Changes in Hepcidin Serum Levels Correlate with Clinical Improvement in Idiopathic Restless Legs Syndrome Patients

Associations of anxiety and depression with restless leg syndrome: a systematic review and meta-analysis

Background

The levels of anxiety and depression among patients with restless leg syndrome (RLS) are controversial. The aim of this systematic review and meta-analysis was to compare the levels of depression and anxiety among individuals with RLS with those of healthy controls.

Methods

We conducted an extensive electronic search of the PubMed, Web of Science, EMBASE, and Cochrane Library databases from their inception dates to 20 June 2023. Studies presenting data on depression and anxiety in individuals with RLS were included, and a comprehensive meta-analysis was performed.

Results

Twenty-one studies matched the inclusion criteria. Significantly more depressive symptoms were present in the individuals with RLS than in those without RLS, as measured by the Beck Depression Inventory [mean difference (MD) = 6.58, 95% confidence interval (CI) = 5.54-7.62, p < 0.01; heterogeneity I2 = 0%, p = 0.99]. Similarly, the results from the Beck Anxiety Inventory indicated that there were significantly more pronounced anxiety symptoms in the individuals with RLS than in those without RLS (MD = 9.30, 95%CI = 7.65-10.94, p < 0.01; heterogeneity I2 = 0%, p = 0.92). The other anxiety and depression scales also yielded statistically significant results. Significant heterogeneity was observed in the Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale, with the primary contributing factor probably being the scoring criteria of the scales.

Conclusion

This meta-analysis found that the levels of depression and anxiety symptoms were significantly higher in individuals with RLS than in their healthy counterparts.Systematic review registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023410364, (identifier CRD42023410364).

Review of the role of the endogenous opioid and melanocortin systems in the restless legs syndrome

Restless legs syndrome (RLS) is responsive to opioid, dopaminergic and iron-based treatments. Receptor blocker studies in RLS patients suggest that the therapeutic efficacy of opioids is specific to the opioid receptor and mediated indirectly through the dopaminergic system. An RLS autopsy study reveals decreases in endogenous opioids, β-endorphin and perhaps Met-enkephalin in the thalamus of RLS patients. A total opioid receptor knock-out (mu, delta and kappa) and a mu-opioid receptor knock-out mouse model of RLS show circadian motor changes akin to RLS and, although both models show sensory changes, the mu-opioid receptor knock mouse shows circadian sensory changes closest to those seen in idiopathic RLS. Both models show changes in striatal dopamine, anaemia and low serum iron. However, only in the total receptor knock-out mouse do we see the decreases in serum ferritin that are normally found in RLS. There are also decreases in serum iron when wild-type mice are administered a mu-opioid receptor blocker. In addition, the mu-opioid receptor knock-out mouse also shows increases in striatal zinc paralleling similar changes in RLS. Adrenocorticotropic hormone and α-melanocyte stimulating hormone are derived from pro-opiomelanocortin as is β-endorphin. However, they cause RLS-like symptoms and periodic limb movements when injected intraventricularly into rats. These results collectively suggest that an endogenous opioid deficiency is pathogenetic to RLS and that an altered melanocortin system may be causal to RLS as well.

Evaluation of the relationship between idiopathic restless legs syndrome and serum hepcidin levels

INTRODUCTION

The relationship between restless legs syndrome (RLS) and iron deficiency is a well-known topic. However, the etiology of the disease has not been determined. As the central iron deficiency is the most critical biological abnormality for RLS, we planned a study examining the relationship between RLS and hepcidin, which is the only regulatory hormone of iron metabolism known so far.

METHODS

International Restless Legs Syndrome Study Group diagnostic criteria (2014) were taken as a basis. A total of 40 RLS patients and 40 healthy controls were included in the study. To avoid the potential variables that might cause secondary RLS, all the participants were asked to provide hemogram, ferritin, iron, thyroid function tests, and sedimentation analysis. The hepcidin levels were measured with a Human Hepcidin (Hepc 25) ELISA kit (MyBioSource).

RESULTS

The statistically significant results of our analysis show that the red blood cell count, the neutrophil count, the percentage of lymphocytes and neutrophils, and, more distinctively, hepcidin levels were higher in RLS patients in comparison with the control group.

