Comparing FGFR-3 and TS-HDS Seropositive Small Fiber Neuropathy: Unique Patient Features, Symptoms, Laboratory, and Nerve Conduction Study Findings.

OBJECTIVES: Small fiber neuropathy presents a significant diagnostic and therapeutic challenge. To solve this challenge, efforts have been made to identify autoantibodies associated with this condition. Previous literature has often considered tri-sulfated heparin disaccharide (TS-HDS) and fibroblast growth factor receptor 3 (FGFR3) as a singular seropositive group and/or focused primarily on symptomatic associations. METHODS: One hundred seventy-two small fiber neuropathy patients with a Washington University Sensory Neuropathy panel were selected for TS-HDS seropositivity, FGFR-3 seropositivity, and seronegative controls. Data were collected to on the demographic, symptomatic, and laboratory profiles of each subgroup. RESULTS: Percent female (P = 0.0043), frequency of neuropathic pain symptoms (P = 0.0074), and erythrocyte sedimentation rate (P = 0.0293), vitamin D (P < 0.0001), and vitamin B12 (P = 0.0033) differed between the groups. Skin biopsy was more frequently normal within both the FGFR-3 and the TS-HDS cohort (P = 0.0253). CONCLUSIONS: TS-HDS and FGFR-3 display a distinct phenotype from both controls and one another. Immunoglobulin M (IgM) against FGFR-3 and IgM against TS-HDS may be individually valuable markers for the development of distinct clinical phenotypes.

Association between plasma glycocalyx component levels and poor prognosis in severe influenza type A (H1N1).

Influenza A virus infection causes a series of diseases, but the factors associated with disease severity are not fully understood. Disruption of the endothelial glycocalyx contributes to acute lung injury in sepsis, but has not been well studied in H1N1 influenza. We aim to determine whether the plasma glycocalyx components levels are predictive of disease severity in H1N1 influenza. This prospective observational study included 53 patients with influenza A (H1N1) during the influenza season, and 30 healthy controls in our hospital. Patients were grouped by severity and survival. We collected clinical data and blood samples at admission. Inflammatory factors (tumor necrosis factor-α, interleukin-6, interleukin-10) and endothelial glycocalyx components (syndecan-1, hyaluronan, heparan sulfate) were measured. The plasma levels of syndecan-1, hyaluronan, and heparan sulfate were significantly higher in patients with severe influenza A (H1N1) than in mild cases. Syndecan-1 and hyaluronan were positively correlated with disease severity, which was indicated by the APACHE II and SOFA scores and lactate levels, and negatively correlated with albumin levels. At a cutoff point ≥ 173.9 ng/mL, syndecan-1 had a 81.3% sensitivity and 70.3% specificity for predicting of 28-day mortality. Kaplan-Meier analysis demonstrated a strong association between syndecan-1 levels and 28-day mortality (log-rank 11.04, P = 0.001). Elevated plasma levels of syndecan-1 has a potential role in systemic organ dysfunction and may be indicative of disease severity in patients with influenza A (H1N1).

Distinctive Biomarker Features in the Endotheliopathy of COVID-19 and Septic Syndromes.

