Association between blood Pentraxin-3 concentrations and rheumatic diseases: A systematic review and meta-analysis.

BACKGROUND: Among the Pentraxins, the long Pentraxin-3 (PTX-3) is associated with several processes, particularly in the earliest phases of the innate humoral response. Increased blood PTX-3 concentrations have been observed in a wide range of conditions, from infectious to cardiovascular disorders. Since its increase is more rapid than C-reactive protein (CRP), PTX-3 can be useful to detect and monitor early inflammation. To dissect its pathophysiological role in rheumatic diseases (RD), we conducted a systematic review and meta-analysis comparing blood PTX-3 concentrations in RD patients and healthy individuals and investigating possible associations with clinical, demographic, and study characteristics. METHODS: We performed a search of published evidence until April 2024 in PubMed, Web of Science and Scopus, which led to the selection of 60 relevant manuscripts from a total of 1072 records. RESULTS: Our synthesis revealed a statistically significant difference in PTX-3 concentrations between RD patients and controls (standard mean difference, SMD = 1.02, 95% CI 0.77-1.26, p < .001), that correlated with CRP concentrations. The effect size was associated with geographical region of study conduction, RD type, with a reduction of the observed heterogeneity in patients with low LDL-cholesterol and triglycerides concentrations. CONCLUSIONS: Our study has shown a significant increase in blood PTX-3 concentrations in RD patients, which was associated with specific patient characteristics. Nevertheless, additional studies are needed to better define the utility of measuring PTX-3 in the early phase of RD. Our study was conducted in compliance with the PRISMA 2020 statement (study protocol available at PROSPERO CRD42024516600).

Analytical Insights into Methods for Measuring Ischemia-Modified Albumin.

Ischemia-modified albumin (IMA) has emerged as a pivotal biomarker for the early detection of ischemic conditions, particularly myocardial ischemia, where timely diagnosis is crucial for effective intervention. This review provides an overview of the analytical methods for assessment of IMA, including Albumin Cobalt Binding (ACB), Albumin Copper Binding (ACuB), Enzyme-Linked Immunosorbent Assay (ELISA), new techniques such as liquid crystal biosensors (LCB), quantum dot coupled X-ray fluorescence spectroscopy (Q-XRF), mass spectrometry (MS), and electron paramagnetic resonance (EPR) spectroscopy. Each method was thoroughly examined for its analytical performance in terms of sensitivity, specificity, and feasibility. The ACB assay is the most readily implementable method in clinical laboratories for its cost-effectiveness and operational simplicity. On the other hand, the ACuB assay exhibits enhanced sensitivity and specificity, driven by the superior binding affinity of copper to IMA. Furthermore, nanoparticle-enhanced immunoassays and liquid crystal biosensors, while more resource-intensive, significantly improve the analytical sensitivity and specificity of IMA detection, enabling earlier and more accurate identification of ischemic events. Additionally, different biological matrices, such as serum, saliva, and urine, were reviewed to identify the most suitable for accurate measurements in clinical application. Although serum was considered the gold standard, non-invasive matrices such as saliva and urine are becoming increasingly feasible due to advances in technology. This review underscores the role of IMA in clinical diagnostics and suggests how advanced analytical techniques have the potential to significantly enhance patient outcomes in ischemic disease management.

ADMA and homoarginine independently predict mortality in critically ill patients.

