Vitamin D insufficiency in a large MCTD population

Emerging role of vitamin D in autoimmune diseases: An update on evidence and therapeutic implications

Vitamin D plays a key role in in calcium homeostasis and, thus, provides an important support in bone growth by aiding in the mineralization of the collagen matrix. However, vitamin D performs various immunomodulatory, anti-inflammatory, antioxidant and anti-fibrotic actions. Autoimmune diseases result from an aberrant activation of the immune system, whereby the immune response is directed against harmless self-antigens. Does vitamin D play a role in the pathophysiology of autoimmune diseases? And, if so, what is its role? In the last decade, researchers' interest in vitamin D and its correlations with autoimmune diseases has considerably increased. We conducted a literature review, covering the period January 1, 2009 through March 30, 2019, in PubMed. We analyzed more than 130 studies in order to find a correlation between vitamin D levels and its effect upon several autoimmune diseases. The analysis demonstrated an inverse association between vitamin D and the development of several autoimmune diseases, such as SLE, thyrotoxicosis, type 1 DM, MS, iridocyclitis, Crohn's disease, ulcerative colitis, psoriasis vulgaris, seropositive RA, polymyalgia rheumatica. International multicenter study could allow us to confirm the data already present in the literature in the single clinical studies and to evaluate when to effectively supplement vitamin D in patients who do not take corticosteroids.

Vitamin D deficiency as a risk factor for the development of autoantibodies in patients with ASIA and silicone breast implants: a cohort study and review of the literature

The development of autoimmunity and/or autoimmune diseases is multifactorial. Vitamin D is one of the factors that might play a role. We postulated that both the presence of adjuvants and insufficient levels of vitamin D may result in the development of autoimmunity in patients with autoimmune/inflammatory syndrome induced by adjuvants (ASIA) in relation to silicone implant incompatibility. We measured vitamin D levels in 135 patients with ASIA in relation to silicone implant incompatibility and related findings to the presence of autoantibodies that are commonly used to diagnose systemic autoimmune diseases. Furthermore, we systematically reviewed the literature regarding vitamin D deficiency as a risk factor for the development of autoantibodies. Vitamin D measurements were available for analysis in 131 of 135 patients with ASIA in relation to SIIS. Twenty-three patients (18%) tested positive for autoantibodies, from which 18 patients (78%) had either a vitamin D deficiency or insufficiency (median vitamin D level 60.5 mmol/L), whereas five patients (22%) had sufficient vitamin D levels. The risk to develop autoantibodies was significantly increased in vitamin D deficient and/or insufficient patients [RR 3.14; 95% CI, 1.24–7.95; p = 0.009]. Reviewed literature suggested an association between vitamin D levels and the presence and/or titer levels of autoantibodies in different autoimmune diseases. From our current study and from our review of the literature, we conclude that vitamin D deficiency is related to the presence of autoantibodies. Whether vitamin D supplementation results in a decrease of autoimmunity needs to be studied prospectively.

European multicentre pilot survey to assess vitamin D status in rheumatoid arthritis patients and early development of a new Patient Reported Outcome questionnaire (D-PRO)

OBJECTIVE

To collect data on vitamin D (25(OH)D) serum levels in a large number of rheumatoid arthritis (RA) patients from different European countries, to investigate their relation with disease activity, disability, quality of life, and possibly to construct a new Patient Reported Outcome (PRO) questionnaire in order to self-estimate if they are at risk for vitamin D insufficiency/deficiency-related clinical implications (D-PRO).

METHODS

This was a European League Against Rheumatism (EULAR) supported cross-sectional study (project No CLI064) which involved 625 RA patients (mean age 55±11years, mean disease duration 11±9years), 276 age and sex matched healthy subjects, and rheumatologists working in academic institutions or hospital centres, as well as PARE organizations (patient representatives) from 13 European countries. Serum samples for 25(OH)D level measurement were collected during winter time and analyzed in a central laboratory using chemiluminescence immunoassay (DiaSorin). Patient past medical history was recorded. RA patients were provided with three questionnaires: the Rheumatoid Arthritis Impact Diseases score (RAID), the Health Assessment Questionnaire (HAQ), and the new D-PRO questionnaire at the time of 25(OH)D serum sampling. D-PRO questionnaire consisted of three domains, Symptom Risk Score (SRS), Habitus Risk Score (HRS) and Global Risk Score (SRS+HRS=GRS), constructed with items possibly related to vitamin D deficiency. D-PRO was correlated with both clinical and PRO scores. DAS28-CRP was also evaluated. Statistical analysis was performed by non parametric tests.

RESULTS

Mean serum concentration of 25(OH)D in RA patients (17.62±9.76ng/ml) was found significantly lower if compared to the levels obtained in matched controls (18.95±9.45ng/ml) (p=0.01), with statistically significant differences among several European countries. Negative correlations were found between 25(OH)D serum levels and DAS28-CRP (p<0.001), RAID (p=0.05) and HAQ (p=0.04) scores in the RA patients group. Negative correlations were also found in the cohort of enrolled RA patients between 25(OH)D serum concentrations and SRS (p=0.04), HRS (p=0.02) and GRS (p=0.02) domains of the D-PRO questionnaire.

CONCLUSIONS

This first multicentre European survey add new evidences that vitamin D insufficiency/deficiency is frequent in RA patients with statistically significant differences among several countries. Vitamin D serum concentrations seem to correlate negatively and significantly with the D-PRO Global Risk Score, clinimetric indexes for quality of life, disease activity and disability in present cohort of RA European patients.

