Teriflunomide and Epstein-Barr virus in a Spanish multiple sclerosis cohort: in vivo antiviral activity and clinical response

Background

Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6) have been associated with multiple sclerosis (MS). Teriflunomide is an oral disease-modifying therapy approved for treatment of relapsing forms of MS. In the preclinical Theiler's murine encephalitis virus model of MS, the drug demonstrated an increased rate of viral clearance versus the vehicle placebo. Furthermore, teriflunomide inhibits lytic EBV infection in vitro.

Objective

1. To evaluate the humoral response against EBV and HHV-6 prior to teriflunomide treatment and 6 months later. 2. To correlate the variation in the humoral response against EBV and HHV-6 with the clinical and radiological response after 24 months of treatment with teriflunomide. 3. To analyze the utility of different demographic, clinical, radiological, and environmental data to identify early biomarkers of response to teriflunomide.

Methods

A total of 101 MS patients (62 women; mean age: 43.4 years) with one serum prior to teriflunomide onset and another serum sample 6 months later were recruited. A total of 80 had been treated for at least 24 months, 13 had stopped teriflunomide before 24 months, and 8 were currently under teriflunomide therapy but with less than 24 months of follow-up. We analyzed the levels of the viral antibodies titers abovementioned in serum samples with ELISA commercial kits, and the levels of serum neurofilament light chain (Nf-L).

Results

Antiviral antibody titers decreased for EBNA-1 IgG (74.3%), VCA IgG (69%), HHV-6 IgG (60.4%), and HHV-6 IgM (73.3%) after 6 months of teriflunomide. VCA IgG titers at baseline correlated with Nf-L levels measured at the same time (r = 0.221; p = 0.028) and 6 months later (r = 0.240; p = 0.017). We found that higher EBNA-1 titers (p = 0.001) and a higher age (p = 0.04) at baseline were associated with NEDA-3 conditions. Thus, 77.8% of patients with EBNA-1 >23.0 AU and >42.8 years (P50 values) were NEDA-3.

Conclusion

Treatment with teriflunomide was associated with a reduction of the levels of IgG antibody titers against EBV and HHV-6. Furthermore, higher EBNA-1 IgG titers prior to teriflunomide initiation were associated with a better clinical response.

Mitochondrial Impairments in Peripheral Blood Mononuclear Cells of Multiple Sclerosis Patients

Simple Summary

Multiple sclerosis (MS) is a chronic, inflammatory disease that affects the central nervous system, and is the most common cause of non-traumatic neurological disability in young adults. Although its origin is unknown, it is thought that the immune system damages the insulating covers of nerve cells. On the other hand, it seems that the mitochondria (the organelle producing energy in the cells) function abnormally in these patients. However, few studies focus on the mitochondria of immune cells. In this study, we compared the mitochondrial function of peripheral blood cells (PBC) from healthy donors to those of MS patients, classifying these patients by the presence (M+) or absence (M−) of lipid-specific oligoclonal immunoglobulin M bands (LS-OCMB). The detection of LS-OCMB has been associated with a highly inflammatory and more aggressive course of MS. We found signs of mitochondrial impairment in the PBCs from M+ patients compared with M− ones, which could affect in greater terms the oldest M+ patients. Currently, there is no treatment for this heterogeneous disease. The results of this study could help to understand its physiopathology better and encourage the consideration of the LS-OCMB presence in further studies delving into the effect of certain drugs.

Abstract

Although impaired mitochondrial function has been proposed as a hallmark of multiple sclerosis (MS) disease, few studies focus on the mitochondria of immune cells. We aimed to compare the mitochondrial function of the peripheral blood mononuclear cells (PBMCs) from MS patients with (M+) and without (M−) lipid-specific oligoclonal immunoglobulin M bands (LS-OCMB), and healthydonors (HD). We conducted an exploratory cross-sectional study with 19 untreated MS patients (M+ = 9 and M− = 10) and 17 HDs. Mitochondrial superoxide anion production and mitochondrial mass in PBMCs were assessed without and with phytohemagglutinin by flow cytometry. The PBMCs’ mitochondrial function was analyzed using Seahorse technology. Superoxide anion production corrected by the mitochondrial mass was higher in MS patients compared with HDs (p = 0.011). Mitochondrial function from M+ patients showed some impairments compared with M− patients. Without stimulus, we observed higher proton leak (p = 0.041) but lower coupling efficiency (p = 0.041) in M+ patients; and under stimulation, lower metabolic potential ECAR (p = 0.011), and lower stressed OCR/ECAR in the same patients. Exclusively among M+ patients, we described a higher mitochondrial dysfunction in the oldest ones. The mitochondrial impairments found in the PBMCs from MS patients, specifically in M+ patients, could help to better understand the disease’s physiopathology.

