Cytokeratin-18 is a sensitive biomarker of alanine transaminase increase in a placebo-controlled, randomized, crossover trial of therapeutic paracetamol dosing (PATH-BP biomarker Sub-study).

Drug-induced liver injury (DILI) is a challenge in clinical medicine and drug development. Highly sensitive novel biomarkers have been identified for detecting DILI following a paracetamol overdose. The study objective was to evaluate biomarker performance in a 14-day trial of therapeutic dose paracetamol. The PATH-BP trial was a double-blind, placebo-controlled, crossover study. Individuals (n = 110) were randomized to receive 1 g paracetamol 4×daily or matched placebo for 2 weeks followed by a 2-week washout before crossing over to the alternate treatment. Blood was collected on days 0 (baseline), 4, 7 and 14 in both arms. Alanine transaminase (ALT) activity was measured in all patients. MicroRNA-122 (miR-122), cytokeratin-18 (K18) and glutamate dehydrogenase (GLDH) were measured in patients who had an elevated ALT on paracetamol treatment (≥50% from baseline). ALT increased in 49 individuals (45%). All 3 biomarkers were increased at the time of peak ALT (K18 paracetamol arm: 18.9 ± 9.7 ng/mL, placebo arm: 11.1 ± 5.4 ng/mL, ROC-AUC = 0.80, 95%CI 0.71-0.89; miR-122: 15.1 ± 12.9fM V 4.9 ± 4.7fM, ROC-AUC = 0.83, 0.75-0.91; and GLDH : 24.6 ± 31.1U/L V 12.0 ± 11.8U/L, ROC-AUC = 0.66,0.49-0.83). All biomarkers were correlated with ALT (K18 r = 0.68, miR-122 r = 0.67, GLDH r = 0.60). To assess sensitivity, biomarker performance was analyzed on the visit preceding peak ALT (mean 3 days earlier). K18 identified the subsequent ALT increase (K18 ROC-AUC = 0.70, 0.59-0.80; miR-122 ROC-AUC = 0.60,0.49-0.72, ALT ROC-AUC = 0.59,0.48-0.70; GLDH ROC-AUC = 0.70,0.50-0.90). Variability was lowest for ALT and K18. In conclusion, K18 was more sensitive than ALT, miR-122 or GLDH and has potential significant utility in the early identification of DILI in trials and clinical practice.

Erratum to "Optical Detection of Distal Lung Enzyme Activity in Human Inflammatory Lung Disease".

[This corrects the article DOI: 10.34133/2021/9834163.].

Evaluation of new or repurposed treatments for COVID-19: protocol for the phase Ib/IIa DEFINE trial platform.

INTRODUCTION: COVID-19 is a new viral-induced pneumonia caused by infection with a novel coronavirus, SARS-CoV-2. At present, there are few proven effective treatments. This early-phase experimental medicine protocol describes an overarching and adaptive trial designed to provide safety data in patients with COVID-19, pharmacokinetic (PK)/pharmacodynamic (PD) information and exploratory biological surrogates of efficacy, which may support further development and deployment of candidate therapies in larger scale trials of patients positive for COVID-19. METHODS AND ANALYSIS: Define is an ongoing exploratory multicentre-platform, open-label, randomised study. Patients positive for COVID-19 will be recruited from the following cohorts: (a) community cases; (b) hospitalised patients with evidence of COVID-19 pneumonitis; and (c) hospitalised patients requiring assisted ventilation. The cohort recruited from will be dependent on the experimental therapy, its route of administration and mechanism of action. Randomisation will be computer generated in a 1:1:n ratio. Twenty patients will be recruited per arm for the initial two arms. This is permitted to change as per the experimental therapy. The primary statistical analyses are concerned with the safety of candidate agents as add-on therapy to standard of care in patients with COVID-19. Secondary analysis will assess the following variables during treatment period: (1) the response of key exploratory biomarkers; (2) change in WHO ordinal scale and National Early Warning Score 2 (NEWS2) score; (3) oxygen requirements; (4) viral load; (5) duration of hospital stay; (6) PK/PD; and (7) changes in key coagulation pathways. ETHICS AND DISSEMINATION: The Define trial platform and its initial two treatment and standard of care arms have received a favourable ethical opinion from Scotland A Research Ethics Committee (REC) (20/SS/0066), notice of acceptance from The Medicines and Healthcare Products Regulatory Agency (MHRA) (EudraCT 2020-002230-32) and approval from the relevant National Health Service (NHS) Research and Development (R&D) departments (NHS Lothian and NHS Greater Glasgow and Clyde). Appropriate processes are in place in order to be able to consent adults with and without capacity while following the necessary COVID-19 safe procedures. Patients without capacity could be recruited via a legal representative. Witnessed electronic consent of participants or their legal representatives following consent discussions was established. The results of each study arm will be submitted for publication in a peer-reviewed journal as soon as the treatment arm has finished recruitment, data input is complete and any outstanding patient safety follow-ups have been completed. Depending on the results of these or future arms, data will be shared with larger clinical trial networks, including the Randomised Evaluation of COVID-19 Therapy trial (RECOVERY), and to other partners for rapid roll-out in larger patient cohorts. TRIAL REGISTRATION NUMBER: ISRCTN14212905, NCT04473053.

Activated neutrophil fluorescent imaging technique for human lungs.

Neutrophil activation is an integral process to acute inflammation and is associated with adverse clinical sequelae. Identification of neutrophil activation in real time in the lungs of patients may permit biological stratification of patients in otherwise heterogenous cohorts typically defined by clinical criteria. No methods for identifying neutrophil activation in real time in the lungs of patients currently exist. We developed a bespoke molecular imaging probe targeting three characteristic signatures of neutrophil activation: pinocytosis, phagosomal alkalinisation, and human neutrophil elastase (HNE) activity. The probe functioned as designed in vitro and ex vivo. We evaluated optical endomicroscopy imaging of neutrophil activity using the probe in real-time at the bedside of healthy volunteers, patients with bronchiectasis, and critically unwell mechanically ventilated patients. We detected a range of imaging responses in vivo reflecting heterogeneity of condition and severity. We corroborated optical signal was due to probe function and neutrophil activation.

Optical Detection of Distal Lung Enzyme Activity in Human Inflammatory Lung Disease.

Objective and Impact Statement. There is a need to develop platforms delineating inflammatory biology of the distal human lung. We describe a platform technology approach to detect in situ enzyme activity and observe drug inhibition in the distal human lung using a combination of matrix metalloproteinase (MMP) optical reporters, fibered confocal fluorescence microscopy (FCFM), and a bespoke delivery device. Introduction. The development of new therapeutic agents is hindered by the lack of in vivo in situ experimental methodologies that can rapidly evaluate the biological activity or drug-target engagement in patients. Methods. We optimised a novel highly quenched optical molecular reporter of enzyme activity (FIB One) and developed a translational pathway for in-human assessment. Results. We demonstrate the specificity for matrix metalloproteases (MMPs) 2, 9, and 13 and probe dequenching within physiological levels of MMPs and feasibility of imaging within whole lung models in preclinical settings. Subsequently, in a first-in-human exploratory experimental medicine study of patients with fibroproliferative lung disease, we demonstrate, through FCFM, the MMP activity in the alveolar space measured through FIB One fluorescence increase (with pharmacological inhibition). Conclusion. This translational in situ approach enables a new methodology to demonstrate active drug target effects of the distal lung and consequently may inform therapeutic drug development pathways.