Infections as a cause of autoimmune rheumatic diseases

Exogenous and endogenous environmental exposures and particularly infections may participate in the breakage of tolerance and the induction of autoimmunity in rheumatic diseases. Response to infections apparently occurs years before clinical manifestations and features of autoimmunity, such as autoantibodies, are detected years before clinical manifestations in autoimmune rheumatic diseases. In this review, we summarize the current evidence for a potential causal link between infectious agents and rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis, Sjogren’s syndrome and ANCA-associated vasculitis.

Cytokine Milieu in Undifferentiated Connective Tissue Disease: a Comprehensive Review

Undifferentiated connective tissue disease (UCTD) is a unique clinical entity, a potential forerunner of well-established systemic autoimmune/rheumatic diseases. UCTD is characterized by the presence of various clinical symptoms, as well as a diverse repertoire of autoantibodies, resembling systemic autoimmune diseases. Since approximately one third of these patients consequently transform into a full-blown systemic autoimmune/rheumatic disease, it is of major importance to assess pathogenic factors leading to this progression. In view of the fact that the serological and clinical picture of UCTD and systemic autoimmune diseases are very similar, it is assumed that analogous pathogenic factors perpetuate both disease entities. In systemic autoimmune conditions, a quantitative and qualitative impairment of regulatory T cells has been shown previously, and in parallel, a relative dominance of pro-inflammatory Th17 cells has been introduced. Moreover, the imbalance between regulatory and Th17 cells plays a pivotal role in the initiation and propagation of UCTD. Additionally, we depict a cytokine imbalance, which give raise to a biased T cell homeostasis from the UCTD phase throughout the fully developed systemic autoimmune disease stage. The levels of interleukin (IL)-6, IL-12, IL-17, IL-23, and interferon (IFN)-γ were pathologically increased with a parallel reduction of IL-10. We believe that the assessment of Th17/Treg cell ratio, as well as the simultaneous quantitation of cytokines may give a useful diagnostic tool at the early UCTD stage to identify patients with a higher chance of consecutive disease progression toward serious systemic autoimmune diseases. Moreover, the early targeted immunomodulating therapy in these patients may decelerate, or even stop this progression, before the development of serious autoimmune conditions with organ damage.

Infectomics and autoinfectomics: a tool to study infectious-induced autoimmunity

The exposome represents all exogenous and endogenous environmental exposures that begin at preconception and carry on throughout life, while the microbiome reflects the microbial component of the exposome. We recently introduced the concept of infectome and autoinfectome as a means of studying the totality of infections throughout life that participate in the induction as well as the progression of autoimmune diseases in an affected individual. The investigation of the autoinfectome could help us understand why some patients develop more than one autoimmune disease, a phenomenon also known as mosaic of autoimmunity. It could also explain the infectious and autoantibody burden of various autoimmune rheumatic diseases. The close interplay between infections and the immune system should be studied over time, long before the onset of autoaggression and autoimmunity. Tracking down each individual's exposure to infectious agents (as defined by the autoinfectome) would be important for the establishment of a causative link between infection and autoimmunity.

Vitamin D as a risk factor for premature atherosclerosis in patients with type 2 diabetes

BACKGROUND

Several cardiovascular risk factors have been recognized in patients with diabetes and vitamin D deficiency is emerging as a new risk. The aim of this study was to determine the effect of vitamin D deficiency on the incidence of premature atherosclerosis in patients with type 2 diabetes.

METHODS

A total of 78 patients with type 2 diabetes were subjected to history taking, physical examination, fasting glucose level, homeostasis model assessment of insulin resistance, lipid profile, 25(OH) vitamin D measurement, and carotid Doppler.

RESULTS

Patients with normal carotid intima-media thickness (CIMT) had sufficient vitamin D. Of those with increased CIMT 23.1% had insufficient vitamin D while 76.9% had sufficient vitamin D (six patients had plaques, one of them had vitamin D insufficiency, and the other five patients had sufficient vitamin D). There was a statistically significant difference in the serum level of vitamin D between patients with increased CIMT, and those with normal intima, with a decreased level in the first group. There was a significant negative correlation between vitamin D and fasting blood glucose. There was a statistically significant correlation in left CIMT between the vitamin D sufficiency group and the vitamin D insufficiency group, with higher values in the second group. There was no statistically significant difference in serum cholesterol, triglycerides, HDL cholesterol, and LDL cholesterol in patients with increased CIMT and those with normal intima.

CONCLUSIONS

Decreased vitamin D levels in patients with diabetes lead to increased CIMT. The absence of a statistically significance difference in lipid profile between increased and normal CIMT groups raises the possibility of underlying causes for atherosclerosis in patients with diabetes other than dyslipidemia.

Vitamin D in primary biliary cirrhosis, a plausible marker of advanced disease

Vitamin D immune-modulating effects were extensively studied, and low levels have been linked with autoimmune diseases. The associations of vitamin D with autoimmune diseases of the liver, and particularly primary biliary cirrhosis (PBC), are yet to be defined. Hence, in this study, serum levels of vitamin D were determined in 79 patients with PBC and 70 age- and sex-matched controls by the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). Clinical and serological parameters of patients were analyzed with respect to vitamin D status. Mean levels of vitamin D were significantly lower among patients with PBC compared with controls (16.8 ± 9 vs. 22.1 ± 9 ng/ml; p = 0.029), and vitamin D deficiency (≤10 ng/ml) was documented in 33% of patients with PBC versus 7% of controls (p < 0.0001). Vitamin D levels inversely correlated with advanced liver damage and the presence of concomitant autoimmune diseases. In contrast, higher levels of vitamin D were observed among patients with PBC treated with ursodeoxycholic acid (UDCA). In conclusion, low vitamin D levels are common among patients with PBC and correlate with advanced disease, lack of UDCA therapy and autoimmune comorbidity. This alludes to the plausible roles of vitamin D as a prognostic marker of PBC severity, and as a potential player in this disease pathogenesis. While further studies are awaited, monitoring vitamin D in patients with PBC and use of supplements may be advisable.

