Association Between Inflammatory Bowel Disease and Both Psoriasis and Psoriatic Arthritis: A Bidirectional 2-Sample Mendelian Randomization Study

Assessing the causal relationship between obesity and ankylosing spondylitis: A two-sample Mendelian randomization study

This study aims to explore the potential causal relationship between obesity and ankylosing spondylitis (AS) using the Mendelian randomization (MR) approach. Data were derived from a comprehensive genome-wide association study dataset. Genetic loci that demonstrated significant, independent associations with both obesity and AS in populations of European ancestry were selected as instrumental variables. Multiple MR analyses, including MR-Egger, weighted median, and inverse variance weighting, were employed to assess the causal impact of obesity on AS risk. To ensure reliability, heterogeneity, and multiplicity tests were conducted, and the robustness of the findings was evaluated through sensitivity analyses using the "leave-one-out" method. The inverse variance weighting analysis revealed an odds ratio (OR) of 0.95 with a 95% confidence interval of 0.76 to 1.19 and a P value of .653. These results indicated no significant causal link between obesity and AS development. Additionally, the heterogeneity and multiplicity tests showed no significant findings, while sensitivity analyses reinforced the consistency and robustness of the conclusions. This research did not find evidence of a causal relationship between obesity and the development of AS based on two-sample MR analysis and genetic data evaluation. However, the current study's limitations, including sample size and study design, highlight the need for future research with larger cohorts to further explore the intricate relationship between obesity and AS.

Investigating the causal impact of body mass index on meniscus injuries: A 2-sample Mendelian randomization study

The aim of this study was to explore the possible causal association between body mass index (BMI) and meniscal injuries using Mendelian randomization (MR), a genetic research method. Relying on pooled data from a large genome-wide association study, we carefully selected a set of genetic variants as instrumental variables that were significantly associated with BMI and meniscal injuries and were independently distributed in populations of European origin. The potential impact of BMI on meniscal injuries was systematically assessed by implementing multiple MR analysis strategies including MR-Egger, weighted median and inverse variance weighting. In addition, heterogeneity and multiple validity tests were introduced in the study, together with the "leave-one-out" sensitivity analysis to ensure the robustness and reliability of the results. Inverse variance weighting analysis revealed a significant positive causal association between BMI and meniscus injury, as shown by the ratio (OR) and its 95% confidence interval of 1.46 (1.22-1.75), with a P-value of <.001. Further tests did not reveal significant heterogeneity and pleiotropy, and the results of the sensitivity analyses supported the robustness of the study findings. Combined with the use of 2-sample MR analysis, this study strongly confirms that BMI is an independent risk factor for meniscal injuries, and this finding provides a new genetic perspective for meniscal injury prevention and intervention.

Body mass index and risk of lumbar spondylolisthesis: An observational study based on two-sample Mendelian randomization analysis

This study aims to investigate the potential causal relationship between body mass index (BMI) and lumbar spondylolisthesis through the application of Mendelian randomization (MR) analysis. We utilized comprehensive data derived from large-scale genome-wide association studies to examine the association between BMI and lumbar spondylolisthesis in populations of European ancestry. Independent genetic variants with significant correlations to BMI and lumbar spondylolisthesis were selected as instrumental variables to ensure methodological rigor. To evaluate the causal impact of BMI on the risk of developing lumbar spondylolisthesis, 3 distinct MR approaches were employed: MR-Egger regression, Weighted Median analysis, and inverse variance weighted estimation. Robustness and consistency of the findings were assessed through heterogeneity testing, multiplicity analysis, and a leave-one-out sensitivity evaluation to confirm the stability of the results. The inverse variance weighted analysis revealed a significant positive association between BMI and lumbar spondylolisthesis risk, with an odds ratio of 1.66 and a 95% confidence interval of 1.20 to 2.29 (P = .002). This finding indicates that individuals with higher BMI are more predisposed to developing lumbar spondylolisthesis. Complementary results from heterogeneity and multiplicity assessments demonstrated no evidence of significant heterogeneity or horizontal pleiotropy, reinforcing the reliability of the findings. Furthermore, the leave-one-out sensitivity analysis confirmed the stability and robustness of the results, providing additional validation of the causal relationship. This investigation offers valuable insights by leveraging two-sample Mendelian randomization analysis to explore the causal link between BMI and lumbar spondylolisthesis. The evidence strongly suggests that elevated BMI contributes significantly to the risk of lumbar spine slippage. These findings highlight the importance of weight management as a preventive strategy for lumbar spine disorders. Promoting healthy BMI levels may serve as a critical intervention to mitigate the risk of lumbar spondylolisthesis, emphasizing the necessity for targeted public health initiatives focused on weight control to enhance spinal health and overall well-being.

Identification and validation of shared biomarkers and drug repurposing in psoriasis and Crohn's disease: integrating bioinformatics, machine learning, and experimental approaches

Background

Psoriasis and Crohn's disease (CD) are chronic inflammatory diseases that involve complex immune-mediated mechanisms. Despite clinical overlap and shared genetic predispositions, the molecular pathways connecting these diseases remain incompletely understood. The present study seeks to identify shared biomarkers and therapeutic targets for psoriasis and CD.

Methods

Differentially expressed genes (DEGs) were identified from publicly available transcriptomic datasets related to psoriasis and CD. Simultaneously, weighted gene co-expression network analysis (WGCNA) was performed to identify gene modules associated with the clinical traits of psoriasis and CD. Subsequently, biomarkers were prioritized from shared key genes by integrating protein-protein interaction (PPI) networks with machine learning models. Gene Set Enrichment Analysis (GSEA), along with Gene Ontology (GO) and KEGG pathway analyses, were performed to determine the biological significance of the identified genes. Immune infiltration analysis underscored the involvement of hub genes in immune regulation, while single-cell transcriptomic analysis revealed the cellular localization of these hub genes. Additional targeted molecular biology experiments validated the shared biomarkers. DSigDB predictions were employed to identify potential therapeutic compounds. Molecular docking simulations were performed to assess the binding affinity of the drugs to key target proteins. Finally, additional in vitro experiments were conducted to validate the therapeutic effects of the identified compounds.

Results

The study identified KIF4A, DLGAP5, NCAPG, CCNB1, and CEP55 as key regulatory molecules and shared biomarkers for both diseases. GSEA and pathway analysis highlighted the importance of cell cycle regulation and immune response pathways in the comorbidities of psoriasis and CD. Immune infiltration analysis emphasized the role of hub genes in immune regulation. Furthermore, DSigDB predictions and molecular docking simulations indicated strong therapeutic potential for Etoposide, Lucanthone, and Piroxicam, with Etoposide showing the highest affinity for key targets. In cellular models, Etoposide demonstrated promising therapeutic effects by significantly downregulating the expression of psoriasis-related keratinocytes marker genes (KRT6, KRT16) and CD-related inflammatory cytokines (IL6, IL8, TNF-α), highlighting its potential in treating psoriasis and CD.

Discussion

This study integrates bioinformatics, machine learning, and molecular validation to identify the shared molecular mechanisms of psoriasis and CD, uncovering novel biomarkers and potential combined therapeutic candidates. These findings provide valuable insights into potential treatment strategies for these diseases.

Association between sarcopenia and intervertebral disc degeneration: A bidirectional two-sample Mendelian randomization

BackgroundSarcopenia (SP) and Intervertebral Disc Degeneration (IVDD) are common age-related diseases that significantly affect the physical and mental health of patients. A substantial body of evidence suggests a potential association between SP and IVDD. However, the causal relationship between SP and IVDD remains uncertain.ObjectivesThis study aimed to determine whether the association between SP and IVDD is causal by employing Mendelian randomization (MR) analysis.MethodsGenome-wide association study (GWAS) data related to SP (measured by muscle lean mass, left- and right-hand grip strength, and walking speed) and IVDD were obtained from the UK Biobank and FinnGen. To investigate the causal relationship between SP and IVDD, three MR analysis methods were employed, primarily focusing on the Inverse-Variance Weighted (IVW) approach. The robustness of causal effects was ensured through multiple methods: Instrumental Variables (IVs) were evaluated using F-values; heterogeneity was assessed using Cochran's Q; horizontal pleiotropy was evaluated using MR Egger regression; and outliers was detected using MR-PRESSO and the leave-one-out method.ResultsThe analysis indicates a potential causal relationship between appendicular lean mass (ALM) and the risk of IVDD (OR = 0.89, 95% CI: 0.809-0.98; P < 0.05). Similarly, left-hand grip strength shows a potential causal relationship with IVDD risk (OR = 1.52, 95% CI:1.08-2.14; P < 0.05), as does right-hand grip strength (OR = 1.50, 95% CI:1.09-2.07; P < 0.05). Additionally, a potential causal relationship is observed between IVDD and walking speed (OR = 0.99, 95% CI:0.97-1.00; P < 0.05).ConclusionThe findings suggest that ALM may serve as a protective factor against IVDD, while left- and right-hand grip strength may be risk factors for the development of IVDD. Furthermore, IVDD appears to be a risk factor associated with reduced walking speed. Further research is necessary to elucidate the underlying mechanisms of these associations.

Unveiling the molecular mechanisms of Haitang-Xiaoyin Mixture in psoriasis treatment based on bioinformatics, network pharmacology, machine learning, and molecular docking verification

OBJECTIVE

Psoriasis is a common clinical skin inflammatory disease. Haitang-Xiaoyin Mixture (HXM) represents a traditional Chinese medicine formulation utilized clinically for the management of psoriasis, which can reduce the psoriasis area and severity index (PASI) score, IL-23 and IL-23 levels in patients with psoriasis. However, the main active components and specific targets of HXM in the treatment of psoriasis and the relevant mechanisms of action are not clear. Therefore, in the study we aimed to elucidate the mechanistic basis of HXM's therapeutic action in psoriasis treatment through the application of bioinformatics, network pharmacology, machine learning and molecular docking methodologies.

