Associations between serum 25-hydroxyvitamin D and disease activity, inflammatory cytokines and bone loss in patients with rheumatoid arthritis

Can Vitamin D Supplementation Improve Inflammation in Relapsing-Remitting Multiple Sclerosis Patients?

(1) Background: Studies indicate that vitamin D (VitD) may reduce inflammation in multiple sclerosis (MS). The aim of the study was to assess the effect of supplementation with different doses of VitD on inflammation in relapsing-remitting MS (RRMS) patients. (2) Methods: The effect of 6-month supplementation with different doses of oral VitD (2000 IU/day) in a high-dose group (HD, n = 23) and a low-dose group (15,960 IU/month) (LD, n = 29) on selected markers of inflammation was assessed in 52 RRMS patients. (3) Results: Females constituted the majority of participants (63.46%). The median age [years] was 39.5 [34.5-49.8] and 47 [40.0-55.0] in the HD and LD groups, respectively. Significant differences were observed in age (p = 0.028), body weight (p = 0.014) and height (p = 0.001) between the study groups. Considering the BMI, statistically significant differences were not found (p = 0.496). The median 25(OH)D concentration [ng/mL] increased from 23.023 [15.578-25.76] in the HD group and 28.318 [20.644-32.232] in the LD group to 29.819 [24.937-38.064] and 30.837 [25.382-36.789], respectively (p < 0.01), and the increase was significantly higher in the HD group (p = 0.01). Hypovitaminosis D was found in most patients (71.2%) initially, and serum VitD levels were still <30.0 ng/mL in 46.2% of the participants at the follow-up. A significant increase in the levels of IL-4, IL-6, IL-17A, IL-22, IL-23 and TNF -α [pg/mL] and a decrease in IL-10 levels were reported during the study (p < 0.01). A significant positive correlation was observed between 25(OH)D serum levels and sCD40L (R = 0.33; p < 0.05) and TNF-α (R = 0.28; p < 0.05), and a significant negative correlation was reported between 25(OH)D and IL-23 (R = -0.32; p < 0.01) at the beginning of the study. (4) Conclusions: In RRMS patients, the doses of VitD were probably too low to induce beneficial effects on inflammation. Further studies are warranted to determine the effect of VitD supplementation on inflammatory markers in MS patients.

Association of sarcopenia and vitamin D deficiency with glucocorticoid-induced osteoporosis in Chinese patients with rheumatoid arthritis

OBJECTIVES

The study aimed to explore the association of sarcopenia and vitamin D deficiency with glucocorticoid-induced osteoporosis (GIOP) in Chinese patients with rheumatoid arthritis (RA).

METHOD

Skeletal muscle mass, serum 25(OH)D levels, and bone mineral density (BMD) were assessed.

RESULTS

The prevalence of OP, sarcopenia, and vitamin D deficiency in RA patients was significantly higher than in controls (all P < 0.001). The percentage of GC use was 56.9%, and the prevalence of GIOP was 38.1% in 480 RA patients. The prevalence of OP in RA patients without sarcopenia was lower than that in RA patients with sarcopenia (P < 0.05). In RA patients with and without GC, the prevalence of OP in patients without sarcopenia was significantly lower than that in patients with sarcopenia (P < 0.001 and P < 0.05). Female sex (OR = 54.737; 95% CI: 7.103-421.809; P < 0.0001), age (OR = 1.078; 95% CI: 1.048-1.110; P < 0.0001), sarcopenia, and vitamin D deficiency (OR = 2.250; 95% CI: 1.246-64.065; P = 0.007) were risk factors for GIOP in RA patients.

CONCLUSIONS

GIOP is associated with sarcopenia and vitamin D deficiency and is widespread among Chinese patients with RA. Key points ·Percentage of using GC and the prevalence of OP were all high in Chinese patients with RA. ·GIOP was widely existed in Chinese RA patients, which was associated with sarcoprnia and vitamin D deficiency.

Vitamin D and Autoimmune Rheumatic Diseases

Vitamin D is a steroid hormone with potent immune-modulating properties. It has been shown to stimulate innate immunity and induce immune tolerance. Extensive research efforts have shown that vitamin D deficiency may be related to the development of autoimmune diseases. Vitamin D deficiency has been observed in patients with rheumatoid arthritis (RA) and has been shown to be inversely related to disease activity. Moreover, vitamin D deficiency may be implicated in the pathogenesis of the disease. Vitamin D deficiency has also been observed in patients with systemic lupus erythematosus (SLE). It has been found to be inversely related to disease activity and renal involvement. In addition, vitamin D receptor polymorphisms have been studied in SLE. Vitamin D levels have been studied in patients with Sjogren's syndrome, and vitamin D deficiency may be related to neuropathy and the development of lymphoma in the context of Sjogren's syndrome. Vitamin D deficiency has been observed in ankylosing spondylitis, psoriatic arthritis (PsA), and idiopathic inflammatory myopathies. Vitamin D deficiency has also been observed in systemic sclerosis. Vitamin D deficiency may be implicated in the pathogenesis of autoimmunity, and it may be administered to prevent autoimmune disease and reduce pain in the context of autoimmune rheumatic disorders.

Latitude and Celiac Disease Prevalence: A Meta-Analysis and Meta-Regression

BACKGROUND & AIMS

The latitudinal gradient effect is described for several autoimmune diseases including celiac disease in the United States. However, the association between latitude and global celiac disease prevalence is unknown. We aimed to explore the association between latitude and serology-based celiac disease prevalence through meta-analysis.

METHODS

We searched MEDLINE, Embase, Cochrane, and Scopus databases from their beginning through June 29, 2018, to identify screening studies that targeted a general population sample, used serology-based screening tests, and provided a clear location from which we could assign a latitude. Studies were excluded if sampling was based on symptoms, risk factors, or referral. Study selection and data extraction were performed by independent reviewers. The association measures between latitude and prevalence of serology-based celiac disease were evaluated with random-effects meta-analyses and meta-regression.

RESULTS

Of the identified 4667 unique citations, 128 studies were included, with 155 prevalence estimates representing 40 countries. Celiac disease was more prevalent at the higher latitudes of 51° to 60° (relative risk [RR], 1.62; 95% CI, 1.09-2.38) and 61° to 70° (RR, 2.30; 95% CI, 1.36-3.89) compared with the 41° to 50° reference level. No statistically significant difference was observed at lower latitudes. When latitude was treated as continuous, we found a statistically significant association between CD prevalence and latitude overall in the world (RR, 1.03, 95% CI, 1.01-1.05) and a subregional analysis of Europe (RR, 1.05; 95% CI, 1.02-1.07) and North America (RR, 1.1; 95% CI, 1.0-1.2).

CONCLUSIONS

In this comprehensive review of screening studies, we found that a higher latitude was associated with greater serology-based celiac disease prevalence.

Autoimmune disease and interconnections with vitamin D

Vitamin D has well-documented effects on calcium homeostasis and bone metabolism but recent studies suggest a much broader role for this secosteroid in human health. Key components of the vitamin D system, notably the vitamin D receptor (VDR) and the vitamin D-activating enzyme (1α-hydroxylase), are present in a wide array of tissues, notably macrophages, dendritic cells and T lymphocytes (T cells) from the immune system. Thus, serum 25-hydroxyvitamin D (25D) can be converted to hormonal 1,25-dihydroxyvitamin D (1,25D) within immune cells, and then interact with VDR and promote transcriptional and epigenomic responses in the same or neighbouring cells. These intracrine and paracrine effects of 1,25D have been shown to drive antibacterial or antiviral innate responses, as well as to attenuate inflammatory T cell adaptive immunity. Beyond these mechanistic observations, association studies have reported the correlation between low serum 25D levels and the risk and severity of human immune disorders including autoimmune diseases such as inflammatory bowel disease, multiple sclerosis, type 1 diabetes and rheumatoid arthritis. The proposed explanation for this is that decreased availability of 25D compromises immune cell synthesis of 1,25D leading to impaired innate immunity and over-exuberant inflammatory adaptive immunity. The aim of the current review is to explore the mechanistic basis for immunomodulatory effects of 25D and 1,25D in greater detail with specific emphasis on how vitamin D-deficiency (low serum levels of 25D) may lead to dysregulation of macrophage, dendritic cell and T cell function and increase the risk of inflammatory autoimmune disease.

