Tamara Alempijevic

Diffusion-weighted MRI versus transient elastography in quantification of liver fibrosis in patients with chronic cholestatic liver diseases

PURPOSE To evaluate the diagnostic value of diffusion-weighted magnetic resonance imaging (DWMRI) and transient elastography (TE) in quantification of liver fibrosis in patients with chronic cholestatic liver diseases. MATERIALS AND METHODS Forty-five patients underwent DWMRI, TE, and liver biopsy for staging of liver fibrosis. Apparent diffusion coefficient (ADC) was calculated for six locations in the liver for combination of five diffusion sensitivity values b=0, 50, 200, 400 and 800 s/mm(2). A receiver operating characteristic (ROC) analysis was performed to determine the diagnostic performance of DWMRI and TE. Segmental ADC variations were evaluated by means of coefficient of variation. RESULTS The mean ADCs (× 10(-3)mm(2)/s; b=0-800 s/mm(2)) were significantly different at stage F1 versus F ≥ 2 (p<0.05) and F2 versus F4. However, no significant difference was found between F2 and F3. For prediction of F ≥ 2 and F ≥ 3 areas under the ROC curves were 0.868 and 0.906 for DWMRI, and 0.966 and 0.960 for TE, respectively. The sensitivity and specificity were 90.9% and 89.3% for F ≥ 2 (ADC ≤ 1.65), and 92.3% and 92.1% for F ≥ 3 (ADC ≤ 1.63). Segmental ADC variation was lowest for F4 (CV=9.54 ± 6.3%). CONCLUSION DWMRI and TE could be used for assessment of liver fibrosis with TE having higher diagnostic accuracy and DWMRI providing insight into liver fibrosis distribution.

Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphism in Patients with Chronic Pancreatitis and Pancreatic Cancer

The purpose of this study was to determine the frequency of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and to investigate its role as a potential risk factor in patients with chronic pancreatitis and pancreatic cancer. Deletion polymorphism of the 287-bp fragment of intron 16 of the ACE gene results in higher levels of circulating enzyme and therefore may represent a risk factor for disease development. The study included 55 patients with chronic pancreatitis, 45 patients with pancreatic cancer and 128 healthy subjects. The presence of I and D variants in the ACE gene was analyzed by a polymerase chain reaction (PCR) method. Distribution of ACE ID genotypes was analyzed by means of logistic regression. When chronic pancreatitis and pancreatic cancer groups were compared in the univariate analysis, the following factors were identified as statistically significant predictors of pancreatic disease: age, gender, smoking, fat intake, ACE II genotype and ACE DD genotype. However, in the multivariate analysis, only age, gender and smoking were singled out as predictors for the occurrence of pancreatic disease. Our findings indicate that the ACE I/D polymorphism could play a role in the development of chronic pancreatitis and pancreatic cancer through interaction with other genetic and environmental factors.

Alpha-1-antitrypsin phenotypes in adult liver disease patients

Abstract Alpha-1-antitrypsin (AAT) is an important serine protease inhibitor in humans. Hereditary alpha-1-antitrypsin deficiency (AATD) affects lungs and liver. Liver disease caused by AATD in paediatric patients has been previously well documented. However, the association of liver disease with alpha-1-antitrypsin gene polymorphisms in adults is less clear. Therefore, we aimed to study AAT polymorphisms in adults with liver disease. We performed a case-control study. AAT polymorphisms were investigated by isoelectric focusing in 61 patients with liver cirrhosis and 9 patients with hepatocellular carcinoma. The control group consisted of 218 healthy blood donors. A significant deviation of observed and expected frequency of AAT phenotypes from Hardy-Weinberg equilibrium (chi-square = 34.77, df 11, P = 0.000) in the patient group was caused by a higher than expected frequency of Pi ZZ homozygotes (f = 0.0143 and f = 0.0005, respectively, P = 0.000). In addition, Pi M homozygotes were more frequent in patients than in controls (63% and 46%, respectively, P = 0.025). Our study results show that Pi ZZ homozygosity in adults could be associated with severe liver disease. Presence of Pi M homozygosity could be associated with liver disease via some mechanism different from Z allele-induced liver damage through accumulation of AAT polymers.