BACKGROUND: Endotheliopathy is a key element in COVID-19 pathophysiology, contributing to both morbidity and mortality. Biomarkers distinguishing different COVID-19 phenotypes from sepsis syndrome remain poorly understood. OBJECTIVE: To characterize circulating biomarkers of endothelial damage in different COVID-19 clinical disease stages compared with sepsis syndrome and normal volunteers. METHODS: Patients with COVID-19 pneumonia (n = 49) were classified into moderate, severe, or critical (life-threatening) disease. Plasma samples were collected within 48 to 72 h of hospitalization to analyze endothelial activation markers, including soluble Vascular Cell Adhesion Molecule-1 (sVCAM-1), von Willebrand Factor (VWF), A disintegrin-like and metalloprotease with thrombospondin type 1 motif no. 13 (ADAMTS-13) activity, thrombomodulin (TM), and soluble TNF receptor I (sTNFRI); heparan sulfate (HS) for endothelial glycocalyx degradation; C5b9 deposits on endothelial cells in culture and soluble C5b9 for complement activation; circulating dsDNA for neutrophil extracellular traps (NETs) presence, and α2-antiplasmin and PAI-1 as parameters of fibrinolysis. We compared the level of each biomarker in all three COVID-19 groups and healthy donors as controls (n = 45). Results in critically ill COVID-19 patients were compared with other intensive care unit (ICU) patients with septic shock (SS, n = 14), sepsis (S, n = 7), and noninfectious systemic inflammatory response syndrome (NI-SIRS, n = 7). RESULTS: All analyzed biomarkers were increased in COVID-19 patients versus controls (P < 0.001), except for ADAMTS-13 activity that was normal in both groups. The increased expression of sVCAM-1, VWF, sTNFRI, and HS was related to COVID-19 disease severity (P < 0.05). Several differences in these parameters were found between ICU groups: SS patients showed significantly higher levels of VWF, TM, sTNFRI, and NETS compared with critical COVID-19 patients and ADAMTS-13 activity was significantly lover in SS, S, and NI-SIRS versus critical COVID-19 (P < 0.001). Furthermore, α2-antiplasmin activity was higher in critical COVID-19 versus NI-SIRS (P < 0.01) and SS (P < 0.001), whereas PAI-1 levels were significantly lower in COVID-19 patients compared with NI-SIRS, S, and SS patients (P < 0.01). CONCLUSIONS: COVID-19 patients present with increased circulating endothelial stress products, complement activation, and fibrinolytic dysregulation, associated with disease severity. COVID-19 endotheliopathy differs from SS, in which endothelial damage is also a critical feature of pathobiology. These biomarkers could help to stratify the severity of COVID-19 disease and may also provide information to guide specific therapeutic strategies to mitigate endotheliopathy progression.

High Level of Serum and Cerebrospinal Fluid of Heparan Sulfate and Hyaluronic Acid Might Be a Biomarker of Severity of Neuromyelitis Optica.

Background: Neuromyelitis optica (NMO), multiple sclerosis (MS) and autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy are idiopathic inflammatory demyelinating diseases (IIDDs) that mainly present as encephalomyelitis. Heparan sulfate (HS) and hyaluronic acid (HA) are two components of glycocalyx, a carbohydrate-rich layer on the surface of blood vessels that mediates interaction with blood. Degradation of glycocalyx in NMO is poorly understood. Purpose: To detect the serum and cerebrospinal fluid (CSF) levels of shed HS and HA and to correlate these levels with disease severity to determine their diagnostic value. Methods: We obtained serum and CSF samples from 24 NMO patients, 15 MS patients, 10 autoimmune GFAP astrocytopathy patients, and 18 controls without non-inflammatory neurological diseases. Soluble HS and HA, and IFNγ, IL17A, and matrix metalloproteinase (MMP) 1 were detected via ELISA. Results: Serum and CSF levels of HS, HA and related cytokines but not of plasma MMP1 were significantly elevated in these diseases. Notably, HS and HA levels were positively correlated with Expanded Disability Status Scale scores. Conclusions: Our results indicate glycocalyx degradation and inflammation in NMO, MS and autoimmune GFAP astrocytopathy. Moreover, increased shedding of HS or HA may indicate a worse clinical situation. Furthermore, therapeutic strategies that protect glycocalyx may be effective in these diseases.

A Randomized, Multicenter, Open-Label, Blinded End Point, Phase 2, Feasibility, Efficacy, and Safety Trial of Preoperative Microvascular Protection in Patients Undergoing Major Abdominal Surgery.

