Marginal false discovery rate control for likelihood-based penalized regression models

Seroprevalence and risk factors for Lassa virus infection in South-West and North-Central Nigeria: a community-based cross-sectional study

BACKGROUND

Understanding the level of exposure to Lassa virus (LASV) in at-risk communities allows for the administration of effective preventive interventions to mitigate epidemics of Lassa fever. We assessed the seroprevalence of LASV antibodies in rural and semiurban communities of two cosmopolitan cities in Nigeria with poorly understood Lassa epidemiology.

METHODS

A cross-sectional study was conducted in ten communities located in the Abuja Municipal Area Council (AMAC), Abuja, and Ikorodu Local Government Area (LGA), Lagos, from February 2nd to July 5th, 2022. Serum samples collected from participants were analyzed for IgG and IgM antibodies using a ReLASV® Pan-Lassa NP IgG/IgM enzyme-linked immunosorbent assay (ELISA) kit. A questionnaire administered to participants collected self-reported sociodemographic and LASV exposure information. Seroprevalence of LASV IgG/IgM was estimated overall, and by study site. Univariate and multivariate log-binomial models estimated unadjusted and adjusted prevalence ratios (aPRs) and 95% confidence intervals (CI) for site-specific risk factors for LASV seropositivity. Grouped Least Absolute Shrinkage and Selection Operator (LASSO) was used for variable selection for multivariate analysis.

RESULTS

A total of 628 participants with serum samples were included in the study. Most participants were female (434, 69%), married (459, 73%), and had a median age of 38 years (interquartile range 28-50). The overall seroprevalence was 27% (171/628), with a prevalence of 33% (126/376) in Abuja and 18% (45/252) in Lagos. Based on site-specific grouped LASSO selection, enrollment in the dry season (vs. wet; aPR, 95% CI: 1.73, 1.33-2.24), reported inconsistent washing of fruits and vegetables (aPR, 95% CI: 1.45, 1.10-1.92), and a positive malaria rapid test (aPR, 95% CI: 1.48, 1.09-2.00) were independently associated with LASV seropositivity in Abuja, whereas, only a self-reported history of rhinorrhea (PR, 95% CI: 2.21, 1.31-3.72) was independently associated with Lassa seropositivity in Lagos.

CONCLUSIONS

The LASV seroprevalence was comparable to that in other areas in Nigeria. Our findings corroborate those from other studies on the importance of limiting human exposure to rodents and focusing on behavioral factors such as poor hygiene practices to reduce exposure to LASV.

Biomarker and transcriptomics profiles of serum selenium concentrations in patients with heart failure are associated with immunoregulatory processes

BACKGROUND

Low selenium concentrations are associated with worse outcomes in heart failure (HF). However, the underlying pathophysiologic mechanisms remain incompletely understood. Therefore, we aimed to contrast serum selenium concentrations to blood biomarker and transcriptomic profiles in patients with HF.

METHODS

Circulating biomarkers, whole blood transcriptomics and serum selenium measurements in a cohort of 2328 patients with HF were utilized. Penalized linear regression and gene expression analysis were used to assess biomarker and transcriptomics profiles, respectively. As a proof-of-principle, potential causal effects of selenium on excreted cytokines concentrations were investigated using human peripheral blood mononuclear cells (PBMCs).

RESULTS

Mean selenium levels were 60.6 μg/L in Q1 and 122.0 μg/L in Q4. From 356 biomarkers and 20 clinical features, the penalized linear regression model yielded 44 variables with <5 % marginal false discovery rate as predictors of serum selenium. Biomarkers associated positively with selenium concentrations included: epidermal growth factor receptor (EGFR), IFN-gamma-R1, CD4, GDF15, and IL10. Biomarkers associated negatively with selenium concentrations included: PCSK9, TNFSF13, FGF21 and PAI. Additionally, 148 RNA transcripts were found differentially expressed between high and low selenium status (Padj.<0.05; log-fold-change<|0.25|). Enrichment analyses of the selected biomarkers and RNA transcripts identified similar enriched processes, including regulation processes of leukocyte differentiation and activation, as well as cytokines production. The mRNA expression of two selenoproteins (MSRB1 and GPX4) were strongly correlated with serum selenium, while GPX4, SELENOK, and SELENOS were associated with prognosis. In the in-vitro setting, PBMCs supplemented with selenium showed significantly lower abundance of several (pro-)inflammatory cytokines.

