Author Of 4 Presentations
LB1240 - A kappa free light chain index of 6.6 represents an alternative to positive oligoclonal bands in the 2017 McDonald criteria (ID 2125)
- G. Arrambide
- C. Espejo
- R. Dieli
- C. Auger
- M. Castillo
- M. Rodriguez-Barranco
- P. Carbonell-Mirabent
- J. Río
- J. Castilló
- A. Vidal-Jordana
- Í. Galán
- C. Nos
- M. Comabella
- B. Rodríguez-Acevedo
- L. Midaglia
- A. Zabalza
- A. Cobo Calvo
- P. Tagliani
- S. Cárdenas-Robledo
- J. Sastre-Garriga
- A. Rovira
- M. Hernández-González
- X. Montalban
- M. Tintore
Oligoclonal bands (OB) are part of the 2017 McDonald criteria but their determination is rater-dependent. Kappa free light chains (KFLC) are determined quantitatively and could be an alternative to OB, but a vendor-specific index cut-off is needed.
To compare the proportion of patients with clinically isolated syndromes (CIS) and positive OB and a KFLC index equal or greater than 6.6 (KFLC-6.6, Leurs CE Mult Scler 2020) or 10.61 (KFLC-10.61, Gaetani L J Neuroimmunol 2020). To compare the diagnostic properties of OB, KFLC-6.6 and KFLC-10.61 for 2nd attack and 2017 MRI dissemination in space (DIS) and time (DIT).
MRIs were obtained 3-5 months after the CIS, at 1 year and every 5 years. OB were determined by isoelectric focusing combined with immunoblotting. We selected 228 patients with sufficient data to assess DIS and DIT, OB determination and enough remnant frozen samples to measure KFLC by turbidimetry (Optilite, The Binding Site). We compared the proportion of patients with positive OB, KFLC-6.6 and KFLC-10.61 and the 3-year diagnostic properties for the following outcomes: 2nd attack (n=179) and MRI DIS and DIT (n=192).
Of all patients, 146 (64.0%) had OB, 147 (65.5%) KFLC-6.6 and 137 (60.1%) KFLC-10.61. In total, 130 (57.0%) had OB and KFLC-6.6, 16 (7.0%) only OB, 17 (7.5%) only KFLC-6.6 and 65 (28.5%) had neither. As for OB and KFLC-10.61, 122 (53.5%) had both, 24 (10.5%) only OB, 15 (6.6%) only KFLC-10.61 and 67 (29.4%) had neither. At baseline, the criteria were fulfilled by patients with OB, KFLC-6.6 and KFLC-10.61 as follows: DIS 109/135 (80.7%), 114 (84.4%) and 106 (78.5%); DIT 70/87 (80.5%), 78 (89.7%) and 74 (85.1%); DIS plus DIT 64/78 (81.2), 71 (91.0%) and 67 (85.9); DIS plus OB 109 (100.0%), 101 (92.7%) and 94 (86.2); and McDonald 111/130 (85.4%), 113 (86.9%) and 106 (81.5%). The diagnostic properties of OB, KFLC-6.6 and KFLC-10.61 for 2nd attack were sensitivity 77.8, 85.6 and 78.0; specificity 44.9, 48.3 and 51.7; and accuracy 61.5, 67.0 and 65.4. Results for MRI DIS plus DIT were sensitivity 81.8, 87.9 and 82.6; specificity 66.7, 70.0 and 73.3; and accuracy 77.1, 82.3 and 79.7.
KFLC-10.61 had the greatest specificity and KFLC-6.6 the best overall diagnostic properties. The results were probably due to the higher proportion of positive KFLC patients with DIT compared to those with positive OB, suggesting KFLC-6.6 could be used as an alternative to OB in the McDonald criteria.
P0020 - A down-regulation of the type I interferon signaling pathway is associated with the response to teriflunomide in multiple sclerosis. (ID 1584)
Teriflunomide is an oral first-line treatment of patients with relapsing-remitting multiple sclerosis (RRMS) that has been shown to decrease clinical relapses, reduce brain magnetic resonance imaging (MRI) activity, and slow progression of disability. However, the drug exhibits only limited effectiveness and does not produce clinical benefits in a proportion of MS patients.
We aimed to identify differentially expressed genes and cellular pathways associated with the responder and non-responder status in RRMS patients treated with teriflunomide by means of RNA sequencing (RNA-seq).
RRMS patients treated with teriflunomide were classified into those with No evidence of disease activity (NEDA 3) and those with EDA after 12 months of treatment. Eleven responders [8 females; mean age (standard deviation): 45.8 years (4.5)] and 10 non-responders [8 females; 41.8 years (10.3)] were included in the study. RNA-seq was performed in RNA samples isolated from peripheral blood mononuclear cells before and after 12 months of teriflunomide treatment. 100 bp, paired-end RNA sequencing was performed by using DNAseqTM Technology. Comparative analysis of differentially expressed genes between responders and non-responders was performed at baseline and after 12 months of treatment. Pathway analysis was based on KEGG database using statistically significant genes.
