The Impact of Obesity and a High-Fat Diet on Clinical and Immunological Features in Systemic Lupus Erythematosus

The causal associations of inflammatory cytokines with obesity and systemic lupus erythematosus: A Mendelian randomization study

OBJECTIVE

Previous studies have partly discussed the roles of inflammatory cytokines in obesity and systemic lupus erythematosus (SLE), but the causal relationship among inflammatory cytokines, obesity, and SLE is unclear. It is challenging to comprehensively evaluate the causal relationship between these variables. This study aimed to investigate the role of cytokines as intermediates between obesity and SLE.

METHODS

The inverse-variance weighted method (IVW) of mendelian randomization (MR) is mainly used to explore the causal relationship between exposure and outcome by using the genetic variation of the open large genome-wide association studies (GWAS), namely single-nucleotide polymorphisms (SNPs) related to obesity (more than 600 000 participants), inflammatory cytokines (8293 healthy participants) and SLE (7219 cases). Methods such as weighted median, MR-Egger are used to evaluate the reliability of causality. Reverse analysis is performed for each MR analysis to avoid reverse causality. Cochran's Q statistic and funnel chart are used to detect heterogeneity, MR-Egger intercept test and leave-one-out sensitivity analyses evaluated pleiotropy.

RESULTS

Obesity was associated with 25 cytokines, and 3 cytokines were associated with SLE, including CTACK (OR = 1.19, 95% CI: 1.06, 1.33, p = .002), IL-18 (OR = 1.13, 95% CI: 1.01, 1.26, p = .027), SCGFb (OR = 0.89, 95% CI: 0.79, 0.99, p = .044). In the opposite direction, SLE was associated with 18 cytokines, and 2 cytokines were associated with obesity, including IP-10 (βIVW = -.03, 95% CI: -0.05, -0.01, p = .002), MIP-1B (βIVW = -.03, 95% CI: -0.05, -0.01, p = .004).

CONCLUSION

Our MR study suggested that CTACK, IL-18 and SCGFb may play an intermediary role in obesity to SLE, while IP-10 and MIP-1B may play an intermediary role in SLE to obesity.

A comprehensive exploration of the heterogeneity of immune cells in Han and Zang systemic lupus erythematosus patients via single-cell RNA sequencing

Systemic Lupus Erythematosus (SLE) is an autoimmune sickness with unclear pathogenesis. The goal of this research was to reveal the heterogeneity of immune cells in SLE patients of Han and Zang nationality by single-cell RNA sequencing (scRNA-seq) and bioinformatics profiling.

METHODS

A total of 94,102 peripheral blood mononuclear cells (PBMCs) from six volunteers with SLE (3 Zang, 3 Han) and six healthy controls were first conducted through scRNA-seq analysis. The immune cell subsets in the pathogenesis of SLE were analyzed as well. Real-time quantitative PCR (RT-qPCR) was applied to confirm the results of sc-RNA seq analysis.

RESULTS

For the Tibetan samples, the ratios of Naïve CD4 RPS4Y1 cells, Naïve CD4 cells, Memory BC CD24 and Memory BC differed significantly between the SLE and control samples, while that of CD8 CTL MAL cells was significantly different between the two groups in Han nationality samples. Variable differentiation states of CD8 CTL MAL cells, CD8 CTL GZMK cells, and Naïve CD4 cells were detected through pseudotime analysis. Moreover, T-cell receptor (TCR) abundance was notably higher in Tibetan SLE specimens than that in controls, while B-cell receptor (BCR) abundance in Tibetan and Han samples was higher than in control groups.

CONCLUSIONS

In summary, the immune cellular heterogeneity of SLE patients both Han and Zang nationality was explored based on various bioinformatics approaches, providing new perspectives for immunological characteristics of SLE among different ethnic groups.

Impact of prior bariatric surgery on outcomes of hospitalized patients with systemic lupus erythematosus: a propensity score-matched analysis of the U.S. nationwide inpatient sample

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease that primarily affects young women, has many different manifestations, and the disease severity can wax and wane.

OBJECTIVES

This study aims to determine the association between prior bariatric surgery and SLE outcomes.

SETTING

A population-based, retrospective study using data from the U.S. Nationwide Inpatient Sample (NIS) database between 2005 and 2018.

METHODS

Data of hospitalized patients with SLE and morbid obesity were extracted. Exclusion criteria were age <18 years and missing information on mortality. Patients were separated into 2 groups: with or without prior bariatric surgery. One: 4 propensity score matching (PSM) were performed to balance the characteristics between the groups. Associations between prior bariatric surgery and inpatient outcomes were determined by logistic regressions.