BACKGROUND: Arginine metabolites are associated with cardiovascular and all-cause mortality in several patient groups. We investigated whether arginine metabolites are associated with mortality in patients with critical illness and whether associations are independent of other factors affecting prognosis in an Intensive Care Unit (ICU). METHODS: 1155 acutely unwell adult patients admitted to a mixed medical-surgical ICU were studied. Arginine, asymmetric dimethyl-l-arginine (ADMA), monomethyl-l-arginine (MMA), symmetric dimethyl-l-arginine (SDMA) and l-homoarginine were measured in a plasma sample collected at admission to ICU by liquid chromatography tandem mass spectrometry. Risk of death score was calculated using data submitted to the Australia and New Zealand Intensive Care Society. RESULTS: In this cohort, 163 patients (14.1%) died. ADMA (odds ratio = 1.159 (1.033-1.300) per 0.1 µmol/L increment, p = 0.012), homoarginine (odds ratio = 0.963 (0.934-0.992), p = 0.013) and risk of death score (odds ratio = 1.045 (1.037-1.053) per 1% increment, p < 0.001) were independently associated with mortality in ICU patients. The area under the receiver operator characteristic curve for risk of death score, ADMA and homoarginine combined for mortality was greater than for risk of death score alone (0.815 (95% CI 0.790-0.837) vs 0.796 (95% CI 0.781-0.820), p = 0.019). Other arginine metabolites were not independently associated with mortality. CONCLUSIONS: ADMA is positively and homoarginine negatively associated with mortality in ICU patients, independent of other clinical factors. Measuring ADMA and homoarginine may refine models to predict ICU mortality. Reducing ADMA and increasing homoarginine are potential therapeutic targets to reduce mortality in critically ill patients.

A Capillary Electrophoresis-Based Method for the Measurement of Hydroxychloroquine and Its Active Metabolite Desethyl Hydroxychloroquine in Whole Blood in Patients with Rheumatoid Arthritis.

A capillary electrophoresis method was developed to detect and measure hydroxychloroquine (HCQ) and its active metabolite desethyl hydroxychloroquine (DHCQ) in whole blood in patients with rheumatoid arthritis. The best separation in terms of peak area reproducibility, migration time, peak shape, and resolution of adjacent peaks was obtained in a 60 cm, 75 µm i.d. uncoated fused-silica capillary using a background electrolyte mixture of an aqueous 55 mmol/L TRIS solution brought to pH 2.6 with phosphoric acid and methanol (85:15) and a voltage and a temperature of separation of 20 kV and 30 °C, respectively. Analytes were separated in less than 12 min, with excellent linearity (R2 ≥ 0.999) in the concentration range of 0.5-8 µmol/L. The recovery of analytes spiked in whole blood was 99-101% for HCQ and 98-99% for DHCQ. Analysis of five samples from patients with rheumatoid arthritis receiving HCQ 400 mg daily yielded mean steady-state concentrations of 2.27 ± 1.61 and 1.54 ± 0.55 µmol/L for HCQ and DHCQ, respectively, with a HCQ to DHCQ ratio of 1.40 ± 0.77.

Methodological Fallacies in the Determination of Serum/Plasma Glutathione Limit Its Translational Potential in Chronic Obstructive Pulmonary Disease.

This study aimed to review and critically appraise the current methodological issues undermining the suitability of the measurement of serum/plasma glutathione, both in the total and reduced form, as a measure of systemic oxidative stress in chronic obstructive pulmonary disease (COPD). Fourteen relevant articles published between 2001 and 2020, in 2003 subjects, 1111 COPD patients, and 892 controls, were reviewed. Nine studies, in 902 COPD patients and 660 controls, measured glutathione (GSH) in the reduced form (rGSH), while the remaining five, in 209 COPD patients and 232 controls, measured total GSH (tGSH). In the control group, tGSH ranged between 5.7 and 7.5 µmol/L, whilst in COPD patients, it ranged between 4.5 and 7.4 µmol/L. The mean tGSH was 6.6 ± 0.9 µmol/L in controls and 5.9 ± 1.4 µmol/L in patients. The concentrations of rGSH in the control group showed a wide range, between 0.47 and 415 µmol/L, and a mean value of 71.9 ± 143.1 µmol/L. Similarly, the concentrations of rGSH in COPD patients ranged between 0.49 and 279 µmol/L, with a mean value of 49.9 ± 95.9 µmol/L. Pooled tGSH concentrations were not significantly different between patients and controls (standard mean difference (SMD) = -1.92, 95% CI -1582 to 0.0219; p = 0.057). Depending on whether the mean concentrations of rGSH in controls were within the accepted normal range of 0.5-5.0 µmol/L, pooled rGSH concentrations showed either a significant (SMD = -3.8, 95% CI -2.266 to -0.709; p < 0.0001) or nonsignificant (SMD = -0.712, 95% CI -0.627 to 0.293; p = 0.48) difference. These results illustrate the existing and largely unaddressed methodological issues in the interpretation of the serum/plasma concentrations of tGSH and rGSH in COPD.

