Differential peripheral memory T cell subsets sensitively indicate the severity of nonalcoholic fatty liver disease

Peripheral blood lymphocyte subsets of Chinese adults with liver steatosis

To evaluate the effect of liver steatosis on systematic cellular immunity through the changes of peripheral blood lymphocyte subsets, we retrospectively reviewed subjects receiving lymphocyte subtyping during annual medical check-ups. Liver steatosis was detected by abdominal computerized tomography or ultrasound. Immunophenotyping of peripheral blood lymphocytes was analyzed by flow cytometry. Cell counts of lymphocyte subsets were calculated using a dual-platform method. The relationship between lymphocyte subsets and liver steatosis was analyzed using multivariate linear models. Using the database from January 2017 to December 2022, we included 5042 subjects, including 1441 participants with liver steatosis. After adjusting for age, gender, and metabolic dysfunctions, the presence of liver steatosis increased the absolute values of CD19+, CD16+56+, CD3+, CD4+, CD4+CD28+, CD4+CD45RA-, CD4+CD45RA+, CD4+CD45RA+62L+, CD8+, CD8+CD28+, CD8+DR+, and CD8+CD38+ cell. In males, T lymphocyte counts of all T subsets increased in liver steatosis. In females, the significant differences in subsets included increased CD4+CD28+, CD4+CD45RA-, CD8+, and CD8+DR+ cells. Significant decreases were revealed in functional and naïve T cells with aging. Metabolic factors such as hypertension and abnormal glucose metabolism increase CD4+, CD4+CD28+, and CD4+CD45RA subsets. Hyperlipidaemia appears not to affect T cell counts, whereas obesity has some effect on both CD4+ (β = 0.041, 95% CI 0.032-0.051) and CD8+ cells (β = 0.036, 95% CI 0.025-0.048). Liver steatosis potentially affects peripheral blood lymphocyte subsets, while age, gender, and metabolic dysfunctions are also associated with these immune alterations.

Identifying disease progression biomarkers in metabolic associated steatotic liver disease (MASLD) through weighted gene co-expression network analysis and machine learning

BACKGROUND

Metabolic Associated Steatotic Liver Disease (MASLD), encompassing conditions simple liver steatosis (MAFL) and metabolic associated steatohepatitis (MASH), is the most prevalent chronic liver disease. Currently, the management of MASLD is impeded by the lack of reliable diagnostic biomarkers and effective therapeutic strategies.

METHODS

We analyzed eight independent clinical MASLD datasets from the GEO database. Differential expression and weighted gene co-expression network analyses (WGCNA) were used to identify 23 genes related to inflammation. Five hub genes were selected using machine learning techniques (SVM-RFE, LASSO, and RandomForest) combined with a literature review. Nomograms were created to predict MASLD incidence, and the diagnostic potential of the hub genes was evaluated through receiver operating characteristic (ROC) curves. Additionally, Protein-Protein Interaction (PPI) networks, functional enrichment, and immune infiltration analyses were performed. Potential transcription factors and therapeutic agents were also explored. Finally, the expression and biological significance of these hub genes were validated using MASLD animal model, histological examination and transcriptomic profiles.

RESULTS

We identified five hub genes-UBD/FAT10, STMN2, LYZ, DUSP8, and GPR88-that are potential biomarkers for MASLD. These genes exhibited strong diagnostic potential, either individually or in combination.

CONCLUSION

This study highlights five key biomarkers as promising candidates for understanding MASLD. These findings offer new insights into the disease's pathophysiology and may contribute to the development of better diagnostic and therapeutic approaches.

Examination of the causal role of immune cells in non-alcoholic fatty liver disease by a bidirectional Mendelian randomization study

Background

Non-alcoholic fatty liver disease (NAFLD) is a globally widespread disease. Recent investigations have highlighted a close association between immunity and NAFLD, but the causality between them has not been thoroughly examined.

Methods

A total of 731 immunological traits and NAFLD cohorts were derived from genome-wide association study summary data, and single nucleotide polymorphisms significantly associated with immune traits were identified as instrumental variables. Moreover, 731 phenotypes include absolute cell counts, median fluorescence intensity (MFI), morphological parameters, and relative cell counts. The bidirectional two-sample Mendelian randomization (MR) was performed primarily using the inverse-variance weighted methods, and sensitivity analysis was carried out simultaneously.

Results

Four immunophenotypes were identified to exert a protective effect against NAFLD, including HLA-DR+ CD4+ %lymphocytes, SSC-A on CD4+, CD24 MFI on IgD-CD38-, and CD8 MFI on CD28-CD8br. Seven immunophenotypes were identified to be hazardous, including CD28+ CD45RA+ CD8dim%CD8dim, CD127 MFI on CD28+ DN (CD4-CD8-), CD20 MFI on IgD+ CD38br, CD20 MFI on transitional, IgD MFI on transitional, CD3 MFI on central memory CD8br, and CD45 MFI on CD33brHLA-DR+ CD14-. However, reverse MR showed NAFLD had no causal effect on immunophenotypes.

