Interferon-beta modulates bone-associated cytokines and osteoclast precursor activity in multiple sclerosis patients

Can Vitamin D Reduce Inflammation? The Influence of Supplementation on Selected Immunological Markers

There is increasing evidence that vitamin D (VitD) supplementation may reduce inflammation in individuals with multiple sclerosis (MS). The aim of this study was to evaluate the effect of different doses of VitD on selected markers of inflammation in patients with relapsing-remitting MS (RRMS). Participants were divided depending on the supplemented dose of VitD into a high-dose (2000 IU/d; HD) group and a low-dose (15,960 IU/month; LD) group (n = 23 and n = 29, respectively). The concentration of 25(OH)D and the levels of CXCL16, PTX3, ALCAM, IL-1RA, and OPG were measured initially and after six months of VitD supplementation in blood serum. A significant increase in the concentrations of CXCL16, PTX3, and OPG was observed during the study (p = 0.02, p = 0.01, and p < 0.01, respectively). Furthermore, a higher increase in PTX3 and OPG in the LD group was observed (p = 0.04 and p = 0.03, respectively). A significant positive correlation was observed between the 25(OH)D serum concentration and PTX3 (R = 0.28, p < 0.05) and OPG (R = 0.28, p < 0.05) only at the beginning of the study. In patients with RRMS, such doses of VitD might be too low to induce obvious beneficial effects on the pro-inflammatory and inflammatory balance.

Increased Risk for Acute Periapical Abscesses in Multiple Sclerosis Patients and the Possible Association with Epstein-Barr Virus

INTRODUCTION

Multiple sclerosis (MS) is a severe inflammatory neuroimmune degenerative condition affecting more than 2 million individuals worldwide. The purpose of this study was to assess the prevalence of acute periapical abscesses in patients with MS and to evaluate whether acute periapical abscesses (PAs) are more likely to affect patients who were previously infected by Epstein-Barr virus (EBV).

METHODS

Integrated data of hospital patients were used. Data from the corresponding diagnosis codes for MS and acute PA were retrieved by querying the appropriate International Classification of Diseases, Tenth Revision codes in the database.

RESULTS

Of the total hospital patient population, 0.18% were diagnosed with a history of MS. Females were more affected than males 3.25-fold. Whites were more affected than African Americans 6-fold. Whites were more affected than African Americans combined with other ethnicities 3.6-fold. The odds ratio (OR) for acute PAs in patients with a history of MS was 2.2 (P < .0001). After adjustment for diabetes mellitus comorbidity, the OR for acute PAs in patients with a history of MS was 2.6. After adjustment for cardiovascular disease comorbidity, the OR for acute PAs in patients with a history of MS was 1.27. Of the patients who presented with PAs, 0.2% were diagnosed with a history of EBV infection. The OR was 3.98, and the difference in prevalence was statistically significant (P < .0001).

CONCLUSIONS

Under the conditions of this cross-sectional study, it appears that the prevalence of acute PAs is higher in patients with MS and that EBV may play a role.

Targeting STING: From antiviral immunity to treat osteoporosis

The cGAS-STING signaling pathway can trigger innate immune responses by detecting dsDNA from outside or within the host. In addition, the cGAS-STING signaling pathway has emerged as a critical mediator of the inflammatory response and a new target for inflammatory diseases. STING activation leads to dimerization and translocation to the endoplasmic reticulum Golgi intermediate compartment or Golgi apparatus catalyzed by TBK1, triggers the production of IRF3 and NF-κB and translocates to the nucleus to induce a subsequent interferon response and pro-inflammatory factor production. Osteoporosis is a degenerative bone metabolic disease accompanied by chronic sterile inflammation. Activating the STING/IFN-β signaling pathway can reduce bone resorption by inhibiting osteoclast differentiation. Conversely, activation of STING/NF-κB leads to the formation of osteoporosis by increasing bone resorption and decreasing bone formation. In addition, activation of STING inhibits the generation of type H vessels with the capacity to osteogenesis, thereby inhibiting bone formation. Here, we outline the mechanism of action of STING and its downstream in osteoporosis and discuss the role of targeting STING in the treatment of osteoporosis, thus providing new ideas for the treatment of osteoporosis.