BACKGROUND: The endothelial glycocalyx, a carbohydrate-rich layer coating all endothelial surfaces, plays a fundamental role in the function of microcirculation. The primary aim of this study was to evaluate the feasibility of using dexamethasone and albumin to protect the endothelial glycocalyx in patients undergoing abdominal surgery. Secondary and exploratory outcomes included efficacy and safety. METHODS: We conducted a multicenter, open-label, blinded end point, phase 2, randomized trial. Patients undergoing colorectal, pancreas, or liver surgery were recruited and randomized to receive either intravenous dexamethasone (16 mg) and 20% albumin (100 mL) at induction of anesthesia, then 200 mL of 20% albumin with each subsequent 1000 mL of crystalloid administered (dexamethasone and albumin [Dex-Alb] group), or crystalloid fluid only with no dexamethasone (control group). Feasibility end points included patient recruitment and retention, consent rate, and successful study drug administration. The primary efficacy end point was the measurement of plasma syndecan-1 level on postoperative day (POD) 1, and secondary end points were heparan sulfate levels and inflammatory markers measured at 4 perioperative timepoints. Safety end points included errors in administration of the intervention, hyperglycemia, occurrence of postoperative complications, and patient retention. RESULTS: Seventy-two patients were randomized. All feasibility end points were achievable. There were no statistically significant differences observed in median (interquartile range) syndecan-1 levels on POD 1 (39 ng·mL-1 [20-97] in the Dex-Alb group versus 41 ng·mL-1 [19-84] in the control group; difference in medians -2.1, 95% confidence interval [CI], -13 to 8.6; P = .69). The Dex-Alb group had lower POD 1 heparan sulfate levels (319 ng·mL-1 [161-717] in the Dex-Alb group versus 1422 [670-2430] ng·mL-1 in the control group; difference in medians -1085, 95% CI, -1779 to -391) and C-reactive protein (CRP) levels on POD 1 (48 [29-77] mg·L-1 in the Dex-Alb group versus 85 mg·L-1 [49-133] in the control group; difference in medians -48, 95% CI, -75 to -21). Fewer patients had one or more postoperative complication in the Dex-Alb group than in the control group (6 [17%] vs 18 patients [50%]; odds ratio = 0.2, 95% CI, 0.06-0.6). CONCLUSIONS: Intravenous dexamethasone and albumin administration was feasible but did not reduce syndecan-1 on POD 1 in patients undergoing abdominal surgery. Given the clinically important CIs observed between the groups for heparan sulfate, CRP, and postoperative complications, a larger trial assessing the associations between dexamethasone and albumin administration and these outcomes is warranted.

External quality assessment in the absence of proficiency testing: A split-sample testing program experience.

In the field of laboratory medicine, proficiency testing is a vehicle used to improve the reliability of reported results. When proficiency tests are unavailable for a given analyte, an alternative approach is required to ensure adherence to the International Organization for Standardization (ISO) 15189:2012 standard. In this study, we report the results of a split-sample testing program performed as an alternative to a formal PT. This testing method was based on recommendations provided in the Clinical and Laboratory Standards Institute (CLSI) QMS24 guideline. Two different laboratories measured, in duplicate, the heparan sulfate concentration in five samples using ultra-performance liquid chromatography and tandem mass spectrometry. The data analysis to determine the criterion used for the comparability assessment between the two laboratories was based on Appendix E of the QMS24 guideline. Mean interlaboratory differences fell within the maximum allowable differences calculated from the application of the QMS24 guideline, indicating that the results obtained by the two laboratories were comparable across the concentrations tested. Application of the QMS24 split-sample testing procedure allows laboratories to objectively assess test results, thus providing the evidence needed to face an accreditation audit with confidence. However, due to the limitations of statistical analyses in small samples (participants and/or materials), laboratory specialists should assess whether the maximum allowable differences obtained are suitable for the intended use, and make adjustments if necessary.

Prophylactic Norepinephrine Infusion Reduces Postoperative Complications and Hospitalization Time in Elderly Patients Undergoing Posterior Lumbar Spinal Fusion.

This single-center prospective randomized controlled trial explores the effect of prophylactic norepinephrine infusion on the incidence of complications and hospitalization time in elderly patients (60-85 years old) undergoing posterior lumbar spinal fusion. In total, 129 elderly patients were randomized into two groups: a group that received norepinephrine during general anesthesia and a control group not receiving norepinephrine. The primary outcomes were in-hospital complications and 90-day postoperative complications and hospitalization time. The results show that in-hospital complications occurred in 24 of 60 patients (40%) in the control group versus 11 of 60 patients (18.3%) in the norepinephrine group (RR, 2.182; 95% CI, 1.177-4.045; P = 0.015). Cardiac events occurred significantly more frequently in the control than in the norepinephrine group. Total number of patients experiencing complications within 90 days postoperatively was lower in the norepinephrine (11 of 60; 18.3%) than in the control group (26 of 60; 43.3%; RR, 2.364; 95% CI, 1.288-4.339; P = 0.005). The median length of hospital stay was 17 days (11-27) in the control group and 15 days (10- 23) in the norepinephrine group (P = 0.01). The secondary outcomes were serum levels of syndecan-1, hyaluronic acid, heparan sulfate, and brain natriuretic peptide. Logistic regression analysis is used to describe the relationship between selected independent variables and in-hospital complications. Intraoperative total fluid, crystalloid, and colloid volumes were significantly higher in the control than in the norepinephrine group. The patients in the norepinephrine group had a higher MAP but a lower heart rate than those in the control group after the induction of anesthesia and intraoperatively. Syndecan-1, hyaluronic acid, and heparan sulfate serum levels showed a different course in the two groups. In conclusion, prophylactic norepinephrine infusion during posterior lumbar spinal fusion is preferable for elderly patients undergoing lumbar spinal fusion under general anesthesia. It can reduce postoperative complications and hospitalization time by reducing the injury to the vascular endothelium. This trial is registered with Clinical Trial Registration http://www.chictr.org.cn/showproj.aspx?proj=33660, identifier ChiCTR-1900021309.

