Vitamin D and juvenile idiopathic arthritis

Can vitamin D be an adjuvant therapy for juvenile rheumatic diseases?

Vitamin D, known for its essential role in calcium and bone homeostasis, has multiple effects beyond the skeleton, including regulation of immunity and modulation of autoimmune processes. Several reports have shown suboptimal serum 25 hydroxyvitamin D [25(OH)D] levels in people with different inflammatory and autoimmune rheumatic conditions, and an association between 25(OH)D levels, disease activity and outcomes. Although most available data pertain to adults, insights often are extended to children. Juvenile rheumatic diseases (JRDs) are a significant health problem during growth because of their complex pathogenesis, chronic nature, multisystemic involvement, and long-term consequences. So far, there is no definitive or clear evidence to confirm the preventive or therapeutic effect of vitamin D supplementation in JRDs, because results from randomized controlled trials (RCTs) have produced inconsistent outcomes. This review aims to explore and discuss the potential role of vitamin D in treating selected JRDs. Medline/PubMed, EMBASE, and Scopus were comprehensively searched in June 2023 for any study on vitamin D supplementary role in treating the most common JRDs. We used the following keywords: "vitamin D" combined with the terms "juvenile idiopathic arthritis", "juvenile systemic scleroderma", "juvenile systemic lupus erythematosus", "juvenile inflammatory myopathies", "Behcet disease", "periodic fever syndromes" and "juvenile rheumatic diseases". Observational studies have found that serum 25(OH)D concentrations are lower in juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, juvenile systemic scleroderma, Behcet disease and proinflammatory cytokine concentrations are higher. This suggests that vitamin D supplementation might be beneficial, however, current data are insufficient to confirm definitively the complementary role of vitamin D in the treatment of JRDs. Considering the high prevalence of vitamin D deficiency worldwide, children and adolescents should be encouraged to supplement vitamin D according to current recommendations. More interventional studies, especially well-designed RCTs, assessing the dose-response effect and adjuvant effect in specific diseases, are needed to determine the potential significance of vitamin D in JRDs treatment.

A comprehensive overview of juvenile idiopathic arthritis: From pathophysiology to management

Rheumatoid Arthritis (RA) is a progressive autoimmune disease. It is among the most widespread chronic illnesses in children, with an annual incidence of 1.6 to 23 new instances per 100,000 adolescents. About 1 child in every 1000 develops Juvenile Idiopathic Arthritis (JIA) type of chronic arthritis. The cause of JIA is not well known but what known is that it involves inflammation of the synovium and destruction of tissues in joints which can cause early-onset of oligo articular JIA. It is challenging to diagnose the condition in some children who initially complain of pain and joint swelling as there is no blood test discovered that can confirm the diagnoses of JIA. As JIA patients are immunosuppressed due to the use of drugs, making them vulnerable to catch infections like COVID 19 which can lead to cardiovascular diseases having high rate of morbidity and mortality. The comorbidity like Diabetes has higher incidence in these patients resulting in synergistic effect on inflammation. Currently, the connection of genetics in JIA provides evidence that HLA Class I and II alleles have a role in the pathophysiology of various subtypes of JIA which includes inflammation in the axial skeletal. The primary objective of therapy in juvenile idiopathic arthritis is the suppression of clinical symptoms. The pharmacological approach includes use of medications like DMARDs, NSAIDs etc. and non-pharmacological approach includes physiotherapy, which helps in restoring normal joint function and herbs as adjuvants which has the benefit of no side effects.

Vitamin D Levels and Risk of Juvenile Idiopathic Arthritis: A Mendelian Randomization Study

OBJECTIVES

Observational studies report mixed findings regarding the association between vitamin D and juvenile idiopathic arthritis (JIA) incidence or activity; however, such studies are susceptible to considerable bias. Because low vitamin D levels are common within the general population and easily corrected, there is potential public health benefit in identifying a causal association between vitamin D insufficiency and JIA incidence. To limit bias due to confounding and reverse causation, we examined the causal effect of the major circulating form of vitamin D, 25-hydroxy vitamin D (25-[OH]D), on JIA incidence using Mendelian randomization (MR).