Relationship between Body Mass Composition, Bone Mineral Density, Skin Fibrosis and 25(OH) Vitamin D Serum Levels in Systemic Sclerosis

A reduced bone mineral density (BMD) is observed in several rheumatic autoimmune diseases, including Systemic Sclerosis (SSc); nevertheless, data concerning the possible determinants of bone loss in this disease are not fully investigated. The aim of this study is to evaluate the relationship between BMD, body mass composition, skin sclerosis and serum Vitamin D levels in two subsets of SSc patients. 64 post-menopausal SSc patients, classified as limited cutaneous (lcSSc) or diffuse cutaneous (dcSSc) SSc, were studied. As control, 35 healthy post-menopausal women were recruited. Clinical parameters were evaluated, including the extent of skin involvement. BMD at lumbar spine, hip, femoral neck and body mass composition were determined by dual-energy X-ray absorptiometry. Serum calcium, phosphorus, alkaline phosphatase, urine pyridinium cross-links, intact parathyroid hormone and 25-hydroxyvitamin D (25OHD) were measured. BMD at spine, femoral neck and total hip was significantly lower in SSc patients compared to controls. In dcSSc subset, BMD at spine, femoral neck and total hip was significantly lower compared to lcSSc. No differences in both fat and lean mass were found in the three study groups even if patients with dcSSc showed a slightly lower total body mass compared to healthy controls. Total mineral content was significantly reduced in dSSc compared to both healthy subjects and lcSSc group. Hypovitaminosis D was observed both in healthy post-menopausal women and in SSc patients, but 25OHD levels were significantly lower in dcSSc compared to lcSSc and inversely correlated with the extent of skin thickness. These results support the hypothesis that the extent of skin involvement in SSc patients could be an important factor in determining low circulating levels of 25OHD, which in turn could play a significant role in the reduction of BMD and total mineral content.

Selected Aspects in the Pathogenesis of Autoimmune Diseases

Autoimmune processes can be found in physiological circumstances. However, they are quenched with properly functioning regulatory mechanisms and do not evolve into full-blown autoimmune diseases. Once developed, autoimmune diseases are characterized by signature clinical features, accompanied by sustained cellular and/or humoral immunological abnormalities. Genetic, environmental, and hormonal defects, as well as a quantitative and qualitative impairment of immunoregulatory functions, have been shown in parallel to the relative dominance of proinflammatory Th17 cells in many of these diseases. In this review we focus on the derailed balance between regulatory and Th17 cells in the pathogenesis of autoimmune diseases. Additionally, we depict a cytokine imbalance, which gives rise to a biased T-cell homeostasis. The assessment of Th17/Treg-cell ratio and the simultaneous quantitation of cytokines, may give a useful diagnostic tool in autoimmune diseases. We also depict the multifaceted role of dendritic cells, serving as antigen presenting cells, contributing to the development of the pathognomonic cytokine signature and promote cellular and humoral autoimmune responses. Finally we describe the function and role of extracellular vesicles in particular autoimmune diseases. Targeting these key players of disease progression in patients with autoimmune diseases by immunomodulating therapy may be beneficial in future therapeutic strategies.

Increased levels of anti-heat-shock protein 60 (anti-Hsp60) indicate endothelial dysfunction, atherosclerosis and cardiovascular diseases in patients with mixed connective tissue disease

Heat-shock protein 60 (Hsp60) has been shown to provoke inflammation, and anti-Hsp60 may facilitate the development of atherosclerosis. In this study, we have investigated 30 patients with mixed connective tissue disease (MCTD) and assessed anti-Hsp60 and their relationship to cardiovascular diseases (CVD). Out of 30 patients with MCTD, 15 had CVDs. Anti-Hsp60 antibody was determined by enzyme-linked immunosorbent assay. Since endothelial dysfunction and accelerated atherosclerosis are characteristic to MCTD, a wide array of MCTD-, endothelial dysfunction- and CVD-associated parameters was investigated: serum lipid levels, paraoxonase activity (PON1), rich nuclear ribonucleoprotein U1 (anti-U1RNP), anti-endothelial cell antibodies, anti-cardiolipin and anti-β2-glycoprotein I antibody isotypes (anti-CL and anti-β2GPI), endothelin-1 (ET-1) levels, also intima-media thickness (IMT), a quantitative indicator of atherosclerosis. In MCTD, anti-Hsp60 antibody levels were significantly higher than in healthy individuals (p < 0.02). MCTD patients with CVD had significantly higher levels of anti-Hsp60 compared to MCTD without CVD (p = 0.001). Patients with MCTD had significantly lower high-density lipoprotein cholesterol (p = 0.02) and PON activity (p < 0.001), and significantly increased systolic (p < 0.0002) and diastolic (p < 0.001) blood pressure compared to healthy individuals. Anti-U1RNP levels (p < 0.002) and IMT were higher in patients compared to controls (p = 0.002). The CVD-positive MCTD patients had increased anti-Hsp60 (p < 0.0013), anti-CL IgG (p = 0.0005), ET-1 serum concentration (p < 0.05) and IMT levels (p < 0.001) compared to MCTD patients without CVD. Anti-Hsp60 showed a strong correlation with anti-oxLDL (r = 0.36, p = 0.01) and serum ET-1 (r = 0.62, p < 0.001) and negative correlation with PON activity (r = -0.47, p = 0.01). Anti-Hsp60 indicates endothelial injury, CVD, and can function as a novel atherosclerotic risk factor, also a valuable diagnostic marker in patients with MCTD.

