Bile acid-induced tissue factor activity in hepatocytes correlates with activation of farnesoid X receptor.

Bile acids (BA) have been found to promote coagulation by increasing tissue factor (TF) activity. The contribution of elevated BA levels and cholestasis to TF decryption within the liver parenchyma and the role of farnesoid X receptor (FXR) in this process remain unclear. We investigated the effects of BA on TF activity and thrombin generation in hepatocytes and correlated these effects with activation of FXR-dependent signaling and apoptosis. HepG2 cells and primary hepatocytes were incubated with chenodeoxycholic acid (CDCA), glycochenodeoxycholic acid (GCDCA), ursodeoxycholic acid (UCDA), or the synthetic FXR agonist GW4064 for 24 h. MTT tests demonstrated cell viability throughout experiments. TF activity was tested via factor Xa generation and thrombin generation was measured by calibrated automated thrombography. Increased TF activity alongside enhanced thrombin generation was observed with CDCA and GW4064 but not with GCDCA and UDCA. TF activity was substantially reduced when FXR activation was blocked with the antagonist DY 268. Quantitative polymerase chain reaction revealed upregulation of FXR target genes only by CDCA and GW4064. Western blot analysis and fluorescence microscopy showed no TF overexpression arguing for TF decryption. Caspase 3 activity measurements and flow cytometric analysis of Annexin V binding showed no signs of apoptosis. Long-term exposure of hepatocytes to nontoxic BA may cause intracellular FXR overstimulation, triggering TF decryption irrespective of the amphiphilic properties of BA. The effect of BA on TF activation correlates with the molecule's ability to enter the cells and activate FXR. TF decryption occurs independently of apoptotic mechanisms.

Long-term outcome of LRBA deficiency in 76 patients after various treatment modalities as evaluated by the immune deficiency and dysregulation activity (IDDA) score.

BACKGROUND: Recent findings strongly support hematopoietic stem cell transplantation (HSCT) in patients with severe presentation of LPS-responsive beige-like anchor protein (LRBA) deficiency, but long-term follow-up and survival data beyond previous patient reports or meta-reviews are scarce for those patients who do not receive a transplant. OBJECTIVE: This international retrospective study was conducted to elucidate the longitudinal clinical course of patients with LRBA deficiency who do and do not receive a transplant. METHOD: We assessed disease burden and treatment responses with a specially developed immune deficiency and dysregulation activity score, reflecting the sum and severity of organ involvement and infections, days of hospitalization, supportive care requirements, and performance indices. RESULTS: Of 76 patients with LRBA deficiency from 29 centers (median follow-up, 10 years; range, 1-52), 24 underwent HSCT from 2005 to 2019. The overall survival rate after HSCT (median follow-up, 20 months) was 70.8% (17 of 24 patients); all deaths were due to nonspecific, early, transplant-related mortality. Currently, 82.7% of patients who did not receive a transplant (43 of 52; age range, 3-69 years) are alive. Of 17 HSCT survivors, 7 are in complete remission and 5 are in good partial remission without treatment (together, 12 of 17 [70.6%]). In contrast, only 5 of 43 patients who did not receive a transplant (11.6%) are without immunosuppression. Immune deficiency and dysregulation activity scores were significantly lower in patients who survived HSCT than in those receiving conventional treatment (P = .005) or in patients who received abatacept or sirolimus as compared with other therapies, and in patients with residual LRBA expression. Higher disease burden, longer duration before HSCT, and lung involvement were associated with poor outcome. CONCLUSION: The lifelong disease activity, implying a need for immunosuppression and risk of malignancy, must be weighed against the risks of HSCT.

Blood parameters in pediatric myelin oligodendrocyte glycoprotein antibody-associated disorders.

BACKGROUND AND OBJECTIVES: Patients with myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) clinically present e.g. with acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), transverse myelitis (TM) or aquaporin-4-IgG (AQP4-IgG) negative neuromyelitis optica spectrum disorders (NMOSD)-like phenotypes. We aimed to analyze and compare blood parameters in children with MOGAD, AQP4-IgG-positive NMOSD (hence NMOSD), multiple sclerosis (MS) and healthy controls (HC). METHODS: We evaluated differences in complete blood counts (CBC), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and C-reactive protein (CRP) between these four groups and within the groups between clinical attack, acute treatment and remission. RESULTS: Our cohort consisted of 174 children and adolescents with a total of 550 timepoints: 66 patients had MOGAD (202 timepoints), 11 NMOSD (76 timepoints), 58 MS (219 timepoints) and 39 were HC (53 timepoints). At clinical attack, leukocyte counts were elevated in MOGAD compared to remission (p < 0.001) and compared to all other groups (p < 0.001). NLR was high in MOGAD and NMOSD, and PLR was high in NMOSD, however, after correction for multiple testing these findings did not remain significant. While glucocorticoids caused an increase of leukocyte counts and NLR in NMOSD and MS, these values remained stable during acute treatment in MOGAD. In remission, NLR normalized in MOGAD, while it stayed high in NMOSD. PLR increased in NMOSD and was significantly higher compared to all other groups. DISCUSSION: Some blood parameters, mainly leukocyte and differential counts, might help clinicians to evaluate disease activity, differentiate relapses from pseudo-relapses and even distinguish between different disease entities.

