Transsulfuration pathway thiols and methylated arginines: the hunter community study

Background: Serum homocysteine, when studied singly, has been reported to be positively associated both with the endogenous nitric oxide synthase inhibitor asymmetric dimethylarginine [ADMA, via inhibition of dimethylarginine dimethylaminohydrolase (DDAH) activity] and with symmetric dimethylarginine (SDMA). We investigated combined associations between transsulfuration pathway thiols, including homocysteine, and serum ADMA and SDMA concentrations at population level. Methods: Data on clinical and demographic characteristics, medication exposure, C-reactive protein, serum ADMA and SDMA (LC-MS/MS), and thiols (homocysteine, cysteine, taurine, glutamylcysteine, total glutathione, and cysteinylglycine; capillary electrophoresis) were collected from a sample of the Hunter Community Study on human ageing [n = 498, median age (IQR) = 64 (60–70) years]. Results: Regression analysis showed that: a) age (P = 0.001), gender (P = 0.03), lower estimated glomerular filtration rate (eGFR, P = 0.08), body mass index (P = 0.008), treatment with beta-blockers (P = 0.03), homocysteine (P = 0.02), and glutamylcysteine (P = 0.003) were independently associated with higher ADMA concentrations; and b) age (P = 0.001), absence of diabetes (P = 0.001), lower body mass index (P = 0.01), lower eGFR (P&lt;0.001), cysteine (P = 0.007), and glutamylcysteine (P&lt;0.001) were independently associated with higher SDMA concentrations. No significant associations were observed between methylated arginines and either glutathione or taurine concentrations. Conclusions: After adjusting for clinical, demographic, biochemical, and pharmacological confounders the combined assessment of transsulfuration pathway thiols shows that glutamylcysteine has the strongest and positive independent associations with ADMA and SDMA. Whether this reflects a direct effect of glutamylcysteine on DDAH activity (for ADMA) and/or cationic amino acid transport requires further investigations.</br

Clinical and biochemical correlates of serum L-ergothioneine concentrations in community-dwelling middle-aged and older adults

Background: Despite the increasing interest towards the biological role of L-ergothioneine, little is known about the serum concentrations of this unusual aminothiol in older adults. We addressed this issue in a representative sample of communitydwelling middle-aged and older adults. Methods: Body mass index, estimated glomerular filtration rate, serum concentrations of L-ergothioneine, taurine, homocysteine, cysteine, glutathione, cysteinylglycine, and glutamylcysteine were evaluated in 439 subjects (age 55–85 years) randomly selected from the Hunter Community Study. Results: Median L-ergothioneine concentration in the entire cohort was 1.01 IQR 0.78–1.33 mmol/L. Concentrations were not affected by gender (P = 0.41) or by presence of chronic medical conditions (P = 0.15). By considering only healthy subjects, we defined a reference interval for L-ergothioneine serum concentrations from 0.36 (90% CI 0.31–0.44) to 3.08 (90% CI 2.45–3.76) mmol/L. Using stepwise multiple linear regression analysis L-ergothioneine was negatively correlated with age (rpartial =20.15; P = 0.0018) and with glutamylcysteine concentrations (rpartial =20.13; P = 0.0063). Conclusions: A thorough analysis of serum L-ergothioneine concentrations was performed in a large group of communitydwelling middle-aged and older adults. Reference intervals were established. Age and glutamylcysteine were independently negatively associated with L-ergothioneine serum concentration.</br

Optimized Cocktail Phenotyping Study Protocol Using Physiological Based Pharmacokinetic Modeling and In silico Assessment of Metabolic Drug–Drug Interactions Involving Modafinil

In vivo cocktail pathway phenotyping (ICPP) is routinely used to assess the metabolic drug–drug interaction (mDDI) potential of new drug candidates (NDC) during drug development. However, there are a number of potential limitations to this approach and the use of validated drug cocktails and study protocols is essential. Typically ICPP mDDI studies assess only the impact of interactions following multiple postulated perpetrator doses and hence the emphasis in terms of validation of these studies has been ensuring that there are no interactions between probe substrates. Studies assessing the comparative impact of single and multiple doses of the postulated perpetrator have the potential to provide richer information regarding both the clinical impact and mechanism of mDDIs. Using modafinil as a model compound, we sought to develop an optimized ICPP mDDI study protocol to evaluate the potential magnitude and clinical relevance of mDDIs using a physiologically based pharmacokinetic modeling approach