Vitamin D3 levels and bone mineral density in patients with psoriasis and/or psoriatic arthritis

Limited data are available on the vitamin D3 status and bone mineral density (BMD) of patients with psoriasis or with psoriatic arthritis. Our study intended to explore possible correlations between vitamin D status and BMD, as well as among these parameters and the features of the underlying disorder. Seventy-two patients with psoriasis/or psoriatic arthritis (female : male ratio, 40:32; mean age, 58.5 ± 11.6 years; mean duration of follow up, 142.7 ± 147.7 months) participated in the study. We evaluated the characteristic clinical features of the underlying disease, performed bone densitometry of the lumbar spine and the hip region, measured the serum vitamin 25(OH)D3 levels of the patients, and undertook the statistical analysis of the relationships between the clinical and the laboratory parameters. The proportion of patients with a low BMD value did not exceed that seen in the general population. We found an inverse correlation between the serum level of vitamin 25(OH)D3 and body mass index, as well as between the former and the severity of skin involvement. Furthermore, the activity of psoriatic arthritis was significantly higher in patients with inadequate vitamin D3 status. In patients with psoriatic arthritis, BMD significantly exceeded the values measured in patients suffering from psoriatic skin lesions only. Our findings suggest the importance of evaluating the vitamin D3 status and screening for comorbid conditions in patients with psoriasis or psoriatic arthritis. This appears justified, in particular, due to the possible role of hypovitaminosis D3 in provoking the development of skin lesions and joint symptoms.

Vitamin D status and metabolic syndrome in the elderly: the Rotterdam Study

OBJECTIVE

The effects of vitamin D in the elderly are inconsistent. The aim of this study was to evaluate the association between vitamin D status and the metabolic syndrome (MetS) in the elderly, as well as between vitamin D status and the components of MetS (i.e. serum glucose, triglycerides (TG), HDL cholesterol (HDL-C), waist circumference (WC), and blood pressure (BP)).

METHODS

The study was embedded in the Rotterdam Study, a population-based cohort of middle-aged and elderly adults. We analyzed data from 3240 people (median age 71.2 years) who did not have type 2 diabetes mellitus at baseline.

RESULTS

We found higher 25-hydroxyvitamin D (25(OH)D) concentrations associated with lower prevalence of MetS (odds ratio (OR); 95% CI: 0.61; 0.49, 0.77 for adequate levels (≥75  nmol/l) vs deficiency (<50  nmol/l). In addition, in analysis of the individual components, the ORs for adequate vs deficient vitamin D levels were: 0.66 (95% CI 0.53, 0.83) for elevated WC, 0.67 (95% CI 0.52, 0.86) for reduced HDL-C, 0.69 (95% CI 0.54, 0.88) for elevated TG, and 0.80 (95% CI 0.65, 0.99) for elevated fasting glucose. Vitamin D was not associated with elevated blood pressure, and ORs for adequacy vs deficiency were 0.82 (95% CI 0.65, 1.03).

CONCLUSION

Higher 25(OH)D concentrations in the elderly are associated with lower prevalence of MetS and, in particular, with more beneficial HDL-C, TG, WC, and serum glucose. Since the prevalence of vitamin D deficiency is common worldwide and its risk increases with age, if causality is proven, benefits of improving vitamin D status among the elderly may be great.

Vitamin D Levels Are Associated with Expression of SLE, but Not Flare Frequency

This study explores links between vitamin D deficiency (25(OH)D = 50 nmol/L) and serological autoimmunity (ANA > 1 : 80) and frequency of self-reported flares (SRF) in participants with clinical autoimmunity (SLE). 25(OH)D levels of 121 females were quantified and compared. The cohort consisted of 80 ACR defined SLE patients and 41 age and sex matched controls. Association analysis of log2 (25(OH)D) levels and ANA 80 positivity was undertaken via two-sample t-tests and regression models. Significant differences were found for 25(OH)D levels (mean: control 74 nmol/L (29.5 ng/ml); SLE 58 nmol/L (23.1 ng/ml), P = 0.04), 25(OH)D deficiency (P = 0.02). Regression models indicate that, for a twofold rise in 25(OH)D level, the odds ratio (OR) for ANA-positivity drops to 36% of the baseline OR. No link was found between SRF-days and 25(OH)D levels. Our results support links between vitamin D deficiency and expression of serological autoimmunity and clinical autoimmunity (SLE). However, no demonstrable association between 25(OH)D and SRF was confirmed, suggesting independent influences of other flare-inducing factors. Results indicate that SLE patients have high risk of 25(OH)D deficiency and therefore supplementation with regular monitoring should be considered as part of patient management.

Immunomodulation in human and experimental arthritis: including vitamin D, helminths and heat-shock proteins

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that is mainly directed to the joints, affecting the synovial membrane, the cartilage and also the bone. This disease affects 1% to 2% of the world population and is associated with significant morbidity and increased mortality. RA experimental models have allowed a great deal of information to be translated to the corresponding human disease. This review summarizes some of the most relevant findings targeting immunomodulation in arthritis. Some general guidelines to choose an adequate experimental model and also our experience with arthritis are supplied.

The implication of vitamin D and autoimmunity: a comprehensive review

Historically, vitamin D has been associated with the regulation of bone metabolism. However, increasing evidence demonstrates a strong association between vitamin D signaling and many biological processes that regulate immune responses. The discovery of the vitamin D receptor in multiple immune cell lineages, such as monocytes, dendritic cells, and activated T cells credits vitamin D with a novel role in modulating immunological functions and its subsequent role in the development or prevention of autoimmune diseases. In this review we, discuss five major areas in vitamin D biology of high immunological significance: (1) the metabolism of vitamin D; (2) the significance of vitamin D receptor polymorphisms in autoimmune diseases, such as multiple sclerosis, type 1 diabetes mellitus, and systemic lupus erythematosus; (3) vitamin D receptor transcriptional regulation of immune cell lineages, including Th1, Th17, Th2, regulatory T, and natural killer T cells; (4) the prevalence of vitamin D insufficiency/deficiency in patients with multiple sclerosis, type 1 diabetes mellitus, and systemic lupus erythematosus; and finally, (5) the therapeutic effects of vitamin D supplementation on disease severity and progression.