Endothelial glycocalyx during early reperfusion in patients undergoing cardiac surgery.

BACKGROUND: Experimental cardiac ischemia-reperfusion injury causes degradation of the glycocalyx and coronary washout of its components syndecan-1 and heparan sulfate. Systemic elevation of syndecan-1 and heparan sulfate is well described in cardiac surgery. Still, the events during immediate reperfusion after aortic declamping are unknown both in the systemic and in the coronary circulation. METHODS: In thirty patients undergoing aortic valve replacement, arterial concentrations of syndecan-1 and heparan sulfate were measured immediately before and at one, five and ten minutes after aortic declamping (reperfusion). Parallel blood samples were drawn from the coronary sinus to calculate trans-coronary gradients (coronary sinus-artery). RESULTS: Compared with immediately before aortic declamping, arterial syndecan-1 increased by 18% [253.8 (151.6-372.0) ng/ml vs. 299.1 (172.0-713.7) ng/ml, p < 0.001] but arterial heparan sulfate decreased by 14% [148.1 (135.7-161.7) ng/ml vs. 128.0 (119.0-138.2) ng/ml, p < 0.001] at one minute after aortic declamping. There was no coronary washout of syndecan-1 or heparan sulfate during reperfusion. On the contrary, trans-coronary sequestration of syndecan-1 occurred at five [-12.96 ng/ml (-36.38-5.15), p = 0.007] and at ten minutes [-12.37 ng/ml (-31.80-6.62), p = 0.049] after reperfusion. CONCLUSIONS: Aortic declamping resulted in extracardiac syndecan-1 release and extracardiac heparan sulfate sequestration. Syndecan-1 was sequestered in the coronary circulation during early reperfusion. Glycocalyx has been shown to degrade during cardiac surgery. Besides degradation, glycocalyx has propensity for regeneration. The present results of syndecan-1 and heparan sulfate sequestration may reflect endogenous restoration of the damaged glycocalyx in open heart surgery.

Acute exercise-induced glycocalyx shedding does not differ between exercise modalities, but is associated with total antioxidative capacity.

OBJECTIVES: Regular physical exercise is known to protect endothelial integrity. It has been proposed that acute exercise-induced changes of the (anti-)oxidative system influence early (glycocalyx shedding) and sustained endothelial activation (shedding of endothelial cells, ECs) as well as endothelial-cell repair by circulating hematopoietic stem and progenitor cells (HPCs). However, results are not conclusive and data in trained participants performing different exercise modalities is lacking. DESIGN: Eighteen healthy, well-trained participants (9 runners, 9 cyclists; age: 29.7 ±â€¯4.2 yrs) performed a strenuous acute exercise session consisting of 4 bouts of 4-min high-intensity with decreasing power profile and 3-min low-intensity in-between. METHODS: Average power/speed of intense phases was 85% of the peak achieved in a previous incremental test. Before and shortly after exercise, total oxidative and antioxidative capacities (TAC), shedding of syndecan-1, heparan sulfate, hyaluronan, ECs, and circulating HPCs were investigated. RESULTS: TAC decreased from 1.81 ±â€¯0.42 nmol/L to 1.47 ±â€¯0.23 nmol/L post-exercise (p = 0.010) only in runners. Exercise-induced early and sustained endothelial activation were enhanced post-exercise- syndecan-1: 103.2 ±â€¯63.3 ng/mL to 111.3 ±â€¯71.3 ng/mL, heparan sulfate: from 2637.9 ±â€¯800.1 ng/mL to 3197.1 ±â€¯1416.3 ng/mL, both p < 0.05; hyaluronan: 84.3 ±â€¯21.8 ng/mL to 121.4 ±â€¯29.4 ng/mL, ECs: from 6.6 ±â€¯4.5 cells/µL to 9.5 ±â€¯6.2 cells/µL, both p < 0.01; results were not different between exercise modalities and negatively related to TAC concentrations post-exercise. HPC proportions and self-renewal ability were negatively, while EC concentrations were positively associated with circulating hyaluronan concentrations. CONCLUSIONS: These results highlight the importance of the antioxidative system to prevent the endothelium from acute exercise-induced vascular injury - independent of exercise modality - in well-trained participants. Endothelial-cell repair is associated with hyluronan signaling, possibly a similar mechanism as in wound repair.

