Treatment of Paraquat-Induced Lung Injury With an Anti-C5a Antibody: Potential Clinical Application. Crit Care Med. 2018;46:e419-e425. [PMID: 29293144 PMCID: PMC5908256 DOI: 10.1097/ccm.0000000000002950]

Pharmacokinetic analysis of vilobelimab, anaphylatoxin C5a and antidrug antibodies in PANAMO: a phase 3 study in critically ill, invasively mechanically ventilated COVID-19 patients

BACKGROUND

Vilobelimab, a complement 5a (C5a)-specific monoclonal antibody, reduced mortality in critically ill COVID-19 patients in a phase 3 multicentre, randomized, double-blind, placebo-controlled study. As part of the study, vilobelimab concentrations and C5a levels as well as antidrug antibodies (ADAs) to vilobelimab were analysed.

RESULTS

From Oct 1, 2020 to Oct 4, 2021, 368 invasively mechanically ventilated COVID-19 patients were randomized: 177 patients were randomly assigned to receive vilobelimab while 191 patients received placebo. Pharmacokinetic sampling was only performed at sites in Western Europe. Blood samples for vilobelimab measurements were available for 93 of 177 (53%) patients in the vilobelimab group and 99 of 191 (52%) patients in the placebo group. On day 8, after three infusions, mean vilobelimab (trough) concentrations ranged from 21,799.3 to 302,972.1 ng/mL (geometric mean 137,881.3 ng/mL). Blood samples for C5a measurements were available for 94 of 177 (53%) patients in the vilobelimab group and 99 of 191 (52%) patients in the placebo group. At screening, C5a levels were highly elevated and comparable between groups. In the vilobelimab group, median C5a levels were 118.3 ng/mL [IQR 71.2-168.2 ng/mL] and in the placebo group, median C5a levels were 104.6 ng/mL [IQR 77.5-156.6 ng/mL]. By day 8, median C5a levels were reduced by 87% in the vilobelimab group (median 14.5 ng/mL [IQR 9.5-21.0 ng/mL], p < 0.001) versus an 11% increase in the placebo group (median 119.2 ng/mL [IQR 85.9-152.1 ng/mL]). Beyond day 8, though plasma sampling was sparse, C5a levels did not reach screening levels in the vilobelimab group while C5a levels remained elevated in the placebo group. Treatment-emergent ADAs were observed in one patient in the vilobelimab group at hospital discharge on day 40 and in one patient in the placebo group at hospital discharge on day 25.

CONCLUSIONS

This analysis shows that vilobelimab efficiently inhibits C5a in critically ill COVID-19 patients. There was no evidence of immunogenicity associated with vilobelimab treatment. Trial registration ClinicalTrials.gov, NCT04333420. Registered 3 April 2020, https://clinicaltrials.gov/ct2/show/NCT04333420.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Anti-C5a Antibody BDB-001 for Severe COVID-19: A Randomized, Double-Blind, Placebo-Controlled Phase 1 Clinical Trial in Healthy Chinese Adults

INTRODUCTION

Severe Coronavirus Disease 2019 (COVID-19) progresses with inflammation and coagulation, due to an overactive complement system. Complement component 5a (C5a) plays a key role in the complement system to trigger a powerful "cytokine and chemokine storm" in viral infection. BDB-001, a recombinant human immunoglobulin G4 (IgG4) that specially binds to C5a, has the potential to inhibit the C5a-triggered cytokine storm in treating COVID-19 patients and other inflammation diseases. Here, we have explored its safety, tolerability, pharmacokinetics, and pharmacodynamics in healthy adults. This trial is registered with http://www.chinadrugtrials.org.cn/(CTR20200429 ).

METHODS

Thirty-two enrolled participants were randomized into three single-dose cohorts (2, 4, and 8 mg/kg) and 1 multi-dose cohort (4 mg/kg), and received either BDB-001 or placebo (3:1) double-blindly. The safety and tolerability after administration were evaluated for 21 days for single-dose cohorts and 28 days for the multi-dose cohort. The pharmacokinetics of BDB-001 in plasma and pharmacodynamics as free C5a in plasma were analyzed.