Genotype-Phenotype Comparison in POGZ-Related Neurodevelopmental Disorders by Using Clinical Scoring.

POGZ-related disorders (also known as White-Sutton syndrome) encompass a wide range of neurocognitive abnormalities and other accompanying anomalies. Disease severity varies widely among POGZ patients and studies investigating genotype-phenotype association are scarce. Therefore, our aim was to collect data on previously unreported POGZ patients and perform a large-scale phenotype-genotype comparison from published data. Overall, 117 POGZ patients' genotype and phenotype data were included in the analysis, including 12 novel patients. A severity scoring system was developed for the comparison. Mild and severe phenotypes were compared with the types and location of the variants and the predicted presence or absence of nonsense-mediated RNA decay (NMD). Missense variants were more often associated with mild phenotypes (p = 0.0421) and truncating variants predicted to escape NMD presented with more severe phenotypes (p < 0.0001). Within this group, variants in the prolin-rich region of the POGZ protein were associated with the most severe phenotypes (p = 0.0004). Our study suggests that gain-of-function or dominant negative effect through escaping NMD and the location of the variants in the prolin-rich domain of the protein may play an important role in the severity of manifestations of POGZ-associated neurodevelopmental disorders.

A retrospective study on disease management in children and adolescents with phenylketonuria during the Covid-19 pandemic lockdown in Austria.

BACKGROUND: In classical phenylketonuria (PKU) phenylalanine (Phe) accumulates due to functional impairment of the enzyme phenylalanine hydroxylase caused by pathogenic variants in the PAH gene. PKU treatment prevents severe cognitive impairment. Blood Phe concentration is the main biochemical monitoring parameter. Between appointments and venous blood sampling, Austrian PKU patients send dried blood spots (DBS) for Phe measurements to their centre. Coronavirus disease-19 (COVID-19), caused by the SARS CoV-2 virus, was classified as a pandemic by the World Health Organization in March 2020. In Austria, two nationwide lockdowns were installed during the first and second pandemic wave with variable regional and national restrictions in between. This retrospective questionnaire study compared the frequency of Phe measurements and Phe concentrations during lockdown with the respective period of the previous year in children and adolescents with PKU and explored potential influencing factors. RESULTS: 77 patients (30 female, 47 male; mean age 12.4 [8-19] years in 2020) from five centres were included. The decline of venous samples taken on appointments in 2020 did not reach significance but the number of patients with none or only one DBS tripled from 4 (5.2%) in 2019 to 12 (15.6%) in 2020. Significantly more patients had a decline than a rise in the number of DBS sent in between 2019 and 2020 (p < 0.001; Chi2 = 14.79). Especially patients ≥ 16 years sent significantly less DBS in 2020 (T = 156, p = 0.02, r = 0.49). In patients who adhered to DBS measurements, Phe concentrations remained stable. Male or female sex and dietary only versus dietary plus sapropterin treatment did not influence frequency of measurements and median Phe. CONCLUSION: During the COVID pandemic, the number of PKU patients who stopped sending DBS to their metabolic centre increased significantly, especially among those older than 16 years. Those who kept up sending DBS maintained stable Phe concentrations. Our follow-up system, which is based on DBS sent in by patients to trigger communication with the metabolic team served adherent patients well. It failed, however, to actively retrieve patients who stopped or reduced Phe measurements.

Effect of body position on ventilation distribution during PEEP titration in a porcine model of acute lung injury using advanced respiratory monitoring and electrical impedance tomography.

BACKGROUND: Lung failure after acute lung injury remains a challenge in different clinical settings. Various interventions for restoration of gas exchange have been investigated. Recruitment of collapsed alveoli by positive end expiratory pressure (PEEP) titration and optimization of ventilation-perfusion ratio by prone positioning have been extensively described in animal and clinical trials. This animal study was conducted to investigate the effects of PEEP and positioning by means of advanced respiratory monitoring including gas exchange, respiratory mechanics, volumetric capnography and electrical impedance tomography. METHODS: After induction of acute lung injury by oleic acid and lung lavage, 12 domestic pigs were studied in randomly assigned supine or prone position during a PEEP titration trial with maximal PEEP of 30 mbar. RESULTS: Induction of lung injury resulted in significant deterioration of oxygenation [partial pressure of arterial oxygen/inspiratory fraction of oxygen (PaO2/FiO2): p = 0.002] and ventilation [partial pressure of arterial carbon dioxide (PaCO2): p = 0.002] and elevated alveolar dead-space ratios (Valv/Vte: p = 0.003) in both groups. Differences in the prone and the supine group were significant for PaCO2 at incremental PEEP 10 and 20 and at decremental PEEP 20 (20d) and 10 (10d), for PaO2/FiO2 at PEEP 10 and 10d and for alveolar dead space at PEEP 10d. Electrical impedance tomography revealed homogenous ventilation distribution in prone position during PEEP 20, 30 and 20d. CONCLUSIONS: Prone position leads to improved oxygenation and ventilation parameters in a lung injury model. Respiratory monitoring with measurement of alveolar dead space and electrical impedance tomography may visualize optimized ventilation in a PEEP titration trial.