Associations between osteoporosis and drug exposure: A post-marketing study of the World Health Organization pharmacovigilance database (VigiBase®)

BACKGROUND

Bone remodeling is a complex process, and many conditions (including drug exposure) lead to osteoporosis. Here, we sought to detect new disproportionality signals for drugs associated with osteoporosis.

METHODS

We performed a disproportionality analysis of the World Health Organization's VigiBase® pharmacovigilance database through April 12, 2020. The frequency of reports on osteoporosis for all identified drug classes was compared with that for all other drugs and quoted as the reporting odds ratio (ROR) [95% confidence interval (CI)].

RESULTS

Of the 7,594,968 cases spontaneously recorded to VigiBase®, 4758 concerned osteoporosis. New disproportionality signals with a pharmacologically plausible mechanism were found for drugs used in neurology (levodopa (ROR [95%CI]: 10.18 [4.33-25.10]), selective serotonin agonists (4.22 [2.34-7.00]) and memantine (4.10 [1.56-8.93])), hematology (romiplostim (4.93 [1.15-21.10])), pulmonology (macitentan (3.02 [1.84-4.90])), ophthalmology (ranibizumab (3.31 [1.00-10.51])) and rheumatology (tofacitinib (3.65 [3.00-4.40])). The robustness of these new results is supported by the significant RORs for the vast majority of drugs already known to induce osteoporosis and/or increase the fracture risk, namely glucocorticoids, gonadotropin-releasing hormone analogs, anti-aromatases, androgen receptor blockers, thyroid hormones, proton pump inhibitors, thiazolidinediones, vitamin K antagonists, loop diuretics, protease inhibitors, nucleoside and nucleotide reverse transcriptase inhibitors, and enzyme-inducing antiepileptics including barbiturates and derivatives, hydantoin derivatives, carboxamide derivatives and fatty acid derivatives.

CONCLUSION

We established up a comprehensive list of drugs potentially associated with osteoporosis and highlighted those with pharmacologically plausible mechanisms leading to bone fragility. Our results might pave the way for additional exploration of these mechanisms.

RANK/RANKL/OPG Signaling in the Brain: A Systematic Review of the Literature

Together with its dominant immunological and bone remodeling involvement, RRO axis, comprising of receptor activator of nuclear factor-κB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG) signaling, is as well-implicated in CNS functioning and corresponding pathologies. The CNS aspects of RANKL/RANK/OPG (RRO) axis were systematically reviewed. With search 10 databases, and 7 additional resources from first article publication to July 2019, resulted in total 2,222 hits, from which 33 relevant articles were selected. The elements of RRO axis in CNS include cells involved in neuroinflammation, predominantly in microglia, but as well in resident macrophages and inflammatory cells migrating across the blood-brain barrier. The expression in neurons and oligodendrocytes is mainly confined to processes of differentiation and cell death. RRO axis tunes the neuroinflammatory response, depending on the molecular, cellular and pathological context. RANK/RANKL signaling is neuroprotective in TLR-mediated inflammation, while OPG seems detrimental in stroke, but beneficial in multiple sclerosis. The levels of RRO axis elements can serve as biomarkers in the blood and cerebrospinal fluid. They act as neuroprotectant after brain damage even being implicated in body weight- and thermo-regulation. As derivatives of RRO axis already exist as therapeutic agents in bone remodeling, it would be intriquing to see if these or new RRO-based pharmaceuticals would appear effective in CNS therapies.

Risk Factors, Epidemiology and Treatment Strategies for Metabolic Bone Disease in Patients with Neurological Disease

Metabolic bone disease is a major public health concern, especially when it manifests as hip fracture which carries significant morbidity and mortality. Individuals with neurological disease are at higher risk of osteopenia, osteoporosis and fragility fracture compared to age-matched controls, yet this is under-appreciated by these patients. Clinician attention to this topic is therefore of importance and should address the bone health of men as well as women, a group in whom it may be an under-recognised problem. Evidence for optimal management of bone health in neurological disease remains to be defined, but a growing literature provides some useful guidance. This review focuses on two conditions, multiple sclerosis and Parkinson's disease, where research has been active over recent years. In neuroinflammation, shared immunological pathways between bone and brain are a current domain of interest and it will be intriguing to interrogate the action of emerging immunotherapies on these dual compartments.