CONCLUSION

In this study, no differences were found in iron and ferritin values. High levels of hepcidin, the main regulator of iron metabolism, in those with primary RLS support the possibility that hepcidin may play a role in the pathogenesis of RLS. We think that larger studies on this subject can give clearer ideas.

Diagnostic performance of artificial intelligence approved for adults for the interpretation of pediatric chest radiographs

Artificial intelligence (AI) applied to pediatric chest radiographs are yet scarce. This study evaluated whether AI-based software developed for adult chest radiographs can be used for pediatric chest radiographs. Pediatric patients (≤ 18 years old) who underwent chest radiographs from March to May 2021 were included retrospectively. An AI-based lesion detection software assessed the presence of nodules, consolidation, fibrosis, atelectasis, cardiomegaly, pleural effusion, pneumothorax, and pneumoperitoneum. Using the pediatric radiologist’s results as standard reference, we assessed the diagnostic performance of the software. For the total 2273 chest radiographs, the AI-based software showed a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 67.2%, 91.1%, 57.7%, 93.9%, and 87.5%, respectively. Age was a significant factor for incorrect results (odds radio 0.821, 95% confidence interval 0.791–0.851). When we excluded cardiomegaly and children 2 years old or younger, sensitivity, specificity, PPV, NPV and accuracy significantly increased (86.4%, 97.9%, 79.7%, 98.7% and 96.9%, respectively, all p < 0.001). In conclusion, AI-based software developed with adult chest radiographs showed diagnostic accuracies up to 96.9% for pediatric chest radiographs when we excluded cardiomegaly and children 2 years old or younger. AI-based lesion detection software needs to be validated in younger children.

Rhythm- or rate-control strategies according to 4S-AF characterization scheme and long-term outcomes in atrial fibrillation patients: the FAMo (Fibrillazione Atriale in Modena) cohort

The 4S-AF scheme [Stroke risk, Symptom severity, Severity of atrial fibrillation (AF) burden, Substrate severity] was recently proposed to characterize AF patients. In this post hoc analysis we evaluated the agreement between the therapeutic strategy (rate or rhythm control, respectively), as suggested by the 4S-AF scheme, and the actual strategy followed in a patients cohort. Outcomes of interest were as follows: all-cause death, a composite of all-cause death/any thromboembolism/acute coronary syndrome, and a composite of all-cause death, any thrombotic/ischemic event, and major bleeding (net clinical outcome). We enrolled 615 patients: 60.5% male, median age 74 [interquartile range (IQR) 67-80] years; median CHA₂DS₂VASc 4 and median HAS-BLED 2. The 4S-AF score would have suggested a rhythm-control strategy in 351 (57.1%) patients while a rate control in 264 (42.9%). The strategy adopted was concordant with the 4S-AF suggestions in 342 (55.6%) cases, and non-concordant in 273 (44.4%). After a median follow-up of 941 days (IQR 365-1282), 113 (18.4%) patients died, 158 (25.7%) had an event of the composite endpoint. On adjusted Cox regression analysis, when 4S-AF score suggested rate control, disagreement with that suggestion was not associated with a worse outcome. When 4S-AF indicated rhythm control, disagreement was associated with a higher risk of all-cause death (HR 7.59; 95% CI 1.65-35.01), and of the composite outcome (HR 2.69; 95% CI 1.19-6.06). The 4S-AF scheme is a useful tool to comprehensively evaluate AF patients and aid the decision-making process. Disagreement with the rhythm control suggestion of the 4S-AF scheme was associated with adverse clinical outcomes.

A simple immunoassay for extracellular vesicle liquid biopsy in microliters of non-processed plasma

BACKGROUND

Extracellular vesicles (EVs), released by most cell types, provide an excellent source of biomarkers in biological fluids. However, in order to perform validation studies and screenings of patient samples, it is still necessary to develop general techniques permitting rapid handling of small amounts of biological samples from large numbers of donors.

RESULTS

Here we describe a method that, using just a few microliters of patient's plasma, identifies tumour markers exposed on EVs. Studying physico-chemical properties of EVs in solution, we demonstrate that they behave as stable colloidal suspensions and therefore, in immunocapture assays, many of them are unable to interact with a stationary functionalised surface. Using flocculation methods, like those used to destabilize colloids, we demonstrate that cationic polymers increase EV ζ-potential, diameter, and sedimentation coefficient and thus, allow a more efficient capture on antibody-coated surfaces by both ELISA and bead-assisted flow cytometry. These findings led to optimization of a protocol in microtiter plates allowing effective immunocapture of EVs, directly in plasma without previous ultracentrifugation or other EV enrichment. The method, easily adaptable to any laboratory, has been validated using plasma from lung cancer patients in which the epithelial cell marker EpCAM has been detected on EVs.

