Thiol/disulphide homeostasis in intensive care unit patients with sepsis and septic shock

Oxidative stress and anti-oxidant status in children with sepsis

BACKGROUND

Sepsis is a life-threating cause in childhood ages. The recognition and treatment early are significant for decreasing mortality. Sepsis has many factors and various biomarkers function in the pathogenesis, the stress indicators oxidants increased and antioxidants decreased. The objective of our study was to investigate the levels of thiol disulfides with and without sepsis in a pediatric intensive care unit (PICU).

MATERIALS AND METHODS

A cohort study was conducted between October 2022 and March 2023 at the PICU, comprising 64 with sepsis and 62 children without sepsis. Blood samples from sepsis and the control group were collected and centrifuged. Subsequently, the samples were stored at -80 °C until the day of the experiment. Once the requisite number of patients had been enrolled, the thiol-disulfide values in the collected samples were analysed in accordance with the ELISA kit method.

RESULTS

The research parameters investigated, namely total oxidant status, plasma 8-OHdG, total-native thiol and native/total thiol percent ratio, were found to be considerably elevated in the sepsis group in comparison to the control (p < 0.05). Furthermore, the oxidative stress parameters investigated (total antioxidant status, paraoxonase 1 activity, disulfide, disulfide/native thiol percent ratio, disulfide/total thiol percent ratio) were found to be significantly lower in the sepsis group than in control (p < 0.05).

CONCLUSIONS

In our study as well, we detected all antioxidant parameters are low and oxidant parameters are statistically significantly higher in sepsis. Our study posits that thiol-disulfide levels have the potential to serve as a diagnostic tool in conjunction with traditional established biomarkers of inflammation in critically ill children in the PICU who are being treated for sepsis.

CLINICAL TRIAL REGISTRATION

Not applicable.

A Droplet Microfluidic Sensor for Point-of-Care Measurement of Plasma/Serum Total Free Thiol Concentrations

Total free thiols are an important marker of the whole-body redox state, which has been shown to be associated with clinical outcome in health and disease. Recent investigations have suggested that increased insight may be gained by monitoring alterations of redox state in response to exercise and hypoxia and to monitor redox trajectories in disease settings. However, conducting such studies is challenging due to the requirement for repeated venous blood sampling and intensive lab work. Droplet microfluidic sensors offer an alternative platform for developing a point-of-care testing approach using small sample volumes and automated systems to complement or ultimately replace laboratory testing. Here we developed a small, portable droplet microfluidic sensor that can measure total free thiol concentrations in 20 μL human plasma (or serum) samples, providing a reading in less than 10 min. This system features a novel method to enhance the mixing of reagent and analyte in droplets containing viscous biological fluids. The results in a range of real-world human plasma samples showed equivalence with current standard laboratory assays while reducing sample volume requirements 9-fold and fully automating the process. Micro hematocrit capillaries allowed testing of capillary blood samples collected by fingerprick lancing. The system was used to monitor total free thiols using fingerprick samples in healthy volunteers and revealed significant changes in total free thiols in response to food intake and exercise. This device has the potential to improve our ability to conduct physiological studies of total free thiol level changes and improve our understanding of redox physiology, which may ultimately be applied in redox medicine to improve patient care.

Oxidative stress, defective proteostasis and immunometabolic complications in critically ill patients

Oxidative stress (OS) develops in critically ill patients as a metabolic consequence of the immunoinflammatory and degenerative processes of the tissues. These induce increased and/or dysregulated fluxes of reactive species enhancing their pro-oxidant activity and toxicity. At the same time, OS sustains its own inflammatory and immunometabolic pathogenesis, leading to a pervasive and vitious cycle of events that contribute to defective immunity, organ dysfunction and poor prognosis. Protein damage is a key player of these OS effects; it generates increased levels of protein oxidation products and misfolded proteins in both the cellular and extracellular environment, and contributes to forms DAMPs and other proteinaceous material to be removed by endocytosis and proteostasis processes of different cell types, as endothelial cells, tissue resident monocytes-macrophages and peripheral immune cells. An excess of OS and protein damage in critical illness can overwhelm such cellular processes ultimately interfering with systemic proteostasis, and consequently with innate immunity and cell death pathways of the tissues thus sustaining organ dysfunction mechanisms. Extracorporeal therapies based on biocompatible/bioactive membranes and new adsorption techniques may hold some potential in reducing the impact of OS on the defective proteostasis of patients with critical illness. These can help neutralizing reactive and toxic species, also removing solutes in a wide spectrum of molecular weights thus improving proteostasis and its immunometabolic corelates. Pharmacological therapy is also moving steps forward which could help to enhance the efficacy of extracorporeal treatments. This narrative review article explores the aspects behind the origin and pathogenic role of OS in intensive care and critically ill patients, with a focus on protein damage as a cause of impaired systemic proteostasis and immune dysfunction in critical illness.

Utility of thiol/disulphide homeostasis as a biomarker for acute appendicitis: a systematic review and meta-analysis

The aim of this study was to analyze the role of thiol/disulfide homeostasis (TDH) parameters as an indicator of oxidative stress in acute appendicitis (AA). PubMed, EMBASE, Web of Science, and Scopus databases were systematically searched. Studies reporting on TDH in AA (both complicated and uncomplicated cases) were included. The comparator group were healthy controls. The TDH domain was compared between the groups using anti-oxidant parameters, namely native thiol and total thiol levels, and native thiol/total thiol ratio; and oxidant parameters, namely disulfide level, disulfide/native thiol ratio, and disulfide/total thiol ratio. The statistical analysis was performed using a random-effects model. The methodological quality of the studies was assessed utilizing the Newcastle-Ottawa scale. Eleven studies with a total of 926 subjects, comprising 457 patients with uncomplicated appendicitis, 147 with complicated appendicitis, and 322 healthy controls were included. Our study demonstrated significantly increased oxidative stress in AA as compared to healthy controls in all TDH parameters and significantly lower total thiol levels in complicated AA as compared to uncomplicated AA. Due to a poor methodological quality in five out of eleven studies, future prospective studies with adequate power are essential to validate these observations and refine the diagnostic approaches to AA.

