Early development of anti-natalizumab antibodies in MS patients

The purpose of this study is to monitor the development of anti-natalizumab antibodies to evaluate their first appearance in multiple sclerosis patients, since their presence has been associated with a reduction in the efficacy of the treatment and an increase of adverse events. A total of 134 multiple sclerosis patients were included in the trial. Anti-natalizumab antibodies were monthly detected by ELISA up to the first year of treatment and subsequently, a determination was made at 18 months. 15.7% of the patients were positive, being 7.5% transiently positive and 8.2% persistently positive. The first appearance of anti-natalizumab antibodies occurred after the first month of treatment onset in 72% of positive patients; 18% did so after the second month, and 9.7% after the third month. Antibodies were never detected for the first time after the fourth infusion. The development of anti-natalizumab antibodies occurs very early after treatment onset. This observation should be considered when standardizing the follow up of patients treated with this drug in order to minimize the risks and optimize the treatment

Neutralizing antibodies against IFN beta in patients with multiple sclerosis: a comparative study of two cytopathic effect tests (CPE) for their detection

The purpose of this study is to monitor the development of anti-natalizumab antibodies to evaluate their first appearance in multiple sclerosis patients, since their presence has been associated with a reduction in the efficacy of the treatment and an increase of adverse events. A total of 134 multiple sclerosis patients were included in the trial. Anti-natalizumab antibodies were monthly detected by ELISA up to the first year of treatment and subsequently, a determination was made at 18 months. 15.7 % of the patients were positive, being 7.5 % transiently positive and 8.2 % persistently positive. The first appearance of anti-natalizumab antibodies occurred after the first month of treatment onset in 72 % of positive patients; 18 % did so after the second month, and 9.7 % after the third month. Antibodies were never detected for the first time after the fourth infusion. The development of anti-natalizumab antibodies occurs very early after treatment onset. This observation should be considered when standardizing the follow up of patients treated with this drug in order to minimize the risks and optimize the treatment

Natalizumab-immunogenicity evaluation in patients with infusion related events or disease exacerbations

IntroductionNatalizumab is a biologic drug for relapsing-remitting multiple sclerosis that may induce the generation of anti-drug antibodies in some patients. Anti-natalizumab antibodies (ANA) increase the risk of adverse events and reduce efficacy, being useful biomarkers for monitoring treatment response.MethodsRetrospective observational study including MS patients treated with natalizumab that experienced infusion-related events (IRE) or disease exacerbations (DE). ANA were tested by Elisa including a screening and a confirmation assay. Patients were further classified as transient (one positive result) or persistent (two or more positive results) ANA.ResultsA total of 1251 MS patients were included and 153 (12.3%) had ANA with at least one single point determination, which were more frequent among patients with IRE compared to those with DE (21,6% vs.10.8%) during the first six infusions. Two or more determinations ANA were performed in 184 patients, being 31.5% permanently positive and 7.1% transiently positive. Interestingly, 26.1% of patients that experienced DE had persistent ANA, while 2.6% were transient. In contrast, 43% of patients with IRE had persistent ANA, and 9.3% had transient antibodies. Patients with persistent antibodies had more frequently high levels at the first sampling compared to patients with transient ANA.ConclusionReal-world evidence shows that the presence of ANA is behind an important percentage of patients treated with natalizumab that experience IRE, as well as DE but in a lower degree. These findings support the need to systematically evaluate ANA towards a personalized management of these patients to avoid undesired complications

TRAIL and TRAIL receptors splice variants during long-term interferon β treatment of patients with multiple sclerosis: evaluation as biomarkers for therapeutic response

Objective We aimed to assess the effects of interferon β (IFNβ) treatment on the expression of the splice variants of the Tumour necrosis factor-Related Apoptosis Inducing Ligand (TRAIL) and its receptors in different cell subpopulations (CD14+, CD4+ and CD8+) from patients with multiple sclerosis (MS), and to determine whether this expression discriminated responders from non-responders to IFNβ therapy. Methods We examined mRNA expression of the TRAIL and TRAIL receptors variants in patients with MS, at baseline and after one year of IFNβ therapy, according to responsiveness to this drug. Results Long-term therapy with IFNβ increased the expression of TRAIL-α in T cell subsets exclusively from responders and decreased the expression of the isoform 2 of TRAILR-2 in monocytes from responders as well as non-responders. Lower expression of TRAIL-α, and higher expression of TRAIL-β in monocytes and T cells, was found before the onset of IFNβ therapy in patients who will subsequently become responders. Baseline expression of TRAILR-1 was also significantly higher in monocytes and CD4+ T cells from responders. Conclusions The present study shows that long-term IFNβ treatment has a direct influence on TRAIL-α and TRAILR-2 isoform 2 expression. Besides, receiver operating characteristic analysis revealed that the baseline expression of TRAIL-α in monocytes and T cells, and that of TRAILR-1 in monocytes and CD4+ T cells, showed a predictive value of the clinical response to IFNβ therapy, pointing to a role of TRAIL system in the mechanism of action of IFNβ in MS that will need further investigation

Killer-cell immunoglobulin-like receptor expression on lymphocyte subsets in multiple sclerosis patients treated with interferon-β: evaluation as biomarkers for clinical response

