Differential impact of environmental factors on systemic and localized autoimmunity

The influence of environmental factors on the development of autoimmune disease is being broadly investigated to better understand the multifactorial nature of autoimmune pathogenesis and to identify potential areas of intervention. Areas of particular interest include the influence of lifestyle, nutrition, and vitamin deficiencies on autoimmunity and chronic inflammation. In this review, we discuss how particular lifestyles and dietary patterns may contribute to or modulate autoimmunity. We explored this concept through a spectrum of several autoimmune diseases including Multiple Sclerosis (MS), Systemic Lupus Erythematosus (SLE) and Alopecia Areata (AA) affecting the central nervous system, whole body, and the hair follicles, respectively. A clear commonality between the autoimmune conditions of interest here is low Vitamin D, a well-researched hormone in the context of autoimmunity with pleiotropic immunomodulatory and anti-inflammatory effects. While low levels are often correlated with disease activity and progression in MS and AA, the relationship is less clear in SLE. Despite strong associations with autoimmunity, we lack conclusive evidence which elucidates its role in contributing to pathogenesis or simply as a result of chronic inflammation. In a similar vein, other vitamins impacting the development and course of these diseases are explored in this review, and overall diet and lifestyle. Recent work exploring the effects of dietary interventions on MS showed that a balanced diet was linked to improvement in clinical parameters, comorbid conditions, and overall quality of life for patients. In patients with MS, SLE and AA, certain diets and supplements are linked to lower incidence and improved symptoms. Conversely, obesity during adolescence was linked with higher incidence of MS while in SLE it was associated with organ damage. Autoimmunity is thought to emerge from the complex interplay between environmental factors and genetic background. Although the scope of this review focuses on environmental factors, it is imperative to elaborate the interaction between genetic susceptibility and environment due to the multifactorial origin of these disease. Here, we offer a comprehensive review about the influence of recent environmental and lifestyle factors on these autoimmune diseases and potential translation into therapeutic interventions.

Essential Trace Element Status in Systemic Lupus Erythematosus: a Meta-analysis Based on Case-Control Studies

The homeostasis of trace elements is essential to regulate different aspects of the immune system and might play important roles in systemic lupus erythematosus (SLE). However, epidemiological evidences that compared the level of essential trace elements in SLE patients and healthy controls (HCs) did not reach a consensus. This was the first meta-analysis to comprehensively assess the level of zinc (Zn), copper (Cu), iron (Fe), and selenium (Se) in SLE and HCs. PubMed, Embase, and Web of Science were systematically searched until April 2022 to find relevant literatures. The PRISMA statement 2020 was followed to make sure the quality of reporting a meta-analysis. The outcomes were assessed by pooled standardized mean difference (SMD) and 95% confidence intervals (CIs). Finally, eleven articles with 1262 subjects were included in the meta-analysis. Significantly lower levels of Zn (SMD = -0.709; 95% CI: -1.173, -0.245; P = 0.003) and Fe (SMD = -1.783; 95% CI: -2.756, -0.809; P = 0.000) were found in SLE compared with HCs. Higher levels of Cu (SMD = 0.808; 95% CI: 0.234, 1.382; P = 0.006) were found in SLE patients. In addition, compared with HCs, Fe and Zn were lower in SLE patients in Asia and Cu was higher in SLE patients in Europe. However, no significant difference was observed in the level of Se (SMD = -0.251; 95% CI: -1.087, 0.586; P = 0.557). Above all, SLE patients exhibited lower Zn and Fe and increased Cu concentrations compared with HCs. Further studies are warranted to investigate the mechanism of Zn, Cu, and Fe in SLE patients.

Methyl Donor Micronutrients: A Potential Dietary Epigenetic Target in Systemic Lupus Erythematosus Patients

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by an aberrant immune response and persistent inflammation. Its pathogenesis remains unknown; however, a complex interaction between environmental, genetic, and epigenetic factors has been suggested to cause disease onset. Several studies have demonstrated that epigenetic alterations, such as DNA hypomethylation, miRNA overexpression, and altered histone acetylation, may contribute to SLE onset and the disease's clinical manifestations. Epigenetic changes, especially methylation patterns, are modifiable and susceptible to environmental factors such as diet. It is well known that methyl donor nutrients, such as folate, methionine, choline, and some B vitamins, play a relevant role in DNA methylation by participating as methyl donors or coenzymes in one-carbon metabolism. Based on this knowledge, this critical literature review aimed to integrate the evidence in animal models and humans regarding the role of nutrients in epigenetic homeostasis and their impact on immune system regulation to suggest a potential epigenetic diet that could serve as adjuvant therapy in SLE.

Selenium nutritional status and its association with SLEDAI-2K, HOMA-IR and lipid profile in Juvenile Systemic Lupus Erythematosus patients

OBJECTIVES

To assess nutritional status regarding selenium in adolescents with Juvenile Systemic Lupus Erythematosus (jSLE) and analyze possible associations with disease activity, insulin resistance and lipid profile.