METHODS

In this 2-sample MR analysis, we used summary level data from the largest and most recent genome-wide association study of 25-(OH)D levels (sample size 443,734), alongside summary data from 2 JIA genetic studies (sample sizes 15,872 and 12,501), all from European populations. To test and account for potential bias due to pleiotropy, we employed multiple MR methods and sensitivity analyses.

RESULTS

We found no evidence of a causal relationship between genetically predicted 25-(OH)D levels and JIA incidence (odds ratio 1.00 [95% confidence interval (95% CI) 0.76, 1.33] per SD increase in standardized natural-log transformed 25-[OH]D levels). This estimate was consistent across all methods tested. Additionally, there was no evidence that genetically predicted JIA causally influences 25-(OH)D levels (-0.002 SD change in standardized natural-log transformed 25-[OH]D levels per doubling odds in genetically predicted JIA [95% CI -0.006, 0.002]).

CONCLUSION

Given the lack of a causal relationship between 25-(OH)D levels and JIA, population level vitamin D supplementation is unlikely to reduce JIA incidence.

Nutritional Aspects of Juvenile Idiopathic Arthritis: An A to Z for Dietitians

Juvenile idiopathic arthritis (JIA) represents a chronic, autoimmune, rheumatic musculoskeletal disease with a diagnosis before 16 years of age. Chronic arthritis is a common manifestation in all JIA subtypes. The nature of JIA, in combination to its therapy often results in the development of nutrition-, gastrointestinal (GI)- or metabolic-related issues. The most-common therapy-related nutritional issues involve methotrexate (MTX) and glucocorticosteroids (GCC) adverse events. MTX is a folic acid antagonist, thus supplementation with folic acid in required for improving GI side effects and correcting low serum levels. On the other hand, long-term GCC administration is often associated with hyperglycemia, insulin resistance and growth delay. This relationship is further aggravated when more joints are affected and greater doses of GCC are being administered. Apart from stature, body mass index z-scores are also suboptimal in JIA. Other signs of malnutrition include decreased phase angle and muscle mass, especially among patients with polyarthritis JIA. Evidence also points to the existence of an inverse relationship between disease activity and overweight/obesity. Specific dietary patterns, including the anti-inflammatory diet, might confer improvements in selected JIA outcomes, but the level of available research is yet insufficient to draw safe conclusions. The majority of patients exhibit suboptimal vitamin D status; hence, supplementation is recommended. Collectively, the evidence indicates that, due to the age of onset and the complexity of the disease, along with its pharmacotherapy, children with JIA are prone to the development of several nutritional problems, warranting expert monitoring. Vitamin deficiencies, oral and GI-problems limiting dietary intake, faltering growth, overweight and obesity, physical inactivity, or impaired bone health are among the many nutritional issues in JIA requiring dietitian support.

Causal analysis of serum polyunsaturated fatty acids with juvenile idiopathic arthritis and ocular comorbidity

BACKGROUND & OBJECTIVE

To investigate the causal effects of plasma Polyunsaturated fatty acids (PUFAs) on the risk of juvenile idiopathic arthritis (JIA) and ocular comorbidity through Mendelian randomization (MR) analysis.

METHODS

Genetic variants (formerly single nucleotide polymorphisms, SNPs) that are strongly associated with PUFAs levels (P < 5×10-8) were selected as instrumental variables. Summary-level MR was performed with outcome estimates for JIA (n = 31,142) and JIA associated iridocyclitis (n = 94,197). The inverse variance-weighted (IVW) method was employed as the main approach to combine the estimation for each SNP. Two set of models with summary statistics were conducted and multiple sensitivity analyses were applied for testing of pleiotropic bias.