Vitamin D levels in Greek patients with systemic lupus erythematosus

OBJECTIVES

Vitamin D deficiency has been observed in autoimmune rheumatic diseases, such as rheumatoid arthritis. The aim was to study vitamin D in patients with systemic lupus erythematosus (SLE) and its relationship with disease activity.

METHODS

In a cohort of 45 patients with SLE, 41 females and 4 males, aged 47.07 ± 2.17 years (mean ± SEM), and range = 21-79 years, 25(OH)D₃ levels were determined by electrochemiluminescence. C₃ and C₄ levels were also analyzed. SLE disease activity was estimated by SLEDAI-2K. Observations were also performed in a control group matched for age and sex.

RESULTS

In this cohort of SLE patients, 25(OH)D₃ levels were 40.36 ± 2.41 nmol/L (mean ± SEM) as opposed to 60.98 ± 4.28 nmol/L in the control group (p < 0.001, Student's t test). Vitamin D levels were related to C₃ (p < 0.001, linear regression analysis), correlation coefficient 0.106, r² = 0.011, and C₄ (p < 0.001); correlation coefficient 0.316 and r² = 0.100; and inversely related to disease activity (p < 0.001), correlation coefficient -0.572 and r² = 0.327. 25(OH)D₃ levels were 17.73 ± 1.20 nmol/L and 12.24 ± 0.93 nmol/L, in the groups without and with renal involvement, respectively (p = 0.001, Student's t test).

CONCLUSIONS

Vitamin D levels are low in SLE patients and are inversely related to disease activity. Routine screening for vitamin D levels should be performed in SLE patients.

Vitamin D status in women with rheumatoid arthritis: frequency of hypovitaminosis, associations with disease activity, body composition and comorbidity

Aim. To evaluate the status of vitamin D in women with rheumatoid arthritis (RA) and establish its associations with comorbidity, disease activity, and body composition components. Materials and methods. 86 women with RA (average age 58.18.5 years) were enrolled in the study. We analyzed the relationship of vitamin D levels with clinical and laboratory parameters and with the results of two-energy x-ray absorptiometry. MannWhitney or KruskalWallis, 2 and Spearman tests were performed using Statistica for Windows 10.0 (StatSoft Inc., USA). Results. Vitamin D level was 22.4 [17.8; 27.3] ng/ml: deficiency was detected in 33%, and insufficiency in 46% of women with RA. Only 41% of patients with low vitamin D levels received supplements of cholecalciferol, while only 9% in a sufficient dose. 25(OH)D level was significantly lower in RA patients with sarcopenia, obesity, high activity according to DAS28 and in those who did not receive vitamin D supplements. There werent differences in 25(OH)D levels among subgroups of patient according to age, fertility, BMD status, comorbidity index, RA duration, ESR and CRP levels, medical therapy performed. Conclusion. 79% of patients with RA had low levels of vitamin D, while less than half of them received additional cholecalciferol supplements. Low vitamin D levels in RA patients were associated with high disease activity, sarcopenia, and obesity.

Hypovitaminosis D in patients with Crohn's disease

Objective Vitamin D has been widely studied as a mediator of the immune response, becoming evident the prevalence of hypovitaminosis D in patients with Crohn's disease. This work aims at evaluating the serum levels of vitamin D in patients suffering from Crohn's disease in a southeast region of Brazil.

Methods It is a prospective study, with statistical analysis of the values of serum vitamin D measured between April 2014 and April 2015 in patients with Crohn's disease. Individuals with mild anal complaints, without any colorectal involvement, comprised the control group.

Results One hundred and four patients whose average age was 40.6 years were evaluated, being 56 (53.8%) female and 48 (46.2%) male. The average serum vitamin D level was 21.6 ng/mL, with standard deviation 13.85. The control group was comprised by 66 individuals, whose average age was 48.9 years. With 38 (57.6%) female and 28 (42.4%) male. In this group the average serum vitamin D level was 40.9 ng/mL. Statistical significance was demonstrated with p < 0.0001.

Conclusion There was high prevalence of hypovitaminosis D in patients with Chron's disease, when compared to the control group. Hypovitaminosis D was not evidenced in patients in the latter group.

Vitamin D as a Key Player in Modulating Rheumatoid Arthritis-derived Immune Response

Rheumatoid arthritis (RA) is a systemic inflammatory disease with chronic nature of joints related to autoimmunity. Vitamin D was found to modulate cell growth, function of immune cells and anti-inflammatory action. The aims of that study were to investigate serum level of vitamin D and some cytokines and to identify the correlation between vitamin D and these cytokines in RA. Totally 40 RA patients without vitamin D supplement were involved in this study. Serum level of vitamin D, interleukin-6 (IL-6), IL-10, IL-35, C-reactive protein (CRP) and tumor necrosis factor α (TNF-α), all of them were measure in all patients by enzyme-linked immunosorbent assay (ELISA). Patients were classified according to Vitamin D levels into two groups; RA patients with Vit. D deficiency (n=25) and RA patients with Vit. D sufficiency (n=15). IL-6 was lower significantly (P = 0.03) in RA patients with Vit. D sufficiency than RA patients with Vit. D deficiency. IL-10 and IL-35 were higher significantly (P = 0.0234, P = 0.0356 respectively) in RA patients with Vit. D sufficiency than RA patients with Vit. D deficiency. Vit. D was significantly positively correlated with both IL-10 (r = 0.4516, P = 0.0034) and IL-35 (r = 0.3424, P = 0.0329) and negatively correlated with IL-6 (r = -0.3188, P = 0.0479). Sufficient serum level of Vit. D is correlated with higher level of anti-inflammatory cytokines (IL-10 and IL-35) and lower level of IL-6. This support the immunomodulatory effect of Vit. D in RA.

Evaluation of the Risk of Getting Peripheral Artery Disease in Rheumatoid Arthritis and the Selection of Appropriate Diagnostic Methods

This study aims to review the evidence regarding the association between peripheral artery disease (PAD) and rheumatoid arthritis (RA), as well as influential underlying factors and diagnostic options. Eligible literature was searched in PubMed published up to June 1, 2020, in English. Case studies, case series, reviews, and meta-analyses were excluded. We also excluded non-human studies and those 20 years and older. A total of 44 studies were finally incorporated in the narrative review. The results indicated that compared to controls, RA patients are more prone to PAD. Traditional risk factors, disease-characteristics, vitamin D deficiency, therapy used, and other relevant conditions have a variable effect on overall PAD progression. Studies comparing diagnostic options revealed that vascular function and morphology are connected but are still distinctive processes. In early-stage disease, there are functional alterations in the endothelium that can be controlled by anti-inflammatory medications. Ankle-Brachial Index (ABI) <0.9 might not be quite susceptible to PAD evaluation. Supplemental diagnostic tools could detect vascular disease in the preclinical stage. Most risk factors are adjustable, and the management will have a good impact on vascular health. PAD is mostly subclinical when the therapeutic options have a better impact. Diagnostic modalities should be chosen depending on the features of RA. In addition, multiple diagnostic options increase the accuracy of PAD diagnosis. Future prospective studies with larger populations at different age groups and different disease activity duration are essential to make firm conclusions and better understand the phenomenon of RA and PAD.

Vitamin D Deficiency and Rheumatoid Arthritis: Epidemiological, Immunological, Clinical and Therapeutic Aspects

Background/Aim:

Vitamin D displays an immunologic effect which can modulate function of Th17-related cytokines and thereby prevent perpetuation of inflammation in chronic disorders like rheumatoid arthritis (RA). This review aims to conduct a literature review to provide a summary of recent studies addressing the relationship between vitamin D deficiency and RA based on epidemiological, immunological and therapeutic aspects.