Vitamin D in systemic and organ-specific autoimmune diseases

Lately, vitamin D has been linked with metabolic and immunological processes, which established its role as an essential component of human health preservation. Vitamin D has been defined as natural immune modulators, and upon activation of its receptors (VDRs), it regulates calcium metabolism, cellular growth, proliferation and apoptosis, and other immunological functions. Epidemiological data underline a strong correlation between poor vitamin D status and higher risk for chronic inflammatory illnesses of various etiologies, including autoimmune diseases. Epidemiological, genetic, and basic studies indicated a potential role of vitamin D in the pathogenesis of certain systemic and organ-specific autoimmune diseases. These studies demonstrate correlation between low vitamin D and prevalence of diseases. In addition, VDRs' polymorphisms observed in some of these autoimmune diseases may further support a plausible pathogenic link. Notably, for some autoimmune disease, no correlation with vitamin D levels could be confirmed. Thus, in the current review we present the body of evidence regarding the plausible roles of vitamin D and VDR's polymorphism in the pathogenesis of autoimmunity. We summarize the data regarding systemic (i.e., systemic lupus erythematosus, rheumatoid arthritis, etc.) and organ-specific (i.e., multiple sclerosis, diabetes mellitus, primary biliary cirrhosis, etc.) autoimmune diseases, in which low level of vitamin D was found comparing to healthy subjects. In addition, we discuss the correlations between vitamin D levels and clinical manifestations and/or activity of diseases. In this context, we address the rational for vitamin D supplementation in patients suffering from autoimmune diseases. Further studies addressing the mechanisms by which vitamin D affects autoimmunity and the proper supplementation required are needed.

Tracing environmental markers of autoimmunity: introducing the infectome

We recently introduced the concept of the infectome as a means of studying all infectious factors which contribute to the development of autoimmune disease. It forms the infectious part of the exposome, which collates all environmental factors contributing to the development of disease and studies the sum total of burden which leads to the loss of adaptive mechanisms in the body. These studies complement genome-wide association studies, which establish the genetic predisposition to disease. The infectome is a component which spans the whole life and may begin at the earliest stages right up to the time when the first symptoms manifest, and may thus contribute to the understanding of the pathogenesis of autoimmunity at the prodromal/asymptomatic stages. We provide practical examples and research tools as to how we can investigate disease-specific infectomes, using laboratory approaches employed from projects studying the “immunome” and “microbiome”. It is envisioned that an understanding of the infectome and the environmental factors that affect it will allow for earlier patient-specific intervention by clinicians, through the possible treatment of infectious agents as well as other compounding factors, and hence slowing or preventing disease development.

The role of the intraplaque vitamin d system in atherogenesis

Vitamin D has been shown to play critical activities in several physiological pathways not involving the calcium/phosphorus homeostasis. The ubiquitous distribution of the vitamin D receptor that is expressed in a variety of human and mouse tissues has strongly supported research on these "nonclassical" activities of vitamin D. On the other hand, the recent discovery of the expression also for vitamin D-related enzymes (such as 25-hydroxyvitamin D-1 α -hydroxylase and the catabolic enzyme 1,25-dihydroxyvitamin D-24-hydroxylase) in several tissues suggested that the vitamin D system is more complex than previously shown and it may act within tissues through autocrine and paracrine pathways. This updated model of vitamin D axis within peripheral tissues has been particularly investigated in atherosclerotic pathophysiology. This review aims at updating the role of the local vitamin D within atherosclerotic plaques, providing an overview of both intracellular mechanisms and cell-to-cell interactions. In addition, clinical findings about the potential causal relationship between vitamin D deficiency and atherogenesis will be analysed and discussed.

Vitamin D status and hypercholesterolemia in Spanish general population

Low serum 25-hydroxyvitamin D [25(OH)D] levels have been associated with increased prevalence of cardiovascular diseases. A possible relation between lipids and 25(OH)D might explain this association. This investigation aimed to determine the association between vitamin D and cholesterol, as well as the influence of statins on this association. This was a cross-sectional population-based study with 177 subjects aged 18-84 years. We collected demographics and data on sun exposure, sun protection habits, current medication including lipid-lowering drugs, and estimated vitamin D intake. Serum measurements included levels of 25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglycerides, and fasting glucose. The mean 25(OH)D level was 24 ± 9 ng/ml. Young age (P = 0.04) and spending more than 1 h outdoors (P = 0.04) were independently associated with higher 25(OH)D levels. The 25(OH)D concentrations correlated negatively with total cholesterol (P = 0.01) and LDL cholesterol (P = 0.04) levels. The adjusted OR for total cholesterol > 200 mg/ml was 2.8 (range, 1.1-7.5). Receiving statins was associated with higher 25(OH)D levels (P = 0.04). In conclusion, this study supports an association between 25(OH)D levels and cholesterol. Further studies are required to explain this association.

