Thomas, Jonathan N.

Abstract IntroductionLiver disease such as cirrhosis is known to cause changes in the composition of volatile organic compounds (VOC) present in patient breath samples. Previous studies have demonstrated the diagnosis of liver cirrhosis from these breath samples, but studies are limited to a handful of discrete, well-characterized compounds.MethodsWe utilized VOC profiles from breath samples from 46 individuals, 35 with cirrhosis and 11 healthy controls. A deep-neural network was optimized to discriminate between healthy controls and individuals with cirrhosis.ResultsA 1D convolutional neural network (CNN) was accurate in predicting which patients had cirrhosis with an AUC of 0.90 (95% CI: 0.75, 0.99). Shapley Additive Explanations characterized the presence of discrete, observable peaks which were implicated in prediction, and the top peaks (based on the average SHAP profiles on the test dataset) were noted.ConclusionCNNs demonstrate the ability to predict the presence of cirrhosis based on a full volatolomics profile of patient breath samples. SHAP values indicate the presence of discrete, detectable peaks in the VOC signal.

Extracellular vesicles (EVs) are a heterogeneous group of biological nano‐sized vesicles that are released from cells and contribute to intercellular communication. Emerging knowledge about their biogenesis, composition, release, and uptake has resulted in broad interest in elucidating their potential roles in disease pathophysiology. The distinct biological properties of these biological nanoparticles emphasize several appealing advantages for potential therapeutic applications compared with the use of synthetic nanoparticles. When administered systemically, EVs are taken up and sequestered within the liver, further emphasizing opportunities for therapeutic use. Consequently, there is growing interest in their use for liver diseases. EVs can be used directly as therapeutics, and several studies have highlighted the intrinsic therapeutic properties of mesenchymal stem cell–derived EVs for chronic and acute liver diseases. Alternatively, EVs can be modified to facilitate their use for the delivery of therapeutic cargo. In this review, we discuss the cellular sources of EV, provide a concise overview of their potential use in diverse processes, and outline several promising applications for the use of EV‐based therapeutics for liver diseases. The use of EV‐based therapeutics provides a viable approach to target hepatic pathophysiology.