Methods:

PubMed, Scopus and Google scholar were searched for relevant papers published between 2000–2018.

Results:

Low intake of vitamin D increases the risk of incident RA, and vitamin D deficiency has been shown to be inversely associated with RA activity in most of these studies. However, characteristics of RA and serum vitamin D status differ across the studies. The results of studies on the effect of supplemental vitamin D in RA vary, from no efficacy to significant improvement in disease activity, as well as quality of life. This should be attributed to variations in dosage of vitamin D, duration of treatment, baseline serum vitamin D in RA patients and characteristics of RA across diverse studies.

Conclusion:

Current data indicate a therapeutic potential for vitamin D in RA. However, further studies are needed to identify an optimal and effective dosage, duration of treatment and patients who will get the best benefit from the treatment.

1,25-Dihydroxyvitamin D3 modulates T cell differentiation and impacts on the production of cytokines from Chinese Han patients with early rheumatoid arthritis

To study the effects of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) on the differentiation of T cells and the levels of cytokines in patients with early rheumatoid arthritis (eRA). The levels of Th1, Th2, Th17, and Treg cells were detected with BDFACS Calibur flow cytometer. The expression of IFN-ɤ, TNF-α, IL-2, IL-4, IL-6, IL-10, IL-17, and IL-22 was examined in 54 patients with eRA using a cytometric bead array (CBA). After 72 h of incubation of PBMCs from eRA patients with 1,25(OH)₂D₃, the levels of IFN-ɤ, TNF-α, IL-2, IL-6, and IL-17 significantly decreased compared to those of the control. 1,25(OH)₂D₃ had no significantly impact on the levels of IL-4, IL-10, and IL-22. The proportion of Th17 and the ratio of Th17/Treg significantly decreased in 1,25(OH)₂D₃-treated groups compared to those of the control. 1,25(OH)₂D₃ had no significantly impact on the proportion of Th1, Th2, Treg, and the ratio of Th1/Th2. Although no statistically significant difference was observed, proportion of Th1 was decreased after 1,25(OH)₂D₃ treatment compared with anti-CD3/CD28 only. The present study demonstrated that 1,25(OH)₂D₃ inhibited the synthesis of specific cytokines: Th1 (IFN-ɤ) and Th17 (IL-17, IL-22, IL-6, TNF-α) might upregulated Th2 cytokine (IL-4), which indicated the possible immunoregulatory roles and bone-sparing effects of 1,25(OH)₂D₃ in eRA through modulation of the Th1 and Th17 cytokine balance.

Micro-CT imaging analysis for the effects of ibandronate and eldecalcitol on secondary osteoporosis and arthritis in adjuvant-induced arthritis rats

We investigated the effects of ibandronate, a bisphosphonate; eldecalcitol, an active vitamin D3 analogue; and combination treatment with both agents on secondary osteoporosis and arthritis using rats with adjuvant-induced arthritis. Arthritis was induced in 8-week-old male Lewis rats. Rats were randomized into four treatment groups and an untreated normal control group: ibandronate, eldecalcitol, ibandronate + eldecalcitol, vehicle, and control. Paw thickness was measured to evaluate arthritis. Joint destruction was evaluated histomorphometrically by the ankle joint stained with Fast Green and safranin O. The femur and lumbar spine were scanned using dual-energy X-ray absorptiometry, and the distal femur was scanned using micro-computed tomography for bone mineral density (BMD) and trabecular microstructural evaluations. Ibandronate and/or eldecalcitol increased BMD in both the lumbar vertebrae and femur and improved several microstructural parameters (bone volume/total volume, structure model index, trabecular number, and trabecular separation of the distal femur). In addition, there was an additive effect of combination treatment compared with single treatments for most trabecular parameters, including BMD and bone volume. However, ibandronate and/or eldecalcitol did not inhibit arthritis and joint destruction. Combination treatment with ibandronate and eldecalcitol may be effective for secondary osteoporosis associated with arthritis.

Impact of vitamin D deficiency on clinical parameters in treatment-naïve rheumatoid arthritis patients

OBJECTIVE

To determine if patients with rheumatoid arthritis (RA) are at risk of vitamin D deficiency and whether the levels of vitamin D are correlated with clinical parameters in RA.

METHODS

A total of 280 treatment-naïve RA patients, and 140 age- and sex-matched healthy volunteers were enrolled. Serum levels of 1,25-dihydroxycholecalciferol (1,25(OH)₂D₃), the active form of vitamin D, were measured by enzyme-linked immunosorbent assay (ELISA). Concentrations of 1,25(OH)₂D₃ less than 25 ng/mL were defined as insufficient. Linear regression was performed to evaluate correlations as (modifying and) confounding factors were controlled.

RESULTS

The levels of serum 1,25(OH)₂D₃ in RA individuals (12.24 ± 6.68 ng/ml) were significantly lower than in healthy controls (21.08 ± 7.14 ng/ml; p < 0.05). An inverse association was found between the levels of 1,25(OH)₂D₃ and ESR in obese and overweight individuals with RA (β_obese = -0.385, β_overweight = -0.395, both p < 0.05), but not in normal and underweight subjects. A significant negative association between levels of 1,25(OH)₂D₃ and DAS28 score (β = -0.164, p = 0.018) was observed. The levels of 1,25(OH)₂D₃ were associated moderately and inversely with the absolute numbers of Th-17 (β = -0.158, p = 0.019) and positively with those of CD4⁺ regulatory T (Treg) cell (β = 0.146, p = 0.025). The levels of 1,25(OH)₂D₃ in anti-cyclic citrullinated peptide (anti-CCP)-positive patients with RA were lower than in the anti-CCP-negative RA patients (10.86 ng/ml versus 15.98 ng/ml; t = -3.08, p < 0.01).

CONCLUSIONS

A significant association was observed between levels of vitamin D and parameters of disease, including body mass index (BMI), DAS28, Th17 cell counts, Treg cell counts, and presence of anti-CCP antibody in RA patients.

Vitamin D supplementation and inflammatory and metabolic biomarkers in patients with knee osteoarthritis: post hoc analysis of a randomised controlled trial

The aim of this study was to determine whether vitamin D supplementation and maintaining vitamin D sufficiency are associated with changes in inflammatory and metabolic biomarkers in patients with knee osteoarthritis (OA) and vitamin D deficiency. A total of 413 participants with symptomatic knee OA and vitamin D deficiency were enrolled in a randomised, placebo-controlled trial and received 1·25 mg vitamin D3 or placebo monthly for 24 months across two sites. In this post hoc analysis, 200 participants from one site (ninety-four from the placebo group and 106 from the vitamin D group; mean age 63·1 (sd 7·3) years, 53·3 % women) were randomly selected for measurement of serum levels of inflammatory and metabolic biomarkers at baseline and 24 months using immunoassays. In addition, participants were classified into two groups according to serum 25-hydroxyvitamin D (25(OH)D) levels at months 3 and 24: (1) not consistently sufficient (25(OH)D≤50 nmol/l at either month 3 or 24, n 61), and (2) consistently sufficient (25(OH)D>50 nmol/l at both months 3 and 24, n 139). Compared with placebo, vitamin D supplementation had no significant effect on change in serum high-sensitive C-reactive protein, IL-6, IL-8, IL-10, leptin, adiponectin, resistin, adipsin and apelin. Being consistently vitamin D sufficient over 2 years was also not associated with changes in these biomarkers compared with not being consistently sufficient. Vitamin D supplementation and maintaining vitamin D sufficiency did not alter serum levels of inflammatory and metabolic biomarkers over 2 years in knee OA patients who were vitamin D insufficient, suggesting that they may not affect systemic inflammation in knee OA patients.