METHODS

This was an observational, cross-sectional study of 31 female adolescents with jSLE and 31 healthy female volunteers as a comparison group. We obtained demographic, anthropometric (weight, stature, waist, and neck circumferences), and clinical data (disease activity measured by SLEDAI-2K) from both groups; laboratory data including: lipid profile, plasma selenium, erythrocyte glutathione peroxidase activity (GPx), plasma malondialdehyde (MDA), ultrasensitive C-reactive protein (usCRP), insulin levels, and glycemia (Homeostasis Model Assessment for Insulin Resistance-HOMA-IR).

RESULTS

Mean age at diagnosis of jSLE group was 15.9±1.7 years, with mean disease duration of 3.6±2.6 years. 48% of patients and controls had below-reference Se levels (≤46mcg/L). GPx was more frequently below reference levels (<4.171U/L) in the jSLE group, compared to controls. A ROC curve was used to assess the power of the variables to discriminate between both groups; insulin (AUC = 0.712; CI 95% 0.584-0.840), waist-to-height ratio (AUC = 0.704; CI 95% 0.572-0.837), and HOMA-IR (AUC = 0.689; CI 95% 0.556-0.822) were the variables with the greatest discriminatory power. Linear regression showed an independent inverse association between Se levels and c-LDL; no such correlation was found for GPx activity. SLEDAI-2 K and HOMA-IR showed no association with levels of Se and GPx activity.

CONCLUSIONS

Approximately, 50% of jSLE adolescents had below reference Se levels. The frequency of inadequate GPx values was higher in patients, compared to controls. There was an independent inverse association between Se and c-LDL levels in both groups; this was not the case for HOMA-IR and SLEDAI-2K. The data show the importance of assessing Se nutritional status in jSLE patients.

Nutritional aspects and cardiovascular risk in systemic lupus erythematosus

OBJECTIVE

Patients with systemic lupus erythematosus present with a higher number of classic risk factors for coronary diseases and a higher prevalence of metabolic syndrome resulting from the disease itself. To evaluate the nutritional indicators of the cardiovascular risk of patients with systemic lupus erythematosus by analyzing eating habits, anthropometry, laboratory data, and disease activity and to describe the prevalence of patients fulfilling the criteria for metabolic syndrome.

METHODS

Anthropometric measurements including waist circumference, food recall, and laboratory tests.

RESULTS

The population presented an insufficient daily intake of micronutrients. Anthropometry revealed that 37.5% of the patients were classified with degree II obesity by body mass index and 76.8% by abdominal obesity. Regarding metabolic syndrome, 18 patients (16%) fulfilled the diagnostic criteria.

CONCLUSIONS

Individuals with systemic lupus erythematosus presented with increased risk factors, as determined using anthropometric measurements and laboratory tests, for cardiovascular disease, indicating the need for nutritional guidance in this population to reduce cardiovascular risk, increase the quality of life, and increase survival of these patients.

Beneficial effect of Mediterranean diet on disease activity and cardiovascular risk in systemic lupus erythematosus patients: a cross-sectional study

OBJECTIVE

To analyse the influence of the Mediterranean diet (Med Diet) on SLE activity, damage accrual and cardiovascular disease risk markers.

METHODS

A cross-sectional study was conducted on 280 patients with SLE [46.9 (12.85) years]. Med Diet adherence was assessed through a 14-item questionnaire on food consumption frequency and habits (total score from 0 to 14 points; higher score is greater adherence to the Med Diet). CRP, homocysteine, SLEDAI-2K (SLE disease activity), and SLICC/ACR and SDI (damage accrual) were measured. Obesity, diabetes mellitus, hypertension and blood lipids, among others, were considered cardiovascular disease risk factors.

RESULTS

Greater adherence to the Med Diet was significantly associated with better anthropometric profiles, fewer cardiovascular disease risk factors, and lower disease activity and damage accrual scores (P ≤ 0.001 for SLEDAI and SDI). An inverse relationship between the Med Diet score and SLEDAI (P ≥ 0.001; β = -0.380), SDI (P ≤ 0.001; β = -0.740) and hsCRP (P = 0.039; β = -0.055) was observed. The odds ratio for having active SLE (SLEDAI ≥5) or the presence of damage (SDI ≥1) was lower among patients whose Med Diet score was higher (P ≤ 0.001). Finally, greater consumption of Med Diet foods (olive oil, fruits, vegetables, fish, etc.) and abstaining from red meat and meat products, sugars and pastries was associated with less SLE clinical activity and damage.

CONCLUSION

Greater adherence to the Med Diet seems to exert a beneficial effect on disease activity and cardiovascular risk in SLE patients. To confirm these findings, further longitudinal studies would be of interest.