Comprehensive arginine metabolomics and peripheral vasodilatory capacity in rheumatoid arthritis: A monocentric cross-sectional study.

BACKGROUND: The relationship between plasma arginine metabolites influencing vascular homeostasis and peripheral vasodilatory capacity in rheumatoid arthritis (RA) patients is not known. METHODS: l-arginine (Arg), monomethyl-l-arginine (MMA), l-homoarginine (hArg), asymmetric dimethyl-l-arginine (ADMA), symmetric dimethyl-l-arginine, and l-citrulline (Cit) were measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) in 164 RA patients and 100 age- and sex-matched healthy controls without previous cardiovascular events. Log-transformed reactive hyperemia index (Ln-RHI) evaluated by flow-mediated pulse amplitude tonometry (PAT, EndoPAT2000 device) was assessed as surrogate measure of peripheral vasodilatory capacity in RA patients. Ln-RHI values <0.51 indicated peripheral endothelial dysfunction (ED). The relationship between plasma arginine metabolite concentrations, RA descriptors and peripheral vasodilatory capacity was evaluated by bivariate correlation and regression analyses. RESULTS: Plasma ADMA concentrations were significantly higher, and plasma hArg concentrations significantly lower, in RA patients than in controls (0.53 ± 0.09 vs 0.465 ± 0.07 µmol/L and 1.50 ± 0.60 vs 1.924 ± 0.78 µmol/L, respectively; p < 0.001 for both comparisons). Bivariate correlation analysis demonstrated no significant correlation between arginine metabolites and disease descriptors. In regression analysis in RA patients, higher plasma ADMA concentrations were independently associated with presence of ED [OR(95% CI) = 77.3(1.478-4050.005), p = 0.031] and lower Ln-RHI [B coefficient(95% CI) = -0.57(-1.09 to -0.05), p = 0.032]. CONCLUSIONS: ADMA was significantly, albeit weakly, associated with impaired microcirculatory vasodilatory capacity and peripheral endothelial dysfunction in RA. This suggests an important pathophysiological role of this metabolite in the vascular alterations observed in this patient group.

Systemic transsulfuration pathway thiol concentrations in chronic obstructive pulmonary disease patients.

BACKGROUND: It is amply reported that patients with chronic obstructive pulmonary disease (COPD) have increased risk of cardiovascular disease (CVD). Recent evidence suggests that COPD patients have elevated concentrations of plasma homocysteine (Hcy), a transsulfuration pathway analyte that is commonly regarded as a CVD risk factor. DESIGN: We comprehensively investigated the plasma concentrations of transsulfuration pathway analytes, and their relationship with markers of oxidative stress and inflammation, to identify which low molecular thiols might play a pathophysiological role both in CVD and in COPD. Hcy, cysteine (Cys), glutathione (GSH), cysteinylglycine (CysGly), glutamylcysteine (GluCys), taurine (Tau), oxidative stress markers (TBARS and protein-SH, PSH) and the inflammation marker kynurenine/tryptophan (Kyn/Trp) ratio were measured in 54 COPD patients and 54 control subjects. RESULTS: We found increased concentrations of total Hcy (P < .01) and total CysGly (P < .05) in COPD patients when compared to controls. Total Hcy and CysGly were also significantly associated with abnormal lung function parameters and COPD severity. In COPD patients, total Hcy was significantly associated with the Kyn/Trp ratio (P = .0017) whereas total CysGly was significantly associated with both PSH (P = .0298) and the Kyn/Trp ratio (P = <.0001). CONCLUSION: Both total Hcy and CysGly concentrations were significantly associated with the presence and severity of COPD and with markers of oxidative stress (total CysGly) and inflammation (total Hcy and CysGly). This suggests that specific low molecular mass thiols might play a role in the inflammatory and oxidative stress pathways involved in both CVD and COPD.

Oxidative Stress Biomarkers and Peripheral Endothelial Dysfunction in Rheumatoid Arthritis: A Monocentric Cross-Sectional Case-Control Study.

