Laboratory parameters related to disease severity and physical performance after reconvalescence of acute COVID-19 infection.

Research into the molecular basis of disease trajectory and Long-COVID is important to get insights toward underlying pathophysiological processes. The objective of this study was to investigate inflammation-mediated changes of metabolism in patients with acute COVID-19 infection and throughout a one-year follow up period. The study enrolled 34 patients with moderate to severe COVID-19 infection admitted to the University Clinic of Innsbruck in early 2020. The dynamics of multiple laboratory parameters (including inflammatory markers [C-reactive protein (CRP), interleukin-6 (IL-6), neopterin] as well as amino acids [tryptophan (Trp), phenylalanine (Phe) and tyrosine (Tyr)], and parameters of iron and vitamin B metabolism) was related to disease severity and patients' physical performance. Also, symptom load during acute illness and at approximately 60 days (FU1), and one year after symptom onset (FU2) were monitored and related with changes of the investigated laboratory parameters: During acute infection many investigated laboratory parameters were elevated (e.g., inflammatory markers, ferritin, kynurenine, phenylalanine) and enhanced tryptophan catabolism and phenylalanine accumulation were found. At FU2 nearly all laboratory markers had declined back to reference ranges. However, kynurenine/tryptophan ratio (Kyn/Trp) and the phenylalanine/tyrosine ratio (Phe/Tyr) were still exceeding the 95th percentile of healthy controls in about two thirds of our cohort at FU2. Lower tryptophan concentrations were associated with B vitamin availability (during acute infection and at FU1), patients with lower vitamin B12 levels at FU1 had a prolonged and more severe impairment of their physical functioning ability. Patients who had fully recovered (ECOG 0) presented with higher concentrations of iron parameters (ferritin, hepcidin, transferrin) and amino acids (phenylalanine, tyrosine) at FU2 compared to patients with restricted ability to work. Persistent symptoms at FU2 were tendentially associated with IFN-γ related parameters. Women were affected by long-term symptoms more frequently. Conclusively, inflammation-mediated biochemical changes appear to be related to symptoms of patients with acute and Long Covid.

The discriminatory power of bleeding assessment tools in adult patients with a mild to moderate bleeding tendency.

BACKGROUND: Bleeding assessment tools (BATs) have been developed to quantify bleeding severity. Their ability to predict for the diagnosis of a bleeding disorder has not been thoroughly investigated. OBJECTIVES: To evaluate the ability of the Vicenza BAT and the ISTH BAT to distinguish patients with an established bleeding disorder from those with bleeding of unknown cause (BUC). PATIENTS/METHODS: Three-hundred fifty-nine patients (228 with BUC, 64%) from the Vienna Bleeding Biobank were assessed in this study. RESULTS: The bleeding scores were similar in patients with an established diagnosis of a bleeding disorder compared to patients with BUC. Both BATs had a low sensitivity and specificity for the diagnosis of a bleeding disorder with areas under the receiver operating characteristic (ROC) curves of 0.53 (95% confidence interval 0.47-0.60) for the Vicenza BAT and 0.52 (0.46-0.59) for the ISTH BAT. In terms of specific diagnoses, both scores were most accurate in diagnosing von Willebrand disease (VWD, areas under the ROC curve; Vicenza BAT 0.67 (0.45-0.90); ISTH BAT 0.70 (0.50-0.90)). A separate evaluation of different bleeding symptoms in patients who had undergone surgery and tooth extraction revealed that postpartum bleeding and bleeding from small wounds was predictive for diagnosing a MBD in multivariable analysis. CONCLUSIONS: The Vicenza- and the ISTH BAT have a low ability to distinguish patients with an established bleeding disorder from those with BUC.

Pharmacological Targets of Kaempferol Within Inflammatory Pathways-A Hint Towards the Central Role of Tryptophan Metabolism.