Deep phenotyping of oxidative stress in emergency room patients reveals homoarginine as a novel predictor of sepsis severity, length of hospital stay, and length of intensive care unit stay

Background

We aimed to determine primary markers of oxidative stress (OS) in ED patients which predict hospital length of stay (LoS), intensive care unit (ICU) LoS, and sepsis severity.

Materials and methods

This prospective, single center observational study was conducted in adult patients recruited from the ED who were diagnosed with either sepsis, infection without sepsis, or non-infectious, age-matched controls. 290 patients were admitted to the hospital and 24 patients had direct admission to the ICU. A panel of 269 OS and related metabolic markers were profiled for each cohort. Clinical outcomes were direct ICU admission, hospital LoS, ICU LoS, and post-hoc, adjudicated sepsis severity scoring. Bonferroni correction was used for pairwise comparisons. Principal component regression was used for dimensionality reduction and selection of plasma metabolites associated with sepsis. Multivariable negative binomial regression was applied to predict admission, hospital, and ICU LoS.

Results

Homoarginine (hArg) was the top discriminator of sepsis severity [sepsis vs. control: ROC-AUC = 0.86 (95% CI 0.81-0.91)], [sepsis vs. infection: ROC-AUC = 0.73 (95% CI 0.68-0.78)]. The 25th percentile of hArg [odds ratio (OR) = 8.57 (95% CI 1.05-70.06)] was associated with hospital LoS [IRR = 2.54 (95% CI 1.83-3.52)] and ICU LOS [IRR = 18.73 (95% CI 4.32-81.27)]. In prediction of outcomes, hArg had superior performance compared to arginine (Arg) [hArg ROC-AUC = 0.77 (95% CI 0.67-0.88) vs. Arg ROC-AUC = 0.66 (95% CI 0.55-0.78)], and dimethylarginines [SDMA ROC-AUC 0.68 (95% CI 0.55-0.79) and ADMA ROC-AUC = 0.68 (95% CI 0.56-0.79)]. Ratio of hArg and Arg/NO metabolic markers and creatinine clearance provided modest improvements in clinical prediction.

Conclusion

Homoarginine is associated with sepsis severity and predicts hospital and ICU LoS, making it a useful biomarker in guiding treatment decisions for ED patients.

Thiol-Disulfide Homeostasis in Neonatal Patients with Urinary Tract Infection

OBJECTIVE

Urinary tract infection (UTI) is a disease that can cause significant complications in the neonatal period. The thiol-disulfide homeostasis is one of the important antioxidant defense mechanisms. The purpose of this study is to show the relationship between UTI and thiol-disulfide homeostasis in newborns.

STUDY DESIGN

In this prospective study, 40 newborns with UTI and 40 healthy controls were included. Thiol-disulfide tests (disulfide, native thiol, and total thiol levels) and septic screening tests were performed before and after antibiotherapy in UTI group. The control group was selected from healthy newborns who applied to the outpatient clinic.

RESULTS

The C-reactive protein and interleukin-6 levels were higher, while native thiol and native thiol/total thiol ratio were significantly lower in pretreatment group compared with posttreatment and control group. Also, the levels of disulfide, ischemia modified albumin, disulfide/native thiol ratio, and disulfide/total thiol ratio were higher in pretreatment group compared with posttreatment group.

CONCLUSION

The thiol-disulfide homeostasis is an important indicator of oxidative stress during infections. It is valuable to be detected with small amounts of serum in newborns. These molecules can be used to support the diagnosis of UTI in the newborn. Further studies are needed to define the role of thiol-disulfide homeostasis in the UTI of newborn.

KEY POINTS

· The thiol-disulfide homeostasis can be an important indicator of oxidative stress during infections such as UTI.. · The thiol-disulfide homeostasis of newborn is valuable to be detected with small amounts of serum in neonatal period.. · Laboratory tests such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein are not significantly different in UTIs..

Role of thiol-disulfide hemostasis in early diagnosis of acute mesentery ischemia: An experimental study

BACKGROUND

Acute mesenteric ischemia (AMI) is a rarely observed acute abdominal disease that may be mortal and is difficult to diagnose early. The aim of our study is to assess the role of Thiol-Disulphide Haemostasis (TDH), a new method for AMI which still has no specific biochemical markers for early diagnosis, and to assess it together with Ischemia-Modified Albumin (IMA) which has previously proven reliability for AMI.

METHODS

The study included 32 Wistar albino rats in four groups. The 1st group (n=8) was the control group, 2nd group (n=8) was the sham group, 3rd group (n=8) had 3 h of arterial mesentery ischemia and the 4th group (n=8) had 6 h of arterial mesentery ischemia. TDH, IMA, and serum lactate values were measured at h 0, 1, 3, and 6.

RESULTS

In the 3rd and 6th h, serum total thiol and native thiol values significantly reduced (p<0.001), while serum disulfide, IMA, and lactate values clearly increased (p<0.001). Serum thiol values were observed to reduce from the 1st h.

CONCLUSION

TDH changes in the early period of AMI. The TDH parameters can be used with IMA as diagnostic parameters for patients with suspected AMI in the early period.