RESULTS

The incidence of drug-related adverse events (AEs) was low, and all AEs were mild or moderate: neither AEs ≥ 3 (NCI-Common Terminology Criteria For Adverse Events, CTCAE 5.0) nor serious adverse events (SAEs) were found. The area under the concentration-time curve from time zero to 480 h (AUC_0-480h), that from time zero to infinity (AUC_inf), and peak plasma concentration ©_max) increased dose-dependently from 2 to 8 mg/kg in the single-dose cohorts and were characterized by a nonlinear pharmacokinetics of target-mediated drug disposal (TMDD). The accumulation index by AUC_0-tau after five administrations (4 mg/kg) from the multi-dose cohort was 6.42, suggesting an accumulation effect. Furthermore, inhibition of C5a at the plasma level was observed.

CONCLUSION

The results of this phase I study supported that BDB-001 is a potent anti-C5a inhibitor with safety, tolerability, and no immunogenicity. TRIAL REGISTRATION NUMBER: CTR20200429.

Mitoquinone mitigates paraquat-induced A549 lung epithelial cell injury by promoting MFN1/MFN2-mediated mitochondrial fusion

Paraquat (PQ) poisoning often leads to severe lung injuries, in which the mitochondria damage plays a critical role. Mitoquinone (MitoQ), a newly designed mitochondria-targeted antioxidant, has been proved for its benefit in mitochondria protection. However, the role of MitoQ in PQ-induced lung injury remains unclear. Thus, this study was performed to investigate the effect of MitoQ on PQ-induced lung injury and its underlying mechanisms. Our work showed that PQ caused the inhibition of A549 lung epithelial cell viability in a dose-dependent manner, while MitoQ remarkably mitigated the PQ-induced cell viability suppression. Besides this, PQ-mediated apoptosis of A549 cells was significantly attenuated by MitoQ, as indicated by the TUNEL assay and mitochondria membrane potential assay. Moreover, the intracellular reactive oxygen species (ROS) production was also dramatically suppressed when cotreated MitoQ with PQ. This could be ascribed to enhanced mitochondrial fusion mediated by Mitofusin 1 (MFN1)/Mitofusin 2 (MFN2), because MitoQ preserved mitochondrial network integrity, as reflected by MitoTracker staining, and MitoQ also increased the expression of MFN1/MFN2 in A549 cells after PQ treatment. Our data suggested MitoQ mitigated PQ-induced lung epithelial cell injury by promoting MFN1/MFN2-mediated mitochondrial fusion, and MitoQ might be a potential candidate drug for the treatment of PQ-induced lung injury.

Silymarin protects the rats against paraquat-induced acute kidney injury via Nrf2

BACKGROUND

Paraquat (PQ) poisoning induces severe acute kidney injury and causes extremely high rate of death. In this study, we aimed to investigate the protective effects of silymarin on PQ-induced acute kidney injury and explore the underlying mechanisms.

METHODS

A rat model was established through intraperitoneal injection of PQ. Rats were administrated with saline or silymarin for 3 days. Then, survival rate, physiological parameters, and renal injury score were evaluated. The apoptosis and oxidative stress in kidney tissues were determined through hematoxylin and eosin staining, quantitative reverse transcription polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assays.

RESULTS

Silymarin administration could significantly increase the survival rate of PQ-poisoned rats. It was found that silymarin treatment improved renal function, decreased injury score in kidney tissues, and inhibited the apoptosis and oxidative stress in PQ-induced acute kidney injury through the activating the signaling pathway of Nrf2 and promoting its nuclear translocation.

CONCLUSION

Silymarin exhibited a protective effect against PQ-induced kidney injury, suggesting that treatment with this flavonoid could be a potential therapeutic agent for the treatment of acute kidney injury.

