Lipidomic profiling of bile in distinguishing benign from malignant biliary strictures: a single-blinded pilot study

Molecular Biomarkers in Cholangiocarcinoma: Focus on Bile

Hepatobiliary system cancers have demonstrated an increasing incidence rate in the past years. Without the presence of early symptoms, the majority of such cancers manifest with a set of similar symptoms, such as cholestasis resulting in posthepatic icterus. Differential diagnosis of hepatobiliary cancers is required for the therapy selection, however, the similarity of the symptoms complicates diagnostics. Thus, the search for molecular markers is of high interest for such patients. Cholangiocarcinoma (CCA) is characterized by a poor prognosis due to a low resectability rate, which occurs because this disease is frequently beyond the limits of surgical therapy at the time of diagnosis. The CCA is diagnosed by the combination of clinical/biochemical features, radiological methods, and non-specific serum tumor biomarkers, although invasive examination is still needed. The main disadvantage is limited specificity and sensitivity, which complicates early diagnostics. Therefore, prognostic and predictive biomarkers are still lacking and urgently needed for early diagnosis. In contrast to serum, bile is more accessible to identify biliary disease due to its simpler composition. Moreover, bile can contain higher concentrations of tumor biomarkers due to its direct contact with the tumor. It is known that the composition of the main bile component - bile acids, may vary during different diseases of the biliary tract. This review summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in serum and bile and provides an overview of the methods of bile acids analysis.

Pathological and molecular diagnoses of early cancer with bile and pancreatic juice

The dismal prognosis of pancreaticobiliary malignancies is mainly attributed to the extremely difficult detection of early-stage lesions, including intraepithelial neoplasia. To improve prognosis, several studies on the early detection of cancer have been conducted using bile and pancreatic juices for pathological or molecular analyses. One approach is liquid biopsy that includes information about the tumor, such as circulating tumor cells, circulating tumor DNA, microRNAs, and exosomes released by the tumor. Another approach is proteomics/metabolomics that reflects specific conditions in the tumor. These two approaches lead to artificial intelligence-based multiomics analyses that comprises genomics, proteomics/metabolomics, and transcriptomics. Based on the findings of molecular analysis, pathological analysis using immunohistochemical staining/fluorescence in situ hybridization has also been developed. Moreover, there have been reports of new methods/ingenuities for obtaining appropriate samples for the diagnosis of early-stage cancer. Here we review the knowledge on cutting-edge pathological and molecular analyses of bile and pancreatic juices, introduce some ingenuities in sampling and sample processing to promote effective clinical practice, and provide a basis for future studies.

Research progress of bile biomarkers and their immunoregulatory role in biliary tract cancers

Biliary tract cancers (BTCs), including cholangiocarcinoma and gallbladder carcinoma, originate from the biliary epithelium and have a poor prognosis. Surgery is the only choice for cure in the early stage of disease. However, most patients are diagnosed in the advanced stage and lose the chance for surgery. Early diagnosis could significantly improve the prognosis of patients. Bile has complex components and is in direct contact with biliary tract tumors. Bile components are closely related to the occurrence and development of biliary tract tumors and may be applied as biomarkers for BTCs. Meanwhile, arising evidence has confirmed the immunoregulatory role of bile components. In this review, we aim to summarize and discuss the relationship between bile components and biliary tract cancers and their ability as biomarkers for BTCs, highlighting the role of bile components in regulating immune response, and their promising application prospects.

Diagnosis Biomarkers of Cholangiocarcinoma in Human Bile: An Evidence-Based Study

Simple Summary

A liquid biopsy has the characteristics of low trauma and easy acquisition in the diagnosis of cholangiocarcinoma. Many researchers try to find diagnostic or prognostic biomarkers of CCA through blood, urine, bile and other body fluids. Due to the close proximity of bile to the lesion and the stable nature, bile gradually comes into people’s view. The evaluation of human bile diagnostic biomarkers is not only to the benefit of screening more suitable clinical markers but also of exploring the pathological changes of the disease.

Abstract

Cholangiocarcinoma (CCA) is a multifactorial malignant tumor of the biliary tract, and the incidence of CCA is increasing in recent years. At present, the diagnosis of CCA mainly depends on imaging and invasive examination, with limited specificity and sensitivity and late detection. The early diagnosis of CCA always faces the dilemma of lacking specific diagnostic biomarkers. Non-invasive methods to assess the degree of CAA have been developed throughout the last decades. Among the many specimens looking for CCA biomarkers, bile has gotten a lot of attention lately. This paper mainly summarizes the recent developments in the current research on the diagnostic biomarkers for CCA in human bile at the levels of the gene, protein, metabolite, extracellular vesicles and volatile organic compounds.