Role of Helicobacter pylori infection in gastric carcinogenesis: Current knowledge and future directions

Helicobacter pylori (H. pylori) plays a role in the pathogenesis of gastric cancer. The outcome of the infection depends on environmental factors and bacterial and host characteristics. Gastric carcinogenesis is a multistep process that is reversible in the early phase of mucosal damage, but the exact point of no return has not been identified. Therefore, two main therapeutic strategies could reduce gastric cancer incidence: (1) eradication of the already present infection; and (2) immunization (prior to or during the course of the infection). The success of a gastric cancer prevention strategy depends on timing because the prevention strategy must be introduced before the point of no return in gastric carcinogenesis. Although the exact point of no return has not been identified, infection should be eradicated before severe atrophy of the gastric mucosa develops. Eradication therapy rates remain suboptimal due to increasing H. pylori resistance to antibiotics and patient noncompliance. Vaccination against H. pylori would reduce the cost of eradication therapies and lower gastric cancer incidence. A vaccine against H. pylori is still a research challenge. An effective vaccine should have an adequate route of delivery, appropriate bacterial antigens and effective and safe adjuvants. Future research should focus on the development of rescue eradication therapy protocols until an efficacious vaccine against the bacterium becomes available.

Drug-induced liver injury: Do we know everything?

Interest in drug-induced liver injury (DILI) has dramatically increased over the past decade, and it has become a hot topic for clinicians, academics, pharmaceutical companies and regulatory bodies. By investigating the current state of the art, the latest scientific findings, controversies, and guidelines, this review will attempt to answer the question: Do we know everything? Since the first descriptions of hepatotoxicity over 70 years ago, more than 1000 drugs have been identified to date, however, much of our knowledge of diagnostic and pathophysiologic principles remains unchanged. Clinically ranging from asymptomatic transaminitis and acute or chronic hepatitis, to acute liver failure, DILI remains a leading causes of emergent liver transplant. The consumption of unregulated herbal and dietary supplements has introduced new challenges in epidemiological assessment and clinician management. As such, numerous registries have been created, including the United States Drug-Induced Liver Injury Network, to further our understanding of all aspects of DILI. The launch of LiverTox and other online hepatotoxicity resources has increased our awareness of DILI. In 2013, the first guidelines for the diagnosis and management of DILI, were offered by the Practice Parameters Committee of the American College of Gastroenterology, and along with the identification of risk factors and predictors of injury, novel mechanisms of injury, refined causality assessment tools, and targeted treatment options have come to define the current state of the art, however, gaps in our knowledge still undoubtedly remain.

Cystic Dystrophy in Heterotopic Pancreas of the Duodenal Wall

Background: Cystic dystrophy in heterotopic pancreas (CDHP) is a rare condition. It has been recently reported as one of the etiologic obstructive factors of chronic pancreatitis. The aim of our study was to evaluate diagnosis and management of CDHP in the duodenal wall in a surgical series. Methods: We retrospectively reviewed 13 patients with available clinical data. Results: There were 11 male and 2 female patients, median age 42 years. The average duration of symptoms was 7.5 months. 6 of them (46%) were alcoholics, and 10 (75%) had signs of chronic pancreatitis. Almost all of them (12/13; 92%) revealed disabling pain, while 4 (31%) had associated jaundice. In 4 of 7 patients (57%), weight loss was observed. Most often the patients were suspected of having pancreatic head mass with or without signs of chronic pancreatitis. All patients underwent surgical treatment. Pathological examination showed the presence of cysts surrounded by inflammation and fibrosis in the duodenal wall, as well as the presence of chronic pancreatitis in the pancreas proper. Conclusions: Cystic dystrophy of the duodenal wall represents a significant proportion of patients undergoing surgery for chronic pancreatitis. Pancreatoduodenectomy is the best therapeutic option.

