Sensitivity of dose-estimations for acute acetaminophen overdose in predicting hepatotoxicity risk using the Rumack-Matthew Nomogram

Rapid and non-invasive analysis of paracetamol overdose using paper arrow-mass spectrometry: a prospective observational study

BACKGROUND

Paracetamol is the most consumed medicine globally. Its accessibility contributes to common overdose. Paracetamol overdose is responsible for > 50% of acute liver failure cases, making it the second most common reason for a liver transplant. Rapid quantitation of paracetamol is crucial to guide treatment of paracetamol overdose. Current tests require invasive sampling and relatively long turnaround times. Paper arrow-mass spectrometry (PA-MS) combines sample collection, extraction, separation, enrichment and ionisation onto a single paper strip, achieving rapid, accurate, cost-effective and eco-friendly analysis direct from raw human saliva.

METHODS

To validate PA-MS against an established test, 17 healthy adults were recruited. Samples were collected before and at 15, 30, 60, 120 and 240 min after ingesting 1 g of paracetamol. Plasma measured with an established clinical test served as the reference standard to validate PA-MS with three biofluids-plasma, resting saliva (RS) and stimulated saliva (SS). Participants' views of blood, RS and SS sampling procedures were assessed qualitatively. Cross-validation was assessed using Lin's concordance correlation coefficients (CCC), Bland-Altman difference plots, and ratios of PA-MS to the reference standard test.

RESULTS

PA-MS using stimulated saliva offers a reliable alternative to intravenous blood sampling. The CCC is 0.93, the mean difference with the reference test is - 0.14 mg/L, and the ratios compared to the reference test are 0.84-1.27 from correlated samples collected at 5 intervals over 4 h for each participant.

CONCLUSIONS

Paracetamol detection from SS with PA-MS provides a reliable result that can aid timely treatment decisions. Differences between paracetamol concentration in resting and stimulated saliva were also identified for the first time, highlighting the importance of standardising saliva collection methods in general. This study marks a major milestone towards rapid and convenient saliva analysis.

Augmenting the sensitivity for hepatotoxicity prediction in acute paracetamol overdose: combining psi (ψ) parameter and paracetamol concentration aminotransferase activity multiplication product

INTRODUCTION

While factors like high serum paracetamol (acetaminophen) concentration and delayed acetylcysteine treatment increase hepatotoxicity risk, existing predictive tools, such as the paracetamol concentration aminotransferase activity multiplication product and the psi (ψ) parameter, lack definitive accuracy. This study evaluated the paracetamol psi parameter multiplication product addition against the psi parameter and the paracetamol concentration aminotransferase activity multiplication product for predicting hepatotoxicity following an acute paracetamol overdose.

METHODS

A retrospective analysis of patients with acute paracetamol overdose from January 2007 to December 2016 was conducted. The paracetamol psi parameter multiplication product addition, calculated by summing the psi parameter (mmol/L × h) and the paracetamol concentration aminotransferase activity multiplication product (g U/L2), was used. Hepatotoxicity was defined as aspartate or alanine aminotransferase activities ≥1,000 U/L. Diagnostic accuracy was assessed through sensitivity, specificity, the area under the receiver operating characteristic curve, and their corresponding 95% CI, with the optimal cutoff determined using the maximum Youden index method.

RESULTS

The study comprised 421 patients, mostly female (82.9%) with a median age of 23 years. Hepatotoxicity occurred in 13.5% (57 patients). The paracetamol psi parameter multiplication product addition showed an area under the receiver operating characteristic curve of 0.989 (95% CI: 0.974-0.997), with an optimal cutoff at 9.723, providing 96.5% sensitivity and 97.3% specificity. The paracetamol psi parameter multiplication product addition demonstrated superior performance in area under the receiver operating characteristic curve compared to the individual assessments of the psi parameter (0.916; 95% CI: 0.885-0.941) and the paracetamol concentration aminotransferase activity multiplication product (0.901; 95% CI: 0.868-0.928).

DISCUSSION

The paracetamol psi parameter multiplication product addition appears to be a more effective diagnostic tool than the psi parameter or the paracetamol concentration aminotransferase activity multiplication product alone.

CONCLUSION

Incorporating the paracetamol psi parameter multiplication product addition into clinical protocols could improve paracetamol overdose management by enabling precise identification of individuals at heightened risk for hepatotoxicity, thereby facilitating the customization of treatment approaches.