Soluble syndecan-1 and glycosaminoglycans in preeclamptic and normotensive pregnancies.

Preeclampsia, an important cause of maternal and fetal morbidity and mortality, is associated with increased sFLT1 levels and with structural and functional damage to the glycocalyx contributing to endothelial dysfunction. We investigated glycocalyx components in relation to preeclampsia in human samples. While soluble syndecan-1 and heparan sulphate were similar in plasma of preeclamptic and normotensive pregnant women, dermatan sulphate was increased and keratan sulphate decreased in preeclamptic women. Dermatan sulphate was correlated with soluble syndecan-1, and inversely correlated with blood pressure and activated partial thromboplastin time. To determine if syndecan-1 was a prerequisite for the sFlt1 induced increase in blood pressure in mice we studied the effect of sFlt1 on blood pressure and vascular contractile responses in syndecan-1 deficient and wild type male mice. The classical sFlt1 induced rise in blood pressure was absent in syndecan-1 deficient mice indicating that syndecan-1 is a prerequisite for sFlt1 induced increase in blood pressure central to preeclampsia. The results show that an interplay between syndecan-1 and dermatan sulphate contributes to sFlt1 induced blood pressure elevation in pre-eclampsia.

Heparin Anti-Xa Activity, a Readily Available Unique Test to Quantify Apixaban, Rivaroxaban, Fondaparinux, and Danaparoid Levels.

BACKGROUND: Despite their usefulness in perioperative and acute care settings, factor-Xa inhibitor-specific assays are scarcely available, contrary to heparin anti-Xa assay. We assessed whether the heparin anti-Xa assay can (1) be used as a screening test to rule out apixaban, rivaroxaban, fondaparinux, and danaparoid levels that contraindicate invasive procedures according to current guidelines (>30 ng·mL-1, >30 ng·mL-1, >0.1 µg·mL-1, and >0.1 IU·mL-1, respectively), (2) quantify the anticoagulant level if found significant, that is, if it exceeded the abovementioned threshold. METHODS: In the derivation cohort then in the validation cohort, via receiver operating characteristics (ROC) curve analysis, we evaluated the ability of heparin anti-Xa assay to detect levels of factor-Xa inhibitors above or below the abovementioned safety thresholds recommended for an invasive procedure (screening test). Among samples with relevant levels of factor-Xa inhibitor, we determined the conversion factor linking the measured level and heparin anti-Xa activity in a derivation cohort. In a validation cohort, the estimated level of each factor-Xa inhibitor was thus inferred from heparin anti-Xa activity. The agreement between measured and estimated levels of factor-Xa inhibitors was assessed. RESULTS: Among 989 (355 patients) and 756 blood samples (420 patients) in the derivation and validation cohort, there was a strong linear relationship between heparin anti-Xa activities and factor-Xa inhibitors measured level (r = 0.99 [95% confidence interval {CI}, 0.99-0.99]). In the derivation cohort, heparin anti-Xa activity ≤0.2, ≤0.3, <0.1, <0.1 IU·mL-1 reliably ruled out a relevant level of apixaban, rivaroxaban, fondaparinux, and danaparoid, respectively (area under the ROC curve ≥0.99). In the validation cohort, these cutoffs yielded excellent classification accuracy (≥96%). If this screening test indicated relevant level of factor-Xa inhibitor, estimated and measured levels closely agreed (Lin's correlation coefficient close to its maximal value: 95% CI, 0.99-0.99). More than 96% of the estimated levels fell into the predefined range of acceptability (ie, 80%-120% of the measured level). CONCLUSIONS: A unique simple test already widely used to assay heparin was also useful for quantifying these 4 other anticoagulants. Both clinical and economic impacts of these findings should be assessed in a specific study.