METHODS

The psoriasis-related genes were obtained from the Gene Expression Omnibus (GEO) dataset, which psoriasis-associated disease genes were identified utilizing the GeneCard and DisGeNEt databases. The active ingredients of HXM were retrieved from HERB and TCMSP databases. Protein-Protein Interactions (PPI), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to identify potential targets and signaling pathways. Psoriasis key targets were determined using LASSO, SVM-RFE, and Boruta algorithms, followed by Receiver Operating Characteristic (ROC) analysis. Key targets were GESA enriched and analyzed for transcription factors and immune cell infiltration. Finally molecular docking and molecular dynamics simulations were performed to validate the binding of active compounds to core targets, elucidating their mechanism of action.

RESULTS

A total of 233 psoriasis-related targets and 290 drug targets were identified. After data set crossover, 37 pharmacodynamic targets were obtained. PPI network topology analysis revealed 12 core targets. GO and KEGG enrichment analysis suggested that HXM may regulate angiogenesis, chemokine receptor binding process, as well as IL-17 and TNF related signaling pathways. Machine algorithm screening identified two psoriasis characteristic genes: CXCL2 and CXCR4. Immune infiltration results demonstrated a significant positive correlation between the characteristic genes and M1 macrophages, along with identification of the top 20 transcription factors involved. Quercetin and triptolide were recognized as potential core components of HXM for treating psoriasis based on their molecular docking and molecular dynamics simulation results confirming strong binding abilities with CXCL2 and CXCR4 respectively.

CONCLUSION

This study elucidates the active constituents, potential targets, and underlying pathways involved in the therapeutic effects of HXM for psoriasis. Specifically, CXCL2 and CXCR4 are identified as key targets, with quercetin and triptolide representing crucial compounds exerting their effects on these targets.

[Russian Cross-disciplinary Consensus on the diagnosis and treatment of spondyloarthritis associated with inflammatory bowel diseases]

The Russian Cross-disciplinary Consensus on the diagnositic and treatment of spondyloarthritis (SpA) in inflammatory bowel diseases (IBD) was prepared on the initiative of the Loginov Moscow Clinical Scientific Center, using the Delphic system. Its purpose was to consolidate the opinions of experts on the most actual issues of diagnosis and treatment of concomitant immuno-inflammatory diseases (SpA and IBD). An interdisciplinary approach is provided by the participation of leading gastroenterologists and rheumatologists. The working group analyzed domestic and foreign publications on the problem of curation of patients with SpA and IBD. There have been 17 statements and 2 treatment algorithms formulated. Statements 1-3 reflect the fundamental principles of management of patients with SpA and IBD. The principles of early diagnosis of SpA and IBD, including the diagnosis of complications of therapy, are described below. Eleven statements are devoted to current methods of treatment, on the basis of which 2 treatment algorithms have been developed. The statements of the Consensus were submitted to the Expert Council for consideration, edits were made, after which an online vote took place. This paper presents current recommendations for the management, diagnosis and treatment of patients with SpA and IBD.

Exploring the Shared Diagnostic Genes in IBD and Psoriasis through Bioinformatics and Experimental Assays

Background: Inflammatory bowel disease (IBD) is a persistent, non-specific inflammation affecting the intestines. Psoriasis is a long-lasting inflammatory disorder of the skin. There is a comorbidity correlation between IBD and psoriasis, but the specific pathogenesis of the comorbidity is unclear. Materials and methods: In this study, we analyzed datasets sourced from the Gene Expression Omnibus (GEO) database, and identified shared genes of IBD and psoriasis through differential expression analysis and weighted gene co-expression network analysis (WGCNA). Then three machine learning algorithms were applied to identify shared diagnostic genes. Next, the validation of shared diagnostic genes was evaluated with ROC curves, with the AUC determined. Subsequently, single sample gene set enrichment analysis (ssGSEA) and immune infiltration analysis were conducted. Furthermore, we obtained potential drugs such as securinine in the Drug Signature Database (DsigDB) and 7 traditional Chinese medicines in the Coremine database, which might have therapeutic effects on the comorbidity of IBD and psoriasis. Finally, we confirmed the expression of the shared diagnostic gene in colitis and psoriasis mice tissues through RT-PCR, Western blot and immunohistochemistry (IHC) methods. Results: The results showed that AQP9 had the highest diagnostic value for two diseases. AQP9 had AUC values of 93.681% for UC, 89.629% for CD,and 78.689% for psoriasis in the internal validation datasets. In the external validation datasets, AQP9 had AUC values of 90.394% for UC, 93.909% for CD,and 82.906% for psoriasis. Immune infiltration analysis and ssGSEA revealed that AQP9 might impact the disease process of IBD and psoriasis by participating in the NF-kappaB signaling pathway, and modulating immune cell differentiation. Furthermore, the expression levels of AQP9 were consistently validated, showing upregulation in IBD and downregulation in psoriasis, compared to the control group. Conclusions: This study revealed the shared diagnostic genes and potential mechanisms of the comorbidity of IBD and psoriasis, providing new directions for future research on exploring the comorbidity mechanisms and treatment targets.

Obstructive sleep apnea's causal links to depression, well-being, and negative moods: a bidirectional mendelian randomized study

Previous observational studies showed associations between obstructive sleep apnea (OSA) and depression and other negative moods. However, the causality has not been determined. Single nucleotide polymorphisms were identified as instrumental variables by screening from genome-wide association studies. Bidirectional two-sample mendelian randomization (MR) was applied to assess the potential causal relationship between OSA and depression, subjective well-being, negative moods. Inverse variance weighting (IVW) method and weight median were chosen as the main methods to estimate possible causal effects. MR-Egger, MR pleiotropy residual sum and outlier and leave-one-out analysis methods, were used as sensitivity analysis methods to ensure robust results. MR analyses indicated significantly causal association of OSA on depression (OR = 1.22, P = .010) and major depressive disorder (OR = 1.02, P = .006). Furthermore, genetically predicted OSA was negatively associated with subjective well-being (βIVW = -0.06, P = .009), and was positively associated with negative moods including depressed affect (OR = 1.04, P = .012), irritable mood (P = .006), feeling lonely (P = .011), feeling fed-up (P = .005) and mood swings (P = .017). There is no reverse effect of the above psychiatric traits on OSA. Genetic predisposition to OSA causally increased depression and major depressive disorder. Consistently, OSA has causal impacts on both subjective well-being, representing positive emotions, and negative moods.

Prescription of commonly used drugs in patients with functional bowel disorders. A cross-sectional comparison with the general population

OBJECTIVES

Comorbidity with other conditions is common in functional bowel disorders. We aimed to investigate the prescription patterns of commonly used drugs in patients with irritable bowel syndrome (IBS) and functional unspecific bowel disorder, compared to the general population.

MATERIAL AND METHODS

Prescriptions of commonly used drugs in 2022 were compared between patients and the general population from the same age group and region in Sweden.

RESULTS

Of 526 patients, 317 were followed up in 2022 (219 women and 98 men) and were compared to 51,001 women and 55,571 men in the general population. The median follow-up time from the first visit to 2022 was 8 years (25th-75th percentile 6-11 years). Female patients were significantly more likely than controls to be prescribed PPIs, antibiotics, NSAIDs, paracetamol, opioids, muscle relaxants, antimigraine drugs, antidepressants and asthma medications. Male patients were significantly more likely than controls to be prescribed PPIs, opioids, antidepressants, and asthma medications. In the year prior diagnosis and through 2022, female patients showed a significant decline in the use of PPIs (38% vs.10%; p < 0.001), antibiotics (27.5% vs. 20.1%; p = 0.0426), NSAIDs (23.3% vs.14.6%; p = 0.012), opioids (20.6% vs. 7.5%; p < 0.001), and a significantly increase in the use of asthma medications (15.5% vs. 24.2%; p = 0.0088). Male patients showed a significant decline in the use of PPIs and NSAIDs.

CONCLUSION

Patients with functional bowel disorders are more likely to be prescribed medications for conditions other than IBS. Over time, there was a decline in the prescriptions of most drugs, except for antidepressants and asthma medications.

Joint Manifestations in Inflammatory Bowel Diseases, "Red Flags" for the Early Recognition and Management of Related Arthropathies: A Narrative Review

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, frequently present with extra-intestinal manifestations. Virtually all patients with IBD could be at risk for developing inflammatory arthropathies within the spectrum of spondyloarthritis (SpA). In this context, prompt recognition of musculoskeletal "red flags" (lower back pain, dactylitis, enthesitis, swelling of peripheral joints, musculoskeletal chest pain, family history of SpA, psoriasis, and anterior uveitis) is crucial for early referral and multidisciplinary management by gastroenterologists and rheumatologists. Recent advances have refined diagnostic tools including questionnaires, alongside imaging modalities and laboratory markers, enhancing the detection of SpA in IBD patients. Effective treatment strategies targeting both gastrointestinal and musculoskeletal symptoms may significantly reduce long-term morbidity in these patients. In this narrative review, we aimed to underscore the importance of integrating clinical, diagnostic, and therapeutic approaches for optimal patient management and outcome over time.

