Two-stage multivariate Mendelian randomization on multiple outcomes with mixed distributions

CAUSAL ROLES OF SERUM URIC ACID LEVELS AND GOUT IN SEPSIS: A MENDELIAN RANDOMIZATION STUDY

ABSTRACT

Objective: Several epidemiological studies have identified a potential link between serum uric acid (UA), gout, and sepsis. The primary objective of this study is to delve deeper into this connection, investigating the causal effect of UA and gout on sepsis by applying Mendelian randomization (MR). Methods: The causal relationship was analyzed using data from Genome-Wide Association Study (GWAS). Inverse variance weighting (IVW) was used as the main analysis method. Three complementary methods were used for our MR analysis, which included the MR-Egger regression method, the weighted median method, the simple median method. Horizontal pleiotropy was identified by MR-Egger intercept test. Cochran's Q statistics were employed to assess the existence of instrument heterogeneity. The leave-one-out method was used as a sensitivity analysis. Results: The IVW results indicated that there was a positive causal relationship between UA and sepsis (critical care) (odds ratio [OR] = 0.24, 95% confidence interval [CI]: 0.04 to 0.43, P = 0.018, F = 4,291.20). There was no significant association between UA and sepsis (28-day death in critical care) (OR = 0.10, 95% CI = -0.29 to 0.50, P = 0.604). There was no significant association between gout and sepsis (critical care) (OR = 0.85, 95% CI = -4.87 to 6.57, P = 0.771), and sepsis (28-day death in critical care) (OR = -6.30, 95% CI = -17.41 to 4.81, P = 0.267). Horizontal pleiotropy was absent in this study. The results were robust under all sensitivity analyses. Conclusion: The study revealed that elevated UA levels were causally linked with sepsis (critical care). No causal relationship had been found between UA and sepsis (28-day death in critical care), as well as between gout and sepsis.

Causal association between adiponectin and risk of trigeminal neuralgia: A Mendelian randomization study

OBJECTIVE

To determine whether adiponectin levels and the risk of trigeminal neuralgia (TN) were causally related, a two-sample Mendelian Randomization (MR) study design was used.

METHODS

We obtained data regarding adiponectin from the UK Biobank genome wide association studies (GWAS) (n = 39,883) as the exposure and TN, using GWAS summary statistics generated from FinnGen, (total n = 195 847 159; case = 800, control = 195 047) as the outcome. We conducted a two-sample Mendelian randomization analysis employing inverse variance-weighted (IVW), MR-Egger regression, weighted median, and weighted mode analyses.

RESULTS

We selected 14 single nucleotide polymorphisms (SNPs) with genome-wide significance from the GWAS on adiponectin as instrumental variables. Based on the IVW method, a causal association between adiponectin levels and TN was evidenced (OR= 0.577, 95 %CI: 0.393-0.847). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = -0.01; P = 0.663), but it showed no causal association between adiponectin and TN (OR=0.627, 95 %CI: 0.369-1.067). However, the weighted median (OR=0.569, 95 %CI: 0.353-0.917) and Weighted mode (OR= 0.586, 95 %CI: 0.376-0.916) approach yielded evidence of a causal association between adiponectin and TN. Cochran's Q-statistics and funnel plots indicated no evidence of heterogeneity or asymmetry, indicating no directional pleiotropy.

CONCLUSION

The results of the MR analysis suggested that adiponectin may be causally associated with an increased TN risk.

Integrative single-cell analysis: dissecting CD8 + memory cell roles in LUAD and COVID-19 via eQTLs and Mendelian Randomization

Lung adenocarcinoma exhibits high incidence and mortality rates, presenting a significant health concern. Concurrently, the COVID-19 pandemic has emerged as a grave global public health challenge. Existing literature suggests that T cells, pivotal components of cellular immunity, are integral to both antiviral and antitumor responses. Yet, the nuanced alterations and consequent functions of T cells across diverse disease states have not been comprehensively elucidated. We gathered transcriptomic data of peripheral blood mononuclear cells from lung adenocarcinoma patients, COVID-19 patients, and healthy controls. We followed a standardized analytical approach for quality assurance, batch effect adjustments, and preliminary data processing. We discerned distinct T cell subsets and conducted differential gene expression analysis. Potential key genes and pathways were inferred from GO and Pathway enrichment analyses. Additionally, we implemented Mendelian randomization to probe the potential links between pivotal genes and lung adenocarcinoma susceptibility. Our findings underscored a notable reduction in mature CD8 + central memory T cells in both lung adenocarcinoma and COVID-19 cohorts relative to the control group. Notably, the downregulation of specific genes, such as TRGV9, could impede the immunological efficacy of CD8 + T cells. Comprehensive multi-omics assessment highlighted genetic aberrations in genes, including TRGV9, correlating with heightened lung adenocarcinoma risk. Through rigorous single-cell transcriptomic analyses, this investigation meticulously delineated variations in T cell subsets across different pathological states and extrapolated key regulatory genes via an integrated multi-omics approach, establishing a robust groundwork for future functional inquiries. This study furnishes valuable perspectives into the etiology of multifaceted diseases and augments the progression of precision medicine.