Acute severe hepatitis as a presenting symptom in clinically stable patients admitted with SARS-CoV-2 Omicron infection

BACKGROUND

Suggested mechanisms for SARS-CoV-2 direct liver infection have been proposed by others to involve both cholangiocytes and hepatocytes. Early clinical studies have highlighted abnormal liver biochemistry with COVID-19 infection as often not being severe, with elevated liver enzymes <5X the upper limit of normal.

METHODS

Liver enzymes were evaluated and compared in patients admitted with a diagnosis of COVID-19 in a deidentified Internal Medicine-Medical Teaching Unit/hospitalist admission laboratory database. Comparisons in the incidence of severe liver injury (alanine aminotransferase >10 times upper limit of normal) were made for patients with pre-Omicron SARS-CoV-2 (November 30, 2019, to December 15, 2021) and Omicron SARS-CoV-2 (December 15, 2021, to April 15, 2022). Comprehensive hospital health records were also reviewed for the 2 patient cases discussed. One patient had a liver biopsy that was evaluated with H&E and immunohistochemistry staining using an antibody against COVID-19 spike protein.

RESULTS

The evaluation of a deidentified admissions laboratory database found the incidence of severe liver injury was 0.42% with Omicron versus 0.30% with pre-Omicron variants of COVID-19. In both patient cases discussed, abnormal liver biochemistry and a negative comprehensive workup strongly suggest COVID-19 as the cause of severe liver injury. In the one patient with liver biopsy, immunohistochemistry staining suggests SARS-CoV-2 presence in the portal and lobular spaces in association with immune cell infiltration.

CONCLUSIONS

The Omicron variant of SARS-CoV-2 should be considered in the differential diagnosis of severe acute liver injury. Our observation suggests that this new variant, either through direct liver infection and/or mediating immune dysfunction, can result in severe liver injury.

ADAM Metalloproteinase Domain 17 Regulates Cholestasis-Associated Liver Injury and Sickness Behavior Development in Mice

Disintegrin and metalloproteinase domain-containing protein 17 (ADAM17) is a ubiquitously expressed membrane-bound enzyme that mediates shedding of a wide variety of important regulators in inflammation including cytokines and adhesion molecules. Hepatic expression of numerous cytokines and adhesion molecules are increased in cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC), however, the pathophysiological role of ADAM17 in regulating these conditions remains unknown. Therefore, we evaluated the role of ADAM17 in a mouse model of cholestatic liver injury due to bile duct ligation (BDL). We found that BDL enhanced hepatic ADAM17 protein expression, paralleled by increased ADAM17 bioactivity. Moreover, inhibition of ADAM17 bioactivity with the specific inhibitor DPC 333 significantly improved both biochemical and histological evidence of liver damage in BDL mice. Patients with cholestatic liver disease commonly experience adverse behavioral symptoms, termed sickness behaviors. Similarly, BDL in mice induces reproducible sickness behavior development, driven by the upregulated expression of cytokines and adhesion molecules that are in turn regulated by ADAM17 activity. Indeed, inhibition of ADAM17 activity significantly ameliorated BDL-associated sickness behavior development. In translational studies, we evaluated changes in ADAM17 protein expression in liver biopsies obtained from patients with PBC and PSC, compared to normal control livers. PSC and PBC patients demonstrated increased hepatic ADAM17 expression in hepatocytes, cholangiocytes and in association with liver-infiltrating immune cells compared to normal controls. In summary, cholestatic liver injury in mice and humans is associated with increased hepatic ADAM17 expression. Furthermore, inhibition of ADAM17 activity improves both cholestatic liver injury and associated sickness behavior development, suggesting that ADAM17 inhibition may represent a novel therapeutic approach for treating patients with PBC/PSC.

Oncogenic HBV variants and integration are present in hepatic and lymphoid cells derived from chronic HBV patients

The hepatitis B virus (HBV) is a major cause of hepatocellular carcinoma (HCC), partly driven by viral integration and specific oncogenic HBV variants. However, the biological significance of HBV genomes within lymphoid cells (i.e., peripheral blood mononuclear cells, PBMCs) is unclear. Here, we collected available plasma, PBMC, liver, and tumor from 52 chronic HBV (CHB) carriers: 32 with HCC, 19 without HCC, and one with dendritic cell sarcoma, DCS. Using highly sensitive sequencing techniques, next generation sequencing, and AluPCR, we demonstrate that viral genomes (i.e., HBV DNA, RNA, and cccDNA), oncogenic variants, and HBV-host integration are often found in all sample types collected from 52 patients (including lymphoid cells and a DCS tumor). Viral integration was recurrently identified (n = 90 such hits) in genes associated with oncogenic consequences in lymphoid and liver cells. Further, HBV genomes increased in PBMCs derived from 7 additional (treated or untreated) CHB carriers after extracellular mitogen stimulation. Our study shows novel HBV molecular data and replication not only liver, but also within 63.8% of lymphoid cells analysed (including a representative lymphoid cell malignancy), that was enhanced in ex vivo stimulated PBMC.