Causal association between gastroesophageal reflux disease and sepsis, and the mediating role of gut bacterial abundance, a Mendelian randomization study

Gastroesophageal reflux disease (GERD), akin to sepsis, is mediated by inflammatory reactions and exhibits a strong correlation with intestinal dysbiosis. We sought to examine whether these associations reflect causality using the Mendelian randomization (MR) mediation analysis. Genetic data were obtained from genome-wide association studies. Two-sample MR were performed to evaluate the causal association, accompanied by sensitivity analyses. Reverse direction MR was undertaken to assess the potential for reverse causation. Then, mediation analysis was performed to evaluate the mediating effect of gut bacterial pathway abundance in this relationship. Genetic predisposition to GERD was significantly associated with sepsis [inverse variance weighting: odds ratio = 1.366, P = 2.13E-09, 95% confidence interval [CI] 1.233-1.513] and sepsis-related 28-day mortality (inverse variance weighting: odds ratio = 1.412, P = 6.64E-03, 95% CI 1.101-1.812). There is no convincing evidence for reverse causation. Gut bacterial pathway abundance (ARO.PWY..chorismate.biosynthesis.I) mediates the effect of GERD on sepsis (β = 0.036, 95% CI 0.004-0.067, P = .025), accounting for 11.406% of the total effect; Gut bacterial pathway abundance (PWY.7219..adenosine.ribonucleotides.de.novo.biosynthesis) mediates the effect of GERD on sepsis (β = 0.026, 95% CI -0.003 to 0.056, P = .083), accounting for 8.486% of the total effect; gut bacterial pathway abundance (ARO.PWY..chorismate.biosynthesis.I) mediates the effect of GERD on sepsis (28-day death) (β = 0.079, 95% CI 0.005-0.153, P = .036), accounting for 22.890% of the total effect; gut bacterial pathway abundance (TRNA.CHARGING.PWY..tRNA.charging) mediates the effect of GERD on sepsis (28-day death) (β = -0.066, 95% CI -0.140 to 0.007, P = .078), accounting for -19.171% of the total effect. The present MR study supported GERD as a causal risk factor of sepsis and sepsis-related 28-day mortality. Three specific gut bacterial pathway abundances were identified that played a partial mediating role in the aforementioned causal relationship between GERD and sepsis.

Casual effect of ulcerative colitis on chronic heart failure: results from a bidirectional Mendelian randomization study

This study aimed to detect the causal effect of ulcerative colitis (UC) on heart failure. A bidirectional two-sample Mendelian randomization (MR) analysis was performed. The causal impact of UC on heart failure was determined via MR by performing a genome-wide association study in which 4 UCs descending from European ancestors were set as individual exposures. The inverse-variance weighted (IVW) method was used as the main method, and 4 other methods were set as assistant parameters. Susbequently, the MR results were combined with meta-analysis results. The MR Egger method was employed to investigate pleiotropy. The leave-one-out method was utilized for sensitivity analysis. Furthermore, a reverse-directional study was conducted. There was evidence of the causal effect of UC on heart failure in MR estimates using 4 UC datasets. The IVW method revealed that the odds ratio (OR) = 1.03, 95% confidence interval (CI) = 1.01-1.06, P = 0.0441 when the first UC dataset was used; OR = 1.03, 95% CI = 1.01-1.05, P = 0.0445 when the second UC dataset was used; OR = 2046, 95% CI = 1.37-3.05E + 06, P = 0.0409 when the third UC dataset was used; and OR = 8.12E + 04, 95% CI = 29.09-2.27E + 08, P = 0.0052 when the fourth UC dataset was used. A meta-analysis of 4 MR studies revealed that UC had a statistically significant causal effect on heart failure (OR = 1.03, 95% CI = 1.01-1.05; P = 0.0074). Reverse MR analysis revealed that heart failure did not have a causal effect on UC. There was no pleiotropy. This MR study demonstrated that UC had a causal effect on heart failure and that there was no reverse causal effect.

Genetic insights into the shared molecular mechanisms of Crohn's disease and breast cancer: a Mendelian randomization and deep learning approach

The objective of this study was to explore the potential genetic link between Crohn's disease and breast cancer, with a focus on identifying druggable genes that may have therapeutic relevance. We assessed the causal relationship between these diseases through Mendelian randomization and investigated gene-drug interactions using computational predictions. This study sought to identify common genetic pathways possibly involved in immune responses and cancer progression, providing a foundation for future targeted treatment research. The dataset comprises single nucleotide polymorphisms used as instrumental variables for Crohn's disease, analyzed to explore their possible impact on breast cancer risk. Gene ontology and pathway enrichment analyses were conducted to identify genes shared between the two conditions, supported by protein-protein interaction networks, colocalization analyses, and deep learning-based predictions of gene-drug interactions. The identified hub genes and predicted gene-drug interactions offer preliminary insights into possible therapeutic targets for breast cancer and immune-related conditions. This dataset may be valuable for researchers studying genetic links between autoimmune diseases and cancer and for those interested in the early identification of potential drug targets.

Antibiotic-mediated dysbiosis leads to activation of inflammatory pathways

Introduction

The gut microbiota plays a pivotal role in influencing host health, through the production of metabolites and other key signalling molecules. While the impact of specific metabolites or taxa on host cells is well-documented, the broader impact of a disrupted microbiota on immune homeostasis is less understood, which is particularly important in the context of the increasing overuse of antibiotics.

Methods

Female C57BL/6 mice were gavaged twice daily for four weeks with Vancomycin, Polymyxin B, or PBS (control). Caecal microbiota composition was assessed via 16S rRNA sequencing and caecal metabolites were quantified with NMR spectroscopy. Immune profiles of spleen and mesenteric lymph nodes (MLNs) were assessed by flow cytometry, and splenocytes assessed for ex vivo cytokine production. A generalised additive model approach was used to examine the relationship between global antibiotic consumption and IBD incidence.

Results

Antibiotics significantly altered gut microbiota composition, reducing alpha-diversity. Acetate and butyrate were significantly reduced in antibiotic groups, while propionate and succinate increased in Vancomycin and PmB-treated mice, respectively. The MLNs and spleen showed changes only to DC numbers. Splenocytes from antibiotic-treated mice stimulated ex vivo exhibited increased production of TNF. Epidemiological analysis revealed a positive correlation between global antibiotic consumption and IBD incidence.

Discussion

Our findings demonstrate that antibiotic-mediated dysbiosis results in significantly altered short-chain fatty acid levels but immune homeostasis in spleen and MLNs at steady state is mostly preserved. Non-specific activation of splenocytes ex vivo, however, revealed mice with perturbed microbiota had significantly elevated production of TNF. Thus, this highlights antibiotic-mediated disruption of the gut microbiota may program the host towards dysregulated immune responses, predisposing to the development of TNF-associated autoimmune or chronic inflammatory disease.

Advances in Microbiome-Based Therapeutics for Dermatological Disorders: Current Insights and Future Directions

The human skin hosts an estimated 1000 bacterial species that are essential for maintaining skin health. Extensive clinical and preclinical studies have established the significant role of the skin microbiome in dermatological disorders such as atopic dermatitis, psoriasis, diabetic foot ulcers, hidradenitis suppurativa and skin cancers. In these conditions, the skin microbiome is not only altered but, in some cases, implicated in disease pathophysiology. Microbiome-based therapies (MBTs) represent an emerging category of live biotherapeutic products with tremendous potential as a novel intervention platform for skin diseases. Beyond using established wild-type strains native to the skin, these therapies can be enhanced to express targeted therapeutic molecules, offering more tailored treatment approaches. This review explores the role of the skin microbiome in various common skin disorders, with a particular focus on the development and therapeutic potential of MBTs for treating these conditions.

Genetic Study of Psoriasis Highlights its Close Link with Socioeconomic Status and Affective Symptoms

Psoriasis is an inflammatory skin disease with an estimated heritability of around 70%. Previous GWASs have detected several risk loci for psoriasis. To further improve the understanding of the genetic risk factors impacting the disease, we conducted a discovery GWAS in FinnGen and a subsequent replication and meta-analysis with data from the Estonian Biobank and the UK Biobank; the study sample included 925,649 individuals (22,659 cases and 902,990 controls), the largest sample for psoriasis yet. In addition, we conducted downstream analyses to find out more about psoriasis' cross-trait genetic correlations and causal relationships. We report 6 risk loci, which, to our knowledge, are previously unreported, most of which harbor genes related to NF-κB signaling pathway and overall immunity. Genetic correlations highlight the relationship between psoriasis and smoking, higher body weight, and lower education level. In addition, we report causal relationships between psoriasis and mood symptoms as well as 2-directioned causal relationship between psoriasis and lower education level. Our results provide further knowledge on psoriasis risk factors, which may be useful in the development of future treatment strategies.

Mendelian Randomization Study Investigating the Causal Relationship Between Thyroid Dysfunction and Cerebral Infarction

BACKGROUND

There is an association between thyroid dysfunction and cerebral infarction (CI), but the causality cannot be determined. A two-sample two-way Mendelian randomization (MR) study was conducted to assess the causal relationship between thyroid function and CI.

METHODS

We selected single-nucleotide polymorphisms (SNPs) associated with five phenotypes, including CI from the UK Biobank (n = 361,194), hyperthyroidism from the IEU Open GWAS database (n = 484,598), hypothyroidism from the IEU Open GWAS database (n = 473,703), normal thyroid-stimulating hormone (TSH) (n = 271,040), and normal free thyroxine (FT4) (n = 119,120) from the Thyroidomics Consortium database. For the forward MR analysis, the exposures were hyperthyroidism, hypothyroidism, TSH, and FT4. The inverse variance weighted (IVW) method, weighted median (WM), and MR-Egger revealed the causality with CI. For the reverse MR analysis, CI was regarded as the exposure, and four thyroid function phenotypes were the outcomes. The sensitivity and heterogeneity test was assessed using Cochran's Q test, MR-Egger regression, and leave-one-out analysis.

RESULTS

The MR analysis indicated that genetic susceptibility to hyperthyroidism increased the risk of CI (IVW-OR = 1.070; 95% CI: 1.015-1.128; p = 0.003). In reverse MR, genetic susceptibility to RA is not associated with hyperthyroidism (IVW-OR = 1.001; 95% CI: 1.000-1.001; p = 0.144). Any positive or reverse causal relationship between hypothyroidism, FT4, and TSH with CI could not be established. Sensitivity and heterogeneity test consolidated our findings.

CONCLUSION

The causality between CI and hyperthyroidism demonstrated patients with hyperthyroidism have a risk of genetic variants for CI. In the future, further studies are needed to fully explore their mechanisms of action.

