Mechanisms of IVIG Efficacy in Chronic Inflammatory Demyelinating Polyneuropathy

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common treatable acquired chronic polyneuropathy. Corticosteroids, plasmapheresis and intravenous immunoglobulins (IVIG) have been shown to be effective in randomized controlled clinical trials and IVIG is widely used as a first-line initial and maintenance treatment for CIDP. Studies in animal models of autoimmune diseases indicated that the inhibitory Fc-gamma receptor FcγRIIB, expressed on myeloid cells and B cells, is required for the anti-inflammatory activity of IVIG. Summary: We found that untreated patients with CIDP, compared to demographically matched healthy controls, show lower FcγRIIB expression levels on naïve B cells and fail to upregulate or to maintain upregulation of FcγRIIB as B cells progress from the naive to the memory compartment. Furthermore, FcγRIIB protein expression is upregulated on B cells and monocytes following clinically effective IVIG therapy suggesting that impaired expression of the inhibitory FcγR in CIDP can, at least partially, be restored by IVIG treatment. In B cells, FcγRIIB transduces an inhibitory signal upon colligation with the B cell receptor, thereby preventing B cells with low affinity or self-reactive receptors from entering the germinal center and becoming IgG positive plasma cells. Our data suggest that this late B cell differentiation checkpoint is impaired in CIDP. Modulating FcγRIIB function might be a promising approach to efficiently limit antibody-mediated immunopathology in CID

EBNA1-specific T cells from patients with multiple sclerosis cross react with myelin antigens and co-produce IFN-γ and IL-2

Symptomatic primary Epstein-Barr virus (EBV) infection and elevated humoral immune responses to EBV are associated with an increased risk of developing multiple sclerosis (MS). We explored mechanisms leading to this change in EBV-specific immunity in untreated patients with MS and healthy virus carriers matched for MS-associated HLA alleles. MS patients showed selective increase of T cell responses to the EBV nuclear antigen 1 (EBNA1), the most consistently recognized EBV-derived CD4+ T cell antigen in healthy virus carriers, but not to other EBV-encoded proteins. In contrast, influenza and human cytomegalovirus–specific immune control was unchanged in MS. The enhanced response to EBNA1 was mediated by an expanded reservoir of EBNA1-specific central memory CD4+ T helper 1 (Th1) precursors and Th1 (but not Th17) polarized effector memory cells. In addition, EBNA1-specific T cells recognized myelin antigens more frequently than other autoantigens that are not associated with MS. Myelin cross-reactive T cells produced IFN-γ, but differed from EBNA1-monospecific cells in their capability to produce interleukin-2, indicative of a polyfunctional phenotype as found in controlled chronic viral infections. Our data support the concept that clonally expanded EBNA1-specific CD4+ T cells potentially contribute to the development of MS by cross-recognition of myelin antigens

Efficacy and safety of Privigen® in patients with chronic inflammatory demyelinating polyneuropathy: results of a prospective, single-arm, open-label Phase III study (the PRIMA study)

This prospective, multicenter, single-arm, open-label Phase III study aimed to evaluate the efficacy and safety of Privigen (R) (10% liquid human intravenous immunoglobulin [IVIG], stabilized with l-proline) in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Patients received one induction dose of Privigen (2g/kg body weight [bw]) and up to seven maintenance doses (1g/kg bw) at 3-week intervals. The primary efficacy endpoint was the responder rate at completion, defined as improvement of 1 point on the adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale. The preset success criterion was the responder rate being 35%. Of the 31 screened patients, 28 patients were enrolled including 13 (46.4%) IVIG-pretreated patients. The overall responder rate at completion was 60.7% (95% confidence interval [CI]: 42.41%-76.43%). IVIG-pretreated patients demonstrated a higher responder rate than IVIG-naive patients (76.9% vs. 46.7%). The median (25%-75% quantile) INCAT score improved from 3.5 (3.0-4.5) points at baseline to 2.5 (1.0-3.0) points at completion, as did the mean (standard deviation [SD]) maximum grip strength (66.7 [37.24] kPa vs. 80.9 [31.06] kPa) and the median Medical Research Council sum score (67.0 [61.5-72.0] points vs. 75.5 [71.5-79.5] points). Of 108 adverse events (AEs; 0.417 AEs per infusion), 95 AEs (88.0%) were mild or moderate in intensity and resolved by the end of study. Two serious AEs of hemolysis were reported that resolved after discontinuation of treatment. Thus, Privigen provided efficacious and well-tolerated induction and maintenance treatment in patients with CIDP