Serum active 1,25(OH)2D, but not inactive 25(OH)D vitamin D levels are associated with cardiometabolic and cardiovascular disease risk in psoriasis

BACKGROUND AND AIMS

Vitamin D exists as an inactive 25-hydroxyvitamin D (25(OH)D) in the bloodstream, which is converted to active 1,25-dihydroxyvitaminD (1,25(OH)₂D) in target tissues. Cohort studies reporting cardiovascular disease among individuals with low vitamin D are inconsistent and solely measure 25(OH)D. Psoriasis, a chronic inflammatory disease, is a vitamin D deficient state and is associated with increased cardiovascular disease risk. While serum 25(OH)D is routinely measured, we hypothesized that measurement of 1,25(OH)₂D in psoriasis may perform better than 25(OH)D in capturing cardiovascular risk.

METHODS

Consecutive psoriasis patients (N = 122) at baseline underwent FDG PET/CT and CCTA scans to measure visceral adipose volume, aortic vascular uptake of FDG, and coronary plaque burden respectively. Blood levels of both 1,25(OH)₂D and 25(OH)D were measured by chemiluminescence (LIAISON XL DIaSorin, Stillwater, MN).

RESULTS

The psoriasis cohort was middle-aged (mean ± SD: 49.6 ± 13.0), predominantly male (n = 71, 58%), in majority Caucasians (n = 98, 80%), and had moderate-to-severe skin disease [psoriasis area severity index score, PASI score, med.

(IQR)

5.5 (3.2-10.7)], with almost one-fourth of the cohort on biologic psoriasis therapy for skin disease management (n = 32, 27%) at baseline. Interestingly, serum levels of 1,25(OH)₂D but not 25(OH)D were found to be inversely associated with visceral adipose, a marker of cardiometabolic risk in fully adjusted models (β = - 0.43, p = 0.026 and β = -0.26 p = 0.13). Similarly, we found an inverse relationship between 1,25(OH)₂D, but not 25(OH)D, and aortic vascular uptake of FDG independent of traditional risk factors (β = -0.19, p = 0.01). Finally, we found that serum 1,25(OH)₂D, but not 25(OH)D, was inversely associated with non-calcified coronary plaque burden, as measured by CCTA independent of traditional risk factors (β = -0.18, p = 0.03).

CONCLUSIONS

In conclusion, we demonstrate that low 1,25(OH)₂D levels were associated with visceral adipose volume, vascular uptake of FDG and coronary plaque burden independent of traditional risk factors, suggesting that 1,25(OH)₂D may better capture the cardiometabolic risk associated with vitamin D deficient states.

Elevated circulating IL-17 level is associated with inflammatory arthritis and disease activity: A meta-analysis

OBJECTIVES

Previous studies found that the interleukin (IL)-17 level was elevated in inflammatory arthritis, but results were inconsistent. This meta-analysis aimed to investigate the association of IL-17 cytokine with osteoarthritis (OA), rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA).

METHODS

Relevant studies were searched using databases. Standardized mean difference (SMD) was calculated. Correlation coefficient was utilized to evaluate the relationship between IL-17 and disease activity of AS and RA. Subgroup analysis, sensitivity analysis and meta-regression were applied to explore the sources of heterogeneity.

RESULTS

83 records were enrolled. The IL-17 level was elevated in AS (SMD = 2.348, P < .001), RA (SMD = 1.502, P < .001), PsA (SMD = 1.710, P < .001) and OA (SMD = 1.192, P = .016), and similar results occurred in subgroup analysis. Furthermore, the IL-17 level was positively associated with disease activity of AS and RA.

CONCLUSION

Circulating IL-17 level is significantly elevated in inflammatory arthritis and is related to the disease activity of AS and RA, suggesting that it plays an important role in the pathogenesis and progression of inflammatory arthritis (especially in AS and RA).

Vitamin D as a Principal Factor in Mediating Rheumatoid Arthritis-Derived Immune Response

Rheumatoid arthritis (RA) is a systemic multifactorial autoimmune disorder. The interactions between diverse environmental and genetic factors lead to the onset of this complex autoimmune disorder. Serum levels of vitamin D (VD) are involved in the regulation of various immune responses. Vitamin D is a key signaling molecule in the human body that maintains calcium as well as phosphate homeostasis. It also regulates the functions of the immune system and, thus, can play a substantial role in the etiology of various autoimmune disorders, including RA. Low serum VD levels have been found to be associated with a higher risk of RA, although this finding has not been replicated consistently. The molecular mechanisms by which VD influences autoimmunity need to be further explored to understand how variation in plasma VD levels could affect the pathogenesis of RA. This mini-review focuses on the influence of VD and its serum levels on RA susceptibility, RA-associated complexities, treatment, and transcriptome products of key proinflammatory cytokines, along with other cytokines that are key regulators of inflammation in rheumatoid joints.

Serum and synovial fluid vitamin D metabolites and rheumatoid arthritis

Vitamin D-deficiency has been linked to inflammatory diseases including rheumatoid arthritis (RA). Studies to date have focused on the impact of serum 25-hydroxyvitamin D3 (25(OH)D3), an inactive form of vitamin D, on RA disease activity and progression. However, anti-inflammatory actions of vitamin D are likely to be mediated at sites of RA disease, namely the inflamed joint, and may involve other vitamin D metabolites notably the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). In the current study serum and synovial fluid samples from n = 20 patients with persistent RA and n = 7 patients with reactive arthritis (ReA) were analysed for multiple vitamin D metabolites. Serum data for RA and ReA patients were compared to healthy controls (HC). There was no significant difference between RA or ReA patients relative to HC for 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3 or 25(OH)D2. However, 3-epi-25(OH)D3 was significantly lower in RA and ReA patients compared to HC (p < 0.05). All vitamin D metabolites, apart from 25(OH)D2, were lower in SF compared to serum, and SF 1,25(OH)2D3 was unquantifiable in 13/20 RA and 4/7 ReA samples. SF 25(OH)D3, 3-epi-25(OH)D3 and DBP correlated inversely with swollen joint score, and serum 25(OH)D2 and SF DBP correlated directly with C-reactive protein levels. These data indicate that serum 25(OH)D3 provides only limited insight into the role of vitamin D in RA. Alternative serum metabolites such as 3-epi-25(OH)2D3, and SF metabolites, notably lack of SF 1,25(OH)2D3, may be more closely linked to RA disease severity and progress.

1,25-Dihydroxyvitamin D3 Ameliorates Collagen-Induced Arthritis via Suppression of Th17 Cells Through miR-124 Mediated Inhibition of IL-6 Signaling

Objectives: To explore the molecular mechanisms in which vitamin D (VD) regulates T cells, especially Th17 cells in collagen-induced arthritis (CIA). Methods: DBA1/J mice induced for CIA were intraperitoneally treated with VD. CIA clinical symptoms and inflammatory responses including Th1/Th17/Tregs percentages were determined and compared. Mouse naïve CD4⁺ T cells transduced with miR-124 inhibitor or not were polarized to Th17 cells with or without VD. Subsequently, cellular differentiation and IL-6 signaling moleculars were analyzed. Results: VD treatment significantly delayed CIA onset, decreased incidence and clinical scores of arthritis, downregulated serum IgG levels and ameliorated bone erosion. VD downregulated IL-17A production in CD4⁺ T cells while increased CD4⁺Foxp3⁺Nrp-1⁺ cells both in draining lymph nodes and synovial fluid in arthritic mice. VD inhibited Th17 cells differentiation in vivo and in vitro and potentially functioning directly on T cells to restrain Th17 cells through limiting IL-6R expression and its downstream signaling including STAT3 phosphorylation, while these effects were blocked when naïve CD4⁺ T cells were transduced with miR-124 inhibitor. Conclusions: VD treatment ameliorates CIA via suppression of Th17 cells and enhancement of Tregs. miR-124-mediated inhibition of IL-6 signaling, provides a novel explanation for VD's role on T cells in CIA mice or RA patients and suggests that VD may have treatment implications in rheumatoid arthritis.

