Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis.

Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models.

Glycodeoxycholic acid levels as prognostic biomarker in acetaminophen-induced acute liver failure patients.

Acetaminophen (APAP)-induced acute liver failure (ALF) remains a major clinical problem. Although a majority of patients recovers after severe liver injury, a subpopulation of patients proceeds to ALF. Bile acids are generated in the liver and accumulate in blood during liver injury, and as such, have been proposed as biomarkers for liver injury and dysfunction. The goal of this study was to determine whether individual bile acid levels could determine outcome in patients with APAP-induced ALF (AALF). Serum bile acid levels were measured in AALF patients using mass spectrometry. Bile acid levels were elevated 5-80-fold above control values in injured patients on day 1 after the overdose and decreased over the course of hospital stay. Interestingly, glycodeoxycholic acid (GDCA) was significantly increased in non-surviving AALF patients compared with survivors. GDCA values obtained at peak alanine aminotransferase (ALT) and from day 1 of admission indicated GDCA could predict survival in these patients by receiver-operating characteristic analysis (AUC = 0.70 for day 1, AUC = 0.68 for peak ALT). Of note, AALF patients also had significantly higher levels of serum bile acids than patients with active cholestatic liver injury. These data suggest measurements of GDCA in this patient cohort modestly predicted outcome and may serve as a prognostic biomarker. Furthermore, accumulation of bile acids in serum or plasma may be a result of liver cell dysfunction and not cholestasis, suggesting elevation of circulating bile acid levels may be a consequence and not a cause of liver injury.

Accuracy of Endoscopic Ultrasound-guided Fine Needle Aspiration in Diagnosing Solid Pseudopapillary Tumor.

BACKGROUND: Solid pseudopapillary tumors are rare pancreatic tumors. Accurate preoperative diagnosis helps in planning of the surgery. AIM: This study was to evaluate accuracy of endoscopic ultrasound-guided fine needle aspiration and immunohistochemistry in diagnosing solid pseudopapillary tumors. MATERIALS AND METHODS: A retrospective review was performed by reviewing medical records to identify patients treated for solid pseudopapillary tumors over a 5-year period. Patients who were noted to have pancreatic lesions by computer tomography abdomen underwent endoscopic ultrasound. Fine needle aspiration was obtained from each of these lesions and subjected to immunohistochemistry. RESULTS: Five patients were identified. Endoscopic ultrasound was able to identify the pancreatic lesions in all five patients noted in computer tomography abdomen. Solid pseudopapillary tumors were diagnosed by immunohistochemistry. All five patients underwent surgery and the resected lesions confirmed solid pseudopapillary tumors in 80% patients. CONCLUSION: Endoscopic ultrasound-guided fine needle aspiration has a higher degree of accuracy in diagnosing solid pseudopapillary tumors.

Esophageal intraepithelial eosinophils in dysphagic patients with gastroesophageal reflux disease.

BACKGROUND: Patients with gastroesophageal reflux disease (GERD) often complain of dysphagia and are frequently found to have intraepithelial eosinophils on esophageal biopsy. AIM: The aim of this study was to investigate the relationship between dysphagia and the number of intraepithelial eosinophils in patients with GERD. METHODS: Review of all patients studied in our esophageal function laboratory from 1999 to 2007 identified 1,533 patients with increased esophageal acid exposure. Patients who complained of dysphagia without mechanical or motor causes were identified and divided into three groups based on whether dysphagia was their primary, secondary or tertiary symptom. A control group consisted of randomly selected GERD patients with no dysphagia. The highest number of intraepithelial eosinophils per high-power field (HPF) in biopsies from the squamocolumnar junction (SCJ) and esophageal body was compared across groups. RESULTS: There were 71 patients with unexplained dysphagia. Dysphagia was the primary symptom in 13 (18%), secondary symptom in 34 (48%), and tertiary symptom in 24 (34%) patients. The number of eosinophils differed between the four groups, with the highest number in those with dysphagia as the primary symptom (P = 0.0007). This relationship persisted whether biopsies were from the SCJ (P = 0.0057) or esophageal body (P = 0.0096). CONCLUSION: An association exists between the number of intraepithelial eosinophils and dysphagia in GERD patients, with the highest number of eosinophils in those with the primary symptom of dysphagia.