Elevated Plasma Concentrations of Syndecan-1 Do Not Correlate With Increased Capillary Leakage of 20% Albumin.

BACKGROUND: Preclinical experiments show that an inflammatory reaction causes degradation of the endothelial glycocalyx layer and accelerated capillary leakage of albumin and fluid. The hypothesis in the present study was that elevated plasma concentrations of glycocalyx degradation products are associated with greater capillary leakage in humans. METHODS: This open clinical trial involved administration of an intravenous infusion of 20% albumin at 3 mL/kg over 30 minutes to 15 postburn patients who showed an activated inflammatory response. Blood samples and urine were collected for 300 minutes. The plasma concentrations of 2 biomarkers of glycocalyx degradation-syndecan-1 and heparan sulfate-were measured at 0, 60, and 300 minutes and compared to the capillary leakage of albumin and fluid obtained by mass balance calculations and population kinetic analysis. RESULTS: Patients were studied at 7 days (median) after a burn injury that covered 15% (maximum 48%) of the body surface area. The median plasma syndecan-1 concentration was 71 (25th-75th percentiles, 41-185) ng/mL. The 2 patients with highest values showed 2279 and 2395 ng/mL (normal 15 ng/mL). Heparan sulfate concentrations averaged 915 (673-1539) ng/mL. The infused amount of albumin was 57 (48-62) g, and 6.3 (5.1-7.7)% of that leaked from the plasma per hour.Linear correlation analysis of the relationship between the 10logarithm of the mean syndecan-1 and the albumin leakage showed a slope coefficient of -1.3 (95% confidence interval [CI], -3.6 to 1.0) and a correlation coefficient of -0.33 (P = .24). The kinetic analysis revealed that syndecan-1 served as a statistically significant covariate to the albumin leakage, but the relationship was inverse (power exponent -0.78, 95% CI, -1.50 to -0.05; P < .02). Heparan sulfate levels did not correlate with the capillary leakage of albumin or fluid in any of the analyses. CONCLUSIONS: A raised plasma concentration of syndecan-1 alone cannot be extrapolated to indicate increased capillary leakage of albumin and fluid.

Increased Plasma Heparanase Activity in COVID-19 Patients.

Reports suggest a role of endothelial dysfunction and loss of endothelial barrier function in COVID-19. It is well established that the endothelial glycocalyx-degrading enzyme heparanase contributes to vascular leakage and inflammation. Low molecular weight heparins (LMWH) serve as an inhibitor of heparanase. We hypothesize that heparanase contributes to the pathogenesis of COVID-19, and that heparanase may be inhibited by LMWH. To test this hypothesis, heparanase activity and heparan sulfate levels were measured in plasma of healthy controls (n = 10) and COVID-19 patients (n = 48). Plasma heparanase activity and heparan sulfate levels were significantly elevated in COVID-19 patients. Heparanase activity was associated with disease severity including the need for intensive care, lactate dehydrogenase levels, and creatinine levels. Use of prophylactic LMWH in non-ICU patients was associated with a reduced heparanase activity. Since there is no other clinically applied heparanase inhibitor currently available, therapeutic treatment of COVID-19 patients with low molecular weight heparins should be explored.

Quantitative analysis of heparan sulfate using isotopically labeled calibrants.

Heparan sulfate is a sulfated polysaccharide that displays essential physiological functions. Here, we report a LC-MS/MS-based method for quantitatively determining the individual disaccharide composition and total amount of heparan sulfate. Using eight 13C-labeled disaccharide calibrants and one 13C-labeled polysaccharide calibrant, we complete the analysis in one-pot process. The method is both sensitive and has the throughput to analyze heparan sulfate from mouse tissues and plasma.

Characterization of Fluid Biomarkers Reveals Lysosome Dysfunction and Neurodegeneration in Neuronopathic MPS II Patients.