Effect of vitamin D deficiency in Korean patients with acute respiratory distress syndrome

BACKGROUND/AIMS

Vitamin D modulates innate and adaptive immune responses, and vitamin D deficiency is associated with increased mortality in hospitalized patients with pneumonia. We evaluated the prevalence of vitamin D deficiency in Korean patients with acute respiratory distress syndrome (ARDS) and its effect on the clinical outcomes of ARDS.

METHODS

We retrospectively analyzed the data of 108 patients who had a measured serum level of 25-hydroxy vitamin D3 (25(OH)D3) at the time of diagnosis with ARDS. The clinical outcomes were evaluated based on 25(OH)D3 levels of 20 ng/mL and stratified by quartiles of 25(OH)D3 levels.

RESULTS

The mean age of patients was 59.4 years old; 77 (71.3%) were male. Vitamin D deficiency was found in 103 patients (95.4%). The mean 25(OH)D3 level was 8.3 ± 7.0 ng/mL. Neither in-hospital mortality (40.0% vs. 68.0%) nor 6-month mortality (40.0% vs. 71.8%) significantly differed between groups. There were no significant differences in 25(OH)D3 level between survivors (8.1 ± 7.6 ng/mL) and non-survivors (8.5 ± 6.8 ng/mL, p = 0.765). There were no trends toward a difference in mortality among quartiles of 25(OH)D3 levels. However, 25(OH)D3 levels were inversely related with length of hospital stay and intensive care unit stay among in-hospital survivors.

CONCLUSION

Vitamin D deficiency was prevalent in Korean patients with ARDS. However, levels of vitamin D were not associated with mortality. A large, prospective study is needed to evaluate the effects of vitamin D deficiency on clinical outcomes of ARDS.

Changes in bone density and bone turnover in patients with rheumatoid arthritis treated with rituximab, results from an exploratory, prospective study

Data describing the effect of in vivo B cell depletion on general bone loss in patients with rheumatoid arthritis (RA) are limited. Given the pathogenetic role of B cells in RA, it is tempting to speculate that B cell depletion might have a beneficial effect on bone loss. We prospectively investigated the changes in bone mineral density (BMD), bone turnover, inflammation and disease activity before and after rituximab in 45 RA patients over a 12 month period, 36 patients of whom completed the study and were included in the analysis. There was no significant change in our primary endpoint; lumbar spine BMD after 12 months. However, we found a significant decrease in neck of femur (mean -0.017 g/cm2, 95% CI -0.030, -0.004 p = 0.011) and total femur BMD (mean -0.016 g/cm2, 95% CI -0.025, -0.007 p = 0.001). Additionally, there was a significant increase in procollagen type 1 amino-terminal propeptide (P1NP) and bone specific alkaline phosphatase (BAP); biomarkers of bone formation (median change from baseline to 12 months; P1NP 11.3 μg/L, 95% CI -1.1, 24.8 p = 0.025; BAP 2.5 μg/L, 95% CI 1.2, 3.6 p = 0.002), but no significant change in bone resorption or osteocyte markers. The fall in BMD occurred despite improvement in disease control. Post-menopausal women had the lowest mean lumbar spine, femoral and forearm BMD at baseline and after 12 months, additionally they had a higher level of bone turnover throughout the study. In conclusion, BMD was maintained at the lumbar spine and forearm, but fell at the femur sites. A high prevalence of vitamin D deficiency was observed and these patients had lower BMD and evidence of higher bone turnover.

Marine ω-3, vitamin D levels, disease outcome and periodontal status in rheumatoid arthritis outpatients

OBJECTIVES

Marine ω-3 fatty acids (FAs) and Vitamin D (VitD) are reportedly capable of down-regulating inflammation in rheumatoid arthritis (RA) and periodontal disease. This study was undertaken to relate marine FA and VitD status to RA disease status and periodontal conditions.

METHODS

RA outpatients (age ≥35 y) were consecutively recruited. Rheumatologic clinical data were collected and periodontal status obtained. A food frequency questionnaire was used to estimate fish and supplement intake. FA profiles in whole-blood and serum VitD levels were determined.

RESULTS

A total of 78 RA patients (age 57 ± 12 y, disease duration 15 ± 11 y) were included, 58% had active RA. Periodontitis was diagnosed in 82% of the patients, 18% had severe periodontitis. Seropositivity for rheumatoid factor and/or anticitrullinated protein antibodies was related to higher prevalence of periodontitis (P= 0.008). Seafood intake in accordance with nutritional recommendations was associated with better RA disease outcome (largest P= 0.008). An ω-3 index >8, present in 14% of the patients, correlated with a more desirable patient global health assessment scored on a visual analog scale (VAS; P= 0.004), lower periodontal probing depth (PD; P= 0.021), and ω-3 supplementation (P= 0.001). Serum VitD levels >50 nmol/L were found in 89%, of these 48% had VitD levels ≥75 nmol/L, no differences were found for RA disease activity and periodontal measurements.

CONCLUSIONS

Seropositive RA patients had a higher prevalence of periodontitis than seronegative patients. An ω-3 index >8 was related to ω-3 supplementation and more desirable VAS and lower PD. VitD status was satisfactory for most patients and was not associated with differences in RA severity or periodontal diagnosis.

The association between vitamin D concentration and pain: a systematic review and meta-analysis

Objective

Pain-related conditions, such as chronic widespread pain and fibromyalgia, are major burdens for individuals and the health system. Evidence from previous research on the association between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and pain is conflicting. Thus, we aimed to determine if there is an association between mean 25(OH)D concentration (primary aim), or proportion of hypovitaminosis D (secondary aim), and pain conditions in observational studies.

Design

Published observational research on 25(OH)D concentration and pain-related conditions was systematically searched for in electronic sources (MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials) and a random-effects meta-analysis was conducted on included studies.

Results

Eighty-one observational studies with a total of 50 834 participants were identified. Compared with controls, mean 25(OH)D concentration was significantly lower in patients with arthritis (mean difference (MD): −12·34 nmol/l;P<0·001), muscle pain (MD: −8·97 nmol/l;P=0·003) and chronic widespread pain (MD: −7·77 nmol/l;P<0·001), but not in patients with headache or migraine (MD: −2·53 nmol/l;P=0·06). The odds of vitamin D deficiency was increased for arthritis, muscle pain and chronic widespread pain, but not for headache or migraine, compared with controls. Sensitivity analyses revealed similar results.

Conclusions

A significantly lower 25(OH)D concentration was observed in patients with arthritis, muscle pain and chronic widespread pain, compared with those without. These results suggest that low 25(OH)D concentrations may be associated with pain conditions.

Vitamin D deficiency in sickle cell disease patients in the Eastern Province of Saudi Arabia

BACKGROUND

Vitamin D deficiency (VDD) is a major global health problem. In sickle cell disease (SCD), VDD is highly prevalent, reaching up to 96% of populations. VDD may contribute to many of the complications of SCD.

OBJECTIVE

Estimate the 25-hydroxyvitamin D [25(OH)D] level and the frequency of VDD and insufficiency among among SCD patients by age group and disease status.

DESIGN

Analytical cross-sectional.

SETTING

Ministry of Health (MOH) secondary care hospital.

PATIENTS AND METHODS

Non-probability purposive sampling was used to select SCD patients, aged 12 years and older, of both sexes, who had visited the hospital during a period of 5 years (2010-2014). Blood samples were processed by electrochemiluminescence technology.

MAIN OUTCOME MEASURE(S)

25(OH)D levels by demographic data, and disease activity.

SAMPLE SIZE

640 patients.