RESULTS

A total of 38,286 hospitalized patients with SLE and morbid obesity were identified. After exclusions and PSM, there remained 9050 subjects in the study sample (with prior bariatric surgery: 1810; without prior bariatric surgery: 7240), representing 44,952 U.S. inpatients. After adjusting for confounders in multivariable analysis, prior bariatric surgery was significantly associated with lower odds for prolonged length of stay (LOS), unfavorable discharge, and SLE-related complications. Specifically, prior bariatric surgery was significantly associated with lower risks of acute myocardial infarction (AMI)/stroke (aOR = .44, 95% CI: .30-.65), venous thromboembolism (VTE) (aOR = .74, 95% CI: .57-.96), pneumonia (aOR = .60, 95% CI: .47-.76), sepsis (aOR = .62, 95% CI: .51-.75), acute and chronic glomerulonephritis (aOR = .53, 95% CI: .38-.76), acute kidney injury (AKI) (aOR = .64, 95% CI: .52-.77), and anemia (aOR = .77, 95% CI: .68-.87).

CONCLUSIONS

Prior bariatric surgery is associated with favorable in-hospital outcomes in hospitalized patients with SLE and decreased likelihood for several SLE-related complications.

Factors associated with 25-hydroxyvitamin D level in Chinese hospitalized patients with systemic lupus erythematosus: a retrospective cohort study

We aimed to investigate the factors associated with vitamin D deficiency and changes in 25 (OH)D levels, as well as the impact of those changes on disease activity and renal function among SLE patients. This retrospective cohort study was based on the medical records of SLE patients hospitalized between 2010 and 2021. We collected relevant information from this patient population. Logistic regression analysis was employed to determine the factors associated with vitamin D deficiency and increased 25 (OH)D levels, and we calculated the odds ratios (ORs) and 95% confidence intervals (CIs) accordingly. At baseline, among the 1257 SLE patients, the median and interquartile range of 25 (OH)D levels were 14 (9, 20) ng/ml, with 953 (75.8%) patients exhibiting 25 (OH)D deficiency (< 20 ng/ml). The presence of 25 (OH)D deficiency was found to be associated with renal involvement and a high glucocorticoid (GC) maintenance dose. Among the 383 patients who were followed up for an average of 18 months, an increase of at least 100% in 25 (OH)D levels was positively associated with a decreased GC maintenance dose and vitamin D3 supplementation, with adjusted odds ratios(OR) (95% confidence interval [CI]) of 2.16 (1.02, 4.59) and 1300 (70, 22300), respectively. Furthermore, an increased level of 25 (OH)D was significantly associated with a decrease in the Disease Activity Index 2000 score and the urinary protein/creatinine ratio. Patients with SLE have low vitamin D levels, especially those with impaired kidney function. Increased 25 (OH)D levels can be achieved through supplementation with high doses of vitamin D3 and are associated with improvements in disease activity and the urinary protein/creatinine ratio.

A Comprehensive Literature Review on Managing Systemic Lupus Erythematosus: Addressing Cardiovascular Disease Risk in Females and Its Autoimmune Disease Associations

This review aimed to evaluate the mechanism of premature cardiovascular disease (CVD) in systemic lupus erythematosus (SLE) patients, particularly in the female population, and emphasize the need for early management interventions; explore the association between SLE and two autoimmune diseases, myasthenia gravis (MG) and antiphospholipid antibody syndrome (APS), and their management strategies; and evaluate the effectiveness of pharmacological and non-pharmacological interventions in managing SLE, focusing on premenopausal females, females of childbearing age, and pregnant patients. We conducted a comprehensive literature review to achieve these objectives using various databases, including PubMed, Google Scholar, and Cochrane. The collected data were analyzed and synthesized to provide an evidence-based overview of SLE, its management strategies as an independent disease, and some disease associations. The treatment should be focused on remission, preventing organ damage, and improving the overall quality of life (QOL). Extensive emphasis should also be focused on diagnosing SLE and concurrent underlying secondary diseases timely and managing them appropriately.

Impact of overweight and obesity on disease activity and remission in systemic lupus erythematosus: A systematic review and meta-analysis protocol

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune and inflammatory disease that requires treatment with hydroxychloroquine and glucocorticoids. Glucocorticoids are responsible for adverse effects such as increased weight, which can modify the severity and chronicity of autoimmune pathologies.

AIM

To summarize scientific evidence regarding the impact of overweight and obesity on disease activity and remission in SLE.

METHODS

The protocol was developed according to the Preferred Reporting Items for Systematic Review and Meta-analysis Protocol (PRISMA-P) and published in the International Prospective Register of Systematic Reviews database (PROSPERO-CRD42021268217). PubMed, Scopus, Embase, and Google Scholar will be searched for observational studies including adult patients with SLE who were overweight and obese or not, that included disease activity or remission as outcomes. The search is planned for May 2023. Three independent authors will select the eligible articles and extract their data. Subsequently, three authors will independently extract data from each included study using an extraction form created by the researchers. Methodological quality analyses will be performed using the modified Newcastle-Ottawa scale. The results will be presented as a narrative synthesis according to the synthesis without a meta-analysis reporting guideline (SWiM). Meta-analysis will be conducted where appropriate using random-effects models.

