Stratification of ßSß+ Compound Heterozygotes Based on L-Glutamine Administration and RDW: Focusing on Disease Severity.

Sickle cell disease (SCD) is heterogeneous in terms of manifestation severity, even more so when in compound heterozygosity with beta-thalassemia. The aim of the present study was to stratify ßSß+ patient blood samples in a severity-dependent manner. Blood from thirty-two patients with HbS/ß-thalassemia compound heterozygosity was examined for several parameters (e.g., hemostasis, inflammation, redox equilibrium) against healthy controls. Additionally, SCD patients were a posteriori (a) categorized based on the L-glutamine dose and (b) clustered into high-/low-RDW subgroups. The patient cohort was characterized by anemia, inflammation, and elevated coagulation. Higher-dose administration of L-glutamine was associated with decreased markers of inflammation and oxidation (e.g., intracellular reactive oxygen species) and an altered coagulation profile. The higher-RDW group was characterized by increased hemolysis, elevated markers of inflammation and stress erythropoiesis, and oxidative phenomena (e.g., membrane-bound hemoglobin). Moreover, the levels of hemostasis parameters (e.g., D-Dimers) were greater compared to the lower-RDW subgroup. The administration of higher doses of L-glutamine along with hydroxyurea seems to attenuate several features in SCD patients, probably by enhancing antioxidant power. Moreover, anisocytosis may alter erythrocytes' coagulation processes and hemolytic propensity. This results in the disruption of the redox and pro-/anti-inflammatory equilibria, creating a positive feedback loop by inducing stress erythropoiesis and, thus, the occurrence of a mixed erythrocyte population.

Do the Kinetics of Antibody Responses Predict Clinical Outcome in Hospitalized Patients With Moderate-to-Severe COVID-19?

BACKGROUND/AIM: The relationship between the kinetics of antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the severity of Coronavirus Disease 2019 (COVID-19) is poorly understood. The aim of the present study was to investigate whether serum SARS-CoV-2 antibody kinetics serve as an early predictor of clinical deterioration or recovery in hospitalized patients with COVID-19. PATIENTS AND METHODS: In this prospective observational study, 102 consecutive patients (median age: 60 years, 58% males) with symptomatic COVID-19 infection diagnosed by real-time polymerase chain reaction assay, hospitalized in two tertiary hospitals, were included. Rapid test for qualitative detection of immunoglobulin M (IgM) and immunoglobulin G (IgG) SARS-CoV-2 antibodies was performed at pre-defined time intervals during hospitalization (days: 0, 3, 7, 10, 14, 21 and 28). RESULTS: During a 3-month follow-up period after COVID-19 disease onset, a total of 87 patients were discharged, 12 patients were intubated and entered the Intensive Care Unit, and three patients died. The median time for seroconversion was 10 days for IgM and 12 days for IgG post onset of symptoms. Univariate logistic regression analysis found no associations between IgM or IgG positivity and clinical outcomes or complications during hospitalization for COVID-19 infection. Diabetes and dyslipidemia were the only clinical risk factors predictive of COVID-19-related complications during hospitalization. CONCLUSION: SARS-CoV-2 antibody responses do not predict clinical outcome in hospitalized patients with moderate-to-severe COVID-19 infection.

Acute exposure to diesel affects inflammation and vascular function.

BACKGROUND: Diesel exhaust fumes represent one of the most common toxic pollutants. The prolonged effects of acute exposure to this pollutant on inflammatory status and vascular properties are unknown. METHODS: During a 2-h session, 40 healthy subjects were exposed to diesel exhaust fumes and/or filtered air. Endothelial function was assessed with flow mediated dilation, arterial stiffness with pulse wave velocity and reflected waves with augmentation index. C-reactive protein, fibrinogen, protein C levels and protein S activity were also measured. Standard deviation of normal to normal R-R intervals (SDNN) was used to assess heart rate variability. Measurements were assessed before exposure and 2 and 24 h after diesel exposure. RESULTS: Compared with filtered air, exposure to diesel exhaust fumes decreased flow mediated dilation and increased pulse wave velocity and augmentation index up to 24 h after the exposure (p < 0.001 for all). Similarly, compared with filtered air, diesel exhaust exposure impaired SDNN during the 24-h study period (p = 0.007). C-reactive protein and fibrinogen levels were significantly increased after diesel exhaust exposure while protein C levels and protein S activity decreased (p < 0.01 for all). Exposure to diesel exhaust fumes resulted in higher C-reactive protein concentration in smokers compared with non-smokers (p < 0.001). CONCLUSION: Short-term exposure to diesel exhaust fumes has a prolonged adverse impact on endothelial function and vascular wall properties, along with impaired heart rate variability, abnormal fibrinolytic activity and increased markers of inflammation. These findings give insights into the mechanisms underlining the increased cardiovascular risk of subjects regularly exposed to diesel exhaust fumes.

Coagulation Abnormalities in Renal Pathology of Chronic Kidney Disease: The Interplay between Blood Cells and Soluble Factors.

