Lupus anticoagulant associates with thrombosis in patients with COVID-19 admitted to intensive care units: A retrospective cohort study.

Background: Thrombosis is a frequent and severe complication in patients with coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU). Lupus anticoagulant (LA) is a strong acquired risk factor for thrombosis in various diseases and is frequently observed in patients with COVID-19. Whether LA is associated with thrombosis in patients with severe COVID-19 is currently unclear. Objective: To investigate if LA is associated with thrombosis in critically ill patients with COVID-19. Patients/Methods: The presence of LA and other antiphospholipid antibodies was assessed in patients with COVID-19 admitted to the ICU. LA was determined with dilute Russell's viper venom time (dRVVT) and LA-sensitive activated partial thromboplastin time (aPTT) reagents. Results: Of 169 patients with COVID-19, 116 (69%) tested positive for at least one antiphospholipid antibody upon admission to the ICU. Forty (24%) patients tested positive for LA; of whom 29 (17%) tested positive with a dRVVT, 19 (11%) tested positive with an LA-sensitive aPTT, and 8 (5%) tested positive on both tests. Fifty-eight (34%) patients developed thrombosis after ICU admission. The odds ratio (OR) for thrombosis in patients with LA based on a dRVVT was 2.5 (95% confidence interval [CI], 1.1-5.7), which increased to 4.5 (95% CI, 1.4-14.3) in patients at or below the median age in this study (64 years). LA positivity based on a dRVVT or LA-sensitive aPTT was only associated with thrombosis in patients aged less than 65 years (OR, 3.8; 95% CI, 1.3-11.4) and disappeared after adjustment for C-reactive protein. Conclusion: Lupus anticoagulant on admission is strongly associated with thrombosis in critically ill patients with COVID-19, especially in patients aged less than 65 years.

Thrombosis pathways in COVID-19 vs. influenza-associated ARDS: A targeted proteomics approach.

BACKGROUND: Pulmonary embolism (PE) occurs in one-third of critically-ill COVID-19 patients. Although prior studies identified several pathways contributing to thrombogenicity, it is unknown whether this is COVID-19-specific or also occurs in ARDS patients with another infection. OBJECTIVE: To compare pathway activity among patients having COVID-19 with PE (C19PE+), COVID-19 without PE (C19PE-), and influenza-associated ARDS (IAA) using a targeted proteomics approach. METHODS: We exploited an existing biorepository containing daily plasma samples to carefully match C19PE+ cases to C19PE- and IAA controls on mechanical ventilation duration, PEEP, FiO2, and cardiovascular-SOFA (n = 15 per group). Biomarkers representing various thrombosis pathways were measured using proximity extension- and ELISA-assays. Summed z-scores of individual biomarkers were used to represent total pathway activity. RESULTS: We observed no relevant between-group differences among 22 biomarkers associated with activation of endothelium, platelets, complement, coagulation, fibrinolysis or inflammation, except sIL-1RT2 and sST2, which were lower in C19PE- than IAA (log2-Foldchange -0.67, p = .022 and -1.78, p = .022, respectively). However, total pathway analysis indicated increased activation of endothelium (z-score 0.2 [-0.3-1.03] vs. 0.98 [-2.5--0.3], p = .027), platelets (1.0 [-1.3-3.0] vs. -3.3 [-4.1--0.6], p = .023) and coagulation (0.8 [-0.5-2.0] vs. -1.0 [-1.6-1.0], p = .023) in COVID-19 patients (C19PE+/C19PE- groups combined) compared to IAA. CONCLUSION: We observed only minor differences between matched C19PE+, C19PE-, and IAA patients, which suggests individual biomarkers mostly reflect disease severity. However, analysis of total pathway activity suggested upregulation of some distinct processes in COVID-19 could be etiologically related to increased PE-risk.

Interleukin-6 Receptor Antagonists in Critically Ill Patients with Covid-19.