Detecting cholangiocarcinoma in patients with primary sclerosing cholangitis - The promise of DNA methylation and molecular biomarkers

Cholangiocarcinoma (CCA) is a highly fatal malignancy of the bile ducts that arises in up to 20% of patients with primary sclerosing cholangitis (PSC). Current detection methods for CCA display suboptimal sensitivity and/or specificity, and there is no evidence-based screening strategy for CCA in patients with PSC. Consequently, CCA is often detected too late for surgical resection, contributing to the high mortality associated with this malignancy. Recently, biomarkers have emerged with potential to complement current detection methods, and/or be used for cancer surveillance in high-risk patient groups, including patients with PSC. Aberrant DNA methylation patterns represent promising biomarkers with great potential for CCA detection. Such aberrations are frequent in CCA, often occur early, and can be detected in liquid biopsies, including blood, bile and urine. This review summarises and highlights the most promising DNA methylation biomarkers identified for CCA detection so far, focusing on patients with PSC. Other promising molecular biomarkers for detection of PSC-associated CCA in liquid biopsies will also be briefly covered.

Pilot Multi-Omic Analysis of Human Bile from Benign and Malignant Biliary Strictures: A Machine-Learning Approach

Cholangiocarcinoma (CCA) and pancreatic adenocarcinoma (PDAC) may lead to the development of extrahepatic obstructive cholestasis. However, biliary stenoses can also be caused by benign conditions, and the identification of their etiology still remains a clinical challenge. We performed metabolomic and proteomic analyses of bile from patients with benign (n = 36) and malignant conditions, CCA (n = 36) or PDAC (n = 57), undergoing endoscopic retrograde cholangiopancreatography with the aim of characterizing bile composition in biliopancreatic disease and identifying biomarkers for the differential diagnosis of biliary strictures. Comprehensive analyses of lipids, bile acids and small molecules were carried out using mass spectrometry (MS) and nuclear magnetic resonance spectroscopy (¹H-NMR) in all patients. MS analysis of bile proteome was performed in five patients per group. We implemented artificial intelligence tools for the selection of biomarkers and algorithms with predictive capacity. Our machine-learning pipeline included the generation of synthetic data with properties of real data, the selection of potential biomarkers (metabolites or proteins) and their analysis with neural networks (NN). Selected biomarkers were then validated with real data. We identified panels of lipids (n = 10) and proteins (n = 5) that when analyzed with NN algorithms discriminated between patients with and without cancer with an unprecedented accuracy.

Recent developments in the research on biomarkers of cholangiocarcinoma in primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is characterized by a chronic inflammatory process of the bile ducts of unclear aetiology. It is often complicated by cholangiocarcinoma (CCA) with a dismal prognosis. Early detection of CCA is important because treatment options for advanced disease are limited. Besides the established markers, like CA19-9, recent developments have been made using latest technologies. This review summarizes the recent advances and remaining limitations of biomarkers of CCA in PSC.

Indeterminate biliary strictures: a simplified approach

Pre-operative evaluation of biliary strictures remains challenging. The dilemma that exists is how to balance the risk of failing to detect malignancy and the potential morbidity caused by unnecessary surgery in patients with benign etiologies. With emerging novel diagnostic modalities, this study aims to assess the efficacy of diagnostic techniques and facilitate a clinical approach to indeterminate biliary strictures. Areas covered: Conventional imaging modalities are crucial in identifying the location of a stricture and are helpful for choosing further diagnostic modalities. Utilization of endoscopic techniques, including endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound (EUS), is key in establishing a diagnosis. The emergence of novel diagnostic modalities, such as fluorescence in-situ hybridization (FISH), peroral cholangioscopy (POC), intraductal endoscopic ultrasound (IDUS) and confocal laser endomicroscopy (CLE), enhance the diagnostic yield in the evaluation of indeterminate biliary strictures. Expert commentary: More reliable and validated visual criteria for differentiating malignancy from benign biliary conditions, utilizing advanced imaging modalities such as POC and CLE, need to be established. It is of significance to further evaluate these novel diagnostic modalities through ongoing trials and to develop a diagnostic algorithm that reconciles cost-effectiveness with diagnostic accuracy.