Plasma Concentration After the First Hemoperfusion has a High Predictive Value in Medium Level Acute Paraquat-Poisoned Patients

BACKGROUND

Paraquat ( PQ) is very poisonous to humans and animals and there is no effective clinical antidote . The efficacy of hemoperfusion (HP) treatment for PQ poisoning remains controversial. To explore new ways to predict the prognosis of patients with acute PQ poisoning and assist in the development of better hemopurification treatment strategies.

METHODS

The clinical data of patients who were intoxicated with PQ through contact were diagnosed with PQ poisoning by high-performance liquid chromatography. Samples were collected by the Emergency Intensive Care Unit of the First Affiliated Hospital of Wenzhou Medical University from January 2012 to November 2016. Based on the prognosis, the patients were grouped into survival and death groups. Comparisons of the differences in the clinical indexes were performed, including the initial concentration of PQ at admission, PQ concentration after first HP, the number of HP cartridges used for the first hemoperfusion, whether HP was combined with continuous renal replacement therapy, and the number of concurrent organ injuries between the 2 groups. In addition, data were analyzed using multivariate logistic regression models and receiver operating characteristic curves. Moreover, prognostic factors in patients with acute PQ poisoning were analyzed.

RESULTS

Overall, 128 patients with acute PQ poisoning were enrolled in this study. The median plasma PQ concentrations of the patients at admission were 21 and 834 ng/mL (range: 50-1,099,118 ng/mL). The multiple logistic regression model revealed that the initial concentration of PQ and the PQ concentration after the first perfusion were independent risk factors for death in patients with acute PQ poisoning. The PQ concentration in the survival group after the first HP was <516 ng/mL and was mainly distributed at approximately 100 ng/mL. The percentage of patients whose concentration after the first HP was <516 ng/mL in the death group was only 19%.

CONCLUSIONS

The initial plasma PQ concentration after admission and PQ concentration after the first HP are risk factors for death in patients with acute PQ poisoning. Moreover, PQ concentration after the first HP had a high predictive value for death. When the initial plasma PQ concentration after admission ranges from 50 ng/mL to 5000 ng/mL, the rapid reduction in plasma PQ concentration after HP treatment could improve the prognosis of patients with acute PQ poisoning.

Verbascoside inhibits paraquate-induced pulmonary toxicity via modulating oxidative stress, inflammation, apoptosis and DNA damage in A549 cell

Paraquat (PQ), one of the most frequently used herbicides, can cause serious health problems in an exposed individual. In the present study, we investigated the protective effect of verbascoside (VB), a phenylpropanoid glycoside from lemon verbena, against PQ-induced A549 cell injury with a particular focus on the possible molecular pathways involved. A549 cells were exposed to PQ (300 µM) and different concentrations of VB (12.5, 25, and 50 µM). Cell viability, ROS content, the level of antioxidant enzymes (SOD, CAT and GPx) and inflammatory markers (IL-6 and TNF-α), as well as 8-OHdG, were detected using MTT assay and an ELISA kit. Western blotting and qRT-PCR were performed to measure the levels of caspase3 and NF-κB mRNA and protein expression. Exposure of cells to PQ caused viability loss and ROS increase. PQ also increased the levels of IL-6, TNF-α and 8-OHdG and decreased the antioxidant enzymes content. PQ treatment resulted in cell death by increasing the gene and protein expression level of caspase 3 and NF-κB. Treatment with VB notably increased cell survival, antioxidant enzymes activity, which concomitantly attenuated ROS, NF-κB and inflammatory mediator production. VB also inhibited apoptosis expression markers. These results indicated that VB could protect A549 cells against PQ induced cell injury by attenuation of ROS and inflammatory marker production and modulation of antioxidant enzymes. VB efficiently suppressed increased NF-κB and caspase-3 activity and formation of 8-OHdG and ultimately improved cell viability. Therefore, VB may be useful in the development of a new therapy for PQ-induced pulmonary toxicity.

Can kissing cause paraquat poisoning: A case report and review of literature

BACKGROUND

Paraquat is an effective, broad-spectrum, highly toxic quaternary ammonium herbicide. Paraquat poisoning has been reported frequently in recent years. It has severe lung, kidney, liver, and nervous system toxicity, and there is currently no specific antidote. Paraquat poisoning may follow ingestion, inhalation, and skin contact. There have been no previous reports of paraquat poisoning that resulted from kissing. This rare case provides a new reference for the prevention of paraquat poisoning.