Vitamin D in autoimmune liver disease

The development of autoimmune disease is based on the interaction of genetic susceptibility and environmental causes. Environmental factors include infectious and non-infectious agents, with some of these factors being implicated in several autoimmune diseases. Vitamin D is now believed to play a role in the development (or prevention) of several autoimmune diseases, based on its immunomodulatory properties. As well, the increasing incidence of autoimmune disease as one moves away from the equator, may be due to the lack of sunlight, which is crucial for the maintenance of normal vitamin D levels. A deficiency in vitamin D levels or vitamin D receptors is commonly indicated in autoimmune diseases, with multiple sclerosis (MS) being one of the best-studied and well-known examples. However, the role of vitamin D in other autoimmune diseases is not well defined, including autoimmune liver diseases such as primary biliary cirrhosis, autoimmune hepatitis, and primary sclerosing cholangitis. This review will examine the role of vitamin D as an immunomodulator, followed by a comparison of vitamin D in MS versus autoimmune liver disease. From this comparison, it will become clear that vitamin D likely plays a role in the development of autoimmune liver disease, but this area requires further investigation.

Serum concentrations of 25-hydroxyvitamin D and immunoglobulins in an older Swiss cohort: results of the Senior Labor Study

BACKGROUND

Vitamin D and the components of humoral immunity play important roles in human health. Older people have lower 25-hydroxyvitamin D (25(OH)D) serum levels than younger adults. We aimed to determine the levels of 25(OH)D serum concentrations in healthy senior citizens and to study their relationship to the levels of components of humoral immunity.

METHODS

A total of 1,470 healthy Swiss men and women, 60 years or older, were recruited for this study. A total of 179 subjects dropped out of the study because of elevated serum concentrations of C-reactive protein. Fasting blood sera were analyzed for 25(OH)D with the high-performance liquid chromatography (HPLC) and for parathyroid hormone (PTH), immunoglobulins and complement C4 and C3 concentrations with immunoassays. The percentage of participants in each of the four 25(OH)D deficiency groups--severely deficient (<10 ng/ml), deficient (10 to 20), insufficient (21 to 29 ng/ml) and normal (>=30 ng/ml)--were statistically compared. The relationship of the major components of the humoral system and age with 25(OH)D levels was also assessed.

RESULTS

About 66% of the subjects had insufficient levels of 25(OH)D. Normal levels of 25(OH)D were found in 26.1% of the subjects of which 21% were males and 30.5% were females (total study population). Severely deficient levels of 25(OH)D were found in 7.98% of the total study population. Low levels of 25(OH)D were positively associated with IgG2 (P = 0.01) and with C4 (P = 0.02), yet were inversely related to levels of IgG1 and IgA (P < 0.05) and C3 (P = 0.01). Serum levels of total IgA, IgG, IgG2 and IgG4 peaked together with 25(OH)D during late summer.

CONCLUSIONS

Approximately two-thirds of the healthy, older Swiss population presented with Vitamin D insufficiency. The incremental shift in IgA and C3 levels might not necessarily reflect a deranged humoral immune defense; however, given the high prevalence of vitamin D deficiency, the importance of this condition in humoral immunity will be worth looking at more closely. This study supports the role of vitamin D in the competent immune system.

Clinical course, prognosis, and causes of death in mixed connective tissue disease

OBJECTIVE

To study the survival rate and prognostic indicators of mixed connective tissue disease (MCTD) in a Hungarian population.

METHODS

Two hundred eighty patients with MCTD diagnosed between 1979 and 2011 were followed prospectively. Clinical features, autoantibodies, and mortality data were assessed. Prognostic factors for survival were investigated and survival was calculated from the time of the diagnosis by Kaplan-Meier method.

RESULTS

A total of 22 of 280 patients died: the causes of death were pulmonary arterial hypertension (PAH) in 9 patients, thrombotic thrombocytopenic purpura in 3, infections in 3, and cardiovascular events in 7. The 5, 10, and 15-year survival rates after the diagnosis was established were 98%, 96%, and 88%, respectively. The deceased patients were younger at the diagnosis of MCTD compared to patients who survived (35.5 ± 10.4 vs 41.8 ± 10.7 yrs; p < 0.03), while there was no difference in the duration of the disease (p = 0.835). Our cohort study showed that the presence of cardiovascular events (p < 0.0001), esophageal hypomotility (p = 0.04), serositis (p < 0.001), secondary antiphospholipid syndrome (p = 0.039), and malignancy (p < 0.001) was significantly higher in the deceased patients with MCTD. The presence of anticardiolipin (p = 0.019), anti-β2-glycoprotein I (p = 0.002), and antiendothelial cell antibodies (p = 0.002) increased the risk of mortality.

CONCLUSION

Overall, PAH remained the leading cause of death in patients with MCTD. The prevalence of cardiovascular morbidity and mortality, malignancy, and thrombotic events increased during the disease course of MCTD. The presence of antiphospholipid antibodies raised the risk of mortality.

Assessment of intracellular cytokines and regulatory cells in patients with autoimmune diseases and primary immunodeficiencies - novel tool for diagnostics and patient follow-up

Serum and intracytoplasmic cytokines are mandatory in host defense against microbes, but also play a pivotal role in the pathogenesis of autoimmune diseases by initiating and perpetuating various cellular and humoral autoimmune processes. The intricate interplay and fine balance of pro- and anti-inflammatory processes drive, whether inflammation and eventually organ damage will occur, or the inflammatory cascade quenches. In the early and late, as well as inactive and active stages of autoimmune diseases, different cellular and molecular patterns can dominate in these patients. However, the simultaneous assessment of pro- and anti-inflammatory biomarkers aids to define the immunological state of a patient. A group of the most useful inflammatory biomarkers are cytokines, and with increasing knowledge during the last decade their role have been well-defined in patients with autoimmune diseases and immunodeficiencies. Multiple pathological processes drive the development of autoimmunity and immunodeficiencies, most of which involve quantitative and qualitative disturbances in regulatory cells, cytokine synthesis and signaling pathways. The assessment of these biomarkers does not aid only in the mechanistic description of autoimmune diseases and immunodeficiencies, but further helps to subcategorize diseases and to evaluate therapy responses. Here, we provide an overview, how monitoring of cytokines and regulatory cells aid in the diagnosis and follow-up of patients with autoimmune diseases and immunodeficiencies furthermore, we pinpoint novel cellular and molecular diagnostic possibilities in these diseases.