Previous studies have suggested that oxidative stress may heighten atherosclerotic burden in rheumatoid arthritis (RA), but direct evidence is lacking. OBJECTIVE: To evaluate the relationship between established plasma oxidative stress biomarkers and peripheral endothelial dysfunction (ED), a marker of early atherosclerosis, in RA. METHODS: Paroxonase-1 (PON-1), protein-SH (PSH), and malondialdehyde (MDA) were measured in 164 RA patient s and 100 age- and sex-matched healthy controls without previous cardiovascular events. Peripheral ED, evaluated by flow-mediated pulse amplitude tonometry, was defined by log-transformed reactive hyperemia index (Ln-RHI) values < 0.51. RESULTS: PON-1 activity and PSH concentrations were significantly reduced in RA patients compared to controls. In regression analysis, increased plasma MDA levels were significantly associated with reduced Ln-RHI [B coefficient (95% CI) = -0.003 (-0.005 to -0.0008), p = 0.008] and the presence of peripheral ED (OR (95% CI) = 1.75 (1.06-2.88), p = 0.028). Contrary to our expectations, increased PON-1 activity was significantly associated, albeit weakly, with the presence of ED (OR (95% CI) = 1.00 (1.00-1.01), p = 0.017). CONCLUSIONS: In this first evidence of a link between oxidative stress and markers of atherosclerosis, MDA and PON-1 showed opposite associations with peripheral vasodilatory capacity and the presence of ED in RA. Further studies are needed to determine whether this association predicts atherosclerotic events in the RA population.

New horizons in arginine metabolism, ageing and chronic disease states.

The elucidation of the metabolic pathways of the amino acid arginine and their role in health and disease have been an intensive focus of basic and clinical research for over a century. The recent advent of robust analytical techniques for biomarker assessment in large population cohorts has allowed the investigation of the pathophysiological role of specific arginine metabolites in key chronic disease states in old age, particularly those characterised by a reduced synthesis of endothelial nitric oxide, with consequent vascular disease and atherosclerosis. Two arginine metabolites have been increasingly studied in regard to their potential role in risk stratification and in the identification of novel therapeutic targets: the methylated arginine asymmetric dimethylarginine (ADMA) and the arginine analogue homoarginine. Higher circulating concentrations of ADMA, a potent inhibitor of nitric oxide synthesis, have been shown to predict adverse cardiovascular outcomes. By contrast, there is emerging evidence that homoarginine might exert cardioprotective effects. This review highlights recent advances in the biological and clinical role of ADMA and homoarginine in cardiovascular disease and other emerging fields, particularly chronic obstructive pulmonary disease, dementia, and depression. It also discusses opportunities for future research directions with the ultimate goal of translating knowledge of arginine metabolism, and its role in health and disease, into the clinical care of older adults.

The neutrophil-to-lymphocyte ratio as a marker of chronic obstructive pulmonary disease and its exacerbations: A systematic review and meta-analysis.

INTRODUCTION: The main white blood cell populations, neutrophils and lymphocytes, are involved in the pathophysiology of chronic obstructive pulmonary disease (COPD). We conducted a systematic review and meta-analysis of studies investigating the relationship between the neutrophil to lymphocyte ratio (NLR, a marker of subclinical inflammation), presence of COPD, and its exacerbations. METHODS: A comprehensive literature search was conducted in Pubmed, Web of Science and Scopus databases; two investigators independently reviewed suitable studies. RESULTS: Nine studies, from 247 initially identified, were included in the meta-analysis. Seven studies, in 775 COPD patients with stable disease and 496 healthy controls, showed a significant increase in NLR values in stable COPD (standardised mean difference, SMD, 0.773, 95% CI 0.410-1.136; P < 0.001). Furthermore, in six studies in 527 COPD patients with acute exacerbation and 620 COPD patients with stable disease, NLR values were significantly higher in patients with exacerbations (random effects SMD 0.850, 95% CI 0.549-1.151; P < 0.001). CONCLUSIONS: Our meta-analysis showed that NLR values are significantly higher in stable COPD patients when compared to healthy individuals, although the magnitude of the difference is reduced after trim and fill adjustment, and in patients with COPD exacerbations when compared to patients with stable disease. Further studies, in larger cohorts, are needed to confirm whether the NLR is a useful tool in discriminating between COPD patients with stable disease, those with acute exacerbations, and subjects without the disease.