Epstein-Barr Virus Load Correlates with Multiple Sclerosis-Associated Retrovirus Envelope Expression

pHERV-W ENV and syncytin-1, the envelope proteins of the human endogenous retrovirus W family (HERV-W), have been proposed as etiological factors for MS development. In addition, herpesviruses, such as the Epstein-Barr virus (EBV) and the human herpesvirus 6A/B (HHV-6A/B), have been also strongly associated with the disease. This work aims to study the possible link between viral loads and antibody titers against EBV and HHV-6A/B and the pHERV-W ENV/syncytin-1 protein/gene expression. For this purpose, we conducted a 12-month longitudinal study involving 98 RRMS patients. Peripheral blood samples were obtained from each patient. Serum antibody titers against EBV and HHV-6A/B were determined by ELISA, while viral loads were analyzed using qPCR. HLA MS-related alleles were also genotyped. pHERV-W ENV/syncytin-1 protein and gene expression levels in immune cells were assessed by flow cytometry and qPCR, respectively. We found that the 12-month variation of the pHERV-W ENV gene expression levels positively correlated with the variation of the EBV viral load, especially in those patients with high baseline EBV loads. Therefore, these results could support previous studies pointing to the transactivation of pHERV-W ENV by EBV. However, further studies are needed to better understand this possible relationship.

Short-chain fatty acids during pregnancy in multiple sclerosis: A prospective cohort study

BACKGROUND AND PURPOSE

Short-chain fatty acids (SCFAs) can have pro- or anti-inflammatory properties, but their relationship with multiple sclerosis (MS) relapses during pregnancy remains unknown. This study aimed to explore SCFA profiles in MS patients during pregnancy and to assess their association with the appearance of relapses during pregnancy and postpartum.

METHODS

We prospectively included 53 pregnant MS patients and 21 healthy control women. Patients were evaluated during pregnancy and puerperium. SCFAs were measured by liquid chromatography-mass spectrometry.

RESULTS

Sixteen patients (32%) had relapses during pregnancy or puerperium, and 37 (68%) did not. All MS patients showed significant increases in acetate levels during pregnancy and the postpartum period compared to non-MS women. However, propionate and butyrate values were associated with disease activity. Their values were higher in nonrelapsing patients and remained similar to the control group in relapsing patients. The variable that best identified active patients was the propionate/acetate ratio. Ratios of <0.36 during the first trimester were associated with higher inflammatory activity (odds ratio = 165, 95% confidence interval = 10.2-239.4, p < 0.01). Most nonrelapsing patients showed values of >0.36, which were similar to those in healthy pregnant women.

CONCLUSIONS

Low propionate/acetate ratio values during the first trimester of gestation identified MS patients at risk of relapses during pregnancy and the postpartum period.

Acetate correlates with disability and immune response in multiple sclerosis

Background

Gut microbiota has been related to multiple sclerosis (MS) etiopathogenesis. Short-chain fatty acids (SCFA) are compounds derived from microbial metabolism that have a role in gut-brain axis.

Objectives

To analyse SCFA levels in plasma of MS patients and healthy donors (HD), and the possible link between these levels and both clinical data and immune cell populations.

Methods

Ninety-five MS patients and 54 HD were recruited. Patients were selected according to their score in the Expanded Disability Status Scale (EDSS) (49 EDSS ≤ 1.5, 46 EDSS ≥ 5.0). SCFA were studied in plasma samples by liquid chromatography-mass spectrometry. Peripheral blood mononuclear cells were studied by flow cytometry. Gender, age, treatments, EDSS and Multiple Sclerosis Severity Score (MSSS) were evaluated at the recruitment.

Results

Plasma acetate levels were higher in patients than in HD (p = 0.003). Patients with EDSS ≥ 5.0 had higher acetate levels than those with EDSS≤ 1.5 (p = 0.029), and HD (p = 2.97e–4). Acetate levels correlated with EDSS (r = 0.387; p = 1.08e–4) and MSSS (r = 0.265; p = 0.011). In untreated MS patients, acetate levels correlated inversely with CD4+ naïve T cells (r =  − 0.550, p = 0.001) and directly with CD8+ IL-17+ cells (r = 0.557; p = 0.001).