New approach to decrease post-ERCP adverse events in patients with primary sclerosing cholangitis

BACKGROUND AND STUDY AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is often performed in patients with primary sclerosing cholangitis (PSC). Our aim was to validate a treatment approach with the objective of decreasing ERCP related adverse events (AEs).

PATIENTS AND METHODS

All patients who had undergone ERCP for PSC during the period from 2002 - 2012 were identified (group I). This group had traditional ERCP (no bile aspiration prior to contrast injection with balloon dilation and stent placement for treatment of dominant strictures). To decrease ERCP-related AEs, we changed the ERCP approach in which bile aspiration was performed prior to contrast injection and balloon dilation alone was performed for treatment of dominant strictures. This was tested prospectively in all patients undergoing ERCP for PSC from 2012 - 2014 (group II).

RESULTS

The risk of overall AEs and cholangitis was relatively less in group II compared with group I [(2.1 % vs. 10.3 %; P  = .38) and (0 % vs. 4.4 %; P  = .68)]. On bivariate analysis, change in ERCP approach was associated with decreased risk of post-procedure cholangitis (0 % vs. 10.2 %, P =  .03) and overall AE (0 % vs. 18.6 %, P =  .03). There were no AEs in 22/46 patients in group II who had bile aspiration with balloon dilation. On multivariate analysis, only biliary stent placement was associated with increased risk of AEs (OR 4.10 (1.32 - 12.71); P  = .02) and cholangitis (OR 5.43, 1.38 - 21.38; P  = .02) respectively.

CONCLUSION

Biliary aspiration and avoidance of stenting approach after dilation of strictures during ERCP in PSC patients appears to be associated with decreased risk of cholangitis and overall AEs. Future prospective randomized controlled trials are needed to validate our observation.

浅谈影响ERCP操作的制约因素

内镜下逆行性胆胰管造影术(endoscopic retrograde cholangiopancreatography, ERCP)由于具有创伤小、时间短的优点, 已在胆胰疾病的诊治方面具有举足轻重的作用, 尤其在胆总管结石、胆囊切除术后的胆管复发结石的治疗方面已经成为了首选. 但随着ERCP的广泛开展和认识的不断提高, 大量研究显示局部解剖因素, 尤其是十二指肠周围憩室、乳头嵌顿结石和乳头狭窄是影响ERCP操作成功的主要解剖因素. 同时医护患三者间的配合也是影响ERCP操作成功的重要原因. 本文系统复习相关文献资料, 对ERCP操作失败的原因作一综述.

Unsupervised analysis of combined lipid and coagulation data reveals coagulopathy subtypes among dialysis patients

Hemodialysis (HD) and peritoneal dialysis (PD) are the primary means of managing end stage renal disease (ESRD). However, these treatment modalities are associated with the onset of coagulation abnormalities. Effective management of coagulation risk among these patients requires the identification of surrogate markers that provide an early indication of the coagulation abnormalities. The role of sphingolipids in the manifestation and prediction of coagulation abnormalities among dialysis patients have never been investigated. Herein, we report the first instance of an in depth investigation into the sphingolipid changes among ESRD patients undergoing HD and PD. The results reveal distinct differences in terms of perturbations to specific sphingolipid biosynthetic pathways that are highly dependent on the treatment modality. Our studies also demonstrated strong correlation between specific sphingolipids and coagulation parameters, such as HexCer(d18:1/26:0) and maximal amplitude (MA), SM(d18:1/24:1) and tissue factor pathway inhibitor, and sphingosine 1-phosphate d18:1 and FX (Spearman ρ of 0.93, 0.89, and -0.89, respectively). Furthermore, our study revealed the potential for using HexCer(d18:1/22:0), HexCer(d18:1/24:0), and HexCer(d18:1/26:0) (r² = 0.71, 0.82, and 0.63, respectively) and coagulation parameter MA (r² = 0.7) for successful diagnosis of differential coagulopathies among ESRD patients undergoing HD, providing an opportunity toward personalized disease management.