A review and recommendations on the management of psoriatic arthritis in Australia 2024

Psoriatic arthritis (PsA) is a progressive, systemic inflammatory disease. It can lead to serious joint damage and disability, increased cardiovascular risk and reduced quality of life. Six experts met to develop the recommendations for the management of PsA in Australia. The final recommendations are approved by all panel members. Management and treatment recommendations have been made under six subheadings: Recommendations for non-steroidal anti-inflammatory drugs and glucocorticoids; Disease-modifying treatment; Screening and monitoring; Family planning; Symptom treatment and extra-articular manifestations; Comorbidities and lifestyle considerations. Our recommendations for the management of PsA in Australia draw heavily on the established global guidelines. These recommendations aim to assist clinicians to make informed, patient-centric choices when delivering treatment to people with PsA.

Biometrics and Biomarkers in Patients With Psoriasis

Psoriasis (PsO) is a chronic, systemic, and autoimmune dermatologic condition characterized by dry, scaly, and erythematous plaques on the skin. PsO can present in various forms, including guttate (small, round lesions commonly over the upper trunk and extremities that can be raised and scaly), inverse (smooth plaques of inflamed skin within skin folds of the groin, buttock, and breasts), pustular (white painful pustules within red inflamed blotches widespread over the body), and erythrodermic (red rash present over most of the body). Individuals with PsO can present differently, with unique symptoms and patterns on the skin. These diverse manifestations make PsO a complex condition with mild to severe symptoms affecting different body areas. Researchers have identified intrinsic risk factors (and comorbidities) tied to PsO, including genetics, obesity, metabolic syndrome, infection, cardiovascular disease, stress, and type 2 diabetes mellitus (T2DM). In addition, several extrinsic risk factors have also been shown to be tied to PsO onset and progression, such as ultraviolet (UV) light, air pollution, and various pharmacological treatments. While these intrinsic and extrinsic factors have been tied to disease pathophysiology, the underlying mechanisms of disease activity have yet to be elucidated fully, making diagnosis and treatment cumbersome. Currently, PsO is diagnosed clinically with no definitive test. Noninvasive tools such as dermoscopy aid in diagnosis, while the biopsy is reserved for difficult-to-characterize psoriatic-like lesions. The reliance on clinical presentation and the lack of diagnostic testing available have led to the underdiagnosis of PsO, particularly in minority communities. The goal of this study is to utilize data from the National Health and Nutrition Examination Survey (NHANES) to improve the diagnosis of PsO and target treatment more effectively, and biometric measurements associated with PsO should be studied to aid clinical practitioners in better understanding the disease pathophysiology and improve patient diagnosis, management, and prognosis. Using the dataset, we conducted a retrospective cohort study to find which variables are significantly associated with PsO. These objective measurements can complement clinical assessments by providing quantifiable data that could improve accuracy by detecting PsO in its early stages or distinguishing it from other skin conditions with similar presentations. This enables healthcare providers to adjust management strategies based on measurable changes in disease markers, rather than relying solely on subjective clinical observations.

The role of digital device use on the risk of migraine: a univariable and multivariable Mendelian randomization study

Background

The pervasive integration of digital devices into daily life has raised concerns about their potential health impacts. This study aimed to explore the causal relationships between digital device use and the risk of migraine using Mendelian randomization (MR).

Methods

Genetic data on digital device use and migraines were sourced from large-scale genome-wide association studies conducted by the UK Biobank, the FinnGen study, and the International Headache Genetics Consortium. Univariable MR (UVMR), meta-analysis, and multivariable MR (MVMR) approaches were conducted to explore and verify the causal effects of digital device use (including mobile phone use, computer use, playing computer games, and watching television) on migraine risk. Sensitivity analyses were conducted using Cochran's Q, MR-Egger intercept test, MR pleiotropy residual sum and outlier, MR Radial, MR Steiger, and leave-one-out methods.

Results

UVMR analyses revealed that genetically predicted mobile phone use was significantly associated with an increased risk of overall migraine (odds ratio [OR] = 2.39, p = 9.78e-5) and migraine without aura (MO) (OR = 2.25, p = 0.024). Additionally, there were significant positive associations between genetically predicted television watching and the risk of overall migraine (OR = 1.63, p = 2.12e-5) and MO (OR = 2.10, p = 4.98e-5). These results were further supported by the meta-analysis and MVMR analysis. Sensitivity analysis indicated no heterogeneity or pleiotropy.

Conclusion

This comprehensive MR study provides preliminary evidence for the causal impact of mobile phone use and television watching on the risk of migraines. Further studies are needed to explore these associations across different populations.

Mendelian randomization analysis of causal relationship between cheese intake and diabetic retinopathy

AIM

To assess whether there is a possible causal link between the intake of cheese and the risk of diabetic retinopathy (DR) utilizing a two-sample Mendelian randomization (MR) analysis.

METHODS

The research data were obtained from summary statistics of genome-wide association studies (GWAS). Genetic loci closely related to cheese intake were extracted as instrumental variables (IVs), and DR was the outcome variable. The data were extracted from individuals of European ethnicity. The data of cheese intake consisted of 451 486 samples with 9 851 867 single nucleotide polymorphisms (SNPs), while the DR data consisted of 206 234 samples with 16 380 446 SNPs. Sixty-one genetic loci closely related to cheese intake were selected as IVs. MR analysis was performed by inverse-variance weighted (IVW) method and MR-Egger regression respectively. The causal relationship between cheese intake and DR was evaluated using odds ratios (ORs) and 95% confidence intervals (CIs). Egger-intercept test was used to test horizontal pleiotropy and sensitivity analysis was performed by leave-one-out test.

RESULTS

The P value of the IVW method was less than 0.05, indicating a significant negative correlation between cheese intake and DR. MR-Egger regression showed that the intercept was 0.01 with a standard error of 0.022, and a P-value of 0.634, indicating no evidence of horizontal pleiotropy affecting the IVs related to the exposure factors. Besides, heterogeneity tests confirmed the absence of heterogeneity, and the "leave-one-out" sensitivity analysis demonstrated that the results were stable.

CONCLUSION

Cheese intake is causally negatively correlated with the occurrence of DR, and cheese intake could reduce the risk of DR.

The causal effects of inflammatory bowel disease on skin carcinoma: A two-sample Mendelian randomization study

Observational studies have indicated that inflammatory bowel disease (IBD) patients have higher incidence of skin carcinoma (SC), including melanoma skin carcinoma (MSC) and nonmelanoma skin carcinoma (NMSC) than healthy people. However, whether there is a causal relationship between the 2 is unclear. The purpose of this study was to evaluate the causality of IBD on SC using the Mendelian randomization (MR) analysis. We performed a two-sample MR analysis using publicly available genome-wide association study data. Eligible instrumental variables were selected based on the 3 core assumptions of MR analysis. The inverse-variance weighted (IVW) approach served as the primary analytical method. Supplementary analyses were conducted using MR-Egger regression, the weighted median, the weighted mode, and MR pleiotropy residual sum and outlier methods. Genetically predicted IBD (IVW odds ratio [OR] = 1.07, 95% confidence interval [CI]: 1.02-1.13, P = .011) and ulcerative colitis (UC; IVW OR = 1.09, 95% CI: 1.03-1.16, P = .003) were associated with an increased risk of MSC. Results of complementary methods were consistent with those of the IVW method with the exception of the weighted mode. In addition, Crohn disease (CD; IVW OR = 1.04, 95% CI: 0.99-1.08, P = .128) did not have a causal effect on MSC. Moreover, IBD (IVW OR = 1.03, 95% CI: 1.00-1.07, P = .034) and CD (IVW OR = 1.03, 95% CI: 1.00-1.06, P = .045) were associated with an increased risk of NMSC. However, UC (IVW OR = 1.00, 95% CI: 0.97-1.04, P = .803) was not significantly associated with an increased risk of NMSC. Our study revealed genetically predicted associations between IBD and the risks of MSC and NMSC in European populations. Furthermore, UC was associated with an increased risk of MSC, while CD was associated with a higher risk of NMSC. However, the potential influence of immunosuppressive agents or biologics cannot be excluded.

Causal relationship between smoking and spinal stenosis: Two-sample Mendelian randomization

OBJECTIVE

Currently, the number of patients with spinal stenosis is increasing, and most of the patients are found to have a history of smoking in the clinic. In this study, we used the Mendelian randomization (MR) method to investigate the causal relationship between smoking and spinal stenosis.

METHODS

Genetic loci independently associated with smoking and spinal stenosis in people of European ancestry were selected as instrumental variables using pooled data from large-scale genome-wide association studies (GWAS). Three MR analyses, MR-Egger, Weighted median and inverse variance weighting (IVW), were used to investigate the causal relationship between smoking and spinal stenosis. The results were tested for robustness by heterogeneity and multiplicity tests, and sensitivity analyses were performed using the "leave-one-out" method.

RESULTS

The IVW results showed an OR (95% CI) of 2.40 (0.31-18.71), P = .403, indicating that there was no causal relationship between smoking and spinal stenosis. And no heterogeneity and multiplicity were found by the test and sensitivity analysis also showed robust results.

CONCLUSION

In this study, genetic data were analyzed and explored using 2-sample MR analysis, and the results showed that there is a causal relationship between smoking and the occurrence of spinal stenosis, and more studies need to be included.

Causal relationship between multiple sclerosis and spinal stenosis: Two-sample Mendelian randomization

To investigate the causal relationship between multiple sclerosis and spinal stenosis using Mendelian randomization (MR). Genetic loci independently associated with multiple sclerosis and spinal stenosis in people of European origin were selected as instrumental variables using pooled data from genome wide association studies (GWAS). Three MR analyses, MR-Egger, Weighted median and inverse variance weighting (IVW), were used to investigate the causal relationship between multiple sclerosis and spinal stenosis. Heterogeneity and multiplicity tests were performed, and sensitivity analyses were performed using the "leave-one-out" method to explore the robustness of the results. The IVW results showed an OR (95% CI) of 1.05 (1.01-1.08), P = .016, indicating a causal relationship between MS and spinal stenosis. And no heterogeneity and multiplicity were found by the test, and sensitivity analysis also showed robust results. In this study, genetic data were analyzed and explored using 2-sample MR analysis, and the results showed a causal relationship between multiple sclerosis and the occurrence of spinal stenosis.