Impaired IFN-γ production and proliferation of NK cells in Multiple Sclerosis

NK cells are multicompetent lymphocytes of the innate immune system with a central role in host defense and immune regulation. Studies in experimental animal models of multiple sclerosis (MS) provided evidence for both pathologic and protective effects of NK cells. Humans harbor two functionally distinct NK-cell subsets exerting either predominantly cytotoxic (CD56dimCD16+) or immunoregulatory (CD56brightCD16−) functions. We analyzed these two subsets and their functions in the peripheral blood of untreated patients with relapsing-remitting MS compared with healthy blood donors. While ex vivo frequencies of CD56brightCD16− and CD56dimCD16+ NK cells were similar in patients and controls, we found that cytokine-driven in vitro accumulation and IFN-γ production of CD56brightCD16− NK cells but not of their CD56dimCD16+ counterparts were substantially diminished in MS. Impaired expansion of CD56brightCD16− NK cells was cell intrinsic because the observed effects could be reproduced with purified NK cells in an independent cohort of patients and controls. In contrast, cytolytic NK-cell activity toward the human erythromyeloblastoid leukemia cell line K562, the allogeneic CD4+ T cell line CEM and allogeneic primary CD4+ T-cell blasts was unchanged. Thus, characteristic functions of CD56brightCD16− NK cells, namely cytokine-induced NK cell expansion and IFN-γ production, are compromised in the NK cell compartment of MS patient

Design of TRUST, a non-interventional, multicenter, 3-year prospective study investigating an integrated patient management approach in patients with relapsing-remitting multiple sclerosis treated with natalizumab

Background: Natalizumab provides rapid and high-efficacy control of multiple sclerosis disease activity with long-term stabilization. However, the benefits of the drug are countered by a risk of developing progressive multifocal leukoencephalopathy in patients infected with the John Cunningham Virus. Close monitoring is required in patients with increased progressive multifocal leukoencephalopathy risk receiving natalizumab in the long-term for an optimal benefit-risk evaluation. Standardized high-quality monitoring procedures may provide a superior basis for individual benefit and risk evaluation and thus improve treatment decisions. The non-interventional study TRUST was designed to capture natalizumab effectiveness under real-life conditions and to examine alternate approaches for clinical assessments, magnetic resonance imaging monitoring and use of biomarkers for progressive multifocal leukoencephalopathy risk stratification. Methods/Design: TRUST is a non-interventional, multicenter, prospective cohort study conducted at approximately 200 German neurological centers. The study is intended to enroll 1260 relapsing-remitting multiple sclerosis patients with ongoing natalizumab therapy for at least 12 months. Patients will be followed for a period of 3 years, irrespective of treatment changes after study start. Data on clinical, subclinical and patient-centric outcomes will be documented in order to compare the effectiveness of continuous versus discontinued natalizumab treatment. Furthermore, the type and frequency of clinical, magnetic resonance imaging and biomarker assessments, reasons for continuation or discontinuation of therapy and the safety profile of natalizumab will be collected to explore the impact of a systematic patient management approach and its potential impact on patient outcome. Specifically, the role of biomarkers, the use of expert opinions, the impact of high-frequency magnetic resonance imaging assessment for early progressive multifocal leukoencephalopathy detection and the role of additional radiological and clinical expert advice will be explored. Discussion: TRUST was initiated in spring 2014 and enrollment is anticipated to be completed by mid 2016. Annual interim analyses will deliver continuous information and transparency with regard to the patient cohorts and the completeness and quality of data as well as closely monitor any safety signals in the natalizumab-treated cohort. The study’s results may provide insights into opportunities to improve the benefit-risk assessment in clinical practice and support treatment decisions

Efficacy and safety of IVIG in CIDP : combined data of the PRIMA and PATH studies

Intravenous immunoglobulin (IVIG) is a potential therapy for chronic inflammatory demyelinating polyneuropathy (CIDP). To investigate the efficacy and safety of the IVIG IgPro10 (Privigen) for treatment of CIDP, results from Privigen Impact on Mobility and Autonomy (PRIMA), a prospective, open-label, single-arm study of IVIG in immunoglobulin (Ig)-naive or IVIG pre-treated subjects (NCT01184846, n = 28) and Polyneuropathy And Treatment with Hizentra (PATH), a double-blind, randomized study including an open-label, single-arm IVIG phase in IVIG pre-treated subjects (NCT01545076, IVIG restabilization phase n = 207) were analyzed separately and together (n = 235). Efficacy assessments included change in adjusted inflammatory neuropathy cause and treatment (INCAT) score, grip strength and Medical Research Council (MRC) sum score. Adverse drug reactions (ADRs) and ADRs/infusion were recorded. Adjusted INCAT response rate was 60.7% in all PRIMA subjects at Week 25 (76.9% in IVIG pre-treated subjects) and 72.9% in PATH. In the pooled cohort (n = 235), INCAT response rate was 71.5%; median time to INCAT improvement was 4.3 weeks. No clear demographic differences were noticed between early (responding before Week 7, n = 148) and late responders (n = 21). In the pooled cohort, median change from baseline to last observation was -1.0 (interquartile range -2.0; 0.0) point for INCAT score; +8.0 (0.0; 20.0) kPa for maximum grip strength; +3.0 (1.0; 7.0) points for MRC sum score. In the pooled cohort, 271 ADRs were reported in 105 subjects (44.7%), a rate of 0.144 ADRs per infusion. This analysis confirms the efficacy and safety of IgPro10, a recently FDA-approved IVIG for CIDP, in a population of mainly pre-treated subjects with CIDP [Correction added on 14 March 2019 after first online publication: the INCAT response rate has been corrected.]