Background: Both the adaptative and the innate immune systems interplay in multiple sclerosis (MS) pathogeny. Killer-cell immunoglobulin-like receptors (KIRs) are key regulators of the immune response, with activating and inhibitory isoforms. Objective: In this study we analysed whether the expression of KIR isoforms is implicated in MS pathogenesis and in the therapeutic response to interferon (IFN)-β. Methods: Peripheral blood samples were collected from 78 IFN-β-treated MS patients and 46 healthy controls (HC). KIR expression was evaluated by flow cytometry on natural killer (NK) and T cells. Results: The expression of KIRs on NK cells and T lymphocytes did not differ between MS patients and HC. IFN-β therapy decreased the expression of KIR2DL1/2DS1 and increased that of KIR2DL2/3 on NK cells. This therapy also reduced KIR2DL1/2DS1, KIR2DL2/2DL3 and KIR3DL2 expression on CD8(+) T cells. The baseline evaluation of the percentage of circulating CD16(+) NK cells was predictive of the clinical response to IFN-β; however, response to this therapy did not appear related to KIR expression. Conclusions: This study shows that expression of KIR isoforms on NK and T lymphocytes correlated in different ways with IFN-β therapy, suggesting that KIR dynamics may be associated with the pathways involved in the mechanisms of action of IFN-β

Activation of the JAK-STAT Signaling Pathway after In Vitro Stimulation with IFN beta in Multiple Sclerosis Patients According to the Therapeutic Response to IFN beta

Interferon beta (IFNß) is a common treatment used for multiple sclerosis (MS) which acts through the activation of the JAK-STAT pathway. However, this therapy is not always effective and currently there are no reliable biomarkers to predict therapeutic response. We postulate that the heterogeneity in the response to IFNß therapy could be related to differential activation patterns of the JAK-STAT signaling pathway. Our aim was to evaluate the basal levels and the short term activation of this pathway after IFNß stimulation in untreated and IFNß treated patients, as well as according to therapeutic response. Therefore, cell surface levels of IFNAR subunits (IFNAR1 and IFNAR2) and the activated forms of STAT1 and STAT2 were assessed in peripheral blood mononuclear cells from MS patients by flow cytometry. Basal levels of each of the markers strongly correlated with the expression of the others in untreated patients, but many of these correlations lost significance in treated patients and after short term activation with IFNß. Patients who had undergone IFNß treatment showed higher basal levels of IFNAR1 and pSTAT1, but a reduced response to in vitro exposure to IFNß. Conversely, untreated patients, with lower basal levels, showed a greater ability of short term activation of this pathway. Monocytes from responder patients had lower IFNAR1 levels (p = 0.039) and higher IFNAR2 levels (p = 0.035) than non-responders just after IFNß stimulation. A cluster analysis showed that levels of IFNAR1, IFNAR2 and pSTAT1-2 in monocytes grouped 13 out of 19 responder patients with a similar expression pattern, showing an association of this pattern with the phenotype of good response to IFNß (p = 0.013)

Development and validation of an ELISA for quantification of soluble IFN-β receptor: assessment in multiple sclerosis

Aim: The soluble isoform of the IFN-β receptor (sIFNAR2) can bind IFN-β and modulate its activity, although its role in autoimmune diseases remains unknown. Methods: A recombinant human sIFNAR2 protein was cloned, expressed and purified after which we developed and validated an ELISA for its quantification in human serum. Serum sIFNAR2 were assessed in multiple sclerosis (MS) patients and healthy controls. Results: The ELISA has a dynamic range of 3.9-250 ng/ml and a detection limit of 2.44 ng/ml. Serum sIFNAR2 were significantly lower in untreated-MS patients than in healthy controls. Conclusion: The ELISA is suitable for quantification of sIFNAR2 in serum and should facilitate the study of sIFNAR2 in neuroimmunological diseases such as MS

The CD4+ T-cell subset lacking expression of the CD28 costimulatory molecule is expanded and shows a higher activation state in multiple sclerosis.

Multiple sclerosis (MS) is a chronic debilitating disease, in which T-cells are considered to play a pivotal role. CD28 is the quintessential costimulatory molecule on T-cells and its expression declines progressively with repeated stimulations, leading to the generation of CD28− T-cells. Our aim was to examine whether CD4+CD28- T cells were enriched in MS patients, and characterize the phenotype of this subset in MS patients and healthy controls (HC). All these changes could provide these CD4+CD28- T cell characteristics that might be involved in the pathogenesis of MS, turning this T-cell subset into a potential target for future therapeutic strategies

HLA class II alleles in patients with multiple sclerosis in the Biscay province (Basque Country, Spain)

Genetic susceptibility to multiple sclerosis (MS) is associated with genes of the major histocompatibility complex, particularly with the HLA DRB1*1501-DQA1*0102-DQB1*0602 haplotype in Caucasians. To investigate the association of DRB1, DQA1 and DQB1 alleles and haplotypes with MS in Biscay, Basque Country, northern Spain, we examined 197 patients and 200 regionally matched controls. High resolution HLA class II typing was performed by polymerase chain reaction followed by sequence-specific oligonucleotide probe hybridization. Several alleles were overrepresented in MS patients compared with those of controls: DRB1*0402, DRB1*1303, DRB1*1501, DQA1*0102, DQB1*0301, and DQB1*0602. DQB1*0602 was the only potentially predisposing allele for MS that withstood Bonferroni correction and maintained the association in a logistic regression model. On the other hand, several alleles showed lower frequencies in the MS group: DRB1*0101, DQA1*0101, DQB1*0303, and DQB1*0501, but only DRB1*0101 and DQB1*0303 maintained a negative association with the disease in the regression analysis. Three haplotypes were identified as potentially predisposing for MS in our population: DRB1*1501-DQA1*0102-DQB1*0602, DRB1*0402-DQA1*0301-DQB1*0302, and HLA-DRB1*013-DQA1*05-DQB1*0301. Additionally, three haplotypes associated with a lower risk for MS were identified, exhibiting DRB1*0101-DQA1*0101-DQB1*0501 the strongest negative association with MS [12% in controls vs. 3.8% in MS, Pc = 0.00047, OR = 0.290 (95%CI = 0.160–0.528)], and suggesting, therefore, a putative protective role for this haplotype in the population under study