Shared Pathophysiology of Inflammatory Bowel Disease and Psoriasis: Unraveling the Connection

Psoriasis (PS) and inflammatory bowel disease (IBD) are immune-mediated chronic conditions that share pathophysiological processes, including immune system dysfunction, microbiome dysbiosis, and inflammatory pathways. These pathways result in increased turnover of epithelial cells and compromised barrier function. The assessment of the literature suggests that immunopathogenic mechanisms, such as tumor necrosis factor (TNF)-α signaling and IL-23/IL-17 axis dysregulation, are shared by PS and IBD. Clinical characteristics and diagnostic approaches overlap significantly, and advances in biomarker identification benefit both conditions. Current treatments, namely biologics that target TNF-α, IL-17, and IL-23, show promising results in decreasing inflammation and controlling symptoms. Precision medicine approaches are prioritized in prospective therapeutic procedures to tailor pharmaceuticals based on specific biomarkers, perhaps improving outcomes and minimizing side effects. This study thoroughly examines and evaluates the body of research on PS and IBD. Several papers were examined to compile data on clinical features, diagnosis, therapies, pathophysiology, epidemiology, and potential future therapeutic developments. The selection of articles was based on three methodological qualities: relevance and addition to the knowledge of IBD and PS. The retrieved data were combined to provide a coherent summary of the state of the knowledge and to spot new trends. The overview of the latest studies demonstrates that both PS and IBD share pathophysiological foundations and therapeutic approaches. With a spotlight on particular biomarkers, advances in precision medicine provide a promising path toward enhancing therapeutic effectiveness and minimizing side effects.

Shared Pathophysiology of Inflammatory Bowel Disease and Psoriasis: Unraveling the Connection

Inflammatory bowel disease (IBD) and psoriasis are both chronic autoimmune diseases with a unique set of characteristics. Interestingly, both conditions share considerable overlap in their pathophysiological mechanisms and immune dysregulation. Epidemiological studies validate the relationship by showing a greater prevalence of co-occurrence of the two disorders. At the genetic level, there is a confirmation of a link between shared susceptibility loci and DNA polymorphism, particularly interleukin-23 receptor (IL23R), interleukin-12 subunit beta (IL12B), tumor necrosis factor (ligand) superfamily member 15 (TNFSF15), and signal transducer and activator of transcription 3 (STAT3). In addition, epigenetic factors have a role in genetic predisposition in the development and progression through processes such as DNA methylation and histone modification adding another layer of genetic susceptibility. The relationship between psoriasis and IBD is emphasized by a comparable immunopathogenesis, which involves delicate relationships between the innate and adaptive immune responses. The primary interest is on the T-helper 17 (Th17) cell pathway and the cytokines interleukin-17 (IL-17), interleukin-23 (IL-23), and tumor necrosis factor-alpha (TNF-α). Consequently, both disorders exhibit chronic inflammation and tissue restructuring, resulting from similar cellular and molecular processes. The presence of overlapping pathophysiology highlights the significance of implementing integrated management strategies and employing multidisciplinary techniques for both diagnosis and therapy. Hence, understanding the mutual processes might facilitate the advancement of precise biologic treatments that aim at these commonly shared inflammatory pathways.

Dysbiosis of the Gut Microbiota in Patients with Psoriatic Arthritis is Closely Related to Lymphocyte Subsets and Cytokines

The purpose of this research was to characterize the microbiota of patients with psoriatic arthritis (PsA) and to compare the relationship between the microbiota and peripheral lymphocyte subsets and cytokines. We collected stool samples from 13 PsA patients and 26 sex- and age-matched healthy controls (HCs) and researched the gut microbiota by sequencing the V3-V4 variable region of the bacterial 16S rRNA gene with the Illumina Miseq PE300 system. Flow cytometry was used to assess the peripheral lymphocyte subsets in these participants. Record measures of disease activity such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Alpha and beta diversity were assessed using results from QIIME2. Panel demonstrated the average relative abundance of the different genera in PsA and HCs. Correlation between clinical parameters and the relative abundance of the genus in samples was assessed by the Pearson correlation analysis using R (version 4.0.1). Compared with HC, the abundance of gut microbiota (Chao 1 and ACE) decreased in patients with PsA, and the diversity of bacteria (Shannon and Simpson indices) also decreased in PsA (Fig. 1a). β Diversity analysis indicated differences in microbial communities between PsA and HC (Fig. 1b, r = 0.039, p = 0.264, ANOSIM). Furthermore, 18 bacterial groups were significantly different at the genus level in PsA compared to HCs (p < 0.05) (Fig. 2).In the phylum and genus, lymphocyte subsets and cytokines are associated with the microbiota. The gut microbiota of patients with PsA differs from HC, which was closely related to lymphocyte subsets.

Causality of inflammatory bowel disease and seborrheic keratosis: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Previous studies have revealed a potential link between inflammatory bowel disease (IBD) and seborrheic keratosis (SK). However, whether this association is causal or confounded remains unknown.

METHODS

We conducted this two-sample Mendelian randomization (TSMR) analysis to clarify bidirectional causality between IBD, including its two primary conditions Crohn's disease (CD) and ulcerative colitis (UC), and SK. The summary genetic data of IBD, CD, UC and SK were obtained from accessible genome-wide association studies (GWAS). This TSMR study was primarily performed using inverse-variance weighted (IVW) method, complemented by MR-Egger, weighted median (WM), Bayesian weighted MR (BWMR), MR-robust adjusted profile score (MR-RAPS), MR-pleiotropy residual sum and outlier (MR-PRESSO), and radial IVW MR analyses with modified second-order weights (IVW [Mod 2nd]) methods. Assessment of sensitivity and identification of potential outliers were subsequently conducted to aid interpretation of results.

RESULTS

The forward MR results showed that IBD [odds ratio (OR) = 1.068, 95% confidence interval (CI) = 1.010-1.129, p = 0.020) and its subtype CD (OR = 1.088, 95%CI = 1.038-1.139, p < 0.001) increased the risk of SK. However, the occurrence of SK could not be affected by UC (OR = 1.090, 95%CI = 0.977-1.216, p = 0.123). In the reverse analysis, no causal relationship between SK and IBD (OR = 0.905, 95%CI = 0.813-1.008, p = 0.069), UC (OR = 0.959, 95%CI = 0.860-1.068, p = 0.443), and CD (OR = 0.933, 95%CI = 0.846-1.029, p = 0.165) was identified.

CONCLUSION

These findings demonstrate that IBD and its subtype CD could increase the incidence of SK in European populations, whereas SK does not affect IBD occurrence.

Causal relationship between rheumatoid arthritis and ankylosing spondylitis: Two-sample Mendelian randomization

To investigate the causal relationship between rheumatoid arthritis (RA) and ankylosing spondylitis using Mendelian randomization (MR). Genetic loci independently associated with RA and ankylosing spondylitis in people of European origin were selected as instrumental variables using pooled data from large-scale genome-wide association studies. Three MR analyses, MR-Egger, weighted median, and inverse variance weighting, were used to investigate the causal relationship between RA and ankylosing spondylitis. Heterogeneity and multiplicity tests were used, and a sensitivity test using the "leave-one-out" method was used to explore the robustness of the results. The inverse variance weighting results showed an OR (95 % CI) of 1.25 (1.11-1.41), P < .001, indicating a causal relationship between RA and ankylosing spondylitis. And no heterogeneity and pleiotropy were found by the test and sensitivity analysis also showed robust results. The present study was conducted to analyze and explore the genetic data using two-sample MR analysis and the results showed that there is a causal relationship between RA and the occurrence of ankylosing spondylitis.

Causal relationship between inflammatory skin diseases and breast cancer: A bidirectional Mendelian randomization study

INTRODUCTION

Prior research has explored the relationship between inflammatory skin disorders and breast cancer (BC), yet the causality of this association remains uncertain.

METHODS

Utilizing a bidirectional two-sample Mendelian randomization (MR) approach, this study aimed to elucidate the causal dynamics between various inflammatory skin conditions-namely acne, atopic dermatitis, psoriasis vulgaris, urticaria, and rosacea-and BC. Genetic variants implicated in these disorders were sourced from comprehensive genome-wide association studies representative of European ancestry. In the forward MR, BC was posited as the exposure, while the reverse MR treated each inflammatory skin disease as the exposure. A suite of analytical methodologies, including random effects inverse variance weighted (IVW), weighted median (WME), and MR-Egger, were employed to probe the causative links between inflammatory skin diseases and BC. Sensitivity analyses, alongside evaluations for heterogeneity and pleiotropy, were conducted to substantiate the findings.

RESULTS

The MR analysis revealed an increased risk of acne associated with BC (IVW: OR = 1.063, 95% CI = 1.011-1.117, p = 0.016), while noting a decreased risk of atopic dermatitis (AD) in BC patients (IVW: OR = 0.941, 95% CI = 0.886-0.999, p = 0.047). No significant associations were observed between BC and psoriasis vulgaris, urticaria, or rosacea. Conversely, reverse MR analyses detected no effect of BC on the incidence of inflammatory skin diseases. The absence of pleiotropy and the consistency of these outcomes strengthen the study's conclusions.

CONCLUSION

Findings indicate an elevated incidence of acne and a reduced incidence of AD in individuals with BC within the European population.

Mendelian randomization analysis of psoriasis and psoriatic arthritis associated with risks of ulcerative colitis

OBJECTIVE

This study is designed to explore the potential causal relationship between psoriasis and psoriatic arthritis (PsA) while investigating the genetic basis shared by these inflammatory diseases.