RESULTS

In model 1, genetically predicted n-6 PUFAs linoleic acid (LA) and arachidonic acid (AA) were associated with lower and higher risk of JIA associated iridocyclitis using IVW (ORLA = 0.940, 95% CI: 0.895-0.988, P = 0.015; ORAA = 1.053, 95% CI: 1.007-1.101, P = 0.024). No such association was observed between each plasma PUFAs and JIA susceptibility (P > 0.05). In further MR analysis, results from model 2 also showed a consistent trend. Besides, multiple sensitivity analyses revealed that there was no obvious evidence for unknown pleiotropy (P > 0.05).

CONCLUSIONS

Our MR study provides genetic evidence on the possible causality that plasma LA level might protect against JIA associated iridocyclitis, whereas AA was responsible for opposite effect.

Vitamin D, oral health, and disease characteristics in juvenile idiopathic arthritis: a multicenter cross-sectional study

Background

Vitamin D deficiency has been associated with autoimmune diseases and oral health. Knowledge about the association between vitamin D status and oral conditions in JIA is limited. We aimed to investigate vitamin D status in a cohort of Norwegian children and adolescents with JIA and possible associations between serum vitamin D levels, clinical indicators of oral health, and JIA disease characteristics.

Methods

This multi-center, cross-sectional study, included individuals with JIA aged 4–16 years from three geographically spread regions in Norway. Demographic data, age at disease onset, disease duration, JIA category, disease status, medication, and vitamin D intake were registered. One blood sample per individual was analyzed for 25(OH) vitamin D, and the level of insufficiency was defined as < 50 nmol/L. A clinical oral examination was performed applying commonly used indices in epidemiological studies of dental caries, dental erosion, enamel defects, gingival bleeding, and oral hygiene. Serum vitamin D was used as exposure variable in multivariable regression analyses to estimate the associations between insufficient vitamin D level, JIA disease status, and oral conditions, with adjustments for age, sex, geographical region, BMI, seasonal blood sampling, and parental education.

Results

Among the 223 participants with JIA, 97.3% were Caucasians, 59.2% were girls, and median age was 12.6 years. Median disease duration was 4.6 years, and 44.4% had oligoarticular JIA. Mean serum vitamin D level was 61.4 nmol/L and 29.6% had insufficient levels. Vitamin D levels did not differ between sexes, but between regions, iso-BMI categories, age groups, and seasons for blood sampling. Insufficient vitamin D levels were associated with dentin caries (adjusted OR 2.89, 95% CI 1.43–5.86) and gingival bleeding (adjusted OR 2.36, 95% CI 1.10–5.01). No associations were found with active JIA disease or more severe disease characteristics.

Conclusion

In our study, nearly 30% had vitamin D insufficiency, with a particularly high prevalence among adolescents. Vitamin D insufficiency was associated with dentin caries and gingival bleeding, but not with JIA disease activity. These results point to the need for a multidisciplinary approach in the follow-up of children with JIA, including an increased focus on vitamin D status and oral health.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02349-1.

Prevalence of Vitamin D Deficiency in Patients Treated for Juvenile Idiopathic Arthritis and Potential Role of Methotrexate: A Preliminary Study

Background: Vitamin D deficiency is reported in rheumatological diseases in adults. The aim was to evaluate the prevalence of vitamin D deficiency in children with juvenile idiopathic arthritis (JIA) and to investigate potential correlations between vitamin D status and clinical factors, laboratory traits, and medical treatment, including methotrexate (MTX) and glucocorticoids (GCs). Methods: In 189 patients aged 3−17.7 years, with JIA in the stable stage of the disease, anthropometry, clinical status, serum 25-hydroxyvitamin D [25(OH)D], calcium (Ca), phosphate (PO4), total alkaline phosphatase (ALP), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) were assessed. Results: Median 25(OH)D level was 15.00 ng/mL, interquartile range (IQR) 12.00 ng/mL. Vitamin D deficiency was found in 67.2% and was independent of sex, disease manifestation, and CRP, ESR, ALP, or PO4 levels. Higher doses of MTX corresponded with lower 25(OH)D levels using both univariate and multivariate models (p < 0.05). No such trend was found for GCs treatment. Serum Ca was lower in patients treated with GCs (p = 0.004), MTX (p = 0.03), and combined GCs/MTX (p = 0.034). Conclusions: JIA patients are vitamin D depleted independently of disease activity or inflammatory markers. MTX therapy may be an iatrogenic factor leading to inadequate 25(OH)D levels. Vitamin D supplementation should be considered in all children with JIA, particularly those receiving long-term MTX therapy.