Fingolimod suppresses bone resorption in female patients with multiple sclerosis

Fingolimod is a sphingosine-1-phosphate receptor agonist used to inhibit the inflammatory activity of multiple sclerosis (MS), and has been shown to suppress osteoporosis in mouse models. In this study, levels of bone turnover markers were quantified in serum and urine samples from MS patients treated with fingolimod. Compared with untreated MS patients and healthy controls, fingolimod-treated MS patients had a significantly lower level of the bone resorption marker type I collagen cross-linked N-telopeptide in urine. This finding was prominent in female but was not seen in male subjects. Our results suggest that fingolimod may have a beneficial effect on bone mass loss in female MS patients.

Osteoporosis and multiple sclerosis: risk factors, pathophysiology, and therapeutic interventions

Multiple sclerosis (MS) is a chronic inflammatory-demyelinating disease of the nervous system. There has been mounting evidence showing that MS is associated with increased risk of osteoporosis and fractures. The development of osteoporosis in MS patients can be related to the cumulative effects of various factors. This review summarizes the common risk factors and physiologic pathways that play a role in development of osteoporosis in MS patients. Physical inactivity and reduced mechanical load on the bones (offsetting gravity) is likely the major contributing factor for osteoporosis in MS. Additional possible factors leading to reduced bone mass are low vitamin D levels, and use of medications such as glucocorticoids and anticonvulsants. The role of the inflammatory processes related to the underlying disease is considered in the context of the complex bone metabolism. The known effect of different MS disease-modifying therapies on bone health is limited. An algorithm for diagnosis and management of osteoporosis in MS is proposed.

Impaired ambulation and steroid therapy impact negatively on bone health in multiple sclerosis

BACKGROUND AND PURPOSE

The prevalence of osteopenia and osteoporosis is higher amongst patients with multiple sclerosis in comparison with the general population. In addition to the general determinants of bone health, two factors may contribute to reduced bone mineral density in multiple sclerosis: physical disability and corticosteroid therapy. The aim of this study was to examine the effect of physical disability and steroid exposure on bone health in weight-bearing bones and spine and on the incidence of low-trauma fractures in multiple sclerosis.

METHODS

In this retrospective analysis of prospectively collected data, associations between bone mineral density (at the femoral neck, total femur and the lumbar spine) and its change with disability or cumulative steroid dose were evaluated with random-effect models adjusted for demographic and clinical determinants of bone health. The incidence of low-trauma fractures during the study follow-up was evaluated with Andersen-Gill models.

RESULTS

Overall, 474 and 438 patients were included in cross-sectional and longitudinal analyses (follow-up 2347 patient-years), respectively. The effect of severely impaired gait was more apparent in weight-bearing bones (P ≤ 10(-15) ) than in spine (P = 0.007). The effect of cumulative steroid dose was relatively less pronounced but diffuse (P ≤ 10(-4) ). Risk of low-trauma fractures was associated with disability (P = 0.02) but not with cumulative steroid exposure and was greater amongst patients with severely impaired gait (annual risk 3.5% vs. 3.0%). Synergistic effects were found only between cumulative steroid dose in patients ambulatory without support (P = 0.02).

CONCLUSIONS

Bone health and the incidence of low-trauma fractures in multiple sclerosis are more related to impaired gait than to extended corticosteroid therapy.

Mining gene expression data of multiple sclerosis

OBJECTIVES

Microarray produces a large amount of gene expression data, containing various biological implications. The challenge is to detect a panel of discriminative genes associated with disease. This study proposed a robust classification model for gene selection using gene expression data, and performed an analysis to identify disease-related genes using multiple sclerosis as an example.