CASE SUMMARY

A 27-year-old man came to the emergency department complaining that he had come into contact with paraquat by kissing his girlfriend, who had taken 80-120 mL 20% paraquat. After admission, his lung computed tomography (CT) showed increased lung markings. Redness and a burning sensation developed on his tongue, which progressed to painful erosions and coalescent ulcers. The final diagnosis was mild paraquat poisoning. Anti-inflammatory, antioxidant, and symptomatic treatment were initiated and continued for 7 d. Dyspnea did not occur, subsequent lung CT showed no significant changes, and the tongue pain was slightly improved. One month after discharge, the tongue injury was resolved.

CONCLUSION

This case indicated that the tongue and lung tissues are particularly vulnerable to paraquat toxicity, even after a limited exposure.

Isorhynchophylline ameliorates paraquat-induced acute kidney injury by attenuating oxidative stress and mitochondrial damage via regulating toll-interacting expression

Isorhynchophylline (IRN) is an alkaloid with anti-inflammatory and anti-oxidative activities in cardiovascular and brain diseases, but its role in paraquat (PQ)-induced acute kidney injury (AKI) is yet unknown. The model of PQ-induced AKI in rats was established by intraperitoneal injection of PQ (25 mg/kg). We found that the tail vein injection of IRN (4 mg/kg) significantly increased the survival rate of PQ-intoxicated rats. IRN administration alleviated PQ-induced renal injury and renal dysfunction in rats, as evidenced by decreased apoptosis in renal cortex and reduced serum creatinine, serum BUN, and urine NGAL levels. Furthermore, IRN treatment improved the PQ-triggered oxidative stress in renal cortex by increasing the levels of anti-oxidant indicators (SOD activity, GSH/GSSG ratio, levels of Nrf-2, NQO-1, and HO-1 in renal cortex) and decreasing the levels of oxidative stress indexes (ROS and MDA levels in renal cortex). Interestingly, toll-interacting protein (Tollip), a negative regulator of interleukin 1 receptor associated kinase 1 (IRAK1) phosphorylation, was demonstrated to be increased by IRN injection in the renal cortex of PQ-intoxicated rats. In vitro experiments revealed that IRN protected renal tubular epithelial cells against PQ toxicity through suppressing oxidative stress and mitochondrial damage, and these protective effects were reversed by Tollip shRNA. Collectively, the present study demonstrated that IRN ameliorated PQ-induced AKI by attenuating oxidative stress and mitochondrial damage through upregulating Tollip, which provides new insights into the pathogenesis and treatment of PQ poisoning.

The herbicide paraquat-induced molecular mechanisms in the development of acute lung injury and lung fibrosis

The herbicide paraquat (PQ; 1,1'-dimethyl-4,4'-bipyridylium dichloride) is a highly toxic organic heterocyclic herbicide that has been widely used in agricultural settings. Since its commercial introduction in the early 1960s, numerous cases of fatal PQ poisonings attributed to accidental and/or intentional ingestion of PQ concentrated formulations have been reported. The clinical manifestations of the respiratory system during the acute phase of PQ poisoning mainly include acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), followed by pulmonary fibrosis in a later phase. The focus of this review is to summarize the most recent publications related to PQ-induced lung toxicity as well as the underlying molecular mechanisms for PQ-mediated pathologic processes. Growing sets of data from in vitro and in vivo models have demonstrated the involvement of the PQ in regulating lung oxidative stress, inflammatory response, epigenetics, apoptosis, autophagy, and the progression of lung fibrosis. The article also summarizes novel therapeutic avenues based on a literature review, which can be explored as potential means to combat PQ-induced lung toxicity. Finally, we also presented clinical studies on the association of PQ exposure with the incidence of lung injury and pulmonary fibrosis.