Evaluation of oxidative stress biomarkers in idiopathic pulmonary fibrosis and therapeutic applications: a systematic review.

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF), a fatal lung disease of unknown origin, is characterized by chronic and progressive fibrosing interstitial pneumonia which progressively impairs lung function. Oxidative stress is one of the main pathogenic pathways in IPF. The aim of this systematic review was to describe the type of markers of oxidative stress identified in different biological specimens and the effects of antioxidant therapies in patients with IPF. METHODS: We conducted a systematic search of publications listed in electronic databases (Pubmed, Web of Science, Scopus and Google Scholar) from inception to October 2017. Two investigators independently reviewed all identified articles to determine eligibility. RESULTS: After a substantial proportion of the initially identified articles (n = 554) was excluded because they were duplicates, abstracts, irrelevant, or did not meet the selection criteria, we identified 30 studies. In each study, we critically appraised the type, site (systemic vs. local, e.g. breath, sputum, expired breath condensate, epithelial lining fluid, bronchoalveolar lavage, and lung tissue specimens), and method used for measuring the identified oxidative stress biomarkers. Furthermore, the current knowledge on antioxidant therapies in IPF was summarized. CONCLUSIONS: A number of markers of oxidative stress, with individual advantages and limitations, have been described in patients with IPF. Nevertheless, trials of antioxidant treatments have been unable to demonstrate consistent benefits, barring recent pharmacogenomics data suggesting different results in specific genotype subgroups of patients with IPF.

Circulating serotonin levels in COPD patients: a pilot study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem. Serotonin is a neurotransmitter that participates in several pulmonary functions and it has been involved in oxidative stress, which plays essential roles in the pathogenesis of COPD. The current study aimed at establishing the levels of circulating serotonin in COPD, and investigating eventual relations between serotonin and oxidative stress markers. METHODS: Whole blood serotonin was assessed in 43 consecutive patients with stable COPD and in 43 age and sex-matched healthy controls. RESULTS: Serotonin blood levels were significantly higher in COPD patients than in controls (median 0.81 µmol/L, IQR: 0.61-4.02 vs 0.65 µmol/L, IQR: 0.53-1.39, p = 0.02). The univariate logistic regression analysis evidenced that serotonin levels are independently associated with presence of COPD (crude OR = 7.29, 95% CI: 1.296-41.05, p = 0.003) and such an association was confirmed also after adjusting for several confounders (OR 21.92, 95% CI 2.02-237.83; p = 0.011). CONCLUSIONS: Our study showed higher levels of circulating serotonin in COPD and an inverse correlation with the worsening of airway obstruction. Future studies are necessary to investigate the clinical utility of this finding.

Development of an LC⁻Tandem Mass Spectrometry Method for the Quantitative Analysis of Hercynine in Human Whole Blood.

Given that the peculiar redox behavior of ergothioneine involves a rapid regeneration process, the measurement of its precursor and redox metabolite hercynine could be particularly useful in assessing its role in oxidative stress or other biological processes. Thus, a LC-MS/MS method for the determination of hercynine concentrations in whole blood was developed. After lysis of red blood cells by cold water, samples were filtered on micro concentrators at a controlled temperature of 4 °C. The clear filtered fluid was then treated with diethylpyrocarbonate to derivatize hercynine for the analysis by LC-MS/MS. The derivatized analyte was isocratically separated as a carbethoxy derivative on a C18 column with a mobile phase of an aqueous 0.1% v/v formic acid and acetonitrile (95:5). Effluents were monitored by MRM transitions at m/z 270.28→95 and 273.21→95 for hercynine and its deuterated counterpart, respectively. No cross-talk between MRM transitions was observed and a good linearity was found within a range of 35⁻1120 nmol/L. The LOD and LOQ were, respectively, 10.30 and 31.21 nmol/L with an intraday and intermediate precision below 7%. The average hercynine concentration in whole blood from 30 healthy male volunteers (aged 77 ± 12 years) was 178.5 ± 118.1 nmol/L. Overall, the method is easy to perform, allowing a rapid and accurate assessment of whole blood concentrations of hercynine.