Vitamin D Supplementation in Patients with Juvenile Idiopathic Arthritis

Vitamin D has been implicated in the pathogenesis of skeletal disorders and various autoimmune disorders. Vitamin D can be consumed from the diet or synthesized in the skin upon ultraviolet exposure and hydroxylation in the liver and kidneys. In its bioactive form, vitamin D exerts a potent immunomodulatory effect and is important for bone health. Juvenile idiopathic arthritis (JIA) is a collection of inflammatory joint diseases in children that share the manifestation of inflamed synovium, which can result in growth arrest, articular deformity, bone density loss, and disability. To evaluate the potential effect of vitamin D on JIA disease manifestations and outcomes, we review the role of vitamin D in bone metabolism, discuss the mechanism of vitamin D in modulating the innate and adaptive immune systems, evaluate the clinical significance of vitamin D in patients with JIA, and summarize the supplementation studies.

Vitamin D Status Among Children With Juvenile Idiopathic Arthritis: A Multicenter Prospective, Non-randomized, Comparative Study

BACKGROUND

Juvenile idiopathic arthritis (JIA) is a chronic autoimmune disease characterized by destructive and inflammatory damage to the joints. The aim in this study was to compare vitamin D levels between children and adolescents, 1-18 years of age, with juvenile idiopathic arthritis (JIA) and a health control group of peers. We considered effects of endogenous, exogenous, and genetic factors on measured differences in vitamin D levels among children with JIA.

METHODS

Our findings are based on a study sample of 150 patients with various variants of JIA and 277 healthy children. The blood level of vitamin D was assessed by calcidiol level. The following factors were included in our analysis: age and sex; level of insolation in three regions of country (center, south, north); assessment of dietary intake of vitamin D; effect of prophylactic doses of cholecalciferol; a relationship between the TaqI, FokI, and BsmI polymorphisms of the VDR gene and serum 25(OH)D concentration.

RESULTS

We identified a high frequency of low vitamin D among children with JIA, prevalence of 66%, with the medial level of vitamin D being within the range of "insufficient" vitamin D. We also show that the dietary intake of vitamin D by children with JIA is well below expected norms, and that prophylactic doses of vitamin D supplementation (cholecalciferol) at a dose of 500-1,000 IU/day and 1,500-2,000 IU/day do not meet the vitamin D needs of children with JIA. Of importance, we show that vitamin D levels among children with JIA are not affected by clinical therapies to manage the disease nor by the present of VDR genetic variants.

CONCLUSION

Prophylactic administration of cholecalciferol and season of year play a determining role in the development of vitamin D deficiency and insufficiency.

Role of Environment in Pediatric Rheumatic Diseases

Studying environmental risk factors for pediatric rheumatic diseases (PRD) is important because the identification of these factors may lead to strategies to prevent disease, and to new insights into pathogenesis and therapeutic targets. Compared with other chronic diseases, there are few environmental epidemiology studies in PRD. Although strong risk factors common to all PRDs have not been identified, some exposures including infection, smoke exposure, and ultraviolet radiation have been associated with several of them. High-technology studies, especially of microbiomics and metabolomics, are increasing and will likely lead to new understandings of the complex interplay between environment, genetics, and disease.

Does Juvenile Idiopathic Arthritis Affect the Course of Legg-Calvé-Perthes Disease? A Case-Control Study with a Mean Follow-Up of 8 Years

BACKGROUND

This study aimed to determine the clinical and radiological course in children who had Legg-Calvé-Perthes disease (LCPD) associated with juvenile idiopathic arthritis (JIA).

