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We studied the baseline expression level of 25 interferon-regulated genes (MxA, GPR3, IL17RC, ISG15, TRAIL, OASL, IFIT1, IFIT2, RSAD2, OAS3, IFI44L, TRIM22, IL10, CXCL10, STAT1, OAS1, OAS2, IFNAR1, IFNAR2, IFNβ, ISG20, IFI6, PKR, IRF7, USP18), recurrently proposed in the literature as predictive biomarkers of interferon-beta treatment response, in whole blood of 10 "responders" and 10 "non-responders" multiple sclerosis relapsing-remitting patients, retrospectively selected on the basis of stringent clinical criteria after a five years follow-up. However, we cannot confirm the predictive value of these candidate biomarkers.

Many multiple sclerosis (MS) patients treated with interferon-beta (IFNbeta) develop anti-IFNbeta antibodies (BAbs), which can interfere with both in vitro and in vivo bioactivity of the injected cytokine. Objective of this study was to correlate these measures. Among the 256 enrolled patients, 11 (4.3%) showed a significant inhibition of the IFNbeta activity in vitro, but no measurable BAbs. As a whole, in vivo bioactivity was inhibited in 9/11 (82%) of these patients. A minority of IFNbeta treated patients have a non-antibody mediated neutralising activity, which competitively inhibits the bioactivity both in vitro and in vivo.

identified follicle-like structures containing B cells close to vessels and PDGFRb+ cells forming a reticular network expanding to the parenchyma. To find out if these structures could provide sufficient homing locations which support plasma cells to become long-lived, we performed 5-ethynyl-2′-deoxyuridine (EdU)-pulse experiments. During pulse, EdU is incorporated by dividing cells like plasma blasts. The detection of EdU-positive cells up to seven weeks after pulse suggests that niches in the CNS can favor survival of plasma cells. We then further analyzed the migration of plasma blasts to the CNS. Since the sphingosine-1-phosphate analogon FTY720 (fingolimod) is known to suppress immune cell trafficking, we performed EAE experiments under accompanying treatment with the drug. FTY720treated animals were resistant to EAE in contrast to control animals. Immunofluorescent histological findings confirmed that no immune cell infiltration took place in FTY720-treated animals and the protective effect of FTY720 was not due to retention of immune cells in spleen, lymph nodes or bone marrow, as proved by quantitative FACS analysis. Control mice displayed massive immune cell infiltration in the perivascular space and parenchyma of the CNS, some evidently of long-lived phenotype. These results can be useful to evaluate the therapeutic potential of targeting plasma cells in chronic neuroinflammation.

The current study presents a western blot assay showing good sensitivity (81%) and specificity (97%) for detecting serum antibodies to Aquaporin-4 (AQP4) in patients with Neuromyelitis Optica (NMO). By using western blot, we were able, for the first time, to distinguish serum immunoreactivity against either of the two AQP4 isoforms, showing that antibodies recognizing the linear AQP4-M1 isoform are specific for NMO. Moreover, the high sensitivity and specificity of the western blot assay in detecting serum anti-AQP4 antibodies in NMO patients suggest that such auto-antibodies may be of linear nature, thus recognizing epitopes that are displayed in denatured protein.

This study is the first to evaluate biological response to first injections of interferon-beta (IFNbeta) in patients with multiple sclerosis. MxA mRNA was measured in 96 patients receiving IFNbeta-1a (Avonex, n=32), IFNbeta-1b (Betaferon, n=19), IFNbeta-1a (Rebif) 22 microg (n=30), or IFNbeta-1a 44 microg (n=15). Patients were analysed before, 3 and 24 h after the first injection, and 12 h after the second administration. Results showed that up-regulation was evident within 3 h of IFNbeta injection, peaked 12 h after injection, and progressively declined 24 h after administration. The cumulative responses were similar after a single administration, regardless of product/dose. Moreover, data indicate that the abolition of the biological activity detected during IFNbeta therapy is due to underlying phenomena (e.g., neutralizing antibodies), because all patients were constitutively responders to IFNbeta at treatment initiation.

Microglia expressing keratan sulfate (KS) was studied in normal central nervous system (CNS) and in rat neonatal brain cultures. The majority of KS+ cells are ramified microglia located in the brain parenchyma; positive cells were only exceptionally found in extraparenchymal structures. KS+ cells are ubiquitous, but their density is heterogeneous throughout the CNS. Serial sections incubated with anti-KS MAb and MAb against the complement receptor type 3 (CR3) revealed a higher number of CR3+ cells and double immunofluorescence showed the presence of two microglial populations: the first expressing both KS and CR3, the second expressing only CR3. Two sets of microglial cells were found also in neonatal rat microglial cultures where only a low percentage of microglial cells expressing CR3 was also KS+. KS was not induced by microglia activation.