Evaluation of indeterminate biliary strictures

Biliary strictures frequently present a diagnostic challenge during pre-operative evaluation to determine their benign or malignant nature. A variety of benign conditions, such as primary sclerosing cholangitis (PSC) and IgG4-related sclerosing cholangitis, frequently mimic malignancies. In addition, PSC and other chronic biliary diseases increase the risk of cholangiocarcinoma and so require ongoing vigilance. Although traditional methods of evaluation including imaging, detection of circulating tumour markers, and sampling by endoscopic ultrasound and endoscopic retrograde cholangiopancreatography have a high specificity, they suffer from low sensitivity. Currently, up to 20% of biliary strictures remain indeterminate after pre-operative evaluation and necessitate surgical intervention for a definitive diagnosis. The discovery of novel biomarkers, new imaging modalities and advanced endoscopic techniques suggests that a multimodality approach might lead to better diagnostic accuracy.

Primary Sclerosing Cholangitis as a Premalignant Biliary Tract Disease: Surveillance and Management

Primary sclerosing cholangitis (PSC) is a premalignant biliary tract disease that confers a significant risk for the development of cholangiocarcinoma (CCA). The chronic biliary tract inflammation of PSC promotes pro-oncogenic processes such as cellular proliferation, induction of DNA damage, alterations of the extracellular matrix, and cholestasis. The diagnosis of malignancy in PSC can be challenging because inflammation-related changes in PSC may produce dominant biliary tract strictures mimicking CCA. Biomarkers such as detection of methylated genes in biliary specimens represent noninvasive techniques that may discriminate malignant biliary ductal changes from PSC strictures. However, conventional cytology and advanced cytologic techniques such as fluorescence in situ hybridization for polysomy remain the practice standard for diagnosing CCA in PSC. Curative treatment options of malignancy arising in PSC are limited. For a subset of patients selected by using stringent criteria, liver transplantation after neoadjuvant chemoradiation is a potential curative therapy. However, most patients have advanced malignancy at the time of diagnosis. Advances directed at identifying high-risk patients, early cancer detection, and development of chemopreventive strategies will be essential to better manage the cancer risk in this premalignant disease. A better understanding of dysplasia definition and especially its natural history is also needed in this disease. Herein, we review recent developments in our understanding of the risk factors, pathogenic mechanisms of PSC associated with CCA, as well as advances in early detection and therapies.

Single-operator cholangioscopy and targeted biopsies in the diagnosis of indeterminate biliary strictures: a systematic review

BACKGROUND AND AIMS

Evaluation of indeterminate biliary strictures by brush cytology and intraductal biopsies is limited by low sensitivity. The utility of SpyGlass peroral cholangioscopy for diagnosis of malignant biliary strictures and cholangiocarcinoma (CCA), in particular, remains unclear. Our aim was to study the utility of SpyGlass peroral cholangioscopy and targeted biopsy for diagnosis of malignant biliary strictures and CCA.

METHODS

In this systematic review, PubMed and Embase databases were reviewed for studies published to October 2014. The main outcomes of interest were sensitivity, specificity, and diagnostic odds ratio (DOR) of SpyGlass cholangioscopy in the diagnosis of malignant biliary strictures.

RESULTS

The search yielded 10 studies involving 456 patients. The pooled sensitivity and specificity of cholangioscopy-guided biopsies in the diagnosis of malignant biliary strictures was 60.1% (95% confidence interval [CI], 54.9%-65.2%) and 98.0% (95% CI, 96.0%-99.0%), respectively. The pooled DOR to detect malignant biliary strictures was 66.4 (95% CI, 32.1-137.5). Four studies included patients who had previous negative imaging and brushings and/or intraductal biopsies. Among these 4 studies, the pooled sensitivity and specificity for diagnosis of malignant biliary strictures was 74.7% (95% CI, 63.3%-84.0%) and 93.3% (95% CI, 85.1%-97.8%), respectively. The pooled DOR was 46.0 (95% CI, 15.4-138.1). Only 1 study directly compared the yield of SpyBite biopsies with standard brushings and biopsies. SpyBite biopsies had a sensitivity of 76.5% compared with brushings (5.8%) and biopsies (29.4%). Six studies specifically reported the role of cholangioscopy with targeted biopsies in the diagnosis of CCA. The pooled sensitivity and specificity to detect CCA was 66.2% (95% CI, 59.7%-72.3%) and 97.0% (95% CI, 94.0%-99.0%), respectively. The pooled DOR to detect CCA was 79.7 (95% CI, 32.7-194.7).

CONCLUSIONS

Our study suggests that SpyGlass cholangioscopy with SpyBite biopsies has moderate sensitivity for the diagnosis of malignant biliary strictures.