METHODS

In a retrospective chart review between 2007 and 2019, eight consecutive JIA patients diagnosed with concomitant LCPD were identified and compared with a case-control group of 10 children with LCPD only.

RESULTS

LCPD was diagnosed at a mean age of 8.1 years (3.0-14.7) in children with JIA as compared to 6.1 years (2.9-10.0) in controls. According to the modified Harris Hip Score (mHHS), four children with JIA and all controls had an excellent result. Regarding the fragmentation severity and the duration of each stage, we found no differences using the lateral pillar and modified Elizabethtown classification. Five hips were classified as Stulberg I/II, two hips as Stulberg III, and one hip as Stulberg V with no evidence of hip dysplasia or severe overcoverage in either group.

CONCLUSIONS

The radiological outcome of LCPD did not differ between both groups, while the clinical outcome was slightly better in controls. Physicians should be aware that children with LCPD may have JIA too. In suspicious cases, further investigations are recommended, and patients should be referred to pediatric rheumatologists.

Evaluation of vitamin D profile in juvenile idiopathic arthritis

OBJECTIVE

To observe the association between serum vitamin D level and disease activity in juvenile idiopathic arthritis (JIA).

METHODS

The observational study was conducted at a tertiary care hospital during 2017-2019. Patients suffered from JIA were recruited through purposive sampling which was stratified by the disease activity based on the Juvenile Arthritis Disease Activity Score 27 (JADAS27) criteria. Serum vitamin D was estimated alongside other laboratory parameters. The numerical and categorical variables were analysed with appropriate statistical tests.

RESULTS

40 subjects were studied where inactive disease was observed in nine subjects (22.5%), five subjects (12.5%) were found to be in low disease activity and moderate disease activity groups each, and twenty-one subjects (52.5%) had high disease activity. Considering the total sample size of the study, the mean (SD) JADAS27 score and serum vitamin D level were observed to be 12.02 (11.31) and 23.10 (5.93) respectively. A negative correlation was found between the JADAS27 score and serum vitamin D (r= -0.67). The corrected Chi-square test had revealed significant association between the status of serum vitamin-D and disease activity groups (=16.28; p < .001).

CONCLUSIONS

In JIA, higher grade of disease activity was found to be significantly associated with lower serum vitamin D.

Exploring the Evidence for an Immunomodulatory Role of Vitamin D in Juvenile and Adult Rheumatic Disease

Vitamin D is synthesized in the skin following exposure to UVB radiation or is directly absorbed from the diet. Following hydroxylation in the liver and kidneys, vitamin D becomes its bioactive form, 1,25(OH)₂D, which has been described to have potent immunomodulatory capacity. This review will focus on the effect of vitamin D in modulating the dysregulated immune system of autoimmune rheumatic diseases (ARD) patients across age, in particular in arthritis (rheumatoid arthritis and juvenile idiopathic arthritis), and systemic lupus erythematosus (with adult and juvenile onset). As well as delineating the impact of vitamin D on the innate and adaptive immune functions associated with each disease pathology, this review will also summarize and evaluate studies that link vitamin D status with disease prevalence, and supplementation studies that examine the potential benefits of vitamin D on disease outcomes. Exploring this evidence reveals that better designed randomized controlled studies are required to clarify the impact of vitamin D supplementation on ARD outcomes and general health. Considering the accessibility and affordability of vitamin D as a therapeutic option, there is a major unmet need for evidence-based treatment recommendations for the use of vitamin D in this patient population.

Reflections on the Importance of Cost of Illness Analysis in Rare Diseases: A Proposal

In the field of rare diseases (RDs), the evidence standard is often lower than that required by health technology assessment (HTA) and payer authorities. In this commentary, we propose that appropriate economic evaluation for rare disease treatments should be initially informed by cost-of-illness (COI) studies conducted using a societal perspective. Such an approach contributes to improving countries' understanding of RDs in their entirety as societal and not merely clinical, or product-specific issues. In order to exemplify how the disease burden's distribution has changed over the last fifteen years, key COI studies for Hemophilia, Fragile X Syndrome, Cystic Fibrosis, and Juvenile Idiopathic Arthritis are examined. Evidence shows that, besides methodological variability and cross-country differences, the disease burden's share represented by direct costs generally grows over time as novel treatments become available. Hence, to support effective decision-making processes, it seems necessary to assess the re-allocation of the burden produced by new medicinal products, and this approach requires identifying cost drivers through COI studies with robust design and standardized methodology.