The flavonoid kaempferol is almost ubiquitously contained in edible and medicinal plants and exerts a broad range of interesting pharmacological activities. Interactions with central inflammatory processes can be exploited to treat or attenuate symptoms of disorders associated with chronic immune activation during infections, malignancies, and neurodegenerative or cardiovascular disorders. Many drugs, phytochemicals, and nutritional components target the catabolism of the essential amino acid tryptophan by indoleamine 2,3-dioxygenase 1 (IDO-1) for immunomodulation. We studied the effects of kaempferol by in vitro models with human peripheral blood mononuclear cells (PBMC) and THP-1 derived human myelomonocytic cell lines. Kaempferol suppressed interferon-γ dependent immunometabolic pathways: Formation of the oxidative stress biomarker neopterin and catabolism of tryptophan were inhibited dose-dependently in stimulated cells. In-silico docking studies revealed a potential interaction of kaempferol with the catalytic domain of IDO-1. Kaempferol stimulated nuclear factor kappa B (NF-κB) signaling in lipopolysaccharide (LPS)-treated THP-1 cells, thereby increasing the mRNA expression of interleukin (IL) 1 beta, tumor necrosis factor, and nuclear factor kappa B subunit 1, while IL6 was downregulated. Data suggest that concerted effects of kaempferol on multiple immunologically relevant targets are responsible for its immunomodulatory activity. However, the immunosuppressive effects may be more relevant in a T-cell dominated context.

Ex vivo properties of plasma clot formation and lysis in patients with cancer at risk for venous thromboembolism, arterial thrombosis, and death.

A prothrombotic state is frequently observed in patients with cancer and contributes to the risks of venous thromboembolism (VTE), arterial thromboembolism (ATE), tumor progression, and death. Altered ex vivo properties of plasma clot formation and lysis have been observed in patients with cancer. The aim of this prospective study was to comprehensively characterize the relationship between plasma clot properties, inflammation, hypercoagulability, thrombotic complications, and mortality in patients with cancer using a tissue-factor-based turbidimetric assay of clot formation and lysis. Turbidity parameters were determined in 815 patients with newly-diagnosed or recurrent cancer and 97 healthy controls. Patients were followed-up for 2 years and rates of VTE (n = 72 events), ATE (n = 21 events), and death (n = 304 events) were assessed. Compared to controls, cancer patients' turbidity profiles showed an increased clot formation potential and higher resistance toward fibrinolysis. Elevated biomarkers of inflammation and hemostasis, such as C-reactive protein, FVIII, and thrombin generation explained substantial amounts of variation in turbidity parameters. In a prospective analysis, altered parameters of clot formation identified cancer patients at high risk of ATE (Hazard ratio [HR] per doubling of peak absorbance: 4.43, 95% CI: 1.50-13.07, P = 0.007) and death (HR per doubling of peak absorbance: 2.73, 2.00-3.72, P< 0.0001); these findings were independent of other prognostic covariates. Contrarily, turbidity parameters were not associated with risk of VTE (HR per doubling of peak absorbance: 1.15, 0.66-2.01, P = 0.62). We conclude that patients with cancer have altered ex vivo properties of clot formation which predict risks of ATE and mortality but not VTE.

Localization and production of peptide endocannabinoids in the rodent CNS and adrenal medulla.

The endocannabinoid system (ECS) comprises the cannabinoid receptors CB1 and CB2 and their endogenous arachidonic acid-derived agonists 2-arachidonoyl glycerol and anandamide, which play important neuromodulatory roles. Recently, a novel class of negative allosteric CB1 receptor peptide ligands, hemopressin-like peptides derived from alpha hemoglobin, has been described, with yet unknown origin and function in the CNS. Using monoclonal antibodies we now identified the localization of RVD-hemopressin (pepcan-12) and N-terminally extended peptide endocannabinoids (pepcans) in the CNS and determined their neuronal origin. Immunohistochemical analyses in rodents revealed distinctive and specific staining in major groups of noradrenergic neurons, including the locus coeruleus (LC), A1, A5 and A7 neurons, which appear to be major sites of production/release in the CNS. No staining was detected in dopaminergic neurons. Peptidergic axons were seen throughout the brain (notably hippocampus and cerebral cortex) and spinal cord, indicative of anterograde axonal transport of pepcans. Intriguingly, the chromaffin cells in the adrenal medulla were also strongly stained for pepcans. We found specific co-expression of pepcans with galanin, both in the LC and adrenal gland. Using LC-MS/MS, pepcan-12 was only detected in non-perfused brain (∼ 40 pmol/g), suggesting that in the CNS it is secreted and present in extracellular compartments. In adrenal glands, significantly more pepcan-12 (400-700 pmol/g) was measured in both non-perfused and perfused tissues. Thus, chromaffin cells may be a major production site of pepcan-12 found in blood. These data uncover important areas of peptide endocannabinoid occurrence with exclusive noradrenergic immunohistochemical staining, opening new doors to investigate their potential physiological function in the ECS. This article is part of the Special Issue entitled 'Fluorescent Tools in Neuropharmacology'.