Mucopolysaccharidosis type II is a lysosomal storage disorder caused by a deficiency of iduronate-2-sulfatase (IDS) and characterized by the accumulation of the primary storage substrate, glycosaminoglycans (GAGs). Understanding central nervous system (CNS) pathophysiology in neuronopathic MPS II (nMPS II) has been hindered by the lack of CNS biomarkers. Characterization of fluid biomarkers has been largely focused on evaluating GAGs in cerebrospinal fluid (CSF) and the periphery; however, GAG levels alone do not accurately reflect the broad cellular dysfunction in the brains of MPS II patients. We utilized a preclinical mouse model of MPS II, treated with a brain penetrant form of IDS (ETV:IDS) to establish the relationship between markers of primary storage and downstream pathway biomarkers in the brain and CSF. We extended the characterization of pathway and neurodegeneration biomarkers to nMPS II patient samples. In addition to the accumulation of CSF GAGs, nMPS II patients show elevated levels of lysosomal lipids, neurofilament light chain, and other biomarkers of neuronal damage and degeneration. Furthermore, we find that these biomarkers of downstream pathology are tightly correlated with heparan sulfate. Exploration of the responsiveness of not only CSF GAGs but also pathway and disease-relevant biomarkers during drug development will be crucial for monitoring disease progression, and the development of effective therapies for nMPS II.

Structural characterization of a clinically described heparin-like substance in plasma causing bleeding.

Heparin-like substances (HLS) have been described in various clinical situations, including in settings of liver disease associated with infection, transplant, and metastasis. HLS are generally attributed to circulating glycosaminoglycans. Initial results for this patient showed coagulopathy due to liver disease without HLS. Two weeks after liver transplantation, a 10 year-old female with liver failure patient began to bleed from catheter insertion sites, mouth, and nares and HLS was suspected. The patient subsequently died and these clinical samples resulted in the isolation of a single heparan sulfate (HS) present at high concentrations in the plasma. Analysis of this HS showed it had an intermediate between heparin and HS with low antithrombin-mediated anticoagulant activity. We speculate that this 10-year old patient might have a platelet function defect influenced by this unusual HS. Endothelial defects not measurable by our methods might have also contributed to the observed bleeding complications.

Correlation Between Wall Shear Stress and Acute Degradation of the Endothelial Glycocalyx During Cardiopulmonary Bypass.

Wall shear stress (WSS) plays a key role in maintaining glycocalyx function, gene expression, and structure. Experimental studies have discussed the relationship between the shedding of the endothelial glycocalyx (EG) and WSS. However, rare literature about how WSS affects the EG during cardiopulmonary bypass (CPB) was mentioned. This study aimed to investigate the correlation between the WSS of carotid arteries and shedding of the EG during CPB in humans. The WSS level was calculated in accordance with an equation. The plasma concentrations of heparan sulfate, syndecan-1, and nitric oxide were measured to reflect shedding of the EG at six time points. A negative correlation was observed between the peak wall shear stress (PWSS) and syndecan-1 (R = - 0.5, p < 0.01) and heparan sulfate (R = - 0.461, p < 0.01) during CPB. The WSS is closely associated with the components of glycocalyx shedding during CPB. The WSS produced by non-pulsatile flow during CPB may contribute to the degradation of EG.

Effect of sevoflurane and propofol on tourniquet-induced endothelial damage: a pilot randomized controlled trial for knee-ligament surgery.

BACKGROUND: The glycocalyx layer is a key structure in the endothelium. Tourniquet-induced ischemic periods are used during orthopedic surgery, and the reactive oxygen species generated after ischemia-reperfusion may mediate the shedding of the glycocalyx. Here, we describe the effects of tourniquet-induced ischemia-reperfusion and compare the effects of sevoflurane and propofol on the release of endothelial biomarkers after ischemia-reperfusion in knee-ligament surgery. METHODS: This pilot, single-center, blinded, randomized, controlled trial included 16 healthy patients. After spinal anesthesia, hypnosis was achieved with sevoflurane or propofol according to randomization. During the perioperative period, five venous blood samples were collected for quantification of syndecan-1, heparan sulfate, and thrombomodulin from blood serum by using ELISA assays kits. Sample size calculation was performed to detect a 25% change in the mean concentration of syndecan-1 with an alpha of 0.05 and power of 80%. RESULTS: For our primary outcome, a two-way ANOVA with post-hoc Bonferroni correction analysis showed no differences in syndecan-1 concentrations between the sevoflurane and propofol groups at any time point. In the sevoflurane group, we noted an increase in syndecan-1 concentrations 90 min after tourniquet release in the sevoflurane group from 34.6 ± 24.4 ng/mL to 47.9 ± 29.8 ng/mL (Wilcoxon test, p < 0.01) that was not observed in patients randomized to the propofol group. The two-way ANOVA showed no intergroup differences in heparan sulfate and thrombomodulin levels. CONCLUSIONS: Superficial endothelial damage without alterations in the cell layer integrity was observed after tourniquet knee-ligament surgery. There was no elevation in serum endothelial biomarkers in the propofol group patients. Sevoflurane did not show the protective effect observed in in vitro and in vivo studies. TRIAL REGISTRATION: The trial was registered in www.clinicaltrials.gov (ref: NCT03772054, Registered 11 December 2018).