What is the current role of endoscopy in primary sclerosing cholangitis?

Endoscopy has important roles in the management of primary sclerosing cholangitis (PSC), ranging from narrowing down the differential diagnoses, screening for complications, determining prognosis and therapy. While the need for a diagnostic endoscopic retrograde cholangiopancreatography (ERCP) may be obviated by a positive magnetic resonance cholangiopancreatography (MRCP), a negative MRCP does not exclude PSC and may therefore necessitate an ERCP, which is traditionally regarded as the gold standard. In this editorial we have not covered the endoscopic management of inflammatory bowel disease in the context of PSC nor of endoscopic surveillance and treatment of portal hypertension complicating PSC.

Volatile Organic Compounds in Urine for Noninvasive Diagnosis of Malignant Biliary Strictures: A Pilot Study

BACKGROUND

The use of volatile organic compounds (VOCs) in bile was recently studied and appeared promising for diagnosis of malignancy. Noninvasive diagnosis of malignant biliary strictures by using VOCs in urine has not been studied.

AIM

To identify potential VOCs in urine to diagnose malignant biliary strictures.

METHODS

In this prospective cross-sectional study, urine was obtained immediately prior to ERCP from consecutive patients with biliary strictures. Selected-ion flow-tube mass spectrometry was used to analyze the concentration of VOCs in urine samples.

RESULTS

Fifty-four patients with biliary strictures were enrolled. Fifteen patients had malignant stricture [six cholangiocarcinoma (CCA) and nine pancreatic cancer], and 39 patients had benign strictures [10 primary sclerosing cholangitis (PSC) and 29 with benign biliary conditions including chronic pancreatitis and papillary stenosis]. The concentration of several compounds (ethanol and 2-propanol) was significantly different in patients with malignant compared with benign biliary strictures (p < 0.05). Using receiver operating characteristic curve analysis, we developed a model for the diagnosis of malignant biliary strictures adjusted for age and gender based on VOC levels of 2-propranol, carbon disulfide, and trimethyl amine (TMA). The model [-2.4191 * log(2-propanol) + 1.1617 * log(TMA) - 1.2172 * log(carbon disulfide)] ≥ 7.73 identified the patients with malignant biliary stricture [area under the curve (AUC = 0.83)], with 93.3 % sensitivity and 61.5 % specificity (p = 0.009). Comparing patients with CCA and PSC, the model [38.864 * log(ethane) - 3.989 * log(1-octene)] ≤ 169.9 could identify CCA with 80 % sensitivity and 100 % specificity (AUC = 0.9).

CONCLUSIONS

Measurement of VOCs in urine may diagnose malignant biliary strictures noninvasively.

Bile proteomics for differentiation of malignant from benign biliary strictures: a pilot study

BACKGROUND

Determining the etiology of biliary strictures is challenging, and the sensitivities of the current tests to diagnose them are low. Protein biomarkers in bile, in combination with other tests, may improve sensitivity in diagnosing biliary strictures.

OBJECTIVE

To analyse the differential abundance of proteins in benign and malignant biliary strictures through proteomic analysis of bile.

METHODS

In this prospective, cross-sectional study, bile was aspirated in 24 patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) including six patients with primary sclerosing cholangitis (PSC), three with cholangiocarcinoma (CCA), ten with pancreatic cancer, and five with benign biliary conditions. Liquid chromatography/mass spectrometry was used to examine the bile for differential abundance of protein biomarkers. The relative abundance of various proteins was compared in the malignant vs. benign groups and in CCA vs. PSC.

RESULTS

The majority of the proteins identified in bile were similar to those of the plasma (plasma proteins) and certain proteins were differentially expressed among the different groups (CCA, pancreatic cancer, PSC or benign). A total of 18 proteins were identified as being more abundant in the malignant group (CCA and pancreatic cancer) than in the benign strictures group, including myeloperoxidase, complement C3, inter-alpha-trypsin inhibitor heavy chain H4, apolipoprotein B-100, and kininogen-1 isoform 2. A total of 30 proteins were identified to be less abundant in the malignant group than in the benign group, including trefoil factor 2, superoxide dismutase [Cu-Zn], kallikrein-1, carboxypeptidase B and trefoil factor 1.

CONCLUSIONS

Protein biomarkers in bile may differentiate malignant from benign biliary strictures. Larger studies are warranted to validate these observations.