Complete Epstein-Barr virus seropositivity in a large cohort of patients with early multiple sclerosis

OBJECTIVE: To determine the prevalence of antibodies to Epstein-Barr virus (EBV) in a large cohort of patients with early multiple sclerosis (MS). METHODS: Serum samples were collected from 901 patients with a clinically isolated syndrome (CIS) or early relapsing-remitting multiple sclerosis (RRMS) participating in the German National MS cohort, a prospective cohort of patients with early MS with stringent inclusion criteria. Epstein-Barr nuclear antigen (EBNA)-1 and viral capsid antigen (VCA) antibodies were measured in diluted sera by chemiluminescence immunoassays (CLIAs). Sera of EBNA-1 and VCA antibody-negative patients were retested undiluted by an EBV IgG immunoblot. For comparison, we retrospectively analysed the EBV seroprevalence across different age cohorts, ranging from 0 to >80 years, in a large hospital population (N=16 163) from Berlin/Northern Germany. RESULTS: EBNA-1 antibodies were detected by CLIA in 839 of 901 patients with CIS/RRMS. Of the 62 patients without EBNA-1 antibodies, 45 had antibodies to VCA as detected by CLIA. In all of the remaining 17 patients, antibodies to EBV were detected by immunoblot. Altogether, 901 of 901 (100%) patients with CIS/RRMS were EBV-seropositive. EBV seropositivity increased with age in the hospital population but did not reach 100% in any of the investigated age cohorts. CONCLUSION: The complete EBV seropositivity in this large cohort of patients with early MS strengthens the evidence for a role of EBV in MS. It also suggests that a negative EBV serology in patients with suspected inflammatory central nervous system disease should alert clinicians to consider diagnoses other than MS

Treatment choices and neuropsychological symptoms of a large cohort of early MS

Objective To assess clinical characteristics, distribution of disease-modifying treatments (DMTs), and neuropsychological symptoms in a large cohort of patients with early-stage MS. Methods The German National MS Cohort is a multicenter prospective longitudinal cohort study that has recruited DMT-naive patients with clinically isolated syndrome (CIS) and relapsing-remitting MS (RRMS) since 2010. We evaluated their baseline characteristics and the prevalence of neuropsychological symptoms. Results Of 1,124 patients, with a 2.2: 1 female-to-male ratio and median age at onset of 31.71 years (interquartile range [IQR]: 26.06-40.33), 44.6% and 55.3% had CIS and RRMS, respectively. The median Expanded Disability Status Scale (EDSS) score at baseline was 1.5 (IQR: 1.0-2.0). A proportion of 67.8% of patients started DMT after a median time of 167.0 days (IQR 90.0-377.5) since the first manifestation. A total of 64.7% and 70.4% of the 762 patients receiving early DMT were classified as CIS and RRMS, respectively. Fatigue, depressive symptoms, and cognitive dysfunction were detected in 36.5%, 33.5%, and 14.7% of patients, respectively. Conclusion Baseline characteristics of this large cohort of patients with early, untreated MS corroborated with other cohorts. Most patients received early DMT within the first year after disease onset, irrespective of a CIS or RRMS diagnosis. Despite the low EDSS score, neuropsychological symptoms affected a relevant proportion of patients

IL-17+ CD8+ T cell suppression by dimethyl fumarate associates with clinical response in multiple sclerosis

IL-17-producing CD8+ (Tc17) cells are enriched in active lesions of patients with multiple sclerosis (MS), suggesting a role in the pathogenesis of autoimmunity. Here we show that amelioration of MS by dimethyl fumarate (DMF), a mechanistically elusive drug, associates with suppression of Tc17 cells. DMF treatment results in reduced frequency of Tc17, contrary to Th17 cells, and in a decreased ratio of the regulators RORC-to-TBX21, along with a shift towards cytotoxic T lymphocyte gene expression signature in CD8+ T cells from MS patients. Mechanistically, DMF potentiates the PI3K-AKT-FOXO1-T-BET pathway, thereby limiting IL-17 and RORγt expression as well as STAT5-signaling in a glutathione-dependent manner. This results in chromatin remodeling at the Il17 locus. Consequently, T-BET-deficiency in mice or inhibition of PI3K-AKT, STAT5 or reactive oxygen species prevents DMF-mediated Tc17 suppression. Overall, our data disclose a DMF-AKT-T-BET driven immune modulation and suggest putative therapy targets in MS and beyond