CONCLUSION

These data suggest that immunoregulation is an important mechanism through which selenium might have beneficial roles in HF. The beneficial effects of higher serum selenium concentrations are likely because of global immunomodulatory effects on the abundance of cytokines. MSRB1 and GPX4 are potential modulators of and should be pursued in future research.

The CXCL Family Contributes to Immunosuppressive Microenvironment in Gliomas and Assists in Gliomas Chemotherapy

Gliomas are a type of malignant central nervous system tumor with poor prognosis. Molecular biomarkers of gliomas can predict glioma patient's clinical outcome, but their limitations are also emerging. C-X-C motif chemokine ligand family plays a critical role in shaping tumor immune landscape and modulating tumor progression, but its role in gliomas is elusive. In this work, samples of TCGA were treated as the training cohort, and as for validation cohort, two CGGA datasets, four datasets from GEO database, and our own clinical samples were enrolled. Consensus clustering analysis was first introduced to classify samples based on CXCL expression profile, and the support vector machine was applied to construct the cluster model in validation cohort based on training cohort. Next, the elastic net analysis was applied to calculate the risk score of each sample based on CXCL expression. High-risk samples associated with more malignant clinical features, worse survival outcome, and more complicated immune landscape than low-risk samples. Besides, higher immune checkpoint gene expression was also noticed in high-risk samples, suggesting CXCL may participate in tumor evasion from immune surveillance. Notably, high-risk samples also manifested higher chemotherapy resistance than low-risk samples. Therefore, we predicted potential compounds that target high-risk samples. Two novel drugs, LCL-161 and ADZ5582, were firstly identified as gliomas' potential compounds, and five compounds from PubChem database were filtered out. Taken together, we constructed a prognostic model based on CXCL expression, and predicted that CXCL may affect tumor progression by modulating tumor immune landscape and tumor immune escape. Novel potential compounds were also proposed, which may improve malignant glioma prognosis.

Marginal false discovery rate for a penalized transformation survival model

Survival analysis that involves moderate/high dimensional covariates has become common. Most of the existing analyses have been focused on estimation and variable selection, using penalization and other regularization techniques. To draw more definitive conclusions, a handful of studies have also conducted inference. The recently developed mFDR (marginal false discovery rate) technique provides an alternative inference perspective and can be advantageous in multiple aspects. The existing inference studies for regularized estimation of survival data with moderate/high dimensional covariates assume the Cox and other specific models, which may not be sufficiently flexible. To tackle this problem, the analysis scope is expanded to the transformation model, which is robust and has been shown to be desirable for practical data analysis. Statistical validity is rigorously established. Two data analyses are conducted. Overall, an alternative inference approach has been developed for survival analysis with moderate/high dimensional data.

Cardiovascular magnetic resonance clarifies arrhythmogenicity in asymptomatic young athletes with ventricular arrhythmias undergoing pre-participation evaluation

Pre-participation sports examination (PPE) is a frequent reason for consultation. However, the exact role of cardiovascular magnetic resonance (CMR) in PPE remains undefined. The additive value of CMR in adolescent athletes with ventricular rhythm disturbances (VRDs) was investigated. We prospectively recruited and evaluated with CMR 50 consecutive, asymptomatic young athletes referred to our tertiary center after identification of VRDs on electrocardiogram (ECG) with otherwise normal standard PPE and echocardiography, and 20 age- and sex-matched healthy volunteer athletes who underwent the same evaluations. The primary outcome was case-control status and the secondary outcome was the discrimination between athletes with VRDs with and without non-sustained ventricular tachycardia (VT). CMR identified arrhythmogenic substrates in all athletes with VRDs. The predominant condition was myocarditis and arrhythmogenic right ventricular cardiomyopathy in patients with and without VT, respectively. Based on penalized regression analysis, late gadolinium enhancement (LGE), early gadolinium enhancement (EGE), extracellular volume fraction (ECV), and T2-mapping, best distinguished between case-control status. The aforementioned indices predicted case-control status independent of age and sex: EGE [Odds ratio (95% confidence interval): 6.89 (2.19-21.62) per 0.5-unit, P<0.001], LGE (perfect prediction), ECV [1.66 (1.25-2.22), P<0.001] and T2 mapping [1.40 (1.13-1.72), P=0.002], among other independent CMR-derived predictors. Only indexed ventricular volumes independently discriminated between VRD patients with and without VT. In this study, asymptomatic young athletes with VRDs and normal PPE/echocardiography were optimally discriminated from healthy control athletes by CMR-derived indices, and CMR allowed for the identification of arrhythmogenic substrates in all cases.

