Alternative splicing of the TNFSF13B (BAFF) pre-mRNA and expression of the BAFFX1 isoform in human immune cells.

Human B cell activating factor (TNFSF13B, BAFF) is a tumor necrosis factor superfamily member. Binding its unique receptor (TNFRSF13C, BAFF-R) mediates gene expression and cell survival in B cells via activation of NFκB pathway. Furthermore, there is data indicating a role in T cell function. A functionally inhibitory isoform (ΔBAFF) resulting from the deletion of exon 3 in the TNFSF13B pre-RNA has already been reported. However, data on the complexity of post-transcriptional regulation is scarce. Here, we report molecular cloning of nine TNFSF13B transcript variants resulting from alternative splicing of the TNFSF13B pre-mRNA including BAFFX1. This variant is characterized by a partial retention of intron 3 of the TNFSF13B gene causing the appearance of a premature stop codon. We demonstrate the expression of the corresponding BAFFX1 protein in Jurkat T cells, in ex vivo human immune cells and in human tonsillar tissue. Thereby we contribute to the understanding of TNFSF13B gene regulation and reveal that BAFF is regulated through a post-transcriptional mechanism to a greater extent than reported to date.

Acetylcholine Receptor Antibody Titers and Clinical Course after Influenza Vaccination in Patients with Myasthenia Gravis: A Double-Blind Randomized Controlled Trial (ProPATIent-Trial).

BACKGROUND: It is a continuous matter of discussion whether immune activation by vaccination in general and Influenza vaccination in particular increases the risk for clinical deterioration of autoimmune diseases. This prospective study investigated the serological and clinical course of autoimmune Myasthenia gravis (MG) after a seasonal influenza vaccination. METHODS: This randomized, placebo-controlled, double-blind study enrolled MG patients with antibodies against acetylcholine-receptors (AChR-ab). They were allocated to receive seasonal influenza vaccine or placebo. The primary endpoint was the relative change of AChR-ab-titer over 12weeks. A relative increase of 20% was set as non-inferiority margin. Secondary endpoints were clinical changes in the modified Quantitative Myasthenia Gravis Score (QMG), increase of anti-influenza-ELISA-antibodies, and changes of treatment. The study is registered with Clinicaltrialsregister.eu, EudraCT number 2006-004374-27. FINDINGS: 62 patients were included. Mean±standard deviation (median) in the vaccine and placebo group were AChR-ab-titer changes of -6.0%±23.3% (-4.0%) and -2.8%±22.0% (-0.5%) and QMG score changes of -0.08±0.27 (0.17) and 0.11±0.31 (0.00), respectively. The difference between groups (Hodges-Lehmann estimate with 95% CI) was - for the AChR-ab-titer change 4·0% [-13.3%, 4.5%] (p=0.28 for testing a difference, p<0.0001 for testing non-inferiority) and for the QMG change 0·00 [-0.17, 0.00] (p=0.79 for testing a difference). The occurrence of 74 adverse events (AE) was comparable between groups. The most common AE was flu-like symptoms. One serious AE (hospitalisation following gastrointestinal haemorrhage) in the verum group was not related to the vaccine. INTERPRETATION: Influenza vaccination in MG is safe. Uprating the potential risk of a severe course of MG exacerbation during influenza infection compared to the 95% CI differences for the endpoints, vaccination is principally indicated in this patient population.

Predictors for multiple sclerosis relapses after switching from natalizumab to fingolimod.

BACKGROUND: Risks of natalizumab (NAT) therapy have to be weighed against disease recurrence after stopping NAT. OBJECTIVES: The objective of this paper is to identify risk factors for recurrence of relapses after switching from NAT to fingolimod (FTY) in relapsing-remitting multiple sclerosis (RRMS). METHODS: Patients (n = 33) were treated with NAT for ≥1 year, and then switched to FTY within 24 weeks (mean follow-up on FTY 81.1 (SD 26.5) weeks). Annual relapse rates (ARR) and Expanded Disability Status Scale scores (EDSS) were assessed. Descriptive statistics, univariate logistic regression analysis, and receiver operating characteristic curves were conducted. RESULTS: Overall, 20 patients (61%) had relapses after discontinuation of NAT and 16 (48%) during FTY therapy. The maximum incidence of relapses occurred between weeks 13-24 post-NAT. The last EDSS during the switching period predicted relapses during subsequent FTY therapy. EDSS >3 separated most powerfully between the groups (sensitivity 64%, specificity 88%) and significantly predicted relapses (relative risk 3.27, 95% CI: 1.5-7.3). Seventy-five percent of patients with EDSS ≤ 3 remained free of relapses, compared to 18% of patients with EDSS >3. CONCLUSIONS: There was an increase of the ARR in the first year after switching from NAT to FTY. Last EDSS during the switching period was a predictor of relapses during FTY.