Diagnosis and management of primary sclerosing cholangitis-perspectives from a therapeutic endoscopist

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver condition characterized by inflammation, fibrosis, and destruction of the intra- and extrahepatic bile ducts. The therapeutic endoscopist plays a key role in the diagnosis and management of PSC. In patients presenting with a cholestatic profile, endoscopic retrograde cholangiopancreatography (ERCP) is warranted for a definite diagnosis of PSC. Dominant strictures of the bile duct occur in 36%-57% of PSC patients. Endoscopic balloon dilatation with or without stenting have been employed in the management of dominant strictures. In addition, PSC patients are at increased risk of developing cholangiocarcinoma with a 20% lifetime risk. Brush cytology obtained during ERCP and use of fluorescence in situ hybridization forms the initial diagnostic step in the investigation of patients with dominant biliary strictures. Our review aims to summarize the current evidence supporting the role of a therapeutic endoscopist in the management of PSC patients.

Biomarkers in bile-complementing advanced endoscopic imaging in the diagnosis of indeterminate biliary strictures

Biliary strictures present a diagnostic challenge and a conundrum, particularly when an initial work up including abdominal imaging and endoscopic retrograde cholangiopancreatography based sampling are non-diagnostic. Advances in endoscopic imaging have helped us diagnose these strictures better. However, even with modern technology, some strictures remain a diagnostic challenge. The proximity of bile fluid to the bile duct epithelia makes it an attractive option to investigate for bio-markers, which might be representative of the functions/abnormal changes taking place in the biliary system. A number of biomarkers in bile have been discovered recently in approaching biliary strictures with their potential future diagnostic utility, further supported by the immunohistochemical analysis of the resected tissue specimens. Novel biliary biomarkers especially carcinoembryonic cell adhesion molecule 6 and neutrophil gelatinase-associated lipocalin seem promising in differentiating malignant from benign biliary strictures. Recent developments in lipidomic profiling of bile are also very promising. Biliary biomarkers appear to complement endoscopic imaging in diagnosing malignant etiologies of biliary stricture. Future studies addressing these biomarkers need to be incorporated to the current endoscopic techniques to determine the best approach in determining the etiology of biliary strictures.

Volatile organic compounds in bile for early diagnosis of cholangiocarcinoma in patients with primary sclerosing cholangitis: a pilot study

BACKGROUND

The diagnosis of cholangiocarcinoma (CCA) in patients with primary sclerosing cholangitis (PSC) is particularly difficult. The role of volatile organic compounds (VOCs) for diagnosis of CCA in patients with PSC is not known.

OBJECTIVE

Our aim was to identify potential VOCs in the headspaces (gas above the sample) in bile that may predict CCA in patients with PSC.

DESIGN

Prospective cross-sectional study.

SETTING

Referral center.

PATIENTS

A total of 32 patients undergoing ERCP for PSC and for CCA complicating PSC.

INTERVENTIONS

ERCP, bile aspiration.

MAIN OUTCOME MEASUREMENTS

Selected ion flow tube mass spectrometry was used to analyze the concentration of 22 prevalent VOCs in bile samples. Logistic regression analysis was performed to build a predictive model for diagnosis of CCA.

RESULTS

Levels of several compounds (ethanol, acrylonitrile, acetonitrile, acetaldehyde, benzene, carbon disulfide, dimethyl sulfide, 2-propranolol) were significantly different in patients with CCA complicating PSC compared with those having PSC (P < .05). By using receiver operating characteristic curve analysis, we developed a model for the diagnosis of CCA adjusted for age and sex based on VOC levels of acrylonitrile, 3-methyl hexane, and benzene. The model (2.3239*log [acrylonitrile] + 0.9871*log [3-methyl hexane] + 0.8448*log [benzene]) < -0.12 identified the patients with CCA (area under the curve [AUC] = 0.89), with 90.5% sensitivity and 72.7% specificity (P = .02).

LIMITATIONS

Sample size.

CONCLUSION

The measurement of VOCs in biliary fluid may be useful to diagnose CCA in patients with PSC. A larger study with a longitudinal study design is required to confirm our pilot observations to diagnose CCA early in patients with PSC. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01565460.).

Comparative effectiveness of pyruvate kinase M2 in bile, serum carbohydrate antigen 19-9, and biliary brushings in diagnosing malignant biliary strictures

BACKGROUND

The role of M2-PK (pyruvate kinase) in bile has not been studied in comparison with brushings and carbohydrate antigen (CA) 19-9 in the diagnosis of malignant biliary strictures.