BACKGROUND: The efficacy of interleukin-6 receptor antagonists in critically ill patients with coronavirus disease 2019 (Covid-19) is unclear. METHODS: We evaluated tocilizumab and sarilumab in an ongoing international, multifactorial, adaptive platform trial. Adult patients with Covid-19, within 24 hours after starting organ support in the intensive care unit (ICU), were randomly assigned to receive tocilizumab (8 mg per kilogram of body weight), sarilumab (400 mg), or standard care (control). The primary outcome was respiratory and cardiovascular organ support-free days, on an ordinal scale combining in-hospital death (assigned a value of -1) and days free of organ support to day 21. The trial uses a Bayesian statistical model with predefined criteria for superiority, efficacy, equivalence, or futility. An odds ratio greater than 1 represented improved survival, more organ support-free days, or both. RESULTS: Both tocilizumab and sarilumab met the predefined criteria for efficacy. At that time, 353 patients had been assigned to tocilizumab, 48 to sarilumab, and 402 to control. The median number of organ support-free days was 10 (interquartile range, -1 to 16) in the tocilizumab group, 11 (interquartile range, 0 to 16) in the sarilumab group, and 0 (interquartile range, -1 to 15) in the control group. The median adjusted cumulative odds ratios were 1.64 (95% credible interval, 1.25 to 2.14) for tocilizumab and 1.76 (95% credible interval, 1.17 to 2.91) for sarilumab as compared with control, yielding posterior probabilities of superiority to control of more than 99.9% and of 99.5%, respectively. An analysis of 90-day survival showed improved survival in the pooled interleukin-6 receptor antagonist groups, yielding a hazard ratio for the comparison with the control group of 1.61 (95% credible interval, 1.25 to 2.08) and a posterior probability of superiority of more than 99.9%. All secondary analyses supported efficacy of these interleukin-6 receptor antagonists. CONCLUSIONS: In critically ill patients with Covid-19 receiving organ support in ICUs, treatment with the interleukin-6 receptor antagonists tocilizumab and sarilumab improved outcomes, including survival. (REMAP-CAP ClinicalTrials.gov number, NCT02735707.).

High-salt intake affects retinal vascular tortuosity in healthy males: an exploratory randomized cross-over trial.

The retinal microcirculation is increasingly receiving credit as a relatively easily accessible microcirculatory bed that correlates closely with clinical cardiovascular outcomes. The effect of high salt (NaCl) intake on the retinal microcirculation is currently unknown. Therefore, we performed an exploratory randomized cross-over dietary intervention study in 18 healthy males. All subjects adhered to a two-week high-salt diet and low-salt diet, in randomized order, after which fundus photographs were taken and assessed using a semi-automated computer-assisted program (SIVA, version 4.0). Outcome parameters involved retinal venular and arteriolar tortuosity, vessel diameter, branching angle and fractal dimension. At baseline, participants had a mean (SD) age of 29.8 (4.4) years and blood pressure of 117 (9)/73 (5) mmHg. Overall, high-salt diet significantly increased venular tortuosity (12.2%, p = 0.001). Other retinal parameters were not significantly different between diets. Changes in arteriolar tortuosity correlated with changes in ambulatory systolic blood pressure (r = - 0.513; p = 0.04). In conclusion, high-salt diet increases retinal venular tortuosity, and salt-induced increases in ambulatory systolic blood pressure associate with decreases in retinal arteriolar tortuosity. Besides potential eye-specific consequences, both phenomena have previously been associated with hypertension and other cardiovascular risk factors, underlining the deleterious microcirculatory effects of high salt intake.

Salt increases monocyte CCR2 expression and inflammatory responses in humans.

