Digestive diseases
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Drug-induced liver injury is a rare but serious clinical problem. A number of drugs can cause severe liver injury and acute liver failure at therapeutic doses in a very limited number of patients (<1:10,000). This idiosyncratic drug-induced liver injury, which is currently not predictable in preclinical safety studies, appears to depend on individual susceptibility and the inability to adapt to the cellular stress caused by a particular drug. In striking contrast to idiosyncratic drug-induced liver injury, drugs with dose-dependent hepatotoxicity are mostly detected during preclinical studies and do not reach the market. One notable exception is acetaminophen (APAP, paracetamol), which is a safe drug at therapeutic doses but can cause severe liver injury and acute liver failure after intentional and unintentional overdoses. Key Messages: APAP overdose is responsible for more acute liver failure cases in the USA or UK than all other etiologies combined. Since APAP overdose in the mouse represents a model for the human pathophysiology, substantial progress has been made during the last decade in understanding the mechanisms of cell death, liver injury and recovery. More recently, emerging evidence based on mechanistic biomarker analysis in patients and studies of cell death in human hepatocytes suggests that most of the mechanisms discovered in mice also apply to patients. The rapid development of N-acetylcysteine as an antidote against APAP overdose was based on the early understanding of APAP toxicity in mice. However, despite the efficacy of N-acetylcysteine in patients who present early after APAP overdose, there is a need to develop intervention strategies for late-presenting patients. ⋯ The challenges related to APAP toxicity are to better understand the mechanisms of cell death in order to limit liver injury and prevent acute liver failure, and also to develop biomarkers that better predict as early as possible who is at risk for developing acute liver failure with poor outcome.
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Acute kidney injury (AKI) is a common complication of advanced cirrhosis. Type 1 hepatorenal syndrome is the best-known and most severe form of AKI, and it has a precise definition and a set of specific diagnostic criteria. More recently, it has become recognized that milder degrees of renal dysfunction also have a negative impact on patient outcome in various patient populations. Key Messages: Several definitions and criteria for staging the severity of AKI have been proposed, including the RIFLE (Risk, Injury, Failure, Loss of Function and End-Stage Renal Disease) group, the Acute Kidney Injury Network (AKIN), and the Kidney Disease: Improving Global Outcome (KDIGO) group. All of them incorporate some changes of serum creatinine and urine output in the definition and staging of AKI. The hepatology community has mostly embraced the AKIN diagnostic and staging criteria and has applied them in the prognostication of patients with advanced cirrhosis. However, the AKIN criteria have not been strictly applied in all studies on cirrhosis. This is partly related to the fact that changes in urine output are difficult to assess in advanced cirrhosis, and partly related to the difficulty in defining the baseline serum creatinine from which the change in serum creatinine is calculated. This has led to some confusion in the interpretation of results of the various studies on AKI in cirrhosis. More recently, some investigators have suggested incorporating the AKIN criteria with setting a lower limit of serum creatinine of 1.5 mg/dl in determining the diagnosis and prognosis of AKI in cirrhosis. ⋯ This is an ongoing debate as to how best to define AKI in cirrhosis. In the near future there should be prospective clinical trials that will clarify which diagnostic and staging criteria of AKI will best serve the cirrhotic population.
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Hepatocellular carcinoma (HCC) is a major health concern, and early HCC diagnosis is a primary radiological concern. The goal of imaging liver cirrhosis is the early identification of high-grade dysplastic nodules/early HCC since their treatment is associated with a higher chance of radical cure and lower recurrence rates. The newly introduced MRI contrast agent gadoxetic acid (gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid, Gd-EOB-DTPA) has enabled the concurrent assessment of tumor vascularity and hepatocyte-specific contrast enhancement during the hepatobiliary phase (HBP), which can help to detect and characterize smaller HCCs and their precursors. ⋯ Due to this capability of identifying the precursors and biological behavior of HCC, EOB-MRI has rapidly become a key imaging tool for the diagnosis of HCC and its precursors, despite the scarce MRI availability throughout Europe. With increasing experience, EOB-MRI may eventually be established as the diagnostic imaging modality of choice in this setting. Full recognition by the Western EASL-AASLD guidelines is expected.
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Barrett's esophagus, the condition in which metaplastic columnar epithelium that predisposes to cancer development replaces the squamous epithelium that normally lines the distal esophagus, is a complication of gastroesophageal reflux disease (GERD). Metaplasia is a potentially reversible condition, and partial regression of Barrett's metaplasia has been documented with effective medical or surgical therapy for GERD. The important issue for patient management is not whether antireflux treatment causes Barrett's esophagus to regress, but rather whether antireflux therapy prevents cancer in Barrett's esophagus. ⋯ Furthermore, for individual patients with nondysplastic Barrett's metaplasia, the cancer risk is so small and the number needed to treat for cancer prevention with surgery so large, that it does not matter whether or not surgery provides a tiny margin of extra protection against cancer beyond that provided by medical therapy. The cost and risks of the operation overwhelm any small, additional cancer protective benefit. Antireflux surgery is very effective at controlling the endoscopic signs and symptoms of GERD, but the operation should not be recommended to patients solely with the rationale that it protects against cancer better than medical therapy.
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Biologics have revolutionized several areas of medical therapeutics, and dozens of them are used by millions of patients. Monoclonal antibodies are only one type of biologics, but more than 900 are now in different phases of development. These drugs are complex to make and not cheap. ⋯ Practical issues such as interchangeability and substitution remain unsolved, and it is very likely that there will be different solutions at the national level. Pharmacovigilance plans will be key for obtaining reliable data. Biosimilars are not better drugs, but can be clearly cheaper and may facilitate access to new treatments in many populations.