Infectome: a platform to trace infectious triggers of autoimmunity

The "exposome" is a term recently used to describe all environmental factors, both exogenous and endogenous, which we are exposed to in a lifetime. It represents an important tool in the study of autoimmunity, complementing classical immunological research tools and cutting-edge genome wide association studies (GWAS). Recently, environmental wide association studies (EWAS) investigated the effect of environment in the development of diseases. Environmental triggers are largely subdivided into infectious and non-infectious agents. In this review, we introduce the concept of the "infectome", which is the part of the exposome referring to the collection of an individual's exposures to infectious agents. The infectome directly relates to geoepidemiological, serological and molecular evidence of the co-occurrence of several infectious agents associated with autoimmune diseases that may provide hints for the triggering factors responsible for the pathogenesis of autoimmunity. We discuss the implications that the investigation of the infectome may have for the understanding of microbial/host interactions in autoimmune diseases with long, pre-clinical phases. It may also contribute to the concept of the human body as a superorganism where the microbiome is part of the whole organism, as can be seen with mitochondria which existed as microbes prior to becoming organelles in eukaryotic cells of multicellular organisms over time. A similar argument can now be made in regard to normal intestinal flora, living in symbiosis within the host. We also provide practical examples as to how we can characterise and measure the totality of a disease-specific infectome, based on the experimental approaches employed from the "immunome" and "microbiome" projects.

Cutting-edge issues in autoimmunity and allergy of the digestive system

Autoimmunity and allergy involving the digestive system may be considered as paradigmatic for numerous common themes of complex diseases secondary to tolerance breakdown. Among gastrointestinal autoimmune diseases, for example, we encounter diseases in which a clear environmental trigger is identified (i.e., celiac disease), serum autoantibodies are most specific (i.e., primary biliary cirrhosis), or in which the disease pathophysiology is clearly understood (i.e., autoimmune gastritis). Similarly, it is intriguing that the gastrointestinal tract and the liver circulation represent the crucial environment for the development of immune tolerance. This issue is dedicated to the discussion of recent concepts while identifying two major common issues, i.e., the need for serum biomarkers and the role of vitamin D. Other common themes characterize the etiology and effector mechanisms of these and other autoimmune diseases and are discussed in each cutting-edge overview.

The future of autoimmunity

There have been enormous strides in our understanding of autoimmunity. These strides have come under the umbrellas of epidemiology, immunological phenotype and function, disease definitions and classification and especially new therapeutic reagents. However, while these advances have been herculean, there remains enormous voids. Some of these voids include genetic susceptibility and the interaction of genes and environment. The voids include induction of tolerance in preclinical disease and definitions of host susceptibility and responses to the expensive biologic agents. The voids include the so-called clustering of human autoimmune diseases and the issues of whether the incidence is rising in our western society. Other voids include the relationships between microbiology, vaccination, gut flora, overzealous use of antibiotics, and the role of nanoparticles and environmental pollution in either the induction or the natural history of disease. One cannot even begin to address even a fraction of these issues. However, in this special issue, we are attempting to discuss clinical issues in autoimmunity that are not usually found in generic reviews. The goal is to bring to the readership provocative articles that ultimately will lead to improvement in patient care.

Low levels of vitamin-D are associated with neuropathy and lymphoma among patients with Sjögren's syndrome

BACKGROUND/PURPOSE

Primary Sjögren's syndrome (SS) is a chronic autoimmune disease primarily involving the exocrine glands. The clinical picture of SS ranges from exocrinopathy to systemic disease affecting the lung, kidney, liver, skin, musculockeletal and nervous systems. The morbidity of SS is mainly determined by extraglandular disease and increased prevalence of lymphoma. Environmental and hormonal factors, such as vitamin-D may play a role in the pathogenic process and disease expression. Thus, we aimed to evaluate levels of vitamin-D and their association with manifestations of SS.

METHODS

Vitamin-D levels were determined in 176 primary SS patients and 163 matched healthy volunteers utilizing the LIAISON chemiluminescent immunoassays (DiaSorin-Italy). A correlation between vitamin-D levels and clinical and serological manifestations of SS was performed.

RESULTS

Mean vitamin-D levels were comparable between SS patients and control 21.2 ± 9.4 ng/ml and 22.4 ± 10 ng/ml, respectively. Peripheral neuropathy was diagnosed in 23% of SS patients and associated with lower vitamin-D levels (18.6 ± 5.5 ng/ml vs. 22.6±8 ng/ml (p = 0.04)). Lymphoma was diagnosed in 4.3% of SS patients, who had lower levels of vitamin-D (13.2 ± 6.25 ng/ml), compared to SS patients without lymphoma (22 ± 8 ng/ml), (p = 0.03). Other clinical and serological manifestations did not correlate with vitamin-D status.

CONCLUSIONS

In this study, low levels of vitamin-D correlated with the presence of peripheral neuropathy and lymphoma among SS patients. The link between vitamin-D and neuropathy or lymphoma was reported in other conditions, and may support a role for vitamin-D in the pathogenesis of these processes. Plausible beneficial effect for vitamin-D supplementation may thus be suggested.