AIM

To compare the diagnostic accuracy of biliary M2-PK with cytology and serum CA 19-9 METHODS: In this prospective cross-sectional study, bile was aspirated in 74 patients (discovery and validation cohort) undergoing endoscopic retrograde cholangiopancreatography. Levels of M2-PK were measured in bile and compared to brushings for cytology and CA 19-9.

RESULTS

In the discovery cohort, the median bile M2-PK levels were significantly elevated in patients with malignant biliary strictures [187.9 U/l (interquartile range (IQR) 3.5, 3626.8)] compared to those with benign biliary conditions and primary sclerosing cholangitis [0 U/l (IQR 0, 15)] (P = 0.007). A M2-PK cutoff value of 109.1 U/l distinguished malignant from benign conditions with a sensitivity and specificity of 52.9 and 94.1 %, respectively, and area under curve (AUC) of 0.77. The sensitivity of CA 19-9 and brushings in diagnosing cancer was 52.9 % and 11.1 % and specificity 94.1 and 100 %, respectively. The presence of elevated M2-PK >109.1 U/l or CA 19-9 >33 U/ml or positive brushing was 88.2 % sensitive and 88.2 % specific, AUC of 0.89 in the diagnosis of malignancy. The diagnostic accuracy was confirmed in the validation cohort.

CONCLUSIONS

As a stand-alone factor, none of the markers were able to distinguish benign from malignant biliary strictures with a high sensitivity. However, a combination was highly sensitive in diagnosing malignant biliary strictures.

Comparative effectiveness of biliary brush cytology and intraductal biopsy for detection of malignant biliary strictures: a systematic review and meta-analysis

BACKGROUND

Evaluation of indeterminate biliary strictures typically involves collection and analysis of tissue or cells. Brush cytology and intraductal biopsies that are routinely performed during ERCP to assess malignant-appearing biliary strictures are limited by relatively low sensitivity.

OBJECTIVE

To study the comparative effectiveness of brushings for cytology and intraductal biopsies in the etiology of biliary strictures.

DESIGN

Meta-analysis.

SETTING

Referral center.

PATIENTS

PUBMED and Embase databases were reviewed for studies published to April 2014 where diagnostic correlation of histology was available.

INTERVENTION

Database and review of study findings.

MAIN OUTCOME MEASUREMENTS

Sensitivity and specificity.

RESULTS

The pooled sensitivity and specificity of brushings for the diagnosis of malignant biliary strictures was 45% (95% confidence interval [CI], 40%-50%) and 99% (95% CI, 98%-100%), respectively. The pooled diagnostic odds ratio to detect malignant biliary strictures was 33.43 (95% CI, 14.29-78.24). For intraductal biopsies, the pooled sensitivity and specificity were 48.1% (95% CI, 42.8%-53.4%) and 99.2% (95% CI, 97.6%-99.8%), respectively. The pooled diagnostic odds ratio to detect malignant biliary strictures was 43.18 (95% CI, 19.39-95.83). A combination of both modalities only modestly increased the sensitivity (59.4%; 95% CI, 53.7%-64.8%) with a specificity of 100% (95% CI, 98.8%-100.0%). The Begg-Mazumdar and Egger tests indicated a low potential for publication bias.

LIMITATIONS

Inclusion of low-quality studies.

CONCLUSION

Our study suggests that both brushings and biopsy are comparable and have limited sensitivity for the diagnosis of malignant biliary strictures. A combination of both only modestly increases the sensitivity.

Unmet clinical need in autoimmune liver diseases

Despite recent advances in understanding and treatment, there remain significant areas of unmet clinical need in each of the autoimmune liver diseases (AILDs). The evolving research landscape and emerging large patient cohorts are creating unique opportunities to translate science into new therapies and care pathways, with the potential to significantly improve the lives of AILD patients. However, the areas of unmet need represent real challenges, which need to be addressed, if this vision is to be realised. This review describes the areas of unmet need in AILD in adults relating to diagnostic and prognostic assessment, primary therapy, symptom management, trial design and delivery, and structured care delivery, with the aim of focusing future research prioritisation.

Volatile organic compounds in bile can diagnose malignant biliary strictures in the setting of pancreatic cancer: a preliminary observation

BACKGROUND

Ascertaining the nature of biliary strictures is challenging. The role of volatile organic compounds (VOCs) in bile in determining the cause of biliary strictures is not known.