Coagulation abnormalities in renal pathology are associated with a high thrombotic and hemorrhagic risk. This study aims to investigate the hemostatic abnormalities that are related to the interaction between soluble coagulation factors and blood cells, and the effects of hemodialysis (HD) on it, in end stage renal disease (ESRD) patients. Thirty-two ESRD patients under HD treatment and fifteen healthy controls were included in the study. Whole blood samples from the healthy and ESRD subjects were collected before and after the HD session. Evaluation of coagulation included primary and secondary hemostasis screening tests, proteins of coagulation, fibrinolytic and inhibitory system, and ADAMTS-13 activity. Phosphatidylserine (PS) exposure and intracellular reactive oxygen species (iROS) levels were also examined in red blood cells and platelets, in addition to the platelet activation marker CD62P. Platelet function analysis showed pathological values in ESRD patients despite the increased levels of activation markers (PS, CD62P, iROS). Activities of most coagulation, fibrinolytic, and inhibitory system proteins were within the normal range, but HD triggered an increase in half of them. Additionally, the increased baseline levels of ADAMTS-13 inhibitor were further augmented by the dialysis session. Finally, pathological levels of PS and iROS were measured in red blood cells in close correlation with variations in several coagulation factors and platelet characteristics. This study provides evidence for a complex coagulation phenotype in ESRD. Signs of increased bleeding risk coexisted with prothrombotic features of soluble factors and blood cells in a general hyperfibrinolytic state. Hemodialysis seems to augment the prothrombotic potential, while the persisted platelet dysfunction might counteract the increased predisposition to thrombotic events post-dialysis. The interaction of red blood cells with platelets, the thrombus, the endothelium, the soluble components of the coagulation pathways, and the contribution of extracellular vesicles on hemostasis as well as the identification of the unknown origin ADAMTS-13 inhibitor deserve further investigation in uremia.

The Multi-Faced Extracellular Vesicles in the Plasma of Chronic Kidney Disease Patients.

Extracellular vesicles (EVs) are membrane-enclosed nanoparticles released by most cells in body fluids and extracellular matrix. They function as signal transducers in intercellular communication, contributing to the maintenance of cell and tissue integrity. EVs biogenesis is deregulated in various pathologies, in structural and functional connection to the pathophysiology of donor cells. Consequently, EVs are considered diagnostic and monitoring factors in many diseases. Despite consensus as to their activity in promoting coagulation and inflammation, there is evidence suggesting protective roles for EVs in stress states. Chronic kidney disease (CKD) patients are at high risk of developing cardiovascular defects. The pathophysiology, comorbidities, and treatment of CKD may individually and in synergy affect extracellular vesiculation in the kidney, endothelium, and blood cells. Oxidative and mechanical stresses, chronic inflammation, and deregulation of calcium and phosphate homeostasis are established stressors of EV release. EVs may affect the clinical severity of CKD by transferring biological response modifiers between renal, vascular, blood, and inflammatory cells. In this Review, we focus on EVs circulating in the plasma of CKD patients. We highlight some recent advances in the understanding of their biogenesis, the effects of dialysis, and pharmacological treatments on them and their potential impact on thrombosis and vascular defects. The strong interest of the scientific community to this exciting field of research may reveal hidden pieces in the pathophysiology of CKD and thus, innovative ways to treat it. Overcoming gaps in EV biology and technical difficulties related to their size and heterogeneity will define the success of the project.

Soluble CD146, a novel endothelial marker, is related to the severity of liver disease.

OBJECTIVES: Angiogenesis and inflammation have been involved in the progression of fibrosis in patients with chronic liver disease (CLD). Soluble CD146 (sCD146), a biomarker that was recently characterized as a novel component of the endothelial junction is implicated in endothelial proliferation. Our study evaluates the performance of sCD146 in assessing liver fibrosis and cirrhosis, and determines if its levels are related to the severity of liver disease in patients with cirrhosis. MATERIAL AND METHODS: sCD146 levels were determined by a commercially available immunoenzymatic technique in 62 consecutive patients with cirrhosis, 43 patients with CLD and 27 healthy controls. RESULTS: Patients with cirrhosis compared to non-cirrhotics with CLD had a higher median sCD146 concentration (639 vs. 317 ng/ml). In receiver operating characteristic (ROC) curve analysis, the cut-off of 412 ng/ml showed a sensitivity of 78% and a specificity of 75% for diagnosis of cirrhosis, offering good diagnostic accuracy (area under the ROC curve [AUROC: 0.838]). Patients with compensated compared to those with decompensated cirrhosis had a lower median sCD146 concentration (399 vs. 848 ng/ml, respectively). A cut-off of 534 ng/ml offered a sensitivity of 83% and a specificity of 78% for differentiating compensated from decompensated cirrhosis (AUROC: 0.866). Furthermore, in cirrhotics, sCD146 correlated positively with AST, bilirubin levels and most importantly with international normalized ratio and model for end-stage liver disease (r = 0.648, p < 0.001 and r = 0.567, p < 0.001, respectively). CONCLUSION: sCD146 can be used as a surrogate, inexpensive biomarker for the diagnosis of cirrhosis. It is also well correlated with severity of liver disease in cirrhotic patients. Further studies are needed to define its role in clinical practice.