MATERIALS AND METHODS

Gene expression profiles based on the transcriptome of peripheral blood mononuclear cells from a total of 44 samples from 26 multiple sclerosis patients and 18 individuals with other neurological diseases (control) were analyzed. Feature selection algorithms including Support Vector Machine based on Recursive Feature Elimination, Receiver Operating Characteristic Curve, and Boruta algorithms were jointly performed to select candidate genes associating with multiple sclerosis. Multiple classification models categorized samples into two different groups based on the identified genes. Models' performance was evaluated using cross-validation methods, and an optimal classifier for gene selection was determined.

RESULTS

An overlapping feature set was identified consisting of 8 genes that were differentially expressed between the two phenotype groups. The genes were significantly associated with the pathways of apoptosis and cytokine-cytokine receptor interaction. TNFSF10 was significantly associated with multiple sclerosis. A Support Vector Machine model was established based on the featured genes and gave a practical accuracy of ∼86%. This binary classification model also outperformed the other models in terms of Sensitivity, Specificity and F1 score.

CONCLUSIONS

The combined analytical framework integrating feature ranking algorithms and Support Vector Machine model could be used for selecting genes for other diseases.

Cytokine and chemokine profiles in lung tissues from fatal cases of 2009 pandemic influenza A (H1N1): role of the host immune response in pathogenesis

Pathological studies on fatal cases caused by 2009 pandemic influenza H1N1 virus (2009 pH1N1) reported extensive diffuse alveolar damage and virus infection predominantly in the lung parenchyma. However, the host immune response after severe 2009 pH1N1 infection is poorly understood. Herein, we investigated viral load, the immune response, and apoptosis in lung tissues from 50 fatal cases with 2009 pH1N1 virus infection. The results suggested that 7 of the 27 cytokines/chemokines showed remarkably high expression, including IL-1 receptor antagonist protein, IL-6, tumor necrosis factor-α, IL-8, monocyte chemoattractant protein-1, macrophage inflammatory protein 1-β, and interferon-inducible protein-10 in lung tissues of 2009 pH1N1 fatal cases. Viral load, which showed the highest level on day 7 of illness onset and persisted until day 17 of illness, was positively correlated with mRNA levels of IL-1 receptor antagonist protein, monocyte chemoattractant protein-1, macrophage inflammatory protein 1-β, interferon-inducible protein-10, and regulated on activation normal T-cell expressed and secreted. Apoptosis was evident in lung tissues stained by the TUNEL assay. Decreased Fas and elevated FasL mRNA levels were present in lung tissues, and cleaved caspase-3 was frequently seen in pneumocytes, submucosal glands, and lymphoid tissues. The pathogenesis of the 2009 pH1N1 virus infection is associated with viral replication and production of proinflammatory mediators. FasL and caspase-3 are involved in the pathway of 2009 pH1N1 virus-induced apoptosis in lung tissues, and the disequilibrium between the Fas and FasL level in lung tissues could contribute to delayed clearance of the virus and subsequent pathological damages.

Assessing fracture risk in people with MS: a service development study comparing three fracture risk scoring systems

OBJECTIVES

Suboptimal bone health is increasingly recognised as an important cause of morbidity. Multiple sclerosis (MS) has been consistently associated with an increased risk of osteoporosis and fracture. Various fracture risk screening tools have been developed, two of which are in routine use and a further one is MS-specific. We set out to compare the results obtained by these in the MS clinic population.

DESIGN

This was a service development study. The 10-year risk estimates of any fracture and hip fracture generated by each of the algorithms were compared.

SETTING

The MS clinic at the Royal London Hospital.

PARTICIPANTS

88 patients with a confirmed diagnosis of MS.

OUTCOME MEASURES

Mean 10-year overall fracture risk and hip fracture risk were calculated using each of the three fracture risk calculators. The number of interventions that would be required as a result of using each of these tools was also compared.

RESULTS

Mean 10-year fracture risk was 4.7%, 2.3% and 7.6% using FRAX, QFracture and the MS-specific calculator, respectively (p<0.0001 for difference). The agreement between risk scoring tools was poor at all levels of fracture risk.