Inflammation may play a role in the link between high salt intake and its deleterious consequences. However, it is unknown whether salt can induce proinflammatory priming of monocytes and macrophages in humans. We investigated the effects of salt on monocytes and macrophages in vitro and in vivo by performing a randomized crossover trial in which 11 healthy human subjects adhered to a 2-week low-salt and high-salt diet. We demonstrate that salt increases monocyte expression of CCR2, a chemokine receptor that mediates monocyte infiltration in inflammatory diseases. In line with this, we show a salt-induced increase of plasma MCP-1, transendothelial migration of monocytes, and skin macrophage density after high-salt diet. Macrophages demonstrate signs of an increased proinflammatory phenotype after salt exposure, as represented by boosted LPS-induced cytokine secretion of IL-6, TNF, and IL-10 in vitro, and by increased HLA-DR expression and decreased CD206 expression on skin macrophages after high-salt diet. Taken together, our data open up the possibility for inflammatory monocyte and macrophage responses as potential contributors to the deleterious effects of high salt intake.

High-salt intake affects sublingual microcirculation and is linked to body weight change in healthy volunteers: a randomized cross-over trial.

BACKGROUND: The pathophysiology of salt-sensitive hypertension remains uncertain, but may involve microvascular alterations. High-salt intake decreases microvascular density in hypertensive patients, but due to lack of studies in normotensive patients the causal pathway remains unclear. We studied whether high-salt intake decreases sublingual microvascular density in normotensive individuals and assessed the influence of body weight on changes in microvascular density. METHODS: In an open label randomized cross-over trial 18 healthy men were included to study the effect of a 2-week high-salt (>12 g/day) and low-salt (<3 g/day) diet on microvascular (diameter <20 µm) density with sublingual sidestream darkfield imaging. We used sublingual nitroglycerin (NTG) to recruit microvessels. RESULTS: There was no significant difference in microvascular density between diets (0.96 ±â€Š3.88 mm/mm; P = 0.31, following NTG; and -0.03 ±â€Š1.64 mm/mm; P = 0.95, without NTG). Increased salt intake was correlated with a decrease in microvascular density following NTG (r = -0.47; P = 0.047), but not without NTG (r = 0.06; P = 0.800). The decrease in microvascular density following high-salt intake was significantly larger for those with a large change in body weight as compared with those with a small changer in body weight (-0.79 ±â€Š1.35 and 0.84 ±â€Š1.56 mm/mm respectively, P = 0.031). CONCLUSION: We demonstrate in healthy volunteers that higher salt intake is correlated with decreased sublingual microvascular density following administration of NTG and; larger changes in body weight following high-salt intake coincide with a larger decrease in microvascular density. Changes in microvascular density occurred without blood pressure effects, indicating that high-salt load as such contributes to microvascular changes, and may precede hypertension development.

NADP+ -dependent IDH1 R132 mutation and its relevance for glioma patient survival.

The isocitrate dehydrogenase 1 (IDH1) mutation occurs in high frequency in glioma and secondary glioblastoma (GBM). Mutated IDH1 produces the oncometabolite 2-hydroxyglutarate rather than α-ketoglutarate or isocitrate. The oncometabolite is considered to be the major cause of the association between the IDH1 mutation and gliomagenesis. On the other hand, the IDH1 mutation in GBM is associated with prolonged patient survival. This association is not well understood yet but IDH1 involvement in epigenetic silencing of O-6-methylguanine-DNA methyltransferase (MGMT), a DNA repair enzyme is considered to be an important mechanism. However, it was shown recently that the IDH1 mutation and MGMT silencing are independent prognostic factors. Here, we hypothesize that the IDH1 mutation reduces the capacity to produce NADPH and thus reduces the capacity to scavenge reactive oxygen species that are generated during irradiation and chemotherapy. IDH1 activity is responsible for two-thirds of the NADPH production capacity in normal brain, whereas the IDH1 mutation reduces this capacity by almost 40%. Therefore, we hypothesize that the reduced NADPH production capacity due to the IDH1 mutation renders GBM cells more vulnerable to irradiation and chemotherapy thus prolonging survival of the patients.