Effect of high-dose intravenous vitamin C therapy on the prognosis in patients with moderately severe and severe acute pancreatitis: protocol of a prospective, randomized, double-blinded, placebo-controlled study.

Introduction: Acute pancreatitis is a common gastrointestinal disease. The mortality of patients affected by severe acute pancreatitis (SAP) remains high. It is unclear whether high-dose intravenous vitamin C (HDIVC) therapy could improve the prognosis of these patients. The current prospective, randomized, double-blinded, placebo-controlled study will explore the effect of high-dose intravenous vitamin C therapy on the prognosis in patients with moderately severe and severe acute pancreatitis. Methods and design: A total of 418 participants with moderately severe and severe acute pancreatitis who meet the eligible criteria will be randomly assigned in a 1:1 ratio to receive treatment with HDIVC (200 mg/kg/24 h) or placebo (saline) for a period of 7 days. The primary outcome is 28-day mortality in these patients. The secondary outcomes include organ functions and interventions, laboratory tests, healthcare, and 90-day mortality. Ethics and dissemination: This protocol was approved by the institutional ethics board of the Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China (Registration Number: 2019-90). The report of the study will be published in peer-reviewed journals and presented at conferences, both nationally and internationally. Clinical trial registration: Chinese Clinical Trial Registry (ChiCTR1900022022). Version 1.5.

High-Dose Vitamin C Alleviates Pancreatic Necrosis by Inhibiting Platelet Activation Through the CXCL12/CXCR4 Pathway in Severe Acute Pancreatitis.

Background: Platelet activation in the early stage of pancreatitis is the key step developing into pancreatic necrosis. Studies suggested that vitamin C (Vit C) can inhibit platelet activity by targeting CXCL12/CXCR4 pathway. High-dose Vit C were showed to reduce pancreatic necrosis in severe acute pancreatitis (SAP) but the mechanism remains unclear. Here we speculate high-dose Vit C reduce pancreatic necrosis by inhibiting platelet activation through downregulating CXCL12/CXCR4 pathway. Methods: The pancreatic microcirculation of rats was observed by intravital microscopy. The platelet activity of SAP rats treated with or without high-dose Vit C was analyzed by platelet function test. Besides, the activity of platelets preincubated with high-dose Vit C or vehicle from SAP patients was also evaluated. Then, the TFA (CXCR4 agonist) and rCXCL12 were used to neutralize the effect of high-dose Vit C in SAP rats treated with high-dose Vit C. Meanwhile, the levels of enzymes and inflammatory cytokines in rat plasma, and rats' pancreatic histopathology and mortality were assessed. Results: Platelets from animals and patients with SAP are more sensitive to agonists and are more easily activated. Administration of high-dose Vit C significantly ameliorated excessive activation of platelets in SAP rats, ultimately increasing the microvessel density and inducing microthrombus and blood stasis; these results were consistent with clinical sample analysis. Moreover, high-dose Vit C significantly inhibited the release of amylase, lipase, TNF-α, and IL-6 in SAP rat plasma, reducing pancreatic damage and the mortality of SAP rats. However, using TFA and rCXCL12 significantly reversed the effect of high-dose Vit C on excessive activation of platelets, aggravating microcirculation impairment and pancreatic damage. Conclusion: The present study suggests that high-dose Vit C can ameliorate pancreatic necrosis by improving microcirculation disorders of SAP. For the first time, the underlying mechanism is related with inhibiting platelet activation through the CXCL12/CXCR4 pathway.

High-dose vitamin C on sepsis: Protocol of a prospective, multi-centered, double-blinded, randomized, and placebo-controlled superiority study.

Background: Sepsis is an inflammatory syndrome with life-threatening organ dysfunction and high mortality. In the recent 10 years, high-dose intravenous injection of vitamin C, the first-line antioxidant of humans, has received highlighted attention in the field of critical care. The study aims to examine the efficacy and safety of high-dose intravenous injection of vitamin C in the treatment of sepsis. Methods and design: Here, we are conducting a prospective, multi-centered, double-blinded, randomized, and placebo-controlled superiority study named High-Dose Vitamin C on Sepsis (HDVCOS). A total of 620 participants diagnosed with sepsis in four participating sites across China that satisfy the eligibility criteria will be randomized at a ratio of 1:1 to receive treatment with a high-dose intravenous injection of vitamin C (200 mg/kg/24 h) or placebo (saline) for 4 days. The primary outcome is 28 days of mortality. The secondary outcomes include the incidence of organ failure, Sequential Organ Failure Assessment (SOFA) score change, organ support, the relationship between plasma vitamin C concentration and outcomes, and adverse events. Conclusion: The findings of this study will provide potential evidence for high-dose intravenous injection of vitamin C in the treatment of sepsis. Clinical trial registration: [http://www.chictr.org.cn/showprojen.aspx?proj=29851], identifier [ChiCTR1800017633].