The roles and potential therapeutic implications of C5a in the pathogenesis of COVID-19-associated coagulopathy

Emerging evidence has documented that multisystem organ failure in coronavirus disease 2019 (COVID-19) patients is strongly associated with various coagulopathies. Treatments for COVID-19-associated coagulopathy are still a clinical challenge. An advancement in the knowledge of mechanisms of the excessive or inappropriate activation of the complement cascade involved in the genesis of COVID-19-associated coagulopathy might be a fundamental approach for developing novel classes of anticoagulant drugs. In this context, there is emerging evidence indicating that C5a, a component of the complement system, and its receptors (C5aRs) play a critical role in the genesis of the COVID-19-associated hypercoagulable state. Thus, this review describes the mechanisms by which C5a/C5aR signaling participates in the cascade of events involved in the pathophysiology of COVID-19-associated coagulopathy. Furthermore, it highlights the current possibilities for the development of a novel therapeutic approach for COVID-19 patients that targets C5a/C5aRs signaling.

Use of low-molecular-weight heparin in severe paraquat poisoning: a case report

BACKGROUND

Acute paraquat ingestion remains a leading cause of mortality in developing countries. There is currently no evidence that treatment with high-dose immunosuppressants and antioxidants improves survival in patients with paraquat poisoning, and better options are urgently needed. Here, we describe the unexpected survival and recovery of a patient with a potentially fatal paraquat poisoning.

CASE PRESENTATION

After ingesting 28 mL of paraquat (20% ion w/v), confirmed by a deep blue color in the urine dithionite test (UDT), a 17-year-old Hispanic Colombian boy was treated according to the hospital protocol with cyclophosphamide, methylprednisolone, N-acetylcysteine, vitamin E and propranolol. Gastrointestinal endoscopy showed extensive ulceration and necrosis. As a novelty, enoxaparin at a single dose of 60 mg was added to his treatment. Despite the evidence of severe mucosal burns in the gastrointestinal tract and high paraquat concentrations found in the UDT, the clinical condition began to improve after 1 day of treatment, with full recovery and discharge from hospital after 21 days.

CONCLUSIONS

Although the amount of paraquat ingested by the patient was large and the UDT indicated severe poisoning with a somber prognosis, unexpected survival of the patient was observed, and the addition of enoxaparin was the only change from the standard treatment.

The complement system in COVID-19: friend and foe?

Coronavirus disease 2019 (COVID-19), the disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has resulted in a global pandemic and a disruptive health crisis. COVID-19-related morbidity and mortality have been attributed to an exaggerated immune response. The role of complement activation and its contribution to illness severity is being increasingly recognized. Here, we summarize current knowledge about the interaction of coronaviruses with the complement system. We posit that (a) coronaviruses activate multiple complement pathways; (b) severe COVID-19 clinical features often resemble complementopathies; (c) the combined effects of complement activation, dysregulated neutrophilia, endothelial injury, and hypercoagulability appear to be intertwined to drive the severe features of COVID-19; (d) a subset of patients with COVID-19 may have a genetic predisposition associated with complement dysregulation; and (e) these observations create a basis for clinical trials of complement inhibitors in life-threatening illness.

COVID-19 and Cancer: a Comprehensive Review

Purpose of Review

The outbreak of the novel coronavirus disease 2019 (COVID-19) has emerged to be the biggest global health threat worldwide, which has now infected over 1.7 million people and claimed more than 100,000 lives around the world. Under these unprecedented circumstances, there are no well-established guidelines for cancer patients.

Recent Findings

The risk for serious disease and death in COVID-19 cases increases with advancing age and presence of comorbid health conditions. Since the emergence of the first case in Wuhan, China, in December 2019, tremendous research efforts have been underway to understand the mechanisms of infectivity and transmissibility of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a fatal virus responsible for abysmal survival outcomes. To minimize the mortality rate, it becomes prudent to identify symptoms promptly and employ treatments appropriately. Even though no cure has been established, multiple clinical trials are underway to determine the most optimal strategy. Managing cancer patients under these circumstances is rather challenging, given their vulnerable status and the aggressive nature of their underlying disease.