METHODS

Significant single nucleotide polymorphisms (SNPs) associated with UC, psoriasis, and PsA were selected as genetic instrumental variables using Genome-Wide Association Study (GWAS) datasets. Additionally, Mendelian randomization (MR) methods, including inverse-variance weighting (IVW), MR-Egger regression, and Weighted Median (WME), were utilized to evaluate the causal relationships between these diseases. Moreover, sensitivity analysis and heterogeneity testing were conducted to validate the stability of the results.

RESULTS

A total of 123 significant SNPs associated with psoriasis, PsA, and UC were identified as genetic instrumental variables based on GWAS datasets. The analysis revealed a 36% increased risk of UC with psoriasis (odds ratio [OR] = 1.350, 95% confidence interval [CI] = 1.065-1.729, P = 0.012) and a 32.9% increased risk of UC with PsA (OR = 1.329, 95% CI = 1.176-1.592, P < 0.001). Further analysis showed a 43.5% increased risk of psoriasis with UC (OR = 1.435, 95% CI = 1.274-1.831, P < 0.001) and a 45.8% increased risk of PsA with UC (OR = 1.458, 95% CI = 1.166-1.822, P = 0.0013). In addition, sensitivity analysis and heterogeneity testing demonstrated the high stability of these results. Particularly, neither MR-Egger regression analysis nor leave-one-out analysis revealed significant heterogeneity or pleiotropy bias, indicating the reliability of these causal estimates. Moreover, the use of the MR-PRESSO further confirmed the positive correlation between psoriasis and UC, and the corrected estimates remained consistent with IVW analysis results after excluding potential outlier SNPs, enhancing the credibility of the analysis.

CONCLUSIONS

This study strengthens the understanding of the genetic and causal relationships among UC, psoriasis, and PsA through GWAS and MR methods, revealing the genetic basis they may share. These findings not only provide a novel perspective on the comorbidity mechanisms of these diseases but also offer a valuable reference for the development of future treatment strategies and intervention measures.

Potential drug targets for tumors identified through Mendelian randomization analysis

According to the latest cancer research data, there are a significant number of new cancer cases and a substantial mortality rate each year. Although a substantial number of clinical patients are treated with existing cancer drugs each year, the efficacy is unsatisfactory. The incidence is still high and the effectiveness of most cancer drugs remains unsatisfactory. Therefore, we evaluated the human proteins for their causal relationship to for cancer risk and therefore also their potential as drug targets. We used summary tumors data from the FinnGen and cis protein quantitative trait loci (cis-pQTL) data from a genome-wide association study, and employed Mendelian randomization (MR) to explore the association between potential drug targets and nine tumors, including breast, colorectal, lung, liver, bladder, prostate, kidney, head and neck, pancreatic caners. Furthermore, we conducted MR analysis on external cohort. Moreover, Bidirectional MR, Steiger filtering, and colocalization were employed to validate the main results. The DrugBank database was used to discover potential drugs of tumors. Under the threshold of False discovery rate (FDR) < 0.05, results showed that S100A16 was protective protein and S100A14 was risk protein for human epidermal growth factor receptor 2-positive (HER-positive) breast cancer, phosphodiesterase 5A (PDE5A) was risk protein for colorectal cancer, and melanoma inhibitory activity (MIA) was protective protein for non-small cell lung carcinoma (NSCLC). And there was no reverse causal association between them. Colocalization analysis showed that S100A14 (PP.H4.abf = 0.920) and S100A16 (PP.H4.abf = 0.932) shared causal variation with HER-positive breast cancer, and PDE5A (PP.H4.abf = 0.857) shared causal variation with colorectal cancer (CRC). The MR results of all pQTL of PDE5A and MIA were consistent with main results. In addition, the MR results of MIA and external outcome cohort were consistent with main results. In this study, genetic predictions indicate that circulating S100 calcium binding protein A14 (S100A14) and S100 calcium binding protein A16 (S100A16) are associated with increase and decrease in the risk of HER-positive breast cancer, respectively. Circulating PDE5A is associated with increased risk of CRC, while circulating MIA is associated with decreased risk of NSCLC. These findings suggest that four proteins may serve as biomarkers for cancer prevention and as potential drug targets that could be expected for approval.

Evaluation of bi-directional causal association between obstructive sleep apnoea syndrome and diabetic microangiopathy: a Mendelian randomization study

Background

The relationship between obstructive sleep apnea syndrome (OSAS) and diabetic microangiopathy remains controversial.

Objective

This study aimed to use bidirectional two-sample Mendelian Randomization (MR) to assess the causal relationship between OSAS and diabetic microangiopathy.

Methods

First, we used the Linkage Disequilibrium Score Regression(LDSC) analysis to assess the genetic correlation. Then, the bidirectional two-sample MR study was conducted in two stages: OSAS and lung function-related indicators (forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)) were investigated as exposures, with diabetic microangiopathy as the outcome in the first stage, and genetic tools were used as proxy variables for OSAS and lung function-related measures in the second step. Genome-wide association study data came from the open GWAS database. We used Inverse-Variance Weighted (IVW), MR-Egger regression, Weighted median, Simple mode, and Weighted mode for effect estimation and pleiotropy testing. We also performed sensitivity analyses to test the robustness of the results. Furthermore, we performed multivariate and mediation MR analyses.

Results

In the LDSC analysis, We found a genetic correlation between OSAS, FVC, FEV 1, and diabetic microangiopathy. In the MR analysis, based on IVW analysis, genetically predicted OSAS was positively correlated with the incidence of diabetic retinopathy (DR), diabetic kidney disease (DKD), and diabetic neuropathy (DN). In the subgroup analysis of DR, there was a significant causal relationship between OSAS and background diabetic retinopathy (BDR) and proliferative diabetic retinopathy (PDR). The reverse MR did not show a correlation between the incidence of diabetic microangiopathy and OSAS. Reduced FVC had a potential causal relationship with increased incidence of DR and PDR. Reduced FEV1 had a potential causal relationship with the increased incidence of BDR, PDR, and DKD. Multivariate MR analysis showed that the association between OSAS and diabetic microangiopathy remained significant after adjusting for confounding factors. However, we did not find the significant mediating factors.

Conclusion

Our results suggest that OSAS may be a cause of the development of diabetic microangiopathy, and OSAS may also be associated with a high risk of diabetic microangiopathy, providing a reference for a better understanding of the prevention of diabetic microangiopathy.

The management of patients with inflammatory bowel disease-associated spondyloarthritis: Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) and Italian Society of Rheumatology (SIR) recommendations based on a pseudo-Delphi consensus

Spondyloarthritis (SpA) is the most frequent extraintestinal manifestation in patients with inflammatory bowel diseases (IBD). When IBD and spondyloarthritis coexist, musculoskeletal and intestinal disease features should be considered when planning a therapeutic strategy. Treatment options for IBD and SpA have expanded enormously over the last few years, but randomized controlled trials with specific endpoints focused on SpA are not available in the IBD setting. To address this important clinical topic, the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) and the Italian Society of Rheumatology (SIR) jointly planned to draw updated therapeutic recommendations for IBD-associated SpA using a pseudo-Delphi method. This document presents the official recommendations of IG-IBD and SIR on the management of IBD-associated SpA in the form of 34 statements and 4 therapeutic algorithms. It is intended to be a reference guide for gastroenterologists and rheumatologists dealing with IBD-associated SpA.

Assessing causal relationships between gut microbiota and psoriasis: evidence from two sample Mendelian randomization analysis

Mounting data hints that the gut microbiota's role may be pivotal in understanding the emergence of psoriasis. However, discerning a direct causal link is yet elusive. In this exploration, we adopted a Mendelian randomization (MR) strategy to probe the prospective causal interplay between the gut's microbial landscape and the predisposition to psoriasis. Genetic markers acting as instrumental variables for gut microbiota were extrapolated from a genome-wide association study (GWAS) encompassing 18,340 individuals. A separate GWAS yielded summary data for psoriasis, which covered 337,159 patients and 433,201 control subjects. The primary analysis hinged on inverse variance weighting (IVW). Additional methods like the weighted median approach and MR-Egger regression were employed to validate the integrity of our findings. Intriguing correlations emerged between psoriasis risk and eight specific bacterial traits. To illustrate: Mollicutes presented an odds ratio (OR) of 1.003 with a 95% confidence interval (CI) spanning 1.001-1.005 (p = 0.016), while the family. Victivallaceae revealed an OR of 0.998 with CI values between 0.997 and 0.999 (p = 0.023). Eubacterium (coprostanoligenes group) revealed an OR of 0.997 with CI values between 0.994 and 0.999 (p = 0.027). Eubacterium (fissicatena group) revealed an OR of 0.997 with CI values between 0.996 and 0.999 (p = 0.005). Holdemania revealed an OR of 1.001 with CI values 1-1.003 (p = 0.034). Lachnospiraceae (NK4A136 group) revealed an OR of 0.997 with CI values between 0.995 and 0.999 (p = 0.046). Lactococcus revealed an OR of 0.998 with CI values between 0.996 and 0.999 (p = 0.008). Tenericutes revealed an OR of 1.003 with CI values between 1.001 and 1.006 (p = 0.016). Sensitivity analysis for these bacterial features yielded congruent outcomes, reinforcing statistically significant ties between the eight bacterial entities and psoriasis. This comprehensive probe underscores emerging evidence pointing towards a plausible causal nexus between diverse gut microbiota and the onset of psoriasis. It beckons further research to unravel the intricacies of how the gut's microbial constituents might sway psoriasis's pathogenesis.

Mendelian randomization analysis reveals causal associations of inflammatory bowel disease with Spondylarthritis

OBJECTIVE

Inflammatory bowel disease (IBD) is strongly associated with Spondylarthritis (SpA), but the causal relationship remains unclear. This study explores the causal associations between IBD (Crohn's disease [CD] and ulcerative colitis [UC]) and several common subtypes of SpA (Ankylosing Spondylitis [AS], Psoriatic Arthritis [PsA], and Reactive Arthritis [ReA]), using bidirectional two-sample Mendelian randomization (TSMR).