EXPECTED RESULTS

This review will identify the impact of overweight and obesity on the clinical features of SLE, helping clinicians manage disease activity and remission, both important to optimize disease outcomes and patient quality of life.

Systemic lupus erythematosus: latest insight into etiopathogenesis

Systemic lupus erythematosus (SLE) is a complex autoimmune disorder of unknown etiology. Multifactorial interaction among various susceptible factors such as environmental, hormonal, and genetic factors makes it more heterogeneous and complex. Genetic and epigenetic modifications have been realized to regulate the immunobiology of lupus through environmental modifications such as diet and nutrition. Although these interactions may vary from population to population, the understanding of these risk factors can enhance the perception of the mechanistic basis of lupus etiology. To recognize the recent advances in lupus, an electronic search was conducted among search engines such as Google Scholar and PubMed, where we found about 30.4% publications of total studies related to genetics and epigenetics, 33.5% publications related to immunobiology and 34% related to environmental factors. These outcomes suggested that management of diet and lifestyle have a direct relationship with the severity of lupus that influence via modulating the complex interaction among genetics and immunobiology. The present review emphasizes the knowledge about the multifactorial interactions between various susceptible factors based on recent advances that will further update the understanding of mechanisms involved in disease pathoetiology. Knowledge of these mechanisms will further assist in the creation of novel diagnostic and therapeutic options.

Bisphenol P exposure in C57BL/6 mice caused gut microbiota dysbiosis and induced intestinal barrier disruption via LPS/TLR4/NF-κB signaling pathway

Despite being one of the most world's widely used and mass-produced compounds, bisphenol A (BPA) has a wide range of toxic effects. Bisphenol P (BPP), an alternative to BPA, has been detected in many foods. The effects of BPP dietary exposure on gut microbiota and the intestinal barrier were unclear. We designed three batches of animal experiments: The first studied mice were exposed to BPP (30 µg/kg BW/day) for nine weeks and found that they gained weight and developed dysbiosis of the gut microbiota. The second, using typical human exposure levels (L, 0.3 µg/kg BW/day BPP) and higher concentrations (M, 30 µg/kg BW/day BPP; H, 3000 µg/kg BW/day BPP), caused gut microbiota dysbiosis in mice, activated the Lipopolysaccharide (LPS) /TLR4/NF-κB signaling pathway, triggered an inflammatory response, increased intestinal permeability, and promoted bacterial translocation leading to intestinal barrier disruption. The third treatment used a combination of antibiotics and alleviated intestinal inflammation and injury. This study demonstrated the mechanism of injury and concentration effects of intestinal damage caused by BPP exposure, providing reference data for BPP use and control and yielding new insights for human disease prevention.

Lupus pathogenesis and autoimmunity are exacerbated by high fat diet-induced obesity in MRL/lpr mice

OBJECTIVE

SLE is an autoimmune disease characterised by persistent inflammation and autoantibody production. Genetic predisposition and environmental factors such as a high-fat diet (HFD) may contribute to lupus development. However, the immune cell profile and gender difference in response to HFD in lupus have not been reported. Here we investigated the impact of HFD on lupus pathogenesis and autoimmunity using lupus-prone mice.

METHODS

Thirty male and 30 female MRL/lymphoproliferation (lpr) mice were fed with regular diet (RD) or HFD. Body weights were recorded weekly. SLE progression was monitored by skin lesion, urine protein, titres of antidouble-strand DNA (dsDNA) and ANA. At week 14, kidney and skin tissue sections were stained with H&E and periodic acid-Schiff to detect histological kidney index and skin score. Splenocytes were identified by immunofluorescence staining and flow cytometry.

RESULTS

HFD significantly increased body weight and lipid levels compared with RD (p<0.01). Skin lesions were observed in 55.6% of the HFD group compared with 11.1% of the RD group, with greater histopathological skin scores in the female HFD group (p<0.01). Although both male and female mice had higher serum IgG in the HFD group than in the RD group, only the male HFD group showed an increased trend in anti-dsDNA Ab and ANA titres. Kidney pathological changes in the HFD group were more severe in male mice than in female mice (p<0.05), detected by proteinuria, kidney index and glomerular cell proliferation. Significant increases of germinal centre B cells and T follicular helper cells were observed in the spleens of HFD mice (p<0.05).

CONCLUSION

HFD induced an accelerated and exacerbated lupus development and autoimmunity in MRL/lpr mice. Our results parallel many known clinical lupus phenotypes and sexual dimorphism in which male patients are likelier to have a severe disease (nephritis) than female lupus patients who may have a broader range of lupus symptoms.