The Doubled-Edged Sword of T1-Mapping in Systemic Sclerosis-A Comparison with Infectious Myocarditis Using Cardiovascular Magnetic Resonance

AIMS

T1-mapping is considered a surrogate marker of acute myocardial inflammation. However, in diffuse cutaneous systemic sclerosis (dcSSc) this might be confounded by coexisting myocardial fibrosis. We hypothesized that T1-based indices should not by themselves be considered as indicators of myocardial inflammation in dcSSc patients.

METHODS/RESULTS

A cohort of 59 dcSSc and 34 infectious myocarditis patients was prospectively evaluated using a 1.5-Tesla system for an indication of suspected myocardial inflammation and was compared with 31 healthy controls. Collectively, 33 (97%) and 57 (98%) of myocarditis and dcSSc patients respectively had ≥1 pathologic T2-based index. However, 33 (97%) and 45 (76%) of myocarditis and dcSSc patients respectively had ≥1 pathologic T2-based index. T2-signal ratio was significantly higher in myocarditis patients compared with dcSSc patients (2.5 (0.6) vs. 2.1 (0.4), p < 0.001). Early gadolinium enhancement, late gadolinium enhancement and T2-mapping did not differ significantly between groups. However, both native T1-mapping and extracellular volume fraction were significantly lower in myocarditis compared with dcSSc patients (1051.0 (1027.0, 1099.0) vs. 1120.0 (1065.0, 1170.0), p < 0.001 and 28.0 (26.0, 30.0) vs. 31.5 (30.0, 33.0), p < 0.001, respectively). The original Lake Louise criteria (LLc) were positive in 34 (100%) myocarditis and 40 (69%) dcSSc patients, while the updated LLc were positive in 32 (94%) and 44 (76%) patients, respectively. Both criteria had good agreement with greater but nonsignificant discordance in dcSSc patients.

CONCLUSIONS

~25% of dcSSc patients with suspected myocardial inflammation had no CMR evidence of acute inflammatory processes. T1-based indices should not be used by themselves as surrogates of acute myocardial inflammation in dcSSc patients.

Combined Brain-Heart Magnetic Resonance Imaging in Autoimmune Rheumatic Disease Patients with Cardiac Symptoms: Hypothesis Generating Insights from a Cross-sectional Study

BACKGROUND

Autoimmune rheumatic diseases (ARDs) may affect both the heart and the brain. However, little is known about the interaction between these organs in ARD patients. We asked whether brain lesions are more frequent in ARD patients with cardiac symptoms compared with non-ARD patients with cardiovascular disease (CVD).

METHODS

57 ARD patients with mean age of 48 ± 13 years presenting with shortness of breath, chest pain, and/or palpitations, and 30 age-matched disease-controls with non-autoimmune CVD, were evaluated using combined brain-heart magnetic resonance imaging (MRI) in a 1.5T system.

RESULTS

52 (91%) ARD patients and 16 (53%) controls had white matter hyperintensities (p < 0.001) in at least one brain area (subcortical/deep/periventricular white matter, basal ganglia, pons, brainstem, or mesial temporal lobe). Only the frequency and number of subcortical and deep white matter lesions were significantly greater in ARD patients (p < 0.001 and 0.014, respectively). ARD vs. control status was the only independent predictor of having any brain lesion. Specifically for deep white matter lesions, each increase in ECV independently predicted a higher number of lesions [odds ratio (95% confidence interval): 1.16 (1.01-1.33), p = 0.031] in ordered logistic regression. Penalized logistic regression selected only ARD vs. control status as the most important feature for predicting whether brain lesions were present on brain MRI (odds ratio: 5.46, marginal false discovery rate = 0.011).

CONCLUSIONS

Subclinical brain involvement was highly prevalent in this cohort of ARD patients and was mostly independent of the severity of cardiac involvement. However, further research is required to determine the clinical relevance of these findings.