Blood global DNA methylation is decreased in non-severe chronic obstructive pulmonary disease (COPD) patients.

BACKGROUND: Alterations in global DNA methylation have been associated with oxidative stress (OS). Since chronic obstructive pulmonary disease (COPD) is characterized by increased oxidative stress we aimed to evaluate the levels of global DNA methylation in this patient group. METHODS: We assessed methylcytosine (mCyt) levels in DNA from blood collected in 43 COPD patients (29 with mild and 14 with moderate disease) and 43 age- and sex-matched healthy controls. RESULTS: DNA methylation was significantly lower in COPD patients vs. controls (4.20 ± 0.18% mCyt vs. 4.29 ± 0.18% mCyt, p = 0.02). Furthermore, DNA methylation in COPD patients with moderate disease was significantly lower than that in patients with mild disease (4.14 ± 0.15% mCyt vs. 4.23 ± 0.19% mCyt, p < 0.05). Univariate logistic regression analysis showed that lower DNA methylation levels were associated with presence of COPD (crude OR = 0.06, 95% CI 0.00 to 0.67, p = 0.023). This relationship remained significant after adjusting for several confounders (OR 0.03, 95% CI 0.00 to 0.67; p = 0.028). Receiver operating characteristics (ROC) curve analysis demonstrated the area under the curve of mCyt was 0.646, with 46.6% sensitivity and 79.1% specificity for presence of COPD. CONCLUSIONS: There were no significant correlations between methylation and OS indices. The presence and severity of COPD is associated with progressively lower DNA methylation in blood. However, this epigenetic alteration seems independent of oxidative stress.

N- and S-homocysteinylation reduce the binding of human serum albumin to catechins.

PURPOSE: The dietary flavonoids epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) have been shown to interact with circulating albumin for transport in blood to different body tissues. This interaction may modulate their bioavailability and effectiveness. METHODS: Using affinity capillary electrophoresis to assess binding constants (K b), we investigated whether posttranslational modification of human serum albumin (HSA) through N- and S-homocysteinylation, commonly observed in hyperhomocysteinemia, may modify its interaction with catechins. RESULTS: S-Hcy HSA had lower Kb values toward EC (14 %), EGC (18 %), ECG (24 %) and EGCG (30 %). Similarly, N-Hcy HSA had lower Kb values toward EC (17 %), EGC (22 %), ECG (23 %) and EGCG (32 %). No differences were observed in the affinity between catechins, albumin and mercaptalbumin. CONCLUSION: Therefore, HSA posttranslational modifications typical of hyperhomocysteinemia reduce its affinity to catechins, potentially affecting their pharmacokinetics and availability at the active sites.

Protective Effects of Methotrexate against Proatherosclerotic Cytokines: A Review of the Evidence.

There is good epidemiological evidence that patients with autoimmune rheumatic disease states, particularly rheumatoid arthritis, have an increased risk of cardiovascular morbidity and mortality when compared to the general population. The presence of a chronic systemic proinflammatory state in this patient group disrupts the structural and functional integrity of the endothelium and the arterial wall, favouring the onset and progression of atherosclerosis. A significant role in the detrimental effects of inflammation on endothelial function and vascular homeostasis is played by specific proatherosclerotic cytokines such as tumour necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), and interleukin-6 (IL-6). Recent systematic reviews and meta-analyses have shown that treatment with methotrexate, a first-line disease-modifying antirheumatic drug (DMARD), is associated with a significant reduction in atherosclerosis-mediated cardiovascular events, such as myocardial infarction and stroke, and mortality, when compared to other DMARDs. This suggests that methotrexate might exert specific protective effects against vascular inflammation and atherosclerosis in the context of autoimmune rheumatic disease. This review discusses the available evidence regarding the potential antiatherosclerotic effects of methotrexate through the inhibition of TNF-α, IL-1, and IL-6 and provides suggestions for future experimental and human studies addressing this issue.

