Linda Rolf

Vitamin D effects on B cell function in autoimmunity.

Vitamin D seems to be implicated in the pathophysiology of autoimmune disorders as a natural immune modulator. Beneficial effects of vitamin D have been associated with different cells of the immune system; however, thus far, B cells seem to be somewhat neglected. In this paper, we describe the possible direct effects of vitamin D on B cells, with a focus on antibody production and the more recently identified regulatory B (Breg) cells. B cells upregulate the vitamin D receptor (VDR) upon activation. Furthermore, due to regulated expression of the metabolizing enzymes CYP27B1 and CYP24A1, B cells have the potential to control the local availability of active vitamin D. B cells, therefore, may participate in vitamin D–mediated immune homeostasis, including plasma cell generation. Whether or not other B cell subsets, such as Breg cells, are equally responsive to vitamin D remains to be established.

Illuminating vitamin D effects on B cells – the multiple sclerosis perspective

Vitamin D is associated with many immune‐mediated disorders. In multiple sclerosis (MS) a poor vitamin D status is a major environmental factor associated with disease incidence and severity. The inflammation in MS is primarily T‐cell‐mediated, but increasing evidence points to an important role for B cells. This has paved the way for investigating vitamin D effects on B cells. In this review we elaborate on vitamin D interactions with antibody production, T‐cell‐stimulating capacity and regulatory B cells. Although in vitro plasma cell generation and expression of co‐stimulatory molecules are inhibited and the function of regulatory B cells is promoted, this is not supported by in vivo data. We speculate that differences might be explained by the B‐cell–Epstein–Barr virus interaction in MS, the exquisite role of germinal centres in B‐cell biology, and/or in vivo interactions with other hormones and vitamins that interfere with the vitamin D pathways. Further research is warranted to illuminate this tube‐versus‐body paradox.

A low vitamin D status at diagnosis is associated with an early conversion to secondary progressive multiple sclerosis

Low circulating 25-hydroxyvitamin D (25(OH)D) levels have been associated with an increased risk of relapses in relapsing remitting multiple sclerosis (RRMS), but an association with disability progression is uncertain. Lower 25(OH)D levels are found in secondary progressive MS (SPMS) when compared to RRMS. We hypothesized that a poor vitamin D status in RRMS is associated with an increased risk of conversion to SPMS. In a retrospective longitudinal study we measured 25(OH)D levels at the start of a 3-year follow-up, and analyzed whether these levels predict the risk of RRMS to SPMS conversion. In 338 RRMS patients, vitamin D status did not predict the 3-year risk of conversion to SPMS (n=51; OR 0.970; p=0.65). However, in diagnostic blood samples of SPMS patients with a relatively short RRMS duration (n=19) 25(OH)D levels were significantly lower (38nmol/L; Q1-Q3: 24-50) than in diagnostic samples of matched RRMS patients with no progression to SPMS ((n=38; 55nmol/L; Q1-Q3: 40-70) (p<0.01). These data indicate an association between a low vitamin D status at the start of RRMS and the early conversion to SPMS. Therefore, time to SPMS conversion is of interest as clinical measure in (follow-up of) clinical vitamin D supplementation studies.

Vitamin D Status Does Not Affect Disability Progression of Patients with Multiple Sclerosis over Three Year Follow-Up.

Background and Objective The risk of developing multiple sclerosis (MS) as well as MS disease activity is associated with vitamin D (25(OH)D) status. The relationship between the main functional disability hallmark of MS, disability progression, and 25(OH)D status is less well established though, especially not in MS patients with progressive disease. Methods This retrospective follow-up study included 554 MS patients with a serum baseline 25(OH)D level and Expanded Disability Status Scale (EDSS) with a minimum follow-up of three years. Logistic regressions were performed to assess the effect of baseline 25(OH)D status on relapse rate. Repeated measures linear regression analyses were performed to assess the effect on disability and disability progression. Results Baseline deseasonalized 25(OH)D status was associated with subsequent relapse risk (yes/no), but only in the younger MS patients (≤ 37.5 years; OR = 0.872, per 10 nmol/L 25(OH)D, p = 0.041). Baseline 25(OH)D status was not significantly associated with either disability or disability progression, irrespective of MS phenotype. Conclusion Within the physiological range, 25(OH)D status is just significantly associated with the occurrence of relapses in younger MS patients, but is not associated with disability or disability progression over three years follow-up. Whether high dose supplementation to supra physiological 25(OH)D levels prevents disability progression in MS should become clear from long term follow-up of supplementation studies.