Intravenous immunoglobulin maintenance treatment in myasthenia gravis: a randomized, controlled trial sample size simulation.

INTRODUCTION: In cases of exacerbation or crisis, myasthenia gravis (MG) patients can be treated with intravenous immunoglobulin (IVIg), plasmapheresis, or immunoadsorption. However, IVIg efficacy data in maintenance treatment are sparse. METHODS: We prospectively observed 16 index patients with chronic and insufficiently controlled MG under standard immunosuppressant therapy and symptomatic treatment. The IVIg treatment response was measured using changes in quantitative myasthenia gravis (QMG) score and surrogates. Based on these results, a sample size calculation for a future randomized, controlled trial (RCT) was simulated. RESULTS: There was an enduring decline in QMG score and other parameters of about 50% under IVIg maintenance treatment. RCT sample size calculation results in 73 or 33 patients per arm to detect at least a 20% vs. 30% clinical difference in QMG score. CONCLUSION: We recommend using the QMG score as a primary endpoint for an RCT of IVIg maintenance for chronic MG.

Preference-based Health status in a German outpatient cohort with multiple sclerosis.

BACKGROUND: To prospectively determine health status and health utility and its predictors in patients with multiple sclerosis (MS). METHODS: A total of 144 MS patients (mean age: 41.0 ± 11.3 y) with different subtypes (patterns of progression) and severities of MS were recruited in an outpatient university clinic in Germany. Patients completed a questionnaire at baseline (n = 144), 6 months (n = 65) and 12 months (n = 55). Health utilities were assessed using the EuroQol instrument (EQ-5D, EQ VAS). Health status was assessed by several scales (Expanded Disability Severity Scale (EDSS), Modified Fatigue Impact Scale (M-FIS), Functional Assessment of MS (FAMS), Beck Depression Inventory (BDI-II) and Multiple Sclerosis Functional Composite (MSFC)). Additionally, demographic and socioeconomic parameters were assessed. Multivariate linear and logistic regressions were applied to reveal independent predictors of health status. RESULTS: Health status is substantially diminished in MS patients and the EQ VAS was considerably lower than that of the general German population. No significant change in health-status parameters was observed over a 12-months period. Multivariate analyses revealed M-FIS, BDI-II, MSFC, and EDSS to be significant predictors of reduced health status. Socioeconomic and socio-demographic parameters such as working status, family status, number of household inhabitants, age, and gender did not prove significant in multivariate analyses. CONCLUSION: MS considerably impairs patients' health status. Guidelines aiming to improve self-reported health status should include treatment options for depression and fatigue. Physicians should be aware of depression and fatigue as co-morbidities. Future studies should consider the minimal clinical difference when health status is a primary outcome.

Myasthenia gravis: analysis of serum autoantibody reactivities to 1827 potential human autoantigens by protein macroarrays.

BACKGROUND: Myasthenia gravis is a disorder of neuromuscular transmission associated with autoantibodies against the nicotinic acetylcholine receptor. We have previously developed a customized protein macroarray comprising 1827 potential human autoantigens, which permitted to discriminate sera of patients with different cancers from sera of healthy controls, but has not yet been evaluated in antibody-mediated autoimmune diseases. OBJECTIVE: To determine whether autoantibody signatures obtained by protein macroarray separate sera of patients with myasthenia gravis from healthy controls. METHODS: Sera of patients with acetylcholine receptor antibody-positive myasthenia gravis (n = 25) and healthy controls (n = 32) were analyzed by protein macroarrays comprising 1827 peptide clones. RESULTS: Autoantibody signatures did not separate patients with myasthenia gravis from controls with sufficient sensitivity, specificity, and accuracy. Intensity values of one antigen (poly A binding protein cytoplasmic 1, p = 0.0045) were higher in patients with myasthenia gravis, but the relevance of this and two further antigens, 40S ribosomal protein S13 (20.8% vs. 0%, p = 0.011) and proteasome subunit alpha type 1 (25% vs. 3.1%, p = 0.035), which were detected more frequently by myasthenia gravis than by control sera, currently remains uncertain. CONCLUSION: Seroreactivity profiles of patients with myasthenia gravis detected by a customized protein macroarray did not allow discrimination from healthy controls, compatible with the notion that the autoantibody response in myasthenia gravis is highly focussed against the acetylcholine receptor.