A systematic review and meta-analysis of neopterin in rheumatic diseases

IntroductionNovel biomarkers of inflammation and oxidative stress might enhance the early recognition, management, and clinical outcomes of patients with rheumatic diseases (RDs). We assessed the available evidence regarding the pathophysiological role of neopterin, the oxidation product of 7,8-dihydroneopterin, a pteridine generated in macrophages activated by interferon-γ, by conducting a systematic review and meta-analysis of studies reporting its concentrations in biological fluids in RD patients and healthy controls.MethodsWe searched electronic databases for relevant articles published between inception and 31 August 2023. The risk of bias and the certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development and Evaluation Working Group system, respectively.ResultsIn 37 studies, when compared to healthy controls, RD patients had significantly higher concentrations of neopterin both in plasma or serum (standard mean difference, SMD=1.31, 95% CI 1.01 to 1.61; p&lt;0.001; moderate certainty of evidence) and in the urine (SMD=1.65, 95% CI 0.86 to 2.43, p&lt;0.001; I2 = 94.2%, p&lt;0.001; low certainty of evidence). The results were stable in sensitivity analysis. There were non-significant associations in meta-regression and subgroup analysis between the effect size and age, male to female ratio, year of publication, sample size, RD duration, C-reactive protein, erythrocyte sedimentation rate, specific type of RD, presence of connective tissue disease, analytical method used, or biological matrix investigated (plasma vs. serum). By contrast, the effect size was significantly associated with the geographical area in studies assessing serum or plasma and with the type of RD in studies assessing urine.DiscussionPending additional studies that also focus on early forms of disease, our systematic review and meta-analysis supports the proposition that neopterin, a biomarker of inflammation and oxidative stress, can be useful for the identification of RDs. (PROSPERO registration number: CRD42023450209).Systematic review registrationPROSPERO, identifier CRD4202345020

Endostatin as a biomarker of systemic sclerosis: insights from a systematic review and meta-analysis

IntroductionThe critical role played by vascular dysfunction and ineffective angiogenesis in the pathophysiology of systemic sclerosis (SSc) suggests that circulating biomarkers reflecting these alterations may be useful in the clinical evaluation of this patient group. We sought to address this issue by conducting a systematic review and meta-analysis of studies investigating a such candidate biomarker, endostatin, an endogenous glycoprotein exerting anti-angiogenic effects, in SSc patients and healthy controls.MethodsA literature search was conducted in the electronic databases Web of Science, PubMed, and Scopus from inception to 27 May 2024. Risk of bias and certainty of evidence were assessed using the JBI checklist for analytical studies and GRADE, respectively.ResultsIn 19 eligible studies, circulating endostatin concentrations were significantly higher in SSc patients than controls (standard mean difference, SMD=0.90, 95% CI 0.56 to 1.23, p&lt;0.001; low certainty of evidence). Endostatin concentrations were also significantly higher in SSc patients with digital ulcers than those without (SMD=0.43, 95% CI 0.24 to 0.62, p&lt;0.001; very low certainty of evidence) and in patients with pulmonary arterial hypertension than those without (SMD=1.21, 95% CI 0.67 to 1.76, p&lt;0.001; very low certainty of evidence). By contrast, no significant differences were observed between SSc patients with limited vs. diffuse disease and those with different video capillaroscopy patterns. There was limited evidence regarding endostatin concentrations in SSc patients with interstitial lung disease, telangiectasias, and gastrointestinal manifestations. There were no significant associations in meta-regression and subgroup analysis of studies investigating endostatin in SSc patients and controls between the effect size and various patient and study characteristics.DiscussionTherefore, the results of this systematic review and meta-analysis suggest that measuring endostatin can be useful in assessing the presence of SSc and specific complications, i.e., digital ulcers and pulmonary arterial hypertension, in these patients.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42024558174

sCD40 and sCD40L as candidate biomarkers of rheumatic diseases: a systematic review and meta-analysis with meta-regression

There is an ongoing search for novel biomarkers to enhance diagnosing and monitoring patients with rheumatic diseases (RDs). We conducted a systematic review and meta-analysis to investigate the potential role of the soluble cluster of differentiation 40 (sCD40) and sCD40 ligand (sCD40L), involved in humoral and cellular immune response, as candidate biomarkers of RDs. We searched PubMed, Web of Science, and Scopus from inception to 30 June 2024 for studies investigating circulating sCD40 and sCD40L concentrations in RD patients and healthy controls. We assessed the risk of bias using the Joanna Briggs Institute Critical Appraisal Checklist for analytical studies and the certainty of evidence using the Grades of Recommendation, Assessment, Development and Evaluation Working Group system. Compared to controls, RD patients had significantly higher sCD40L (31 studies; standard mean difference, SMD=0.87, 95% CI 0.60 to 1.13, p&lt;0.001; low certainty of evidence) and sCD40 (five studies; SMD=1.32, 95% CI 0.45 to 2.18, p=0.003; very low certainty of evidence) concentrations. In meta-regression and subgroup analysis, the effect size of the between-group differences in sCD40L was significantly associated with sample size, mean RD duration, specific RD, biological matrix assessed, and analytical method used. By contrast, there were no associations with age, sex, C-reactive protein, erythrocyte sedimentation rate, use of disease-modifying antirheumatic drugs or glucocorticoids, or geographical location. There were no significant differences in sCD40L concentrations between RD patients with and without active disease (eight studies; SMD=0.12, 95% CI -0.09 to 0.33, p=0.26; very low certainty). By contrast, sCD40 concentrations were significantly higher in RD patients with active disease (three studies; SMD=0.36, 95% CI 0.08 to 0.84, p=0.013; very low certainty). Our systematic review and meta-analysis suggests the potential role of sCD40 and sCD40L as candidate biomarkers to detect the presence of RDs (sCD40 and sCD40L) and monitor disease activity (sCD40). Large, appropriately designed prospective studies in a wide range of RDs are warranted to investigate whether measuring sCD40 and sCD40L can significantly improve the performance of currently available diagnostic criteria and serological biomarkers. (PROSPERO registration number: CRD42024577430).Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD42024577430, identifier PROSPERO CRD42024577430