Immune regulatory effects of high dose vitamin D3 supplementation in a randomized controlled trial in relapsing remitting multiple sclerosis patients receiving IFNβ; the SOLARIUM study

Multiple sclerosis (MS) is characterized by a disturbed immune homeostasis and low serum vitamin D levels are associated with an increased disease activity. While vitamin D has been hypothesized to promote the maintenance of immune homeostasis, vitamin D supplementation could be of benefit to patients with MS. The SOLAR study investigated the effects of high dose vitamin D3 supplementation on clinical outcomes in a randomized controlled trial. Here we present the immune regulatory effects, investigated in the SOLARIUM sub-study. Thirty Dutch relapsing remitting (RR) MS patients treated with IFNβ-1a received high dose vitamin D3 supplementation and 23 patients received placebo during a period of 48weeks. Lymphocytes were phenotypically characterized by flow cytometry and in vitro cytokine secretion was assessed in the presence or absence of 1,25(OH)2D3 using Luminex technology. Changes in immune regulatory parameters were determined within subjects as well as between treatment groups. The proportion of cells in the immune regulatory cell compartment (nTreg, iTreg and Breg) was not altered upon high dose vitamin D3 supplementation. Proportions of T helper subsets were not affected by vitamin D3, except for the proportion of IL4+ Th cells, which decreased in the placebo but not in the vitamin D3 group. T cell cytokine secretion increased, most pronounced for IL5 and latency activated protein of TGFβ, in the placebo group but not in the vitamin D3 group. Lymphocytes remained equally reactive to in vitro 1,25(OH)2D3. In conclusion, high dose vitamin D3 supplementation did not result in a relative increase in lymphocytes with a regulatory phenotype. However, this study supports the hypothesis that vitamin D contributes to the maintenance of immune homeostasis by preventing further disturbance of the T cell compartment early in the disease course of MS.

Network of nuclear receptor ligands in multiple sclerosis: Common pathways and interactions of sex-steroids, corticosteroids and vitamin D3-derived molecules.

Sex-steroids, corticosteroids and vitamin D3-derived molecules have all been subject to experimental studies and clinical trials in a plethora of autoimmune diseases. These molecules are all derived from cholesterol metabolites and are ligands for nuclear receptors. Ligation of these receptors results in direct regulation of multiple gene transcription involved in general homeostatic and adaptation networks, including the immune system. Indeed, the distinct ligands affect the function of both myeloid and lymphoid cells, eventually resulting in a less pro-inflammatory immune response which is considered beneficial in autoimmune diseases. Next to the immune system, also the central nervous system is prone to regulation by these nuclear receptor ligands. Understanding of the intricate interactions between sex-steroids, corticosteroids and vitamin D3 metabolites, on the one hand, and the immune and central nervous system, on the other hand, may reveal novel approaches to utilize these nuclear receptor ligands to full extent as putative treatments in multiple sclerosis, the prototypic immune-driven disease of the central nervous system.

Paroxysmal atrial fibrillation after initiation of fingolimod for multiple sclerosis treatment

Fingolimod (FTY720, Gilenya, Novartis Pharma AG, Basel, Switzerland) is an oral disease-modifying therapy (DMT) approved for relapsing multiple sclerosis (MS) that acts via modulation of the sphingosine-1-phosphate (S1P) receptor.1 Fingolimod also targets the cardiovascular system, frequently causing reduced heart rate after the first dose.2 We describe a patient with MS who developed paroxysmal atrial fibrillation (PAF) after initiating fingolimod therapy.