RESULTS

Of those, 82% (n=523) had suboptimal 25(OH)D (0-<30 ng/ mL), and 67% were deficient (0-<20 ng/mL). Patients with any SCD crisis (20.7%, 144/694) had lower 25(OH)D (median, IQR: 10.1 ng/mL [8.6] ng/mL) compared to patients without crisis (71.0%, 493/694) (15.7 ng/ mL [18.2] ng/mL) (P<.001). Deficiency was more common in the young.er age groups and in sickle cell anemia patients with crisis.

CONCLUSIONS

VDD is highly prevalent in this population. Established vitamin D screening is a necessity, so that affected patients can be treated.

LIMITATIONS

Presence of residual confounders such as nutritional status, physical activity, lack of sun exposure, medications that alleviate SCD crises (such as hydroxyurea), and comorbid illnesses. The relationship between sickle cell disease genotype and vitamin D level was not analyzed.

CONFLICT OF INTEREST

None.

Vitamin D and rheumatoid arthritis: an ongoing mystery

PURPOSE OF REVIEW

In recent years, there has been a growing interest in the value of vitamin D and its effects on autoimmunity. The aim of this review is to summarize the current knowledge on the association between vitamin D and rheumatoid arthritis (RA) in terms of prevalence, disease activity, clinical expression, serology and gene polymorphisms of vitamin D receptors.

RECENT FINDINGS

Studies have shown contrasting findings concerning the association between vitamin D levels and RA. Vitamin D seems to have immunomodulatory properties. Therefore, low vitamin D levels could contribute to increased immune activation. However, the potential role of vitamin D supplementation in preventing RA manifestation and its beneficial role as a component of RA treatment remain controversial. The relationship between RA susceptibility and vitamin D polymorphisms is also unclear.

SUMMARY

Despite advancements synthesized by some recent meta-analyses, the relationship between vitamin D and RA requires further evaluation. Further research is needed to confirm the relationship between RA susceptibility and vitamin D polymorphisms and to determine whether vitamin D plays a role in preventing the manifestation of RA. Finally, additional studies are required to determine the impact and optimal amount of vitamin D supplementation in the treatment of RA patients.

Changes in intestinal flora, TNF-α, L-17, and IL-6 levels in patients with gestational diabetes mellitus

To study the changes in intestinal flora and different inflammatory factors in patients with gestational diabetes mellitus (GDM), a total of 80 patients with GDM treated in our hospital were selected as the study group. Meanwhile, another 60 normal pregnant women were selected as the control group. The contents of intestinal Bifidobacterium, Lactobacillus, and Bacteroides were measured in both groups followed by comparison of the incidence of intestinal flora imbalance. In the meantime, the levels of tumor necrosis factor alpha (TNF-α), interleukin-17 (IL-17), and interleukin-6 (IL-6) in serum were detected and compared between those two groups. Afterwards, multivariate logistic regression was used to analyze the risk factors related to GDM. The number of Bifidobacterium, Lactobacillus, and Bacteroides in the study group was significantly less than those in the control group. The incidence of intestinal flora imbalance in the study group was 33.75%, which is higher than that in the control group. The serum levels of inflammatory factors, including TNF-α, IL-17, and IL-6 in the study group were significantly higher than those in the control group. The result of multivariate logistic regression analysis showed that Bifidobacterium, Lactobacilli, Bacteroides, TNF-α, IL-17, and IL-6 were risk factors related to GDM. Patients with GDM are prone to intestinal flora imbalance with elevated different inflammatory, which affects immune function in patients and may play an important role in the development of diabetes mellitus.

Vitamin D Status, Disease Activity, and Endothelial Dysfunction in Early Rheumatoid Arthritis Patients

Cardiovascular diseases represent important complications in rheumatoid arthritis (RA) patients, generated by an accelerated atherosclerosis. The aim of this study is represented by the assessment of the correlations between serum levels of vitamin D, disease activity, and endothelial dysfunction in patients with early RA. Material and Methods. The study was performed on a group of 35 patients with early RA and 35 healthy subjects matched for age and gender, as controls. In all studied subjects, the following were determined: inflammatory markers, insulin resistance, vitamin D levels, and endothelial dysfunction. Statistical analysis were performed using the Student's t-test and the Pearson's test. p values of less than 0.05 were considered statistically significant. Results. The group of patients with RA patients presented inflammation, low levels of vitamin D, elevated insulin resistance, and reduced flow-mediated vasodilation, statistically significant compared to the control group (p < 0.00001). Significant inverse correlations between the levels of 25(OH) vitamin D and DAS28, respective insulin resistance, and significant positive correlation between 25(OH) vitamin D and endothelial function were demonstrated. Conclusion. In early RA patients with moderate and high disease activity, low serum levels of vitamin D were associated with disease activity, increased insulin resistance, and endothelial dysfunction.

Decreased sensitivity to 1,25-dihydroxyvitamin D3 in T cells from the rheumatoid joint

1,25-dihydroxyvitaminD₃ (1,25(OH)₂D₃), has potent anti-inflammatory effects, including suppression of IL-17 + and IFNγ+ T cells implicated in rheumatoid arthritis (RA), but efficacy at the site of active disease is unclear. To investigate this, T cells from synovial fluid (SF) and paired blood of patients with active RA were studied. 1,25(OH)₂D₃ had significantly less suppressive effect on Th17 cells (IL-17+IFNγ-) and Th17.1 cells (IL-17+IFNγ+) from SF compared to those from blood, and had no effect on SF CD4⁺ or CD8⁺ IFNγ+ T cell frequencies. Memory T cells (CD45RO+) predominate in SF, and 1,25(OH)₂D₃ had less effect on memory T cells relative to naïve (CD45RA+) T cells. RT-PCR and flow cytometry showed that this was not due to decreased expression of the vitamin D receptor or its transcription partners in memory T cells. Further studies using stimulated CD4⁺ T cells sorted according to IL-17 and IFNγ expression confirmed the ability of 1,25(OH)₂D₃ to suppress pre-existing cytokines. However, 1,25(OH)₂D₃ was most effective at suppressing de novo IL-17 and IFNγ induction. Correspondingly, T cell responses to 1,25(OH)₂D₃ correlated directly with capacity for phenotype change, which was lower in cells from SF compared to blood. These findings indicate that anti-inflammatory effects of 1,25(OH)₂D₃ in active RA are impaired because of reduced effects on phenotype-committed, inflammatory memory T cells that are enriched in SF. Restoration of 1,25(OH)₂D₃ responses in memory T cells may provide a new strategy for treatment of inflammatory diseases such as RA.

Cross-sectional and longitudinal associations between serum inflammatory cytokines and knee bone marrow lesions in patients with knee osteoarthritis

OBJECTIVE

To describe cross-sectional and longitudinal associations between serum levels of interleukin (IL) - 6, IL-17A, IL-17F, IL-23 and knee bone marrow lesions (BMLs) in patients with knee osteoarthritis (OA).

DESIGN

Patients (n = 192) with symptomatic knee OA (mean 63 years, range 50-79, female 53%) were assessed at baseline and after 24 months. At each time point, serum IL-6, IL-17A, IL-17F and IL-23 were measured using Bio-Plex^® Multiplex Immunoassays with Luminex xMAP technology. Knee BMLs were scored using the modified whole organ MRI score (WORMS) from T2 weighted fat-suppressed fast spin echo magnetic resonance imaging (MRI). Multivariable linear regression and log binominal regression were used to determine the associations between cytokines and BMLs.

RESULTS

Baseline IL-6 (quarters) were significantly associated with total knee BMLs (P < 0.01 for the trend) as well as associated with an increase in BML score (P = 0.05 for the trend), after adjustment for confounders. Baseline IL-17F and IL-23 (highest quarters vs others) was associated with an increase in BML score in females (P = 0.04 for IL-17F; P = 0.01 for IL-23), but not in males, in multivariable analyses. In contrast, IL-17A was not significantly associated with BMLs in either females or males.

CONCLUSION

IL-6 is associated with increased knee BMLs in both females and males with OA. Serum IL-17F and IL-23 predicted increased knee BML scores in females only, suggesting that inflammation is involved in BML pathogenesis in knee OA, especially in women.