CONCLUSIONS

The agreement between these three fracture risk scoring tools is poor in the MS population. Further work is required to develop and validate an accurate fracture risk scoring system for use in MS.

TRIAL REGISTRATION

This service development study was approved by the Clinical Effectiveness Department at Barts Health NHS Trust (project registration number 156/12).

Investigation of the relationship between vitamin D and bone mineral density in newly diagnosed multiple sclerosis

The aim of this study was to investigate the relationship between vitamin D and bone mineral density in newly diagnosed multiple sclerosis (MS) and to compare results with data from healthy controls. A total of 60 subjects, including 30 patients with MS, newly diagnosed and untreated (18 females, 12 males, at 18-40 years of age) and 30 healthy controls (20 female, 10 male) were enrolled in this study. Bone mineral density (BMD) of the lumbar spine and left femoral neck region were measured by dual-energy X-ray absorptiometry (DEXA). Serum levels of 25-hydroxyvitamin D (25OHD) were measured by chemiluminescence microparticle immunoassay (CMIA) on the Architect-i2000(®) (Abbott) system. 25OHD levels of MS patients were significantly lower than in controls. 25OHD levels were 27.2 ± 14.1 ng/ml in MS patients and 42.6 ± 8.8 ng/ml in controls (p = 0.001). Twenty-six (86.6 %) of our patients had a reduced BMD in lumbar spine or femoral neck region; of these 24 patients (80 %) had osteopenia and 2 patients (6.6 %) had osteoporosis. Interestingly, there was no significant correlation between 25OHD and BMD in lumbar spine and femoral neck region (r = 0.454, p = 0,074; r = 0.636, p = 0.082). Interestingly, a significant reduction of bone density in female MS patients was observed. In our study, 25OHD deficiency and lower BMD appeared in newly diagnosed multiple sclerosis. This is compatible with shared etiologic or pathogenic factors in MS and osteopenia/osteoporosis, and calls for an active approach to optimize bone health in early stages of MS.

Evidence of vitamin D and interferon-β cross-talk in human osteoblasts with 1α,25-dihydroxyvitamin D3 being dominant over interferon-β in stimulating mineralization

It is well established that 1α-25-dihydroxyvitamin D3 (1,25D3) regulates osteoblast function and stimulates mineralization by human osteoblasts. The aim of this study was to identify processes underlying the 1,25D3 effects on mineralization. We started with gene expression profiling analyses of differentiating human pre-osteoblast treated with 1,25D3. Bioinformatic analyses showed interferon-related and -regulated genes (ISG) to be overrepresented in the set of 1,25D3-regulated genes. 1,25D3 down-regulated ISGs predominantly during the pre-mineralization period. This pointed to an interaction between the vitamin D and IFN signaling cascades in the regulation of osteoblast function. Separately, 1,25D3 enhances while IFNβ inhibits mineralization. Treatment of human osteoblasts with 1,25D3 and IFNβ showed that 1,25D3 completely overrules the IFNβ inhibition of mineralization. This was supported by analyses of extracellular matrix gene expression, showing a dominant effect of 1,25D3 over the inhibitory effect of IFNβ. We identified processes shared by IFNβ- and 1,25D3-mediated signaling by performing gene expression profiling during early osteoblast differentiation. Bioinformatic analyses revealed that genes being correlated or anti-correlated with interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) were associated with osteoblast proliferation. In conclusion, the current study demonstrates a cross talk between 1,25D3 and IFNβ in osteoblast differentiation and bone formation/mineralization. The interaction is complex and depends on the process but importantly, 1,25D3 stimulation of mineralization is dominant over the inhibitory effect of IFNβ. These observations are of potential clinical relevance considering the impact of the immune system on bone metabolism in conditions such as rheumatoid arthritis.

Bone health and multiple sclerosis

People with multiple sclerosis (MS) have many reasons to have low bone mineral density and an increased fracture risk. Osteoporosis is a major cause of morbidity and mortality, and is more common in people with MS than the general population. A number of studies have examined the relationship between multiple sclerosis and reduced bone mineral density. In this topical review we seek to address the risk of low bone mineral density, osteoporosis and fractures associated with MS, and make practical suggestions as to how this pertinent issue may be approached in clinical practice.