Clinical and associated inflammatory biomarker features predictive of short-term outcomes in non-systemic juvenile idiopathic arthritis

OBJECTIVE

To identify early predictors of disease activity at 18 months in JIA using clinical and biomarker profiling.

METHODS

Clinical and biomarker data were collected at JIA diagnosis in a prospective longitudinal inception cohort of 82 children with non-systemic JIA, and their ability to predict an active joint count of 0, a physician global assessment of disease activity of ≤1 cm, and inactive disease by Wallace 2004 criteria 18 months later was assessed. Correlation-based feature selection and ReliefF were used to shortlist predictors and random forest models were trained to predict outcomes.

RESULTS

From the original 112 features, 13 effectively predicted 18-month outcomes. They included age, number of active/effused joints, wrist, ankle and/or knee involvement, ESR, ANA positivity and plasma levels of five inflammatory biomarkers (IL-10, IL-17, IL-12p70, soluble low-density lipoprotein receptor-related protein 1 and vitamin D), at enrolment. The clinical plus biomarker panel predicted active joint count = 0, physician global assessment ≤ 1, and inactive disease after 18 months with 0.79, 0.80 and 0.83 accuracy and 0.84, 0.83, 0.88 area under the curve, respectively. Using clinical features alone resulted in 0.75, 0.72 and 0.80 accuracy, and area under the curve values of 0.81, 0.78 and 0.83, respectively.

CONCLUSION

A panel of five plasma biomarkers combined with clinical features at the time of diagnosis more accurately predicted short-term disease activity in JIA than clinical characteristics alone. If validated in external cohorts, such a panel may guide more rationally conceived, biologically based, personalized treatment strategies in early JIA.

Possible role of vitamin D in Covid-19 infection in pediatric population

PURPOSE

Covid-19 is a pandemic of unprecedented proportion, whose understanding and management is still under way. In the emergency setting new or available therapies to contrast the spread of COVID-19 are urgently needed. Elderly males, especially those affected by previous diseases or with comorbidities, are more prone to develop interstitial pneumonia that can deteriorate evolving to ARDS (acute respiratory distress syndrome) that require hospitalization in Intensive Care Units (ICUs). Even children and young patients are not spared by SARS-CoV 2 infection, yet they seem to develop a milder form of disease. In this setting the immunomodulatory role of Vitamin D, should be further investigated.

METHODS

We reviewed the literature about the immunomodulatory role of Vitamin D collecting data from the databases Medline and Embase.

RESULTS

Vitamin D proved to interact both with the innate immune system, by activating Toll-like receptors (TLRs) or increasing the levels of cathelicidins and β-defensins, and adaptive immune system, by reducing immunoglobulin secretion by plasma cells and pro-inflammatory cytokines production, thus modulating T cells function. Promising results have been extensively described as regards the supplementation of vitamin D in respiratory tract infections, autoimmune diseases and even pulmonary fibrosis.

CONCLUSIONS

In this review, we suggest that vitamin D supplementation might play a role in the prevention and/or treatment to SARS-CoV-2 infection disease, by modulating the immune response to the virus both in the adult and pediatric population.