TRAIL REGISTRATION

ClinicalTrials.gov identifier: NCT01176344; Australian New Zealand Clinical Trials Registry: ACTRN12610000495022.

Serum 25-Hydroxyvitamin D3 and BAFF Levels Are Associated with Disease Activity in Primary Sjogren's Syndrome

The study investigated the association between disease activity and serum 25-hydroxyvitamin D3 (25(OH)-D3), B cell activation of the tumor necrosis factor family (BAFF), or β₂ microglobulin in patients with primary Sjogren's syndrome (SS). Sixty-nine primary SS patients and 22 sicca control patients were included in the study. Disease activity was measured with EULAR Sjogren's syndrome disease activity index (ESSDAI). Serum levels of 25(OH)-D3 and β₂ microglobulin were measured by radioimmunoassay and BAFF was measured by an enzyme-linked immunosorbent assay. Serum levels of 25(OH)-D3 were significantly lower in SS patients compared to the sicca controls (p = 0.036). Serum levels of BAFF tended to be higher (p = 0.225) and those of β₂ microglobulin were significantly higher in patients with SS than in sicca controls (p = 0.023). In univariate regression analyses, ESSDAI was significantly associated with serum levels of 25(OH)-D3, BAFF, and β₂ microglobulin. After stepwise backward multivariate linear regression analyses including age and acute phase reactants, ESSDAI was associated with 25(OH)-D3 (β = −0.042, p = 0.015) and BAFF (β = 0.001, p = 0.015) in SS patients. In SS patients, ESSDAI is negatively associated with serum levels of 25(OH)-D3 and positively associated with BAFF.

Association of arthritis and vitamin D insufficiency with physical disability in Mexican older adults: findings from the Mexican Health and Aging Study

Arthritis and vitamin D insufficiency are prevalent in older adults and are risk factors for disability. The objective of this study was to examine the effect of co-occurring arthritis and vitamin D deficiency on upper-lower extremity functional limitations and disability in older adults. We examined 1533 participants aged ≥50 years from a subsample of the Mexican Health and Aging Study. Measures included sociodemographics, body mass index, comorbid conditions, falls, physical activity, physical function tests, functional limitations, activities of daily living (ADL), and vitamin D. Participants were categorized into four groups according to arthritis and vitamin D status: no vitamin D insufficiency and no arthritis (58.80%), vitamin D insufficiency only (27.49%), arthritis only (8.47%), and arthritis and vitamin D insufficiency (5.24%). Fourteen percent reported arthritis, and 31.2% had vitamin D insufficiency. The arthritis and vitamin D insufficiency group was associated with upper-lower extremity functional limitations [odds ratio (OR) 1.82, 95% confidence interval (CI) 1.06-3.15, and OR 1.90, 95% CI 1.00-3.62, respectively] and ADL disability (OR 3.00, 95% CI 1.63-5.51) when compared with the no vitamin D insufficiency and no arthritis group (reference group). The arthritis only group was three times more likely to report upper-lower extremity functional limitations and ADL disability. The vitamin D insufficiency only group was not significantly associated with functional limitations nor ADL disability. Arthritis and vitamin D insufficiency increased the risk of ADL disability in this population. However, the effect of arthritis and vitamin D insufficiency on upper-lower extremity functional limitations was not higher than the effect of arthritis only, but higher than the effect on vitamin D insufficiency alone.

Vitamin D and its effects on cardiovascular diseases: a comprehensive review

Vitamin D is a molecule that is actively involved in multiple metabolic pathways. It is mostly known for its implications related to calcium metabolism. It has also been determined that it actively participates in the cardiovascular system, influencing blood pressure, coronary artery disease and other vascular diseases, such as heart failure and atrial fibrillation. Furthermore, it has been established that this vitamin is extensively involved in the regulation of both the renin angiotensin aldosterone system and the immune system. In this review, we present the different vitamin D metabolic pathways associated with the cardiovascular pathophysiology, and we include studies in animal and human models, as well as some of the controversies found in the literature. This review also incorporates an overview of the implications in the molecular biology and public health fields.

Vitamin D Level Between Calcium-Phosphorus Homeostasis and Immune System: New Perspective in Osteoporosis

Vitamin D is a key molecule in calcium and phosphate homeostasis; however, increasing evidence has recently shown that it also plays a crucial role in the immune system, both innate and adaptive. A deregulation of vitamin D levels, due also to mutations and polymorphisms in the genes of the vitamin D pathway, determines severe alterations in the homeostasis of the organism, resulting in a higher risk of onset of some diseases, including osteoporosis. This review gives an overview of the influence of vitamin D levels on the pathogenesis of osteoporosis, between bone homeostasis and immune system.

Cistromic and genetic evidence that the vitamin D receptor mediates susceptibility to latitude-dependent autoimmune diseases

The vitamin D receptor (VDR) is a ligand-activated transcription factor that regulates gene expression in many cell types, including immune cells. It requires binding of 1,25 dihydroxy vitamin D3 (1,25D3) for activation. Many autoimmune diseases show latitude-dependent prevalence and/or association with vitamin D deficiency, and vitamin D supplementation is commonly used in their clinical management. 1,25D3 is regulated by genes associated with the risk of autoimmune diseases and predominantly expressed in myeloid cells. We determined the VDR cistrome in monocytes and monocyte-derived inflammatory (DC1) and tolerogenic dendritic cells (DC2). VDR motifs were highly overrepresented in ChIP-Seq peaks in stimulated monocyte (40%), DC1 (21%) and DC2 (47%), P<E(-100) for all. Of the nearly 11 000 VDR-binding peaks identified across the genome in DC1s, 1317 were shared with DC2s (91% of DC2 sites) and 1579 with monocytes (83% of monocyte sites). Latitude-dependent autoimmune disease risk polymorphisms were highly overrepresented within 5 kb of the peaks. Several transcription factor recognition motifs were highly overrepresented in the peaks, including those for the autoimmune risk gene, BATF. This evidence indicates that VDR regulates hundreds of myeloid cell genes and that the molecular pathways controlled by VDR in these cells are important in maintaining tolerance.

Serum Vitamin D Level and Rheumatoid Arthritis Disease Activity: Review and Meta-Analysis

Background

The evidence from epidemiological studies concerning the relationship between serum vitamin D concentrations and rheumatoid arthritis (RA) is inconsistent. This meta-analysis is aimed at determining the magnitude of the correlation between this common autoimmune disease and vitamin D, an important nutrient known to dampen adaptive immune responses.

Methods

Through multiple search strategies, relevant literature was identified and evaluated for quality before May 16 2015. Data extracted from eligible studies was synthesized to calculate pooled correlation coefficient (r), mean difference (MD) and odds ratio (OR). The Venice criteria were applied to assess the credibility of the evidence for each statistically significant association.

Results

A total of 24 reports involving 3489 patients were selected for analysis. RA patients had lower vitamin D levels than healthy controls (MD:-16.52 nmol/L, 95% confidence intervals [CI]:-18.85 to -14.19 nmol/L). There existed a negative relationship between serum 25-hydroxyvitamin D (25OHD) level and disease activity index, e.g. 25OHD vs. Disease Activity Score in 28 joints (DAS28): r = -0.13, 95% CI -0.16 to -0.09; 25OHD vs. C-reactive protein: r = -0.12, 95% CI -0.23 to -0.00. Additionally, latitude-stratified subgroup analysis yielded a relatively stronger negative correlation between 25OHD and DAS28 in low-latitude areas. This inverse relationship also appeared more significant in developing countries than in developed countries. No publication bias was detected.

Conclusion

RA patients had lower vitamin D values than healthy controls. There was a negative association between serum vitamin D and RA disease activity. However, more strictly controlled studies are needed to validate these findings.