Vascular endothelial growth factor as a potential biomarker in systemic sclerosis: a systematic review and meta-analysis

IntroductionSystemic sclerosis (SSc), a chronic autoimmune condition, is characterized by microvascular dysfunction, ineffective angiogenesis, and fibrosis. The identification of robust biomarkers reflecting these processes may assist in clinical management and lead to the discovery of new therapies. We sought to address this issue by conducting a systematic review and meta-analysis of studies investigating one such biomarker, vascular endothelial growth factor (VEGF), in SSc patients and healthy controls and in SSc patients with localized or diffuse disease, different video capillaroscopy patterns (early, active, or late), and presence or absence of complications.MethodsWe searched PubMed, Scopus, and Web of Science from inception to 15 May 2024. We assessed the risk of bias and the certainty of evidence using the JBI checklist for analytical studies and GRADE, respectively.ResultsIn 42 eligible studies, compared to controls, patients with SSc had significantly higher plasma or serum VEGF concentrations (standard mean difference, SMD=0.93, 95% CI 0.71 to 1.15, p&lt;0.001; moderate certainty). In further analyses, VEGF concentrations were significantly higher in SSc patients with diffused disease than those with localized disease (SMD=0.30, 95% CI 0.01 to 0.59, p=0.046; very low certainty), in patients with late vs. active video capillaroscopy pattern (SMD=0.35, 95% CI 0.09 to 0.61, p=0.008; very low certainty), and in patients with pulmonary hypertension than those without (SMD=0.93, 95% CI 0.34 to 1.53, p=0.002; very low certainty). By contrast, no significant differences were observed between SSc patients with and without digital ulcers, interstitial lung disease, and telangiectasias, whereas limited evidence was available for alveolitis. Meta-regression and subgroup analysis of studies investigating VEGF in SSc patients and controls showed no significant associations between the effects size and various patient and study characteristics, including SSc duration and use of corticosteroids, immunosuppressors and vasodilators. By contrast, significant associations were observed with the geographical location where the study was conducted.DiscussionThe results of this systematic review and meta-analysis suggest that VEGF can be useful in the assessment and management of SSc and in the identification of novel therapeutic strategies in this patient group.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero, identifier CRD42024552925

Neutrophil to lymphocyte ratio and clinical outcomes in COPD: recent evidence and future perspectives

Chronic obstructive pulmonary disease (COPD) is a disabling condition that is characterised by poorly reversible airflow limitation and inflammation. Acute exacerbations of COPD are a common cause of hospitalisation and death among COPD patients. Several biochemical markers have been studied as outcome predictors in COPD; however, their measurement often requires significant time and resources. Relatively simple biomarkers of inflammation calculated from routine complete blood count tests, such as the neutrophil to lymphocyte ratio (NLR), might also predict COPD progression and outcomes. This review discusses the available evidence from studies investigating the associations between the NLR, COPD exacerbations and death in this patient group

Serum methylarginines and spirometry-measured lung function in older adults

Rationale: Methylarginines are endogenous nitric oxide synthase inhibitors that have been implicated in animal models of lung disease but have not previously been examined for their association with spirometric measures of lung function in humans. Objectives: This study measured serum concentrations of asymmetric and symmetric dimethylarginine in a representative sample of older community-dwelling adults and determined their association with spirometric lung function measures. Methods: Data on clinical, lifestyle, and demographic characteristics, methylated arginines, and L-arginine (measured using LC-MS/MS) were collected from a population-based sample of older Australian adults from the Hunter Community Study. The five key lung function measures included as outcomes were Forced Expiratory Volume in 1 second, Forced Vital Capacity, Forced Expiratory Volume in 1 second to Forced Vital Capacity ratio, Percent Predicted Forced Expiratory Volume in 1 second, and Percent Predicted Forced Vital Capacity. Measurements and Main Results: In adjusted analyses there were statistically significant independent associations between a) higher asymmetric dimethylarginine, lower Forced Expiratory Volume in 1 second and lower Forced Vital Capacity; and b) lower L-arginine/asymmetric dimethylarginine ratio, lower Forced Expiratory Volume in 1 second, lower Percent Predicted Forced Expiratory Volume in 1 second and lower Percent Predicted Forced Vital Capacity. By contrast, no significant associations were observed between symmetric dimethylarginine and lung function. Conclusions: After adjusting for clinical, demographic, biochemical, and pharmacological confounders, higher serum asymmetric dimethylarginine was independently associated with a reduction in key measures of lung function. Further research is needed to determine if methylarginines predict the decline in lung function