Summary

In this comprehensive review, we discuss the impact of COVID-19 on health and the immune system of those affected, reviewing the latest treatment approaches and ongoing clinical trials. Additionally, we discuss challenges faced while treating cancer patients and propose potential approaches to manage this vulnerable population during this pandemic.

Comparison of severity index and plasma paraquat concentration for predicting survival after paraquat poisoning: A meta-analysis

BACKGROUND

Severity index and plasma paraquat (PQ) concentration can predict the prognosis of patients with PQ poisoning. However, the better parameter is yet to be systematically investigated and determined. Thus, we conduct this systematic review and meta-analysis to investigate the prognostic value of severity index and plasma PQ concentration in patients with PQ poisoning.

METHODS

We searched PubMed, Embase, Web of Science, ScienceDirect, and Cochrane Library to identify all relevant papers that were published up to March 2019. All diagnostic studies that compared severity index and plasma PQ concentration to predict mortality in patients with PQ poisoning were enrolled in this meta-analysis. Odds ratios (ORs) with 95% confidence intervals (CIs) for individual trials were pooled using a random-effect model. We also aggregated heterogeneity testing, sensitivity analysis, and publication bias analysis.

RESULTS

Ultimately, seven studies involving 821 patients were included. The pooled OR with a 95% CI of severity index was 24.12 (95% CI: 9.34-62.34, P < .001), with an area under the curve of 0.88 (95% CI: 0.85-0.90), sensitivity of 0.84 (95% CI: 0.74-0.91), and specificity of 0.81 (95% CI: 0.75-0.87). Meanwhile, the pooled OR with 95% CI of plasma PQ concentration was 34.39 (95% CI: 14.69-80.56, P < .001), with an area under the curve of 0.94 (95% CI: 0.91-0.96), sensitivity of 0.86 (95% CI: 0.75-0.93), and specificity of 0.89 (95% CI: 0.76-0.95). Sensitivity analysis demonstrated the stability of the results of our meta-analysis. No significant publication bias was observed in this meta-analysis.

CONCLUSION

Overall, this study indicated that severity index and plasma PQ concentration have relatively high-prognostic value in patients with PQ poisoning, and that the sensitivity and specificity of plasma PQ concentration are superior to those of severity index.

Tanshinone IIA attenuates paraquat‑induced acute lung injury by modulating angiotensin‑converting enzyme 2/angiotensin‑(1‑7) in rats

Tanshinone IIA (TIIA) is an active compound that can be isolated from the Chinese herb, Salvia miltiorrhizae Bunge, also known as danshen. Previous studies have demonstrated that TIIA can effectively attenuate bleomycin‑induced pulmonary fibrosis in rats. However, it has not been determined whether TIIA can attenuate paraquat (PQ)‑induced acute lung injury (ALI). In the present study, the protective effects exhibited by TIIA on PQ‑induced ALI, as well as its underlying mechanisms, were investigated using Sprague‑Dawley (SD) rats. ALI animal models using rats were established via administration of PQ. Adult male SD rats were randomly divided into three groups: A control group, a PQ group and a PQ + TIIA group. Total cell count, total protein levels and lactic dehydrogenase (LDH) levels in bronchoalveolar lavage fluid (BALF), as well as myeloperoxidase (MPO) activity in lung tissues were determined. Lung histological alterations were also investigated. Angiotensin converting enzyme 2 (ACE2) and Angiotensin 1‑7 [Ang‑(1‑7)] expression levels in the lung were also analyzed. The results demonstrated that administration of PQ induced marked histological alterations, and markedly increased neutrophil infiltration, lung wet/dry weight ratio, total cell count, protein content and LDH levels in BALF. In addition, PQ was revealed to significantly decrease ACE2 and Ang‑(1‑7) expression levels in lung tissues. However, it was demonstrated that TIIA attenuated these effects. Therefore, the results of the present study suggest that that TIIA may exhibit a therapeutic effect regarding PQ‑induced ALI in rats, and that ACE2 and Ang‑(1‑7) may be involved in the underlying mechanisms of this effect.