The nervous system's potential role in multiple sclerosis associated bone loss

Osteoporosis is a degenerative bone disease that causes significant morbidity and mortality in multiple sclerosis (MS) patients; the pathogenesis of this disease being poorly understood in the context of MS. Osteoporosis is seen more frequently in MS patients than in healthy controls matched for age and sex. Extensively studied factors, including impaired ambulation and the use of steroids, do not appear to completely account for the phenomenon. This review summarizes common risk factors, physiologic and genetic, that may contribute to the etiology and progression of osteoporosis in MS patients as well as providing insight into nervous system control of bone metabolism and homeostasis.

IFNβ impairs extracellular matrix formation leading to inhibition of mineralization by effects in the early stage of human osteoblast differentiation

Osteoimmunology is an emerging field of research focused on the interaction of the immune system and bone. In this study we demonstrate that human osteoblasts are sensitive to the immune cytokine interferon (IFN)β. Osteoblasts respond to IFNβ as shown by the induction of several known IFN target genes such as interferon-induced (IFI) proteins (IFIT1, IFI44L), interferon-stimulated gene factor 3 (ISGF3) complex and the induction of IFNβ itself. We demonstrated that IFNβ has severe inhibitory effects on mineralization of osteoblast-derived extracellular matrix (ECM). Analysis of the timing of the IFNβ effects revealed that committed osteoblasts in early stage of differentiation are most sensitive to IFNβ inhibition of mineralization. A single IFNβ treatment was as effective as multiple treatments. During the progress of differentiation osteoblasts become desensitized for IFNβ. This pinpoints to a complex pattern of IFNβ sensitivity in osteoblasts. Focusing on early osteoblasts, we showed that IFNβ decreased gene expression of ECM-related genes, such as type I Collagen (COL1A1), fibronectin (FN1), fibullin (FBLN1), fibrillin (FBN2), and laminin (LAMA1). Additionally, ECM produced by IFNβ-treated osteoblasts contained less collagen protein. IFNβ stimulated gene expression of osteopontin (OPN), annexin2 (ANXA2), and hyaluronan synthase 1 (HAS1), which are important factors in the adhesion of hematopoietic stem cells (HSC) in the HSC niche. In conclusion, IFNβ directly modifies human osteoblast function by inhibiting ECM synthesis eventually resulting in delayed bone formation and mineralization and induces a HSC niche supporting phenotype. These effects are highly dependent on timing of treatment in the early phase of osteoblast differentiation.

Immunomodulators for multiple sclerosis may ameliorate spinal bone loss

BACKGROUND

The effect of immunomodulator therapy (IMT) for multiple sclerosis (MS) on bone turnover is unknown.

AIM

The aim of this study was to assess bone turnover in MS patients on IMT.

METHODS

MS patients (n = 29) on maintenance IMT had repeat measurement of bone mineral density (BMD) after a 4.0 ± 0.4 years; bone turnover markers (BTM) were measured at the time of repeat BMD.

RESULTS

BMD was unchanged at the spine but declined at the hip. BTMs, both resorption and formation, were reduced compared to normative range that may indicate an anti-resorptive action of IMT. Significant negative correlations were noted between BTMs and changes in BMD at spine but not hip.

CONCLUSION

These observations suggest that IMT may have a beneficial effect on spinal bone by an antiresorptive action. A prospective study of the effect of IMT on BMD and bone turnover is warranted.

Cognitive impairment is associated with reduced bone mass in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) has been associated with reduced bone mineral density (BMD), yet the underlying causes are not fully known. The recent discovery that bone homeostasis is directly regulated by the brain led us to hypothesize that it may be impaired by MS pathology. As cognitive impairment (CI) is a well-documented correlate of MS-related brain pathology, we tested the hypothesis that it is associated with reduced BMD.

OBJECTIVE

We aimed to determine if CI is associated with reduced BMD in patients with MS.