Plasma protein thiols: an early marker of oxidative stress in asthma and chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) and asthma are both characterized by heterogeneous chronic airway inflammation and obstruction as well as oxidative stress (OS). However, it is unknown whether OS occurs in early disease and how to best assess its presence. Plasma OS markers (TBARS, PSH, taurine, GSH, ergothioneine and paraoxonase 1 activity) and lung function tests were measured in patients with mild stable asthma (n = 24) and mild stable COPD (n = 29) and in age- and sex-matched controls. Forced expiratory volume in 1 s (FEV1 ) was associated with age both in patients and control groups. By contrast, FEV1 was positively correlated with PSH only in COPD (ρ = 0·49, P = 0·007). In multiple logistic regression analysis, lower PSH was the only OS marker independently associated with increased odds of both asthma (OR = 0·32, 95% CI 0·13-0·78, P = 0·01) and COPD (OR = 0·50, 95% CI 0·26-0·95, P = 0·03). These findings suggest that proteins -SH are a sensitive OS marker in early COPD and asthma.

An isotope dilution capillary electrophoresis/tandem mass spectrometry (CE-MS/MS) method for the simultaneous measurement of choline, betaine, and dimethylglycine concentrations in human plasma.

Plasma concentrations of choline, betaine, and dimethylglycine provide valuable information on the flow of methyl groups in key biological processes, particularly during folate deficiency states. We developed a new method to simultaneously measure these analytes in human plasma. Following sample deproteinization using acetonitrile, an aliquot was evaporated to dryness under vacuum to be then taken up by water. Finally, analytes were separated by capillary electrophoresis and detected by electrospray ionization triple-quadrupole mass spectrometry, in multiple reaction monitoring mode, using two stable isotope-labeled internal standards. Linearity of the calibration curves of each analyte was good (R(2) > 0.99). Average limits of detection (LODs) and limits of quantification (LOQs) for choline, betaine, and dimethylglycine were, respectively, 0.43, 0.62, and 0.31 µmol/L and 1.52, 2.11, and 0.97 µmol/L. Mean recovery of three replicates of two spiked concentrations levels was close to 100 % for all of the analytes. Repeatability and intermediate precision, expressed as %RSD of measurements, were <9 %. The method, applied to measure analytes in samples from 30 patients with chronic kidney disease and 30 age- and sex-matched healthy controls, was able to detect differences between groups and the sexes.

Plasma concentrations of transthyretin in older Sardinians including centenarians.

BACKGROUND AND AIMS: Plasma concentrations of transthyretin (TTR), a negative acute-phase protein, can be influenced by many factors including aging. Under physiological circumstances, TTR concentrations are very low in the fetus, increase slowly after birth up to the fifth decade and, then, decrease slowly. Some studies have shown sex-related differences up to about 70 years, when the differences disappear. The aim of this study was to evaluate the change in TTR concentrations in healthy males and females aged more than sixty, including numerous centenarians living in Sardinia, a large Italian island located in the Mediterranean Sea. METHODS: The study sample consisted of 211 healthy subjects grouped by age and sex (male/female ratio: 1:1). Plasma TTR was assessed using a non-competitive enzyme immunoassay (ELISA Assaypro LLC, prealbumin AssayMAX Human ELISA Kit). RESULTS: In subjects aged between 60 and 99 years, plasma TTR concentrations were higher compared to the reference ranges reported by CRM 470. Moreover, unlike other studies, sex-related differences in TTR concentrations were only observed in nonagenarians and centenarians. CONCLUSIONS: We hypothesize that there are TTR-related genetic differences between the Sardinian population and other Caucasian ethnic groups. Further studies and a larger sample are needed to confirm our hypothesis.

Identification of the Main Intermediate Precursor of l-Ergothioneine Biosynthesis in Human Biological Specimens.

A capillary electrophoresis coupled to tandem mass spectrometry (CE-MS/MS) has been used to make a qualitative determination of hercynine-the main precursor of l-ergothioneine biosynthesis-in some key human biological specimens, such as urine, whole blood, plasma, and saliva. From semiquantitative analysis results, the highest concentrations of hercynine were detected in saliva and whole blood, whereas much lower concentrations were measured in urine and plasma. Whole blood was the biological matrix with the highest concentration of l-ergothioneine followed by plasma, saliva, and urine. The antioxidant effects attributed to l-ergothioneine, along with its peculiar antioxidant mechanism, offer a possible explanation for the presence of the hercynine, as well as its concentration, in the considered biological matrices.