Conclusion

The study demonstrated a potential causal link between several immunophenotypes and NAFLD, which contributes to advancing research and treatment of NAFLD based on immune-mediated mechanisms.

Causal associations of immunophenotypes with metabolic dysfunction-associated fatty liver disease and mediating pathways: a Mendelian randomization study

Background

Increasing evidence suggests that immunophenotypes play a crucial role in Metabolic dysfunction-associated fatty liver disease (MAFLD), but the specific immunophenotypes contributing to its pathogenesis remain unclear.

Objectives

This study aimed to elucidate the causal associations between immunophenotypes and MAFLD and identify the underlying mediation pathways involved.

Design

Mendelian randomization (MR) study.

Methods

This study is a quasi-causal inference analysis using univariable and multivariable MR (UVMR and MVMR). Five MAFLD genome-wide association studies (GWASs) and the largest immunophenotype GWAS were analyzed to assess their causal associations. Two-step MR identified potential mediators and quantified their mediation proportions. Comprehensive MR methods, multiple sensitivity analyses, meta-analyses, and false discovery rate (FDR) further enhanced the robustness of our findings.

Results

Pooled inverse-variance weighted (IVW) estimates in UVMR identified 47 immunophenotypes having a suggestive causal association with MAFLD. After adjusting for FDR, three lymphocyte phenotypes remained significant: CD20 on IgD-CD24- B cells (OR: 1.035, p fdr: 0.006), terminally differentiated CD8+ T cells %T cells (OR: 1.052, p fdr: 0.006), and CD4 on CD39+ secreting CD4+ regulatory T cells (OR: 1.036, p fdr: 0.046). Meta-analysis of IVW MVMR estimates with confounders adjustment confirmed that CD20 on IgD-CD24- B cells and terminally differentiated CD8+ T cells %T cells had significant direct causal associations on MAFLD (p fdr < 0.05). Additionally, two-step MR analysis identified the waist-to-hip ratio as a mediator, accounting for 42.64% of the causal association between CD20 on IgD-CD24- B cells and MAFLD.

Conclusion

The causal associations of three lymphocyte phenotypes with increased MAFLD risk were identified in this study. CD20 on IgD-CD24- B cells may both directly and indirectly elevate MAFLD risk, while terminally differentiated CD8+ T cells have a direct causal relationship with MAFLD. These findings suggest new possibilities for targeted therapies and underscore the potential for personalized immunotherapy in managing MAFLD.

Decreased antioxidant-related superoxide dismutase 1 expression in peripheral immune cells indicates early ethanol exposure

Alcohol consumption increases oxidative stress and imbalances in the antioxidant system, even with ethanol (EtOH) exposure at a young age. This study assessed changes in the antioxidant system following young EtOH exposure in peripheral immunity and measured sensitive indicators of heavy alcohol consumption. We used peripheral blood mononuclear cells (PBMCs) from 197 male university students without smoking habits to examine changes in antioxidant-related gene expression in vitro and in PBMCs. In vitro, the antioxidant system was impaired by EtOH. Next, we examined the expression of 84 antioxidant-related genes in the PBMCs of 162 young adults, among which the superoxide dismutase (SOD) 1 expression was most negatively correlated with alcohol consumption degree. The plasma SOD1 level had the highest area under the curve value (0.806) for heavy alcohol consumption. Our data demonstrated that a decreased SOD1 level is a sensitive indicator of an impaired antioxidant system and heavy alcohol consumption with early EtOH exposure.

Unraveling the immunological landscape in acute pancreatitis progression to sepsis: insights from a Mendelian randomization study on immune cell traits

BACKGROUND

Acute pancreatitis (AP) is a severe digestive system disorder with a significant risk of progressing to sepsis, a major cause of mortality. Unraveling the immunological pathways in AP is essential for developing effective treatments, particularly understanding the role of specific immune cell traits in this progression.

METHODS

Employing a bidirectional two-sample Mendelian Randomization (MR) approach, this study first examined the causal relationship between AP and 731 immune cell traits to identify those significantly associated with AP. Subsequently, we explored the causal associations between 731 immune cell traits and sepsis. The analysis utilized extensive genome-wide association studies (GWAS) summary datasets, with a focus on identifying common immune cell traits with statistically significant causal associations between AP and sepsis.

RESULTS

Our investigation identified 44 immune cell traits unidirectionally associated with AP and 36 traits unidirectionally associated with sepsis. Among these, CD127 on CD28+ CD45RA- CD8+ T cells emerged as a common mediator, accounting for 5.296% of the increased risk of sepsis in AP patients. This finding highlights the significant role of specific memory CD8+ T cells in the pathophysiology of AP and its progression to sepsis.

CONCLUSION

This study elucidates the critical role of specific immune cell traits, particularly CD127hi memory CD8+ T cells, in the progression of AP to sepsis. Our findings provide a foundation for future research into targeted immune-modulatory therapies, potentially improving patient outcomes in AP-related sepsis and offering new insights into the complex immunological dynamics of this condition.