METHODS

We retrospectively studied the medical records of 56 patients with MS, ≤50 years old, with Expanded Disability Status Scale score ≤4.5 and with dual X-ray absorptiometry (DEXA) BMD measurement within 1 year of neuropsychological testing with a standard battery (MACFIMS).

RESULTS

In total, 23 (41.1%) MS patients had osteopenia or osteoporosis. Mean femur BMD was significantly lower in patients with MS with CI (0.89±0.12 g/cm(2)) compared with intact patients (0.99±0.17 g/cm(2), p=0.009). In the cognitively impaired group, 59.3% had either osteopenia or osteoporosis, compared with 24.1% in the non-cognitively impaired group (odds ratio=4.57, p=0.008).

CONCLUSION

CI is associated with reduced BMD in patients with MS, suggesting that central mechanisms involved in bone homeostasis may be directly impaired by MS-related inflammatory and neurodegenerative processes.

Multiple sclerosis, a cause of secondary osteoporosis? What is the evidence and what are the clinical implications?

BACKGROUND

Both women and men with multiple sclerosis (MS) are at increased risk of developing osteoporosis.

METHODS

A non-systematic review of the prevalence,pathogenesis and treatment of osteoporosis in patients with multiple sclerosis.

RESULTS

MS and osteoporosis share aetiological risk factors such as smoking and hypovitaminosis D, as well as pathogenetic players such as osteopontin and osteoprotegerin. Recently, low bone mineral density (BMD) values have been measured shortly after diagnosis of clinically isolated syndrome and MS and in fully ambulatory persons with MS below 50 years of age. Studies consistently show that BMD at the femoral neck decreases with increasing MS-related disability. Osteoporosis-related fractures cause increased morbidity and mortality and add to the burden of having MS.

CONCLUSION

We argue that MS, like a number of other chronic diseases, is a cause of secondary osteoporosis. Therefore, bone health assessment should be a part of the integral management of persons with MS. We suggest that BMD be measured shortly after diagnosis, that BMD measurements be repeated depending on BMD values and individual osteoporosis risk profile, and that serum 25-hydroxyvitamin D be monitored. All persons with MS should receive bone health advice.

Osteoporosis in multiple sclerosis

Fractures resulting from osteoporosis are a major cause of morbidity and mortality in the developed world. People with multiple sclerosis experience reduced mobility and are susceptible to falls. Glucocorticoid use and reduced mobility are known risk factors for osteoporosis. This paper is a review of osteoporosis in people with multiple sclerosis, looking at its prevalence, risk factors and possible mechanisms. We also review management guidelines for osteoporosis in the general population and use these to propose guidelines for osteoporosis management amongst multiple sclerosis patients. A number of studies have examined the incidence of reduced bone mineral density amongst people with multiple sclerosis; the majority provide convincing evidence that bone mineral density is significantly reduced in multiple sclerosis patients. The most significant risk factors appear to arise from the chronic disease process of multiple sclerosis and not from glucocorticoid use. There are currently no guidelines or consensus as how best to treat osteoporosis amongst multiple sclerosis patients despite their being at an increased risk. We propose an algorithm for the screening and treatment of osteoporosis in people with multiple sclerosis.

Predictors and prevalence of low bone mineral density in fully ambulatory persons with multiple sclerosis