Vitamin d receptor polymorphisms predispose to primary biliary cirrhosis and severity of the disease in polish population

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver condition characterized by the immune-mediated damage of the intrahepatic bile ducts. Polymorphisms of vitamin D receptor (VDR) are considered to contribute to its pathogenesis however their incidence varies in different populations and their potential association with the course of the disease has not been studied. In this paper we investigated the incidence and correlation of three VDR polymorphisms (BsmI, ApaI or TaqI) with various clinical, biochemical, and serological factors in a homogenous group of 143 Caucasian patients with PBC. Control group comprises 306 DNA samples from umbilical cord blood of healthy newborn children. When compared to controls, we observed a significant dominance of the b allele in the BsmI (OR = 1.69 [1.27-2.24]; P = 0.0003) and t allele in the TaqI (OR = 0.62 [0.47-0.82], P = 0.0001) in patients with PBC. Moreover the BsmI and TaqI polymorphisms were associated with the presence of advanced fibrosis/liver cirrhosis at the diagnosis of PBC. Pairwise linkage disequilibrium (LD) calculations proved that the analyzed SNPs are within an LD block (100% of LDs were D'>0.9). Our study showed, for the first time, that the analyzed polymorphisms of VRD may exert an effect on a natural history of PBC.

Modest reversal of metabolic syndrome manifestations with vitamin D status correction: a 12-month prospective study

Numerous cross-sectional studies have noted significant negative associations between circulating levels of 25-hydroxyvitamin D and cardiometabolic risk factors, highlighting potential extraskeletal functions of this sterol hormone. Prospective studies, however, have been limited; and hence, no cause-and-effect relations can be inferred. This study aims to determine whether vitamin D status correction can reverse already established manifestations of the metabolic syndrome (MetS). A total of 59 adult nondiabetic, overweight, and obese Saudis (31 male, 28 female) were prospectively enrolled in this 1-year interventional study. Anthropometry and biochemical evaluation were performed, including determination of serum 25-hydroxyvitamin D, calcium, and phosphorous concentrations, as well as fasting blood glucose and lipid profile. Subjects were advised to regularly expose themselves to sunlight and increase intake of vitamin D-rich foods. All measurements were repeated 6 and 12 months later. At the initial baseline visit, the prevalence of both low high-density lipoprotein cholesterol and hypertension was significantly increased among patients with 25-vitamin D deficiency (P < .05), even after adjusting for sex and body mass index. Overall prevalence of MetS patients by the modified National Health and Nutrition Examination Survey Adult Treatment Panel III definition decreased from 25.2% to 13.0%; and this was largely due to a parallel decrease in the prevalence of low high-density lipoprotein cholesterol, triglycerides, and hypertension. Optimization of vitamin D status through sun exposure and increased intake of a vitamin D-rich diet can lead to an improved cardiometabolic profile, offering a promising nonpharmacologic approach in the prevention of MetS manifestations.

Vitamin D deficiency is associated with an increased autoimmune response in healthy individuals and in patients with systemic lupus erythematosus

OBJECTIVES

Vitamin D deficiency is widespread and has been associated with many chronic diseases, including autoimmune disorders. A study was undertaken to explore the impact of low vitamin D levels on autoantibody production in healthy individuals, as well as B cell hyperactivity and interferon α (IFNα) activity in patients with systemic lupus erythematosus (SLE).

METHODS

Serum samples from 32 European American female patients with SLE and 32 matched controls were tested for 25-hydroxyvitamin D (25(OH)D) levels, lupus-associated autoantibodies and serum IFNα activity. Isolated peripheral blood mononuclear cells were tested for intracellular phospho-ERK 1/2 as a measure of B cell activation status.

RESULTS

Vitamin D deficiency (25(OH)D <20 ng/ml) was significantly more frequent among patients with SLE (n=32, 69%) and antinuclear antibody (ANA)-positive controls (n=14, 71%) compared with ANA-negative controls (n=18, 22%) (OR 7.7, 95% CI 2.0 to 29.4, p=0.003 and OR 8.8, 95% CI 1.8 to 43.6, p=0.011, respectively). Patients with high B cell activation had lower mean (SD) 25(OH)D levels than patients with low B cell activation (17.2 (5.1) vs 24.2 (3.9) ng/ml; p=0.009). Patients with vitamin D deficiency also had higher mean (SD) serum IFNα activity than patients without vitamin D deficiency (3.5 (6.6) vs 0.3 (0.3); p=0.02).

CONCLUSIONS

The observation that ANA-positive healthy controls are significantly more likely to be deficient in vitamin D than ANA-negative healthy controls, together with the finding that vitamin D deficiency is associated with certain immune abnormalities in SLE, suggests that vitamin D plays an important role in autoantibody production and SLE pathogenesis.

Vitamin D endocrine system involvement in autoimmune rheumatic diseases

Vitamin D is synthesized from cholesterol in the skin (80-90%) under the sunlight and then metabolized into an active D hormone in liver, kidney and peripheral immune/inflammatory cells. These endocrine-immune effects include also the coordinated activities of the vitamin D-activating enzyme, 1alpha-hydroxylase (CYP27B1), and the vitamin D receptor (VDR) on cells of the immune system in mediating intracrine and paracrine actions. Vitamin D is implicated in prevention and protection from chronic infections (i.e. tubercolosis), cancer (i.e. breast cancer) and autoimmune rheumatic diseases since regulates both innate and adaptive immunity potentiating the innate response (monocytes/macrophages with antimicrobial activity and antigen presentation), but suppressing the adaptive immunity (T and B lymphocyte functions). Vitamin D has modulatory effects on B lymphocytes and Ig production and recent reports have demonstrated that 1,25(OH)2D3 does indeed exert direct effects on B cell homeostasis. A circannual rhythm of trough vitamin D levels in winter and peaks in summer time showed negative correlation with clinical status at least in rheumatoid arthritis and systemic lupus erythematosus. Recently, the onset of symptoms of early arthritis during winter or spring have been associated with greater radiographic evidence of disease progression at 12 months possibly are also related to seasonal lower vitamin D serum levels.