Effect of high-dose intravenous vitamin C on point-of-care blood glucose level in septic patients: a retrospective, single-center, observational case series.

INTRODUCTION: High-dose vitamin C is an essential adjunctive drug for sepsis treatment. This study aimed to determine if high-dose vitamin C could lead to erroneous point-of-care glucose testing results. METHODS AND MATERIALS: This retrospective, single-center, observational case series involved septic patients treated with high-dose vitamin C. We monitored their paired point-of-care glucose and laboratory glucose levels for statistical analysis. The glucose oxidase-peroxidase colorimetric method and hexokinase spectrophotometric method were applied for point-of-care glucose and laboratory glucose monitoring, respectively. Parkes Consensus Error Grid Analysis was used to assess the clinical influence of paired blood glucose values. Subgroup analyses were conducted to explore the effect of different vitamin C dosages and various renal function levels on point-of-care glucose readings. RESULTS: During a 3-year period, 82 eligible septic patients who accepted at least three days of high-dose vitamin C treatment were included in this study. Compliance with ISO15197:2013 criteria was met in 30 (36.59%) paired values, a proportion considerably lower than the minimum criteria for accuracy. Subgroup analysis showed that worse renal function or higher vitamin C dosage could lead to greater bias in point-of-care glucose readings; however, these inaccuracies rarely represented a clinical risk. CONCLUSIONS: High-dose intravenous ascorbate acid infusion may interfere with point-of-care glucose testing results. Thus, laboratory glucose measurements are recommended for more accurate results. Nonetheless, the inaccuracies magnitude of point-of-care glucose readings does not represent a significant clinical risk when physicians alter clinical action based on these results.

High-dose vitamin C alleviates pancreatic injury via the NRF2/NQO1/HO-1 pathway in a rat model of severe acute pancreatitis.

BACKGROUND: Oxidative stress plays a pivotal role in the progress of severe acute pancreatitis (SAP). Vitamin C (VC) is the most important antioxidant in plasma. However, the effects of an intravenous administration of high-dose VC and the mechanisms by which it exerts its antioxidant function in an experimental model of SAP have not been determined. METHODS: Sodium taurocholate was used to induce rat pancreatic injury and AR42J cells injury. After the establishment of SAP model, SAP rat and injured AR42J cells were treated with VC. For the injured AR42J cells, small interfering RNA-mediated knockdown of NRF2 was conducted after VC treatment. The histopathological characteristics, the apoptosis of pancreatic acinar cells, oxidative stress markers and levels of enzymes, biochemical indicators, and inflammatory cytokines were examined in vivo and in vitro. Furthermore, the mortality of rats was assessed. RESULTS: In vivo and in vitro results demonstrated that VC treatment ameliorated apoptosis of pancreatic acinar cells, as evidenced by the increase in Bcl-2, Bcl-XL, and MCL-1 expressions and decrease in Bax and cleaved caspase-3 expression along with decreased TUNEL-positive cells. Also, we found that the elevation of MDA and decrease of SOD, GPx, GSH/GSSG, and T-AOC induced by SAP were reversed by VC treatment in vivo and in vitro, and VC treatment increased expressions of Nrf2, NQO1, and HO-1 in SAP model at protein and gene level, indicating that VC attenuated oxidative stress via the NRF2/NQO1/HO-1 pathway. Meanwhile, it was found that sodium taurocholate significantly induced the release of amylase, lipase, IL-1ß, and IL-6 in rat plasma and AR42J cells, which were declined by VC treatment. In vitro results also revealed that these alterations in sodium taurocholate-injured AR42J cells due to VC treatment was attenuated by NRF2 knockdown. In addition, VC at a dose of 500 mg/kg decreased the levels of lactic acid, Cre, NGAL, AST, and ALT in the plasma of SAP rats, suggesting the improvement of renal and pancreatic injury and liver function of SAP rats. Furthermore, the mortality of SAP rats was 50%, which declined to 30% after VC treatment. CONCLUSIONS: The present study suggests that high-dose of VC ameliorate pancreatic injury of SAP via the NRF2/NQO1/HO-1 pathway to inhibit oxidative stress.