OBJECTIVE

To identify potential VOCs in the headspaces (gas above the sample) of bile in patients with malignant biliary strictures from pancreatic cancer.

DESIGN

Prospective cross-sectional study.

SETTING

Referral center.

PATIENTS

Prospective study in which bile was aspirated in 96 patients undergoing ERCP for benign and malignant conditions.

MAIN OUTCOME MEASUREMENTS

Selected ion flow tube mass spectrometry (VOICE200R SIFT-MS instrument; Syft Technologies Ltd, Christchurch, New Zealand) was used to analyze the headspace and to build a predictive model for pancreatic cancer.

RESULTS

The headspaces from 96 bile samples were analyzed, including 24 from patients with pancreatic cancer and 72 from patients with benign biliary conditions. The concentrations of 6 compounds (acetaldehyde, acetone, benzene, carbon disulfide, pentane, and trimethylamine [TMA]) were increased in patients with pancreatic cancer compared with controls (P < .05). By using receiver-operating characteristic curve analysis, we developed a model for the diagnosis of pancreatic cancer based on the levels of TMA, acetone, isoprene, dimethyl sulfide, and acetaldehyde. The model [10.94 + 1.8229* log (acetaldehyde) + 0.7600* log (acetone) - 1.1746* log (dimethyl sulfide) + 1.0901* log (isoprene) - 2.1401 * log (trimethylamine) ≥ 10] identified the patients with pancreatic cancer (area under the curve = 0.85), with 83.3% sensitivity and 81.9% specificity.

LIMITATIONS

Sample size.

CONCLUSIONS

The measurement of biliary fluid VOCs may help to distinguish malignant from benign biliary strictures. Further studies are warranted to validate these observations. (Clinical Trial Registration Number NCT01565460.).

Biliary strictures: diagnostic considerations and approach

Biliary strictures present a diagnostic challenge, especially when no etiology can be ascertained after laboratory evaluation, abdominal imaging and endoscopic retrograde cholangiopancreatography (ERCP) sampling. These strictures were traditionally classified as indeterminate strictures, although with advances in endoscopic techniques and better understanding of hepato-biliary pathology, more are being correctly diagnosed. The implications of missing a malignancy in patients with biliary strictures—and hence delaying surgery—are grave but a significant number of patients (up to 20%) undergoing surgery for suspected biliary malignancy can have benign pathology. The diagnostic approach to these patients involves detailed history and physical examination and depends on the presence or absence of jaundice, level of obstruction, and presence or absence of a mass lesion. While abdominal imaging helps to find the level of obstruction and provides a ‘road map' for further endoscopic investigations, tissue diagnosis is usually needed to make decisions on management. Initially ERCP was the only modality to investigate these strictures but now, with the development of endoscopic ultrasound with fine needle aspiration and the availability of newer techniques such as intraductal ultrasound, single-operator cholangioscopy and confocal laser endomicroscopy, the diagnostic approach to biliary strictures has changed significantly. In this review, we will focus on the decision-making process for patients with biliary strictures and discuss the key decision points that should dictate further diagnostic investigations at each step.

Hepatobiliary manifestations of ulcerative colitis: an example of gut-liver crosstalk

The interaction between inflammatory bowel disease (IBD) and hepatobiliary manifestations represents a classic example of liver-gut crosstalk. The importance of liver-gut crosstalk in IBD is demonstrated in the pathogenesis and outcome of primary sclerosing cholangitis (PSC) in IBD patients. Immunoglobulin G4-associated cholangitis (IAC), which has recently been described in UC patients, may also illustrate the significance of gut-liver interaction in these patients. Presence of these hepatobiliary manifestations influences the outcome of associated IBD, in particular ulcerative colitis (UC), and vice versa. The pathogenesis of PSC is postulated to be related to gut inflammation in IBD that results in inflammation in the portal tracts (the 'leaky gut'). Enterohepatic circulation of lymphocytes from the gut to the liver is also of potential relevance to PSC pathogenesis and outcomes. The presence of PSC and gut inflammation in IBD influences the course and outcomes of both diseases. Further research is required, to understand the mutual effect of liver-gut crosstalk in the outcomes of UC patients, and highlights the importance of an interdisciplinary approach-involving gastroenterologists, hepatologists, advanced endoscopists and liver transplant surgeons-in the management of these patients.