Serum Vitamin D Level is Inversely Associated With Anti-Cyclic Citrullinated Peptide Antibody Level and Disease Activity in Rheumatoid Arthritis Patients

Objectives

This study aims to assess the relationship between serum vitamin D and anti-cyclic citrullinated peptide (anti-CCP) antibody levels, as well as disease activity in patients with newly diagnosed rheumatoid arthritis (RA).

Patients and methods

These measurements were conducted between January 2014 and June 2014. Serum 25-hydroxy vitamin D (25-OH-D), anti- CCP antibody, and erythrocyte sedimentation rates were measured in a cohort of 154 patients (66 males, 88 females; mean age 53.5±12.4; range 29 to 79 years) with early RA. A control group of 60 healthy participants (25 males, 35 females; mean age 51.4±10.3; range 25 to 75 years) was only evaluated for serum 25-OH-D levels. Disease activity was measured by calculating the 28-Joint Disease Activity Score. Blood samples were drawn from cubital veins. After centrifugation, serum was collected and stored under minus 20 degrees.

Results

Vitamin D deficiency was more prevalent in RA group compared with control group (48.70% vs. 30.00%, p<0.05). Serum 25-OH-D levels were lower in RA group (19.46±8.20 ng/mL) than control group (23.18±6.71 ng/mL) (p<0.05). In the RA group, serum 25-OH-D levels were negatively correlated to anti-CCP antibody levels (rs= -0.360, p<0.001), erythrocyte sedimentation rate (rs= -0.270, p<0.001), age of patients (rs= -0.602, p<0.001), and disease activity (rs= -0.249, p<0.05), respectively. Serum 25-OH-D level did not vary according to sex in the RA group. In control group, females had lower serum 25-OH-D level (p=0.001, rs=0.404). In addition, serum 25-OH-D level was also negatively associated with age in control group (p<0.001, rs= -0.578). There were no differences between RA group and control group in terms of age and sex ratio.

Conclusion

Serum 25-OH-D level was negatively correlated to anti-CCP antibody level and disease activity, which implied the therapeutic role of serum 25-OH-D in RA.

Vitamin D in rheumatoid arthritis-towards clinical application

In addition to its well-documented involvement in mineral homeostasis, vitamin D seems to have broad effects on human health that go beyond the skeletal system. Prominent among these so-called nonclassical effects of vitamin D are its immunomodulatory properties. In vitro studies have shown anti-inflammatory effects of 1,25-dihydroxyvitamin D (1,25(OH)2D), the active form of vitamin D. In addition, epidemiological analysis of patients with established inflammatory disease identified associations between vitamin D deficiency (low serum concentrations of inactive 25-hydroxyvitamin D, abbreviated to 25(OH)D) and inflammatory conditions, including rheumatoid arthritis (RA). The association of vitamin D deficiency with RA severity supports the hypothesis of a role for vitamin D in the initiation or progression of the disease, or possibly both. However, whether 25(OH)D status is a cause or consequence of RA is still incompletely understood and requires further analysis in prospective vitamin D supplementation trials. The characterization of factors that promote the transition from preclinical to clinical phases of RA has become a major focus of research, with the aim to facilitate earlier diagnosis and treatment, and improve therapeutic outcomes. In this Review, we aim to describe the current knowledge of vitamin D and the immune system specifically in RA, and discuss the potential benefits that vitamin D might have on slowing RA progression.

Paget's disease of bone: an osteoimmunological disorder?

Osteoimmunology represents a large area of research resulting from the cross talk between bone and immune systems. Many cytokines and signaling cascades are involved in the field of osteoimmunology, originating from various cell types. The RANK/receptor activator of nuclear factor Kappa-B ligand (RANKL)/osteoprotegerin (OPG) signaling has a pivotal role in osteoimmunology, in addition to proinflammatory cytokines such as tumor necrosis factor-α, interleukin (IL)-1, IL-6, and IL-17. Clinically, osteoimmunological disorders, such as rheumatoid arthritis, osteoporosis, and periodontitis, should be classified according to their pattern of osteoimmunological serum biomarkers. Paget’s disease of bone is a common metabolic bone disorder, resulting from an excessively increased bone resorption coupled with aberrant bone formation. With the exception of the cellular responses to measles virus nucleocapsid protein and the interferon-gamma signature, the exact role of the immune system in Paget’s disease of bone is not well understood. The cytokine profiles, such as the increased levels of IL-6 and the interferon-gamma signature observed in this disease, are also very similar to those observed in other osteoimmunological disorders. As a potential osteoimmunological disorder, the treatment of Paget’s disease of bone may also benefit from progress made in targeted therapies, in particular for receptor activator of nuclear factor Kappa-B ligand and IL-6 signaling inhibition.

Vitamin D Status in Rheumatoid Arthritis: Inflammation, Arterial Stiffness and Circulating Progenitor Cell Number

Background and Aims

Suboptimal vitamin D status was recently acknowledged as an independent predictor of cardiovascular diseases and all-cause mortality in several clinical settings, and its serum levels are commonly reduced in Rheumatoid Arthritis (RA). Patients affected by RA present accelerated atherosclerosis and increased cardiovascular morbidity and mortality with respect to the general population. In RA, it has been reported an impairment of the number and the activity of circulating proangiogenic haematopoietic cells (PHCs), including CD34+, that may play a role in endothelial homeostasis. The purpose of the study is to investigate the association between vitamin D levels and PHCs, inflammatory markers, and arterial stiffening in patients with RA.

Methods and Results

CD34+ cells were isolated from 27 RA patients and 41 controls. Vitamin D levels, C-reactive protein (CRP), fibrinogen, pulse wave velocity (PWV), and carotid intima-media thickness (cIMT) were also evaluated. CD34+ count and vitamin D levels were lower in RA patients as compared to controls, while fibrinogen, CRP, PWV and cIMT were higher in RA patients. CD34+ cell number appeared to be associated with vitamin D levels, and negatively correlated to fibrinogen and early atherosclerosis markers (PWV and cIMT); vitamin D levels appear also to be inversely associated to fibrinogen.

Conclusions

RA patients with moderate disease activity presented with low vitamin D levels, low CD34+ cell count, increased PWV and cIMT; we found that vitamin D deficiency is associated to CD34+ cell reduction in peripheral blood, and with fibrinogen levels. This suggests that vitamin D might contribute to endothelial homeostasis in patients with RA.

Vitamin D levels in juvenile idiopathic arthritis from an equatorial region

We aimed to describe the serum levels of 25-hydroxyvitamin D (25OHD) in juvenile idiopathic arthritis (JIA) patients living in a low-latitude (3°43'S) region. Fifty JIA patients, 31 (62 %) female, seen between May 2012 and April 2013 in the northeast of Brazil had clinical data and serum collected for determination of 25OHD and parathyroid hormone (PTH) using a chemiluminescent ELISA; 20 age- and sex-matched controls were used for comparison. Mean age was 13.4 ± 4 years. Twenty-five (50 %), 15 (30 %), 4 (8 %), 4 (8 %), and 2 (4 %) patients were of the polyarticular, oligoarticular, systemic, enthesitis-related, and undifferentiated categories, respectively. Mean 25OHD was 31.6 ± 10 and 30.4 ± 5.7 ng/mL in patients and controls (P > 0.05), respectively; PTH was normal in JIA and controls; 25OHD was similar regardless of JIA category, disease activity, or severity measured by JADAS-27, CHAQ, or presence of joint deformities. Twenty-six (52 %), 20 (40 %), and 4 (8 %) patients were considered to have optimal, sufficient, and deficient 25OHD levels, respectively, whereas 11 (52 %) and 10 (48 %) controls had optimal and sufficient 25OHD. Ethnicity, body mass index, seasonal variation, and use of steroids did not influence 25OHD levels. This is the first study on 25OHD levels in JIA patients living in a low-latitude region, showing the lowest prevalence of vitamin D deficiency ever reported. Serum 25OHD was similar in JIA and controls and did not vary regardless of JIA category or severity.