The implications of having multiple sclerosis (MS) for bone health are incompletely understood. The aim of this population-based study is to identify past and current exposures that are associated with bone mass in fully ambulatory persons with MS up to age 50 years and to determine the prevalence of low bone mineral density (BMD) in this group. We measured BMD (hips, lumbar spine, forearms), physical function, BMI, and serum 25(OH) vitamin D in 55 women and 25 men with MS. Patients provided information on demographic variables and medical history, as well as past and current vitamin D and calcium intake, physical activity, and lifestyle habits. In regression analyses, BMD levels were adjusted for age, sex, and BMI. At the femoral neck, strong associations were found for walking distance (beta = 0.152; P < 0.001) and age (beta = -0.004; P = 0.003), and less certain associations for male sex (beta = 0.055; P = 0.014) and 10-foot timed tandem walk (-0.008; P = 0.013). At the lumbar spine, walking distance (beta = 0.013; P = 0.006) and possibly physical activity growing up (beta = 0.035; P = 0.028) and male sex (beta = -0.057; P = 0.042), were associated with BMD. At the ultradistal radius, strength of grip (beta = 0.001; P = 0.002), and, less certainly, summer outdoor activities age 16-20 (beta = 0.021; P = 0.009), and age at MS onset (beta = 0.002; P = 0.036) were associated with BMD. Low BMD (z score < or = -2) was present in 19 out of 80 patients. This study shows that MS-related variables as well as past exposures differentially affect BMD at three clinically important skeletal sites. Low BMD is prevalent in these young patients. Bone health should receive attention in care for persons with MS.

Mechanisms of interferon-beta effects on bone homeostasis

Restoration of dysregulated bone homeostasis is a therapeutic goal in many diseases including osteoporosis, rheumatoid arthritis and metastatic cancer. The molecular pathways regulating bone remodeling are major therapeutic targets, and studies continue to reveal endogenous factors that may be pathologically up- or down-regulated and lead to an uncoupling of bone formation and resorption. The purpose of this commentary is to highlight new mechanisms of bone homeostatic regulation mediated through the induction of endogenous interferon-beta (IFN-beta). The receptor activator of nuclear factor-kappaB (RANK) ligand (RANKL) is an important factor in the bone resorption cascade, and the RANK-RANKL interaction has been shown to induce IFN-beta and osteoclastogenesis via induction of the c-fos gene. Subsequent binding of IFN-beta to its biological receptor initiates a signal transduction cascade through the classic JAK/STAT pathway, causing an inhibition of c-fos protein production and osteoclast proliferation and differentiation (negative feedback). Another mechanism pertinent to the anti-resorptive effect of IFN-beta is the induction of nitric oxide which has been shown to inhibit osteoclast formation. The role of IFN-beta in bone metabolism could warrant its systematic evaluation as a potential adjunct to therapeutic regimens of osteolytic diseases. Here we also provide discussion of the potential challenges to optimizing IFN-beta pharmacotherapy for such purposes.

Favorable effect of immunomodulator therapy on bone mineral density in multiple sclerosis

BACKGROUND

Osteoporosis is a complication of multiple sclerosis (MS), especially if corticosteroid therapy is given. Little is known about the effect on bone of immunomodulatory therapy (IMT) for MS.

AIM

We sought to evaluate bone mass in patients with MS on IMT.

METHODS

We measured bone mineral density (BMD) by dual energy X-ray absorptiometry (DXA) in 37 patients with MS who received IMT. Different IMTs were administered: interferon beta-1a in 70%, interferon beta-1b in 27% and Glatiramer in 3%. High-dose pulse corticosteroid therapy (intravenous methylprednisolone 500 mg) was given to 81% ranging from 1 to 17 courses.

RESULTS

Both mean BMD Z-score at spine of 0.53 (CI, 0.15-0.92; P = 0.0084) and mean BMD Z-score at femur of 0.72 (CI, 0.42-1.01; P < 0.0001) were significantly greater than zero.

CONCLUSIONS

IMT may have a favorable effect on bone in patients with MS even in the presence of pulse steroid therapy.

The effect of interferon-β on black holes in patients with multiple sclerosis

Multiple sclerosis (MS) is an immunological disorder of the CNS. Linked to an initial transient inflammation as the result of blood-brain barrier leakage, the disease progresses into a neurodegenerative phase. MRI is the most powerful paraclinical tool for diagnosing and monitoring MS. Although contrast enhancing lesions are the visible events of blood-brain barrier breakdown, accumulation of hypointense lesions, namely black holes, are recognised as irreversible axonal loss. IFN-beta is administered as a first-line drug in MS patients. However, whether the effect of IFN-beta extends beyond just prevention of blood-brain barrier leakage and further prevents the formation of black holes or promotes their recovery once formed, is not yet understood.