Pathway analysis revealed the type I interferon (IFN) signaling pathway as the most significantly associated with the responder phenotype after 12 months of teriflunomide treatment (p<0.0001). In this context, expression levels for genes known to be predominantly or selectively induced by type I IFNs such as SP100, ZBP1, IFI27, ISG20, IFITM1, IFITM2, MX1, STAT1, PARP9, IFI35, RGS1, RSAD2, IFI44L, IRF1, DDX58, IFI6, IFIT1 and IFIT5 were significantly reduced by the effect of teriflunomide after 12 months of treatment in responders compared to non-responders. At baseline, expression levels for type I IFN genes were similar between responders and non-responders.
Type I IFNs are known to activate dendritic cells, enhance humoral immunity, and favor Th1 immune responses. A down-regulation of type I IFN genes after 12 months of treatment may explain the beneficial effect of teriflunomide in responders. Mechanistic studies are currently underway to investigate the functional implication of the type I interferon signaling pathway in the response to teriflunomide.
P0678 - Selected Clostridia strains increase responses related to interferon beta signaling and butyrate levels in experimental autoimmune encephalomyelitis (ID 1576)
MS patients show a significant decrease in Clostridia clusters XIVa and IV in the gut microbiome. We have previously reported that a mixture of human gut-derived 17 Clostridia strains, which belong to Clostridia clusters XIVa, IV, and XVIII, improved the clinical outcome of experimental autoimmune encephalomyelitis (EAE) mice as a therapeutic approach. The clinical improvement was related to lower histopathological signs in the central nervous system (CNS) and to an enhanced immunoregulatory response of regulatory T (Treg) cells in the periphery.
We aimed to study in depth the mechanism of action of the treatment with Clostridia strains in Experimental Autoimmune Encephalomyelitis
In two independent experiments, myelin oligodendrocyte glycoprotein (MOG)-immunized C57BL6/J mice were treated with Clostridia strains (n=15) or vehicle (n=15) via oral gavage from 13-14 days post-immunization (dpi) until the end of the experiment (28 dpi). At 28 dpi, spleens and spinal cords were collected to perform transcriptome studies and serum was collected to determine the short-chain fatty acid (SCFA) levels. In three independent experiments, MOG-immunized C57BL6/J mice were orally gavaged with butyrate (n=19) or vehicle (n=18) from 13-15 dpi until 28 dpi. Then, spinal cords were collected to perform histopathological studies.
Therapeutic administration of Clostridia strains ameliorated EAE clinical course, as previously reported. Transcriptome studies revealed increased antiinflammatory responses related to interferon beta in the periphery and lower activation, differentiation, and proliferation of immune cells in the CNS. Higher levels of the immunomodulatory SCFA butyrate were detected in the serum of Clostridia-treated mice. Therefore, we studied the therapeutic effect of butyrate on EAE. We observed a slight therapeutic impact on EAE clinical course that was connected to a noticeable improve concerning axonal damage and a tendency to lower demyelination, inflammation, and astrogliosis in the CNS.
Clostridia strains perform their therapeutic effect on EAE enhancing the immunoregulatory response of Treg cells and antiinflammatory responses related to interferon beta signaling pathway in the periphery. The beneficial outcome exerted by the oral administration of the 17 Clostridia strains was not exclusively related to the production of the SCFA butyrate.
P0972 - Impact of age on the immune system and the central nervous system in experimental autoimmune encephalomyelitis (ID 1598)
The debut of multiple sclerosis (MS) at an older age associates with increased risk of presenting a primary progressive form, an earlier conversion to the secondary progressive form and a greater disability accumulation. These facts could be due to the impact of immunosenescence (ISC) in elderly MS patients.
To study the impact of aging on clinical outcome, histopathology of the central nervous system (CNS) and peripheral immune system in experimental autoimmune encephalomyelitis (EAE).
8-week old and 40-week old C57BL/6JRccHsd female mice immunized with MOG35-55 were used. Histopathological and immunological studies were performed in non-immunized mice (basal) and in EAE mice 14 days post-immunization (dpi) and 28 dpi. Immunofluorescence staining was performed in spinal cords to evaluate T cell infiltration (CD3), demyelination (MBP), reactive astrogliosis (GFAP), reactive microglia (LEA) and axonal damage (SMI32). Immune cell subsets and intracellular cytokines were analyzed in splenocytes by flow cytometry. Polyclonal and MOG-specific capacity of proliferation were assessed in splenocytes. Differences between young and old mice in each EAE time point and along disease course were analyzed.
Old mice (OM) showed a more severe EAE clinical outcome compared to young ones. Different patterns along EAE course were observed for inflammation, axonal damage and reactive microglia (increased at 28 dpi in OM) as well as for reactive astroglia (decreased at 14 dpi in OM) in the CNS. The adaptive immune cell subsets showed more age-related changes in OM, presenting a different pattern along EAE course: naïve CD8+ T cells (decreased basally and at 28 dpi), effector/effector memory CD4+PD1+ T cells (increased basally and at 14 dpi), regulatory CD39+ T cells (increased basally and at 14 dpi) and MHC-II+ B cells (increased basally and at 14 dpi). Regarding innate immune cells, immature NK cells increased and mature NK cells decreased along EAE course in OM, and NKT cells also presented a different pattern along EAE course (decreased basally and at 28 dpi in OM). Cytokine producing T cells were increased in OM. No differences were observed in splenocyte-proliferative capacity.
Aging has an impact on EAE outcome being more severe in old mice. Major changes take place in the CNS and in the adaptive immune cell subsets in the periphery. Altogether suggest that age modifies the immunopathogenic mechanisms of EAE.