Quality performance for indirect Xa inhibitor monitoring in patients using international external quality data.

Objectives Chromogenic anti-activated factor X (FXa) assays are currently the "gold standard" for monitoring indirect anticoagulants. However, anti-FXa has been shown to vary according to the choice of reagents. In the present study, the performance of anti-FXa measurement was evaluated in order to gain more insight into the clinical applications. Furthermore, the longitudinal coefficient of variation (CV) was studied to investigate whether there is improvement over time. Methods Laboratory tests results were evaluated for samples spiked with unfractionated heparin (UFH), low-molecular-weight-heparin (LMWH), fondaparinux and danaparoid sodium. External quality assessment (EQA) data from multiple years were used from more than 100 laboratories. Results Comparison of the results for all methods showed significant differences in measured values between the frequently used methods (ANOVA: p < 0.001). The largest differences were observed for LMWH and UFH measurements. These differences may be caused by differences in method composition, such as the addition of dextran sulphate. Substantial interlaboratory variation in anti-FXa monitoring was observed for all parameters, particularly at low concentrations. Our results showed that below 0.35 IU/mL, the CVs for UFH and LMWH increase dramatically and results below this limit should be used with caution. Conclusions Our study demonstrates that the choice of the anti-FXa method is particularly important for UFH and LMWH measurement. The variation in measurements may have an effect on clinical implications, such as therapeutic ranges. Furthermore, the longitudinal EQA data demonstrated a constant performance and, in at least 50% of the cases, improvement in the CV% of the anti-Xa results over time.

Circulating heparan sulfate chains and body weight contribute to anti-Xa levels in cancer patients using the prophylactic dose of enoxaparin.

Hospitalized cancer patients are at increased risk of thrombosis and prophylaxis with heparin is recommended. Heparanase is a protein capable of degrading heparan sulfate (HS) chains. The first objective of the study was to examine the effects of weight on anti-Xa levels in cancer patients treated with a fixed dose of enoxaparin as thromboprophylaxis. The second aim was to assess a potential correlation between plasma pre-treatment coagulation parameters and anti-Xa levels in an assumption that heparanase degradation activity towards heparins and HS chains could affect anti-Xa levels. Two blood samples (prior to and 3 h after drug injection) of 76 cancer patients with an indication for prophylaxis with enoxaparin (40 mg) were evaluated for coagulation markers. Sub-prophylactic levels of anti-Xa (< 0.2 U/ml) were found in 16/76 (21%) patients; in 13/76 (13%) patients the values were supra-prophylactic (> 0.5 U/ml). In the subgroup of patients weighing > 80 kg, 7/14 (50%) individuals had a sub-prophylactic level. Overall, anti-Xa levels appeared to correlate with patient's weight (r = - 0.48, p < 0.0001), pre-treatment partial thromboplastin time (PTT), D-dimer, HS, heparanase levels and procoagulant activity. We concluded that plasma anti-Xa levels correlated with patient's weight. A substantial portion of cancer patients receiving enoxaparin prophylaxis was undertreated. For patients > 80 kg, a weight-adjusted prophylactic dose of enoxaparin could be considered. Elevated enoxaparin anti-Xa levels correlated with pre-treatment parameters of coagulation system activation. High pre-treatment HS and elevated plasma anti-Xa levels may potentially serve as biomarkers for the identification of patients at increased thrombosis risk.