Clinical relevance of IL-6 gene polymorphism in severely injured patients

In polytrauma, injuries that may be surgically treated under regular circumstances due to a systemic inflammatory response become life-threatening. The inflammatory response involves a complex pattern of humoral and cellular responses and the expression of related factors is thought to be governed by genetic variations. This aim of this paper is to examine the influence of interleukin (IL) 6 single nucleotide polymorphism (SNP) -174C/G and -596G/A on the treatment outcome in severely injured patients. Forty-seven severely injured patients were included in this study. Patients were assigned an Injury Severity Score. Blood samples were drawn within 24 h after admission (designated day 1) and on subsequent days (24, 48, 72 hours and 7 days) of hospitalization. The IL-6 levels were determined through ELISA technique. Polymorphisms were analyzed by a method of Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR). Among subjects with different outcomes, no statistically relevant difference was found with regards to the gene IL-6 SNP-174G/C polymorphism. More than a half of subjects who died had the SNP-174G/C polymorphism, while this polymorphism was represented in a slightly lower number in survivors. The incidence of subjects without polymorphism and those with heterozygous and homozygous gene IL-6 SNP-596G/A polymorphism did not present statistically significant variations between survivors and those who died. The levels of IL-6 over the observation period did not present any statistically relevant difference among subjects without the IL-6 SNP-174 or IL- 6 SNP -596 gene polymorphism and those who had either a heterozygous or a homozygous polymorphism.

Endoscopic Ultrasound for Differential Diagnosis of Duodenal Lesions

PURPOSE Duodenal tumors are rare and require a different management from that of esophagogastric neoplasia. The present study retrospectively analyses the endoscopic ultrasound (EUS) features of duodenal tumors of both epithelial and subepithelial origin. MATERIALS AND METHODS During a 12 year period, all duodenal tumors with histologic confirmation by surgery or biopsy were collected including endoscopic and endosonographic images. EUS images were analyzed for specific features (echogenicity, wall layer structure and relation, outer margins) to possibly distinguish epithelial (polyps and carcinoma versus lymphoma) and subepithelial (tumor type) tumors. RESULTS 53/80 cases had histologic confirmation (mean age 53.1 ± 11.4 years, m:f = 33:20), 31 were epithelial (13 adenomas, 12 carcinomas, 6 lymphomas) and 22 subepithelial (11 GISTs, 7 Brunneromas, 1 lipoma, 3 NETs). EUS did not recognize carcinomas in 2/13 adenomas. EUS features suggesting carcinoma were loss of wall layers and irregular margins. 5/6 lymphomas showed inhomogeneous thickening with layers partially recognizable. Tumor type of subepithelial lesions correlated with echogenicity: GIST tumors were mostly (62.5 %) hypocheoic with the 3 malignant cases being characterized by heterogeneous echopattern with irregular outer margins. Of the hyperechoic lesions, lipomas had a homogeneous whitish appearance, while NET and Brunneromas were less hyperechoic. In the latter, the endoscopic aspect was also helpful for differential diagnosis. Accuracy of combined endoscopic/EUS imaging for all duodenal lesions was 84.9 % (45/53). No procedural complications occurred among all patients that received EUS examinations. CONCLUSION EUS contributes to the differential diagnosis of epithelial lesions known to be malignant; in subepithelial tumors, tissue confirmation is still required.

Non-alcoholic fatty pancreas disease

Obesity is a growing problem worldwide and disorders associated with excess body fat including the metabolic syndrome, type 2 diabetes mellitus (T2DM), cardiovascular disease and malignant neoplasms are becoming a major cause of morbidity and mortality. Over the past decade, a vast amount of research has furthered our understanding of non-alcoholic fatty liver disease; however, only recently pancreatic fat infiltration is coming to the forefront of investigation. Termed non-alcoholic fatty pancreas disease (NAFPD), it is becoming evident that it has important associations with other diseases of obesity. It appears to arise as obesity progresses and after an initial phase of pancreatic hypertrophy and hyperplasia, fatty infiltration becomes apparent. Various studies have demonstrated that NAFPD may exacerbate the severity of acute pancreatitis, promote pancreatic dysfunction associated with insulin resistance and T2DM, and even have links to the development of pancreatic carcinoma, and therefore, it must be investigated in further detail.

Variations in inflammatory genes as molecular markers for prediction of inflammatory bowel disease occurrence.

Research on inflammatory bowel disease (IBD) has highlighted genes involved in the regulation of inflammatory responses as contributors to disease pathogenesis. This study aimed to evaluate the associations between IBD and variations in NOD2, TLR4, TNF‐α, IL‐6, IL‐1β and IL‐1RN genes, and to use the genetic data obtained in predictive modeling.