Natalizumab treatment decreases serum IgM and IgG levels in multiple sclerosis patients.

BACKGROUND: Treatment with natalizumab, a humanized monoclonal antibody against alpha4beta1 integrin, is associated with an increase in lymphoid progenitor cells and B cells in peripheral blood. OBJECTIVE: The objective of this study was to examine the impact of natalizumab therapy on serum levels of total IgG, IgA and IgM in patients with multiple sclerosis (MS). METHODS: In two independent cross-sectional patient cohorts, serum levels of IgG, IgA and IgM were compared between patients treated with natalizumab and those not receiving natalizumab. Further, serum levels of IgG, IgA and IgM before and during natalizumab treatment were compared in two longitudinal patient cohorts. RESULTS: In patients treated with natalizumab, serum IgM and IgG levels were significantly lower compared with therapy naïve patients (p<0.0001). IgM levels significantly decreased after initiation of natalizumab treatment in both longitudinal patient cohorts (p<0.01). Moreover, patients treated with natalizumab showed a time-dependent decrease in IgM levels during the first 2 years of treatment. CONCLUSION: Natalizumab treatment leads to a significant decrease in serum IgM and IgG levels in patients with MS. IgM levels decrease with treatment duration during the first 2 years of treatment. These findings might support the hypothesis that natalizumab interferes with homing of B cells, possibly leading to impaired differentiation into plasma cells and subsequently disturbed immunoglobulin synthesis.

Fingolimod reduces recurrence of disease activity after natalizumab withdrawal in multiple sclerosis.

After discontinuation of natalizumab (NAT), multiple sclerosis (MS) disease activity often recurs. We assessed the recurrence of clinical disease activity during the first year after switching from NAT to fingolimod (FTY) in patients with relapsing-remitting MS. The number of relapses and the annualized relapse rate (ARR) before, during and after NAT discontinuation were determined and compared between 26 MS patients who switched to FTY within 24 weeks, and 10 MS patients who remained without disease modifying therapy (therapy free group = TFG). Median follow-up post-NAT discontinuation was 55.1 weeks. In a subgroup (n = 20), the occurrence of contrast-enhancing-lesions (Gd+) on magnetic resonance imaging (MRI) was determined. Eleven patients (42 %) in the FTY group and seven patients (70 %) in the TFG had one or more relapses after cessation of NAT during follow-up (p < 0.05). One of the 11 (9 %) patients in the FTY group and 6/9 (67 %) patients in the TFG showed Gd+ lesions during follow-up (p < 0.05). Patients who switched to FTY ≤ 12 weeks after NAT discontinuation (n = 9) showed a trend for a lower post-NAT ARR compared to patients who started FTY therapy >12 weeks after NAT was stopped (n = 17). Most relapses in the FTY group occurred just before or within 8 weeks after starting FTY. Our observation suggests that initiation of FTY treatment after NAT discontinuation reduces the recurrence of disease activity compared to withdrawal without further immunomodulatory treatment. In the FTY group the ARR tended to depend on the time interval between discontinuation of NAT and initiation of FTY.

Sibling disability risk at onset and during disease progression in familial multiple sclerosis.

BACKGROUND: The objective of this study was to address the differences in onset and disease progression between familial and sporadic multiple sclerosis (MS) and the association within sibling pairs. METHODS: Ninety-eight siblings and their controls were included from a database of 763 sporadic MS-patients, randomly pair-matched for age, gender, clinical course, disease duration and treatment. Sixty-eight available siblings completed a prospective six-year follow-up. Outcome parameters included baseline Expanded Disability Status Scale (EDSS), age at onset, mono- or multifocal onset, disease progression and conversion to secondary progression of initially relapsing-remitting MS. For statistical analyses Wilcoxon's signed-rank statistics for categorical differences, t-statistics for continuous variables, McNemar's test for relative frequencies of categories, intra-class correlations for within sibling-pair associations, or Kaplan-Meier analysis for survival analyses were used; all two-sided at the 5% level. RESULTS: Disease onset was slightly earlier (29.01 vs. 29.44 years, p = 0.0492) and multifocal onset significantly more often (p = 0.0052) in familial than in sporadic MS. Notably, a substantial within sibling-pair correlation for disease progression (rho = 0.40; p = 0.0062) as well as a higher risk for siblings than for controls to convert into secondary progression (0.545 vs. 0.227; p = 0.018) could be observed. CONCLUSIONS: Familial MS differs from sporadic cases with respect to age at onset, multifocal involvement as first clinical event, and conversion into secondary progression. The progression rate of one out of two affected siblings may act as a predictor for the other sib.