Effects of high fat diet-induced obesity on pathophysiology, immune cells, and therapeutic efficacy in systemic lupus erythematosus

Prior studies have suggested a strong link between obesity and autoimmune diseases. This study aimed to evaluate the effects of high fat diet (HFD)-induced obesity on the disease pathogenesis, immune cell infiltration, and therapeutic efficacy in systemic lupus erythematosus (SLE). Treatment with methylprednisolone significantly increased the survival in the control diet group, but not in the HFD group. An HFD significantly increased the incidence of severe proteinuria and glucose intolerance. Regardless of the diet, treatment with methylprednisolone significantly decreased the serum levels of anti-dsDNA antibodies, IL-2, IL-10, and interferon γ-induced protein 10 (IP-10), and improved the renal pathology scores. Treatment with methylprednisolone significantly lowered the serum levels of IL-6, MCP-1, and TNF-α in the control diet group, but not in the HFD group. HFD significantly increased the proportions of CD45⁺ and M1 cells and significantly decreased the proportion of M2 cells in white adipose tissue; methylprednisolone treatment significantly rescued this effect. In the HFD group, methylprednisolone treatment significantly decreased the M1:M2 and increased the Foxp3⁺:RORγt⁺ cell in the spleen compared with the untreated group. These data improve our understanding of the effect of HFD on the therapeutic efficacy of corticosteroids in SLE treatment, which could have clinical implications.

The Intersection of Cellular and Systemic Metabolism: Metabolic Syndrome in Systemic Lupus Erythematosus

A high prevalence of metabolic syndrome (MetS) has been reported in multiple cohorts of systemic lupus erythematosus (SLE) patients, most likely as one of the consequences of autoimmune pathogenesis. Although MetS has been associated with inflammation, its consequences on the lupus immune system and on disease manifestations are largely unknown. The metabolism of immune cells is altered and overactivated in mouse models as well as in patients with SLE, and several metabolic inhibitors have shown therapeutic benefits. Here we review recent studies reporting these findings, as well as the effect of dietary interventions in clinical and preclinical studies of SLE. We also explore potential causal links between systemic and immunometabolism in the context of lupus, and the knowledge gap that needs to be addressed.

Lifestyle Interventions and Weight Management in Systemic Lupus Erythematosus Patients: A Systematic Literature Review and Metanalysis

Background

We aimed to identify and describe different types of lifestyle interventions primarily or secondarily focused on weight loss in SLE patients.

Methods

A systematic search of controlled trials published until June 2021 that assigned adults patients after dietary or exercise intervention resulted in 248 studies initially screened.

Results

Six studies with seven interventions (3 dietary and 4 exercise training programs) fulfilled the eligibility criteria and were included in the meta-analysis with a median of age 35.8 (31.3 to 49.0 years); median of BMI 26.6 (25.2 to 33.6 kg/m²). After six to twelve weeks of diet or exercise program, no differences were observed in body weight [-1.539 (-4.482 to 1.405) kg (CI 95%), p = 0.306]. Also, a subgroup analysis also revelated no body weight difference following dietary intervention [-3.561 (-9.604 to 2.481) kg (CI 95%), p = 0.248] or exercise intervention [-0.910 (-4.279 to 2.460) kg (CI 95%), p = 0.597].

Conclusion

The results showed that different protocols of exercise intervention or diets were not effective to reduce body weight in patients with SLE. However, only one of the selected trials had a specific study design and protocol focusing on weight loss management.

The impact of a low-calorie, low-glycemic diet on systemic lupus erythematosus: a systematic review

BACKGROUND

Diet plays a critical role in Systemic Lupus Erythematosus (SLE) patients, impacting on the microbiota composition and, consequently, on the immune response. The objective was to analyze and verify the diet effect on SLE patients.

METHODS

This is a systematic review performed at the Evidences-based Health Lab, Escola Superior em Ciências da Saúde, Brasília (DF), Brazil. In March, 2021, five databases, and grey literature, through JSTOR, Open Grey, and Google Scholar were searched. Randomized Clinical Trials in which SLE patients with calorie restricted, low glycemic index or other diet involving the joint adequacy of these aspects, compared with placebo or different types of diet, were included.

RESULTS

It was identified in the databases 758 articles; 132 were duplicated; 616 references were screened, and 604 were excluded. After reading the title and abstract, 12 articles were included for full-text reading. After the full-text reading, three studies were included for quantitative analysis. The diet improved the quality of life at 6 (MD 16.30; 5.91;26.69) and 12 weeks (MD 14.60; 0.88;28.32). The GRADE was used to evaluate the quality of evidence.

CONCLUSION

There is low evidence that the diet has a positive impact on the quality of life of SLE patients. Trial registration PROSPERO-CRD4202012208.