Study of vitamin D status and vitamin D receptor polymorphisms in a cohort of Italian patients with juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic arthritis of children and adolescents. Autoimmune mechanisms are suspected to have a central role in its development. Vitamin D is an immuno-modulator in a variety of conditions, including autoimmune diseases. Low levels of vitamin D have commonly been found in JIA patients, but the influence of this hormone insufficiency in JIA pathogenesis is still unclear. Vitamin D receptor (VDR) mediates a great majority of vitamin D biological activities; specific polymorphisms of the VDR gene have been associated with different biologic responses to vitamin D. In this study, we analysed clinical characteristics of a cohort of 103 Italian JIA patients. The distribution of VDR polymorphisms in affected patients versus healthy controls was evaluated, as well as if and how these polymorphic variants associate with different disease presentations (active disease vs non-active disease), different JIA subtypes, serum levels of 25-hydroxy-vitamin D and parathyroid hormone (PTH), and lumbar spine Z-score values (osteopenia vs normal bone mineral density). A great majority of our JIA patients (84.5%) showed a suboptimal vitamin D status, in many cases (84.1%) not solved by vitamin D supplementation. Vitamin D status resulted to be independent of VDR genotypes. ApaI genotypes showed a highly significant different distribution between JIA patients and unaffected controls, with both the TT genotype and the T allele significantly more frequent in patient group.

The Immunomodulatory Role of Vitamin D in Respiratory Diseases

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The growing interest in the new role of vitamin D, particularly as an immunomodulatory factor, has spurred basic research and the development of clinical trials to better understand the influence of supplementation on various diseases. Vitamin D is an important nutrient factor in human health due to its role in calcium metabolism regulation, cellular growth, differentiation and its fundamental discovered activity in immune functions. It has influenced different diseases, particularly inflammatory and autoimmune diseases, through immune response regulation, modulating innate and adaptive immunity.

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The aim of this review was to explore the role of vitamin D in the main respiratory diseases in children such as asthma, chronic rhinosinusitis, cystic fibrosis and recurrent respiratory infections.

Adjunctive vitamin D for the treatment of active juvenile idiopathic arthritis: An open-label, prospective, randomized controlled trial

Vitamin D has an important immunomodulatory effect, but no trial has examined the effect of boosting serum levels of 25-hydroxyvitamin D (25OHD) in individuals with juvenile idiopathic arthritis (JIA). The aim of the present study was to assess whether vitamin D supplementation reduced disease activity and adjusted/maintained bone mass in patients with active JIA. A 24-week randomized trial was undertaken at Children's Hospital of Chongqing Medical University. Treatment-naive patients with JIA were randomly assigned (1:1) to one of two groups: Standard treatment with high dose oral cholecalciferol [2,000 IU per day; experimental group (EG)] or without supplementation [control group (CG)]. The primary outcomes were the 27-joint Juvenile Arthritis Disease Activity Score (JADAS-27 score), the Z-score for bone mineral density (BMD), and serum levels of 25OHD. A per-protocol analysis set approach was used. The Mann-Whitney U test was the main tool used for data analysis. A total of 42 participants were assigned randomly to the EG (n=20) or the CG (n=22); of these, 36 (n=18 and n=18, respectively) were included in per-protocol analysis. After 24 weeks, the mean level of 25OHD in the EG was higher than that in the CG (P<0.05). At the end of the intervention, there were no clear differences between the two groups in terms of BMD or JADAS-27 score (both P>0.05). Cholecalciferol supplementation (2000 IU/day) for 24 weeks raised serum levels of 25OHD in JIA patients but did not reduce disease activity or improve BMD (registration no. ChiCTR-INR-16009235; Date of Registration: 2016-10-12).

Review of environmental factors and juvenile idiopathic arthritis

Juvenile idiopathic arthritis is a common rheumatic disease that presents as chronic childhood arthritis. JIA is considered a multifactorial disease that may result from diverse genetic and environmental risk factors. A minority of the population-attributable risk of JIA is estimated to be due to familial factors. Thus, non-genetic or environmental factors likely account for a majority of the risk of developing JIA. Yet, while substantial data have linked environmental factors to the development of rheumatoid arthritis, similar evidence regarding JIA is sparse. This narrative review provides updates on recent literature about environmental factors that might influence the risk of developing JIA, including studies about potentially beneficial and harmful influences as well as factors with unclear effects.