Methanol Induced Optic Neuropathy: Molecular Mysteries, Public Health Perspective, Clinical Insights and Treatment Strategies

Methanol-induced optic neuropathy (MION) represents a critical public health issue, particularly prevalent in lower socioeconomic populations and regions with restricted alcohol access. MION, characterized by irreversible visual impairment, arises from the toxic metabolization of methanol into formaldehyde and formic acid, leading to mitochondrial oxidative phosphorylation inhibition, oxidative stress, and subsequent neurotoxicity. The pathogenesis involves axonal and glial cell degeneration within the optic nerve and potential retinal damage. Despite advancements in therapeutic interventions, a significant proportion of affected individuals endure persistent visual sequelae. The study comprehensively investigates the pathophysiology of MION, encompassing the absorption and metabolism of methanol, subsequent systemic effects, and ocular impacts. Histopathological changes, including alterations in retinal layers and proteins, Müller cell dysfunction, and visual symptoms, are meticulously examined to provide insights into the disease mechanism. Furthermore, preventive measures and public health perspectives are discussed to highlight the importance of awareness and intervention strategies. Therapeutic approaches, such as decontamination procedures, ethanol and fomepizole administration, hemodialysis, intravenous fluids, electrolyte balance management, nutritional therapy, corticosteroid therapy, and erythropoietin (EPO) treatment, are evaluated for their efficacy in managing MION. This comprehensive review underscores the need for increased awareness, improved diagnostic strategies, and more effective treatments to mitigate the impact of MION on global health.

Late N-acetylcysteine for successful recovery of acetaminophen-related acute liver failure: A case report

Acetaminophen toxicity is one of the leading causes of liver failure. Although N-acetylcysteine (NAC) is generally successful in preventing acetaminophen hepatotoxicity when given in a timely manner, if not prescribed in the early golden time, the only practical way to save the patient might be liver transplantation. The case presented was a 20-year-old female with an acetaminophen overdose (30 g), for which more than 24 h had passed since the ingestion. Despite the critical clinical condition, loss of consciousness (Glasgow Coma Score of 4) of the patient, and passing the golden time of antidote administration, the decision was made by the healthcare team to administer NAC. After transferring the patient to the intensive care unit, the three-bag NAC regimen was initiated and appropriate monitoring was performed. After this, the regimen of 3 g q8h was continued for the patient. The patient's condition began to improve slowly on the second day and then she was extubated on the fourth day. Finally, she was discharged on the tenth day. Although the golden period of antidote administration had passed outwardly, there was no need for a liver transplant and the patient recovered successfully with late NAC administration. Hence, clinicians can benefit from the use of NAC even in the late phases of acetaminophen liver toxicity.

Co-Culture of Human Primary Hepatocytes and Nonparenchymal Liver Cells in the Emulate® Liver-Chip for the Study of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is a significant public health issue, but standard animal tests and clinical trials sometimes fail to predict DILI due to species differences and the relatively low number of human subjects involved in preapproval studies of a new drug, respectively. In vitro models have long been used to aid DILI prediction, with primary human hepatocytes (PHHs) being generally considered the gold standard. However, despite many efforts and decades of work, traditional culture methods have been unsuccessful in either fully preserving essential liver functions after isolation of PHHs or in emulating interactions between PHHs and hepatic nonparenchymal cells (NPCs), both of which are essential for the development of DILI under in vivo conditions. Recently, various liver-on-a-chip (Liver-Chip) systems have been developed to co-culture hepatocytes and NPCs in a three-dimensional environment on microfluidic channels, enabling better maintenance of primary liver cells and thus improved DILI prediction. The Emulate® Liver-Chip is a commercially available system that can recapitulate some in vivo DILI responses associated with certain compounds whose liver safety profile cannot be accurately evaluated using conventional approaches involving PHHs or animal models due to a lack of innate immune responses or species-dependent toxicity, respectively. Here, we describe detailed procedures for the use of Emulate® Liver-Chips for co-culturing PHHs and NPCs for the purpose of DILI evaluation. First, we describe the procedures for preparing the Liver-Chip. We then outline the steps needed for sequential seeding of PHHs and NPCs in the prepared Liver-Chips. Lastly, we provide a protocol for utilizing cells maintained in perfusion culture in the Liver-Chips to evaluate DILI, using acetaminophen as an example. In all, use of this system and the procedures described here allow better preservation of the functions of human primary liver cells, resulting in an improved in vitro model for DILI assessment. © 2022 Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Basic Protocol 1: Liver-Chip preparation Basic Protocol 2: Seeding primary human hepatocytes and nonparenchymal cells on Liver-Chips Basic Protocol 3: Perfusion culture for the study of acetaminophen-induced liver injury.