METHODS

The causal effects of genetically predicted IBD on AS, PsA, and ReA were firstly investigated in this forward study. The causal effects from AS, PsA, and ReA on IBD were analyzed in the reverse MR. Inverse variance weighted, weighted median, and MR-Egger were applied in the MR analyses. The pleiotropic effects, heterogeneity, and leave-one-out sensitivity analysis were also evaluated.

RESULTS

The forward MR analysis demonstrated that IBD increased risk for AS (OR:1.278; P = 1.273 × 10-5), PsA (OR:1.192; P = 1.690 × 10-5), and ReA (OR:1.106; P = 1.524 × 10-3). Among them, CD increased risk of AS (OR:1.196; P = 3.424 × 10-4), PsA (OR:1.101; P = 1.537 × 10-3), ReA (OR:1.079; P = 6.321 × 10-3) whereas UC increased risk of AS (OR:1.166; P = 2.727 × 10-2), PsA (OR:1.110; P = 1.944 × 10-2), and ReA (OR:1.091; P = 1.768 × 10-2). The reverse-direction MR disclosed no notable association; neither was any evidence of pleiotropy detected.

CONCLUSION

Our study verifies a causal effect of IBD to AS, PsA as well as ReA, but not vice versa. This might bring new insights for the management of IBD and SpA in clinical practice.

Causal associations between autoimmune diseases and sarcopenia-related traits: a bi-directional Mendelian randomization study

Background

Sarcopenia is common in patients with autoimmune diseases (ADs); however, the causal associations between ADs and sarcopenia remain unclear. Therefore, this study investigated the causal associations using bi-directional Mendelian randomization analysis.

Methods

Exposure-related single-nucleotide polymorphisms (SNPs) were extracted from genome-wide association studies (GWASs). GWAS statistics for common ADs [Crohn's disease (CD), ulcerative colitis (UC), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriasis (PSO), and multiple sclerosis (MS)] and sarcopenia-related traits [hand grip strength (HGS), appendicular fat-free mass (FFM), and walking pace] were obtained from public datasets. Inverse-variance weighting as the main method was used to evaluate the causal effect.

Results

Genetically predicted CD had causal effects on whole-body FFM (β = -0.005, p = 0.001), leg FFM (βleft = -0.006, p = 1.8E-4; βright = -0.007, p = 2.0E-4), and arm FFM (βleft = -0.005, p = 0.005; βright = -0.005, p = 0.001), while RA had causal effects on 8 sarcopenia-related traits, namely, HGS (βleft = -2.06, p = 2.8E-38; βright = -2.311, p = 2E-20), whole-body FFM (β = -0.842, p = 4.7E-10), leg FFM (βleft = -0.666, p = 2.6E-6; βright = -0.073, p = 2.1E-3), arm FFM (βleft = -0.63, p = 4.4E-6; βright = -0.736, p = 4.4E-8), and walking pace (β = -1.019, p = 6.2E-14). In the reverse direction, HGS (odds ratio [OR]left = 10.257, p = 3.6E-5; ORright = 16.445, p = 3.7E-7) had causal effects on CD, while HGS (ORleft = 0.994, p = 0.004; ORright = 0.993, p = 1.4E-4), leg FFM (ORleft = 1.003, p = 0.005; ORright = 1.005, p = 1.9E-4), and walking pace (OR = 0.985, p = 5.7E-5) were causally associated with RA. No evidence showed causal associations of UC, SLE, PSO, or MS with sarcopenia-related traits.

Conclusion

Our study demonstrated that the genetic susceptibility to CD and RA was associated with high risk of sarcopenia, and some sarcopenia-related traits had causal effects on CD or RA.

Mendelian randomisation analysis for intestinal disease: achievement and future

Intestinal disease is a group of complex digestive system diseases imposing a significant burden globally. Identifying the risk factors and potential complications of intestinal disease is important for its prevention and treatment. However, traditional observational clinical studies are limited by confounding factors and reverse causation, making causal inference challenging. Mendelian randomisation (MR) method has been developed to effectively mitigate these constraints and assess the causal relationships. This review briefly introduces the MR method, summarises MR research on intestinal disease and delineates the prospective avenues for future research. Conventional risk factors, such as lifestyle behaviours (eg, physical activity, smoking and alcohol consumption), nutrients (eg, selenium), obesity markers (eg, body mass index and waist-to-hip ratio) and inflammatory biomarkers, have been validated in MR studies. Multiomics MR studies are becoming novel hotspots, which provide a theoretical foundation for the exploration of pathogenesis and the investigation of new drug targets. However, most of the recent studies are based on European individuals, and thus it is necessary to replicate the results in other ancestries. Moreover, triangulation integrating MR and other epidemiology methods is suggested as a validated paradigm for causal inference in future MR studies.

No genetic causal association between iron status and pulmonary artery hypertension: Insights from a two-sample Mendelian randomization

To explore the genetic causal association between pulmonary artery hypertension (PAH) and iron status through Mendelian randomization (MR), we conducted MR analysis using publicly available genome-wide association study (GWAS) summary data. Five indicators related to iron status (serum iron, ferritin, total iron binding capacity (TIBC), soluble transferrin receptor (sTfR), and transferrin saturation) served as exposures, while PAH was the outcome. The genetic causal association between these iron status indicators and PAH was assessed using the inverse variance weighted (IVW) method. Cochran's Q statistic was employed to evaluate heterogeneity. We assessed pleiotropy using MR-Egger regression and MR-Presso test. Additionally, we validated our results using the Weighted median, Simple mode, and Weighted mode methods. Based on the IVW method, we found no causal association between iron status (serum iron, ferritin, TIBC, sTfR, and transferrin saturation) and PAH (p β > 0.05). The Weighted median, Simple mode, and Weighted mode methods showed no potential genetic causal association (p β > 0.05 in the three analyses). Additionally, no heterogeneity or horizontal pleiotropy was detected in any of the analyses. Our results show that there are no genetic causal association between iron status and PAH.

Relationship between bullous pemphigoid and malignancy: A Mendelian randomization study

Bullous pemphigoid (BP) is the most common autoimmune blistering disease, which primarily affects the elderly. However, the relationship between BP and malignancy remains controversial in traditional observational studies. The aim of this study, which included only European populations, was to assess the potential causative link between BP and 13 types of malignant tumors in a two-sample Mendelian randomization (MR) study. BP was not associated with an increased risk of developing 13 types of malignant tumors. This study did not find a causal relationship between BP and malignant tumors. However, further research is warranted to examine the generalizability of this conclusion in non-European populations.

The Role of the Gut-Joint Axis in the Care of Psoriatic Arthritis: A Two-Sample Bidirectional Mendelian Randomization Study

INTRODUCTION

Observational studies and clinical trials have supported the association between gut microbiota and psoriatic arthritis. However, the causal link between gut microbiota and psoriatic arthritis is still unclear.

METHODS

A two-sample bi-directional Mendelian randomization analysis was performed using the summary statistics of gut microbiota from the largest available genome-wide association study meta-analysis (n = 13,266) conducted by the MiBioGen consortium. The summary statistics of psoriatic arthritis were extracted directly from the FinnGen consortium, which consists of 3186 psoriatic arthritis patients and 24,086 controls. Sensitivity analyses were conducted to assess the validity of our findings. Enrichment analyses were used to investigate the biofunction and pathways.

RESULTS

Inverse variance weighted (IVW) estimates suggested that family Rikenellaceae (P = 0.032) and genus Ruminococcaceae UCG011 (P = 0.014) had a detrimental effect on psoriatic arthritis. We also noticed the negative association between the class Methanobacteria (P = 0.032), order Methanobacteriales (P = 0.032), family Methanobacteriaceae (P = 0.032), genus Eubacterium fissicatena group (P = 0.010), genus Methanobrevibacter (P = 0.031), and genus Butyricicoccus (P = 0.041) with psoriatic arthritis. Sensitivity analyses showed that genus Butyricicoccus had pleiotropy and heterogeneity. According to the results of reverse MR analysis, the causal effect of psoriatic arthritis was found on six taxa, respectivelyc family Clostridiaceae1, family Defluviitaleaceae, genus Butyrivibrio, genus Defluviitaleaceae UCG011, genus Clostridium sensu stricto1, and genus Ruminococcaceae UCG011.

CONCLUSION

This two-sample bidirectional Mendelian randomization analysis suggested that the gut microbiota had a causal effect on psoriatic arthritis and implied the potential role of probiotics in the management and prevention of psoriatic arthritis.

The association between psoriasis, psoriasis severity, and inflammatory bowel disease: a population-based analysis

Background

The skin-gut axis, characterized by bidirectional communication between the skin and gut, plays a crucial role in the pathogenesis of psoriasis and inflammatory bowel diseases (IBD).

Objectives

We aimed to explore the association between psoriasis and IBD and identify predictors associated with IBD development among patients with psoriasis.

Design

Retrospective cohort study.

Methods

A retrospective study which utilized an electronic database from the Meuhedet Health Maintenance Organization (MHMO) in Israel. Psoriasis was categorized as severe if any systemic agent or phototherapy was administered. Univariate and multivariate logistic regressions were used to identify specific predictors for IBD, with adjustments made for potential confounders. The study received approval from the Ethical Committee of the MHMO.

Results

In total, 61,003 adult patients who were diagnosed with psoriasis between 2000 and 2022 were included. Among them, 1495/61,003 patients (2.4%) were diagnosed with IBD, as compared to 3834/244,012 patients (1.6%) in the non-psoriasis group [adjusted odds ratio (OR): 1.47; 95% confidence interval (CI): 1.37-1.56; p < 0.001]. Increased age (OR: 1.01; 95% CI: 1.01-1.02; p < 0.001), male gender (OR: 1.22; 95% CI: 1.03-1.45; p = 0.024), and Jewish ethnicity (OR: 2.5; 95% CI: 1.2-4.1; p < 0.001) were identified as significant risk factors for IBD. Spondyloarthropathies, including psoriatic arthritis (OR: 2.27; 95% CI: 1.86-2.77; p < 0.001) and ankylosing spondylitis (OR: 2.82; 95% CI: 1.5-5.32; p < 0.05), were associated with a higher prevalence of IBD. Furthermore, severe psoriasis was significantly associated with a higher likelihood of IBD, compared to mild psoriasis (OR: 16.03; 95% CI: 11.02-23.34; p < 0.001).