Selenium and Autoimmune Diseases: A Review Article

BACKGROUND

Selenium is an essential trace element with fundamental effects on human biology. Trace elements deficiency is not an uncommon finding in autoimmune diseases. This deficiency may be a consequence of autoimmune diseases or may contribute to their etiology. With regard to evidence showing the association between selenium deficiency and generation of reactive oxygen species and subsequent inflammation, reviewing the role of selenium in collagen vascular diseases could help researchers to devise strategies for managing these diseases.

OBJECTIVE

The present study aimed to evaluate the role of selenium and autoimmune rheumatic diseases.

DATA SOURCES

PubMed, Scopus, Science Direct, and Google Scholar.

STUDY ELIGIBILITY CRITERIA

All the studies on the use of selenium without any limitations in terms of the preparation method, administration route, or formulation process were included in the study. The exclusion criteria were: 1) Articles published in languages other than English, 2) Administration of chemical and hormonal drugs rather than selenium, 3) Investigation of the effects of selenium on the autoimmune problems in animal models, and 4) Insufficiency of the presented data or poor description of the applied methods. Furthermore, review articles, meta-analyses, expert opinions, editorial letters, case reports, consensus statements, and qualitative studies were excluded from the study.

DATA EXTRACTION

In this systematic review, articles were evaluated through searching following keywords in combination with selenium: "autoimmune rheumatic diseases "or "scleroderma" or "systemic sclerosis" or "Behcet's disease" or "Sjögren syndrome" or "systemic lupus erythematosus" or "musculoskeletal diseases" or "rheumatoid arthritis" or "vasculitis" or "seronegative arthritis" or "antiphospholipid antibody syndrome".

RESULTS

Of 312 articles, 280 were excluded and 32 articles were entered in this study. Based on the majority of studies assessing selenium level in patients with collagen vascular diseases, lower selenium levels were observed in these patients. Moreover, the majority of articles showed an improvement in clinical symptoms of collagen vascular diseases compared to controls after the treatment of patients with different dosages of L-selenomethionine.

CONCLUSION

A decrease in the serum level of selenium was noted in patients with autoimmune diseases, which may be a risk factor for inflammation and initiation of autoimmunity in these patients. A sufficient quantity of selenium has been shown to contribute to the management of complications of autoimmune diseases and even improved survival in patients with autoimmune diseases, which may be due to the anti-inflammatory effects of selenium. Since this issue is of clinical importance, it can be considered in potential nutrition interventions and have beneficial effects on some autoimmune diseases.

The Resulting Variation in Nutrient Intake With the Inclusion of Walnuts in the Diets of Adults at Risk for Type 2 Diabetes: A Randomized, Controlled, Crossover Trial

PURPOSE

We previously demonstrated that including walnuts in the diets of adults at risk for type 2 diabetes mellitus (T2DM) led to improved overall diet quality. This report examines the specific changes in their nutrient intake.

DESIGN

This was a randomized, controlled, modified Latin square parallel design trial with 2 treatment arms. Participants were randomized to walnut intake with, or without, dietary advice to regulate caloric intake. Within each treatment arm, they were further randomized to one of 2 sequence permutations (walnut-included/walnut-excluded or walnut-excluded/walnut-included diet), with a 3-month washout between treatment phases.

SETTING

Community hospital in Lower Naugatuck Valley in Connecticut.

PARTICIPANTS

Cohort of 112 participants (31 men and 81 women) at risk for T2DM.

INTERVENTION

Participants included 56 g (366 kcal) of walnuts in their daily diets for 6 months.

MEASURES

Nutrient intake was assessed using web-based Automated Self-Administered 24-Hour Dietary Assessment.

ANALYSIS

Data were analyzed using generalized linear models.

RESULTS

Walnut inclusion led to increased intake of total fat, calcium, magnesium, thiamin, total saturated fatty acids, and monounsaturated and polyunsaturated fatty acids (379.0 ± 90.3 g vs -136.5 ± 92.7 g, P < .01; 230.7 ± 114.2 mg vs -95.2 ± 117.4 mg, P = .05; 111.0 ± 33.9 mg vs -32.3 ± 34.9 mg, P < .01; 0.28 ± 0.2 mg vs -0.47 ± 0.2 mg, P = .02; 8.6 ± 3.4 g vs -1.1 ± 3.5 g, P =.05; 6.3 ± 3.9 g vs -6.3 ± 4.0 g, P = .03; and 25.4 ± 4.0 vs -6.6 ± 4.2 g, P < .01, respectively). Vitamin C intake decreased (-65.3 ± 55.3 mg vs 98.9 ± 56.8 mg, P = .04). Protein intake increased from baseline with the inclusion of walnuts (20.0 ± 8.8 g, P < .05). Walnut inclusion led to an increase in total calories consumed when caloric intake is not regulated.

CONCLUSION

Including walnuts in the diets of these adults led to increased dietary intake of some nutrients associated with lower risk of developing T2DM and other cardiometabolic risk factors.