were isolated from a total of 192 patients, Haemophilus influenzae being the most common. Overall pathogen eradication rates were similar for both treatments. Both treatments were well tolerated. In conclusion, a five-day course of cefuroxime axetil is clinically equivalent to a seven-day course of clarithromycin in the treatment of acute exacerbations of chronic bronchitis, and may have potential socioeconomic benefits.