Conclusion

A significant association between psoriasis and IBD was demonstrated, including its subtypes: Crohn's disease and ulcerative colitis. Moreover, such association may depend on psoriasis severity as determined by the treatment used. This association warrants further investigation and implies a potential need for closer monitoring of patients with severe psoriasis.

A Mendelian randomization study on causal effects of inflammatory bowel disease on the risk of erectile dysfunction

This study aimed to evaluate the causal effects of inflammatory bowel disease (IBD) and erectile dysfunction (ED) using Mendelian randomization (MR). All datasets were obtained from the public genome-wide association study database. In the exposure group, 12,882 IBD patients and 21,770 controls were included. A total of 1154 ED patients and 94,024 controls were included in the outcome group. Two-sample MR was conducted to estimate the causal effect of IBD on ED. Furthermore, Crohn's disease (CD) and ulcerative colitis (UC) were exposure factors in subgroup analyses. Weighted median, MR-egger, Inverse-variant weighted (IVW), weighted mode, and simple mode methods were used in MR analysis. Horizontal pleiotropy test, heterogeneity test, and leave-one-out method were utilized to evaluate the sensitivity and stability of results. After analysis, 62, 52, and 36 single nucleotide polymorphisms (SNPs) that IBD-ED, CD-ED, and UC-ED were included, respectively. The incidence of ED was increased by IBD (IVW: OR = 1.110, 95% CI = 1.017-1.211, P = 0.019; P-heterogeneity > 0.05) and, in addition, ED was affected by CD (IVW: OR = 1.085, 95% CI = 1.015-1.160, P = 0.016; P-heterogeneity > 0.05). However, there was no causal effect of UC on ED (IVW: OR = 1.018, 95% CI = 0.917-1.129, P = 0.743; P-heterogeneity < 0.05). All SNPs showed no significant horizontal pleiotropy (P > 0.05). These results indicate that IBD and CD can cause ED; However, UC did not cause ED. Additional research was required to determine causality and potential mechanisms further.

Association between Psoriasis and Renal Functions: An Integration Study of Observational Study and Mendelian Randomization

Psoriasis is an autoimmune-mediated disease with several comorbidities in addition to typical skin lesions. Increasing evidence shows the relationships between psoriasis and renal functions, but the relationship and causality remain unclear. We aimed to investigate the associations and causality between psoriasis and four renal functions, including the estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN), urine albumin to creatinine ratio (UACR), and chronic kidney disease (CKD). For the population-based study, we analyzed the National Health and Nutrition Examination Survey (NHANES) data from five cycles (2003-2006 and 2009-2014) on psoriasis and renal functions. Subgroup analyses were conducted among different categories of participants. Meanwhile, a bidirectional two-sample Mendelian randomization (TSMR) study in European populations was also performed using summary-level genetic datasets. Causal effects were derived by conducting an inverse-variance weighted (MR-IVW) method. A series of pleiotropy-robust MR methods was employed to validate the robustness. Multivariable MR (MVMR) was conducted to complement the result when five competing risk factors were considered. A total of 20,244 participants were enrolled in the cross-sectional study, where 2.6% of them had psoriasis. In the fully adjusted model, participants with psoriasis had significantly lower eGFR (p = 0.025) compared with the healthy group. Individuals who are nonoverweight are more likely to be affected by psoriasis, leading to an elevation of BUN (Pint = 0.018). In the same line, TSMR showed a negative association between psoriasis and eGFR (p = 0.016), and sensitive analysis also consolidated the finding. No causality was identified between psoriasis and other renal functions, as well as the inverse causality (p > 0.05). The MVMR method further provided quite consistent results when adjusting five confounders (p = 0.042). We detected a significant negative effect of psoriasis on eGFR, with marginal association between BUN, UACR, and CKD. The adverse of psoriasis on the renal should merit further attention in clinical cares.

Exploring genetic associations between vitiligo and mental disorders using Mendelian randomization

Although a large number of existing studies have confirmed that people with vitiligo are prone to mental disorders, these observational studies may be subject to confounding factors and reverse causality, so the true causal relationship is inconclusive. We conducted a bidirectional Mendelian randomization (MR) analysis to assess the causality between vitiligo and mental disorders, namely depression, anxiety, insomnia, schizophrenia, bipolar disorder, obsessive-compulsive disorder (OCD) and attention-deficit hyperactivity disorder (ADHD). Summary statistics from large available genome-wide association study (GWAS) datasets for generalized vitiligo (n = 44 266), depression (n = 173 005), anxiety (n = 17 310), insomnia (n = 386 988), schizophrenia (n = 130 644), bipolar disorder (n = 413 466), OCD (n = 9725) and ADHD (n = 225 534) were utilized. Inverse-variance weighted (IVW), MR-Egger and weighted median were employed to estimate causal effects. Sensitivity analysis and MR Pleiotropy Residual Sum and Outliers (MR PRESSO) were conducted to assess heterogeneity and pleiotropy, ensuring the robustness of the results. Additionally, we corrected for estimating bias that might be brought on by sample overlap using MRlap. In our findings, none of the rigorous bidirectional MR analyses uncovered a significant causal association. Even after applying the MRlap correction, the effect sizes remained statistically nonsignificant, thereby reinforcing the conclusions drawn via IVW. In summary, our genetic-level investigation did not reveal a causal link between generalized vitiligo and mental disorders.

Assessment of relationships between bullous pemphigoid and neurological diseases: A bidirectional two-sample Mendelian randomization study

Bullous pemphigoid (BP) is the most prevalent autoimmune vesiculobullous skin illness that tends to affect the elderly. Growing evidence has hinted a correlation between BP and neurological diseases. However, existing observational studies contained inconsistent results, and the causality and direction of their relationship remain poorly understood. To assess the causal relationship between BP and neurological disorders, including Alzheimer's disease (AD), multiple sclerosis (MS), Parkinson's disease (PD), and stroke. A bidirectional two-sample Mendelian randomization (MR) adopted independent top genetic variants as instruments from the largest accessible genome-wide association studies (GWASs), with BP (n = 218 348), PD (n = 482 730), AD (n = 63 926), stroke (n = 446 696), and MS (n = 115 803). Inverse variance weighted (IVW), MR-Egger, weighted mode methods, weighted median, and simple mode were performed to explore the causal association. Multiple sensitivity analyses, MR-Pleiotropy Residual Sum and Outlier (PRESSO) was used to evaluate horizontal pleiotropy and remove outliers. With close-to-zero effect estimates, no causal impact of BP on the risk of the four neurological diseases was discovered. However, we found that MS was positively correlated with higher odds of BP (OR = 1.220, 95% CI: 1.058-1.408, p = 0.006), while no causal associations were observed between PD (OR = 0.821, 95% CI: 0.616-1.093, p = 0.176), AD (OR = 1.066, 95% CI: 0.873-1.358, p = 0.603), stroke (OR = 0.911, 95% CI: 0.485-1.713, p = 0.773) and odds of BP. In summary, no causal impact of BP on the risk of PD, AD, MS and stroke was detected in our MR analysis. However, reverse MR analysis identified that only MS was positively correlated with higher odds of BP, but not PD, AD and stroke.

The bidirectional causal association between psoriasis and psychological illnesses: a 2-sample Mendelian randomization study

There have been reports of association between psoriasis and psychological illnesses. Nevertheless, it is not easy to draw conclusions with high quality causality from conventional observational studies. The objective of this study was to evaluate the causality of psoriasis and psychological illnesses. All summary-level data from genome-wide association studies for psoriasis and psychological illnesses were collected from Neale Lab and MRC Integrative Epidemiology Unit. Bidirectional Mendelian randomization analysis was performed to determine the random orientation with an independent genetic variation. The main estimated effects are derived using Inverse-Variance Weighted, weighted median, and MR Egger methods. Multiple data sets were validated against each other, and a series of sensitivity studies were conducted to ensure the reliability of the results. Mendelian randomization analysis revealed a causal effect of psoriasis [odds ratio (OR) 1·34, 95% confidence interval (CI) 1·21-1·46, P < 0.001; and OR 1.28, CI 1.17-1.39, P < 0.001] on psychological illnesses, and vice versa (OR 1.23, CI 1.14-1.31, P < 0.001; and OR 1.21, CI 1.11-1.31, P < 0.001). The results were supported by a series of sensitivity analyses. The findings of this Mendelian randomization study support a causal effect between psoriasis and psychological illnesses, and vice versa.

Causal relationship between dried fruit intake and meniscal injuries: Two-sample Mendelian randomization

To investigate the causal relationship between dried fruit intake and meniscal injuries using Mendelian randomization (MR). Data were pooled from large-scale genome wide association studies (GWAS), and genetic loci independently associated with dry fruit intake and meniscal injuries in populations of European origin were selected as instrumental variables. Three MR analyses, inverse variance weighting (IVW), weighted median (WME) and MR-Egger, were used to investigate the causal relationship between dried fruit intake and meniscal injuries. The results were tested for robustness by heterogeneity and multiplicity tests, and sensitivity analyses were performed using the "leave-one-out" method. The IVW results showed an OR (95 % CI) of 0.47 (0.28-0.78), P = .003, indicating a causal relationship between dried fruit intake and meniscus injury. And no heterogeneity and multiplicity were found by the test and sensitivity analysis also showed robust results. The present study used a 2-sample MR analysis, and by analyzing and exploring the genetic data, the study showed that too little intake of dry fruits is a risk factor for meniscal injuries.