Vitamin D3 supplementation in multiple sclerosis : Symptoms and biomarkers of depression

Depressive symptoms are common in multiple sclerosis (MS), and both depression and MS have been associated with a poor vitamin D status. As cytokine-mediated inflammatory processes play a role in the pathogenesis of both disorders, we hypothesized that vitamin D3 supplementation reduces depressive symptoms in MS via its immunomodulatory properties. In this randomized pilot study relapsing remitting (RR) MS patients received either vitamin D3 supplementation (n=20; 14.000IU/day) or placebo (n=20) during 48weeks. Pre- and post-supplementation depression scores, measured using the Hospital Anxiety Depression Scale (HADS) depression subscale (HADS-D), showed a significant decrease within the vitamin D3 group (median HADS-D 4.0 to 3.0, p=0.02), a trend towards a decrease within the placebo group (median HADS-D 3.0 to 2.0, p=0.06), but no significantly different reductions between groups (p=0.78). Furthermore, no reductions in pro- and anti-inflammatory cytokine balances, secreted by stimulated leukocytes and CD8+ T cells, were found in the vitamin D3 compared to the placebo arm. Therefore, we found no evidence for a reduction of depressive symptoms or related biomarkers upon vitamin D3 supplementation in RRMS patients in this exploratory study. Whether vitamin D3 supplementation is of benefit in manifest depression in MS needs to be assessed by additional studies.

Exploring the effect of vitamin D3 supplementation on the anti-EBV antibody response in relapsing-remitting multiple sclerosis:

Background: Epstein–Barr virus (EBV) infection and vitamin D insufficiency are potentially interacting risk factors for multiple sclerosis (MS). Objectives: To investigate the effect of high-dose vitamin D3 supplements on antibody levels against the EBV nuclear antigen-1 (EBNA-1) in patients with relapsing-remitting multiple sclerosis (RRMS) and to explore any underlying mechanism affecting anti-EBNA-1 antibody levels. Methods: This study utilized blood samples from a randomized controlled trial in RRMS patients receiving either vitamin D3 (14,000 IU/day; n = 30) or placebo (n = 23) over 48 weeks. Circulating levels of 25-hydroxyvitamin-D, and anti-EBNA-1, anti-EBV viral capsid antigen (VCA), and anti-cytomegalovirus (CMV) antibodies were measured. EBV load in leukocytes, EBV-specific cytotoxic T-cell responses, and anti-EBNA-1 antibody production in vitro were also explored. Results: The median antibody levels against EBNA-1, but not VCA and CMV, significantly reduced in the vitamin D3 group (526 (368–1683) to 455 (380–1148) U/mL) compared to the placebo group (432 (351–1280) to 429 (297–1290) U/mL; p = 0.023). EBV load and cytotoxic T-cell responses were unaffected. Anti-EBNA-1 antibody levels remained below detection limits in B-cell cultures. Conclusion: High-dose vitamin D3 supplementation selectively reduces anti-EBNA-1 antibody levels in RRMS patients. Our exploratory studies do not implicate a promoted immune response against EBV as the underlying mechanism.

Vitamin D3 supplementation and the IL-2/IL-2R pathway in multiple sclerosis: Attenuation of progressive disturbances?

Vitamin D3 upregulates IL-2 receptor alpha (IL2RA, CD25)-expression on CD4+ T cells in vitro. We investigated effects of 48-weeks vitamin D3 supplements on CD25-expression by CD4+ T cells of patients with multiple sclerosis (MS). There was no significant difference between the vitamin D3 (n=30) and placebo group (n=23) in IL2RA mRNA-expression by PBMC. Likewise, CD25 cell surface-expression by conventional or regulatory T cells (Treg) did not differ between groups, although Treg CD25-expression and circulating soluble-CD25 levels decreased significantly in the placebo but not vitamin D3-group. We speculate that vitamin D3 may promote the maintenance of CD25-related immune homeostasis in MS.