CONCLUSIONS

This optimized high throughput, easy to automate, technology allows screening of large numbers of patients to phenotype tumour markers in circulating EVs, breaking barriers for the validation of proposed EV biomarkers and the discovery of new ones.

Relation of Serum Hepcidin Levels and Restless Legs Syndrome in Patients Undergoing Peritoneal Dialysis

Introduction: Restless legs syndrome is a common and severe complication in patients undergoing peritoneal dialysis (PD), which seriously affects the life quality and prognosis of patients undergoing PD. Unfortunately, there are still no effective prevention and treatment measures. Serum hepcidin was demonstrated to be related to primary restless legs syndrome (RLS), whereas there are no studies on the relationship between serum hepcidin and RLS in patients undergoing PD. We aimed to evaluate the role and function of serum hepcidin in patients undergoing PD with RLS.

Methods: A total of 51 patients undergoing PD with RLS and 102 age-and gender-matched patients undergoing PD without RLS were included. We collected the clinical data including serum hepcidin of those patients undergoing PD. We scored the severity of RLS according to the International restless leg Syndrome Research Group rating scale (IRLS). We compared the clinical characteristics of the two groups and evaluated the determinant factors of RLS by Logistic regression analysis. In addition, we evaluated the diagnostic value of serum hepcidin in patients undergoing PD with RLS by receiver operating characteristic (ROC) curve. We also analyzed the influencing factors of IRLS by multivariate linear regression analysis.

Results: The duration of PD, serum hepcidin, and calcium were found to be significantly higher in patients undergoing PD with RLS than those patients undergoing PD without RLS (P < 0.001, P < 0.001, and P = 0.002, respectively). The level of hemoglobin, albumin, and RKF were significantly lower in patients undergoing PD with RLS (P = 0.002, P = 0.042, and P < 0.001, respectively). The duration of PD [odds ratio (OR) 1.038, 95% CI: 1.017, 1.060, P < 0.001], hemoglobulin level (OR 0.969, 95% CI: 0.944, 0.995, P = 0.019), calcium level (OR 9.224, 95% CI: 1.261, 67.450, P = 0.029), albumin level (OR 0.835, 95% CI: 0.757, 0.921, P < 0.001), hepcidin level (OR 1.023, 95% CI: 1.009, 1.038, P = 0.001), and RKF (OR 0.65, 95% CI: 0.495, 0.856, P = 0.002) are independent determinant factors of RLS in patients undergoing PD. Multivariate linear regression analysis revealed that, in addition to albumin, they were also independently associated with the severity of RLS.

Conclusion: A significant relation was detected between serum hepcidin level and RLS in patients undergoing PD.

Unfractionated Heparin Attenuated Histone-Induced Pulmonary Syndecan-1 Degradation in Mice: a Preliminary Study on the Roles of Heparinase Pathway

Endothelial glycocalyx degradation is thought to facilitate the development of sepsis. Histone is a significant mediator in sepsis. Unfractionated heparin (UFH) possessed beneficial effects on sepsis. Thereby, this study aims to figure out whether histone can disrupt glycocalyx and to investigate the protective effect and mechanism of UFH. Male mice (C57BL/6, 8-10 weeks old, weighing 20-25 g) were randomly divided into five groups including control group, histone group, histone + UFH group, histone + heparinase (HPA) inhibitor group, and histone + UFH + HPA inhibitor group. The mice were treated with histone (50 mg/kg) via tail vein immediately after HPA (20 mg/kg) injection. UFH (400 U/kg) was injected 1h after histone administration. The other groups were injected with equal volume of sterile saline accordingly. UFH alleviated histone-induced lung injury and pulmonary edema. UFH inhibited histone-induced lung coagulation activation and inflammatory response. UFH treatment markedly inhibited pulmonary glycocalyx degradation by reducing the histone-induced decrease in the levels of lung syndecan-1 mRNA and protein. UFH downregulated histone-induced expression of HPA mRNA and protein, and thus alleviated glycocalyx degradation. UFH protects against histone-induced pulmonary glycocalyx injury partly by heparinase pathway.