Conclusions

Plasma acetate levels are higher in MS patients than in HD. In MS there exists a correlation between plasma acetate levels, EDSS and increased IL-17+ T cells. Future studies will elucidate the role of SCFA in the disease.

A Polymorphism Within the MBP Gene Is Associated With a Higher Relapse Number in Male Patients of Multiple Sclerosis

Myelin basic protein (MBP) is thought to be one of the key autoantigens in multiple sclerosis (MS) development. A recent study described the association of the single nucleotide polymorphism (SNP) rs12959006, within the MBP gene, with a higher risk of relapse and worse prognosis. We aim at studying potential associations of this SNP to MS in an independent population. Clinical data of the first 5 years of the disease were collected retrospectively from 291 MS confirmed patients. MBP polymorphism rs12959006 was genotyped in all patients. Associations with EDSS, number of relapses and serology for Herpesvirus 6 (HHV-6) and Epstein Barr (EBV) viruses were studied. Lymphocyte activation measured by CD69 expression was also analyzed according to sex and rs12959006 genotype. The rs12959006 polymorphism contributed significantly to a higher number of relapses at 5 years after onset only in male patients (rs12959006^∗TT β = 0.74 [0.36–1.09]; p = 7 × 10^–5). Titers of anti-HHV6 IgG antibodies showed also a mild association with relapses, both in male and female patients (β = 0.01 [0.01–0.02]; p = 3.7 × 10^–8). Both the genetic variation in MBP and HHV-6 infection aid in predicting a higher number of relapses during the first years of MS. The association described in MBP rs12959006^∗T is exclusive to male patients.

Epidemiology of multiple sclerosis and vitamin D levels in Lanzarote, Canary Islands, Spain

Background

Low levels of 25-hydroxyvitamin D (25(OH)D) have been described as one of the possible environmental factors involved in multiple sclerosis (MS) etiopathogenesis.

Objectives

To study epidemiology of MS and 25(OH)D serum levels of patients in Lanzarote (29°02'06″N), a region with high ultraviolet radiation values during the whole year which is located far apart from Iberian Peninsula (36°-43°N), but without genetic/ethnic differences with it.

Methods

Incidence in Lanzarote was assessed according to McDonald 2005 criteria between January 2008 and December 2015 and prevalence date was 12/31/15. For 25(OH)D serum levels analyses, samples from 60 MS patients and 60 healthy donors (HD) were collected monthly in a one-year prospective study.

Results

The prevalence of MS in Lanzarote was 50.0/100,000 and the incidence per year was 2.5/100,000. Median 25(OH)D levels values were 29.1 ng/ml for MS patients (maximum = 36.1 ng/ml, minimum = 22.5 ng/ml) and 27.1 ng/ml for HD (maximum = 34.8 ng/ml, minimum = 22.8 ng/ml). There were no significant differences between 25(OH)D serum levels between MS patients and HD.

Conclusions

Lanzarote possesses lower prevalence and incidence values than peninsular Spain. Moreover, 25(OH)D serum levels do not differ between MS patients and HD.

Study of the possible link of 25-hydroxyvitamin D with Epstein-Barr virus and human herpesvirus 6 in patients with multiple sclerosis

BACKGROUND AND PURPOSE

Although the causes of multiple sclerosis (MS) remain partially unknown, environmental and genetic factors are thought to play a role in its aetiopathogenesis. Hypovitaminosis D, Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6) infections have been described as possible MS triggers. Our aim was to analyse the possible link between 25-hydroxyvitamin D [25(OH)D] and viruses in patients with MS.

METHODS

We included 482 patients with MS in a 2-year study. Serum samples were collected to analyse 25(OH)D levels and, according to sample availability, antibody titres against EBV and HHV-6 by enzyme-linked immunosorbent assay. DNA was extracted from blood in order to analyse EBV and HHV-6 viral load by quantitative real-time polymerase chain reaction and to genotype MS-related single nucleotide polymorphisms (rs3135388, rs2248359 and rs12368653) when possible.

RESULTS

The 25(OH)D levels were significantly higher in the first semester of the year than in the second. Carriers of the risk allele rs2248359-C showed lower 25(OH)D levels than non-carriers. For EBV, viral load was significantly higher when 25(OH)D levels were low, demonstrating an inverse correlation between 25(OH)D levels and EBV load.

CONCLUSIONS

The 25(OH)D levels could be involved in the regulation of EBV replication/reactivation in patients with MS.