Optimization of In vivo Imaging Provides a First Look at Mouse Model of Non-Alcoholic Fatty Liver Disease (NAFLD) Using Intravital Microscopy

Non-alcoholic fatty liver disease is a spectrum of liver pathology ranging from simple steatosis to steatohepatitis and can progress to diseases associated with poor outcomes including cirrhosis and hepatocellular carcinoma (HCC). NAFLD research has typically focused on the pathophysiology associated with lipid metabolism, using traditional measures such as histology and serum transaminase assessment; these methods have provided key information regarding NAFLD progression. Although valuable, these techniques are limited in providing further insight into the mechanistic details of inflammation associated with NAFLD. Intravital microscopy (IVM) is an advanced tool that allows for real-time visualization of cellular behavior and interaction in a living animal. Extensive IVM imaging has been conducted in liver, but, in the context of NAFLD, this technique has been regularly avoided due to significant tissue autofluorescence, a phenomenon that is exacerbated with steatosis. Here, we demonstrate that, using multiple imaging platforms and optimization techniques to minimize autofluorescence, IVM in fatty liver is possible. Successful fatty liver intravital imaging provides details on cell trafficking, recruitment, function, and behavior in addition to information about blood flow and vessel dynamics, information which was previously difficult to obtain. As more than 30% of the global population is overweight/obese, there is a significant proportion of the population at risk for NAFLD and complications due to NAFLD (liver decompensation, cirrhosis, HCC). IVM has the potential to elucidate the poorly understood mechanisms surrounding liver inflammation and NAFLD progression and possesses the potential to identify key processes that may be targeted for future therapeutic interventions in NAFLD patients.

Acoustic Radiation Force Impulse and Conventional Ultrasound in the Prediction of Cirrhosis Complicating Fatty Liver: Does Body Mass Index Independently Alter the Results?

We investigated whether ultrasound (US) could quantify steatosis and fibrosis in non-alcoholic fatty liver disease (NAFLD). Estimates of fat by gray-scale, hepatorenal index (HRI) and fibrosis by acoustic radiation force impulse (ARFI) were made using the interquartile range (IQR)/median for ARFI quality. Biopsy was the gold standard. US fat assessment correlated with histologic grade and predicted steatosis. HRI predicted steatosis but did not improve accuracy. ARFI of good quality was highly sensitive toward severe fibrosis. The median ARFI value depended linearly on body mass index (BMI). Poor quality ARFI data had higher histologic steatosis, leading to higher mean steatosis grades in rejected data (p = 0.018). The ARFI quality cut with IQR/median >0.15 or >0.3 excluded many more patients with severe steatosis versus normal, influenced by increasing BMI. By combining the baseline US with ARFI, patients can be concurrently diagnosed for steatosis and fibrosis, two of the key pathologies of NAFLD and non-alcoholic steatohepatitis (NASH). However, severe steatosis and high BMI may falsely alter ARFI results.

Maternal prebiotic supplementation reduces fatty liver development in offspring through altered microbial and metabolomic profiles in rats

A maternal high-fat/sucrose diet, in the presence of maternal obesity, can program increased susceptibility to obesity and metabolic disease in offspring. In particular, nonalcoholic fatty liver disease risk is associated with poor maternal nutrition and obesity status, which may manifest via alterations in gut microbiota. Here, we report that in a preclinical model of diet-induced maternal obesity, maternal supplementation of a high-fat/sucrose diet with the prebiotic oligofructose improves glucose tolerance, insulin sensitivity, and hepatic steatosis in offspring following a long-term high-fat/sucrose dietary challenge compared with offspring of untreated dams. These improvements are associated with alterations in gut microbial composition and serum inflammatory profiles in early life and improvements in inflammatory and fatty-acid gene expression profiles in tissues. Serum metabolomics analysis highlights potential metabolic links between the gut microbiota and the degree of steatosis, including alterations in 1-carbon metabolism. Overall, our data suggest that maternal prebiotic intake protects offspring against hepatic steatosis and insulin resistance following 21 wk of high fat/sucrose diet, which is in part due to alterations in gut microbiota.-Paul, H. A., Collins, K. H., Nicolucci, A. C., Urbanski, S. J., Hart, D. A., Vogel, H. J., Reimer, R. A. Maternal prebiotic supplementation reduces fatty liver development in offspring through altered microbial and metabolomic profiles in rats.

Evaluation of classical and novel autoantibodies for the diagnosis of Primary Biliary Cholangitis-Autoimmune Hepatitis Overlap Syndrome (PBC-AIH OS)

Background and aims

Up to 20% of Primary Biliary Cholangitis (PBC) patients are estimated to have features that overlap with Autoimmune Hepatitis (AIH). Patients with PBC-AIH overlap syndrome (PBC-AIH OS) have been reported to exhibit suboptimal responses to ursodeoxycholic acid therapy, and are more likely to progress to cirrhosis. Anti-double stranded DNA (anti-dsDNA) and anti-p53 have been previously suggested to be potential autoantibodies for identifying patients with PBC-AIH OS. In our well defined PBC patient cohorts, a comprehensive assessment of various classical and novel autoantibodies was evaluated for their utility in identifying PBC-AIH OS patients.

Methods

PBC-AIH OS was classified according to the Paris criteria and PBC as per the European Association for the Study of the Liver guidelines. Biobanked serum samples from 197 patients at the University of Calgary Liver Unit and the University of Alberta were analyzed for classical and novel autoantibodies. Anti-dsDNA was measured by the Crithidia luciliae immunofluorescence (CLIFT) assay (1:20 dilution) and chemiluminescence (CIA: QUANTA Flash®, Inova Diagnostics, San Diego). Anti-p53, anti-Ro52/TRIM21, anti-YB 1, anti-GW182, anti-Ge-1, and anti-Ago 2 were measured by either an addressable laser bead immunoassay (ALBIA) or line immunoassay (LIA). Autoantibodies against MIT3, gp210, sp100, LKM1, SLA, and the novel autoantibodies Hexokinase-1 (HK-1), and Kelch like protein 12 (KLHL-12) were measured using QUANTA Lite® ELISA assays. We applied non-parametric methods to compare the biomarkers frequencies between study groups. We used multivariate adjusted models and AUROC to compare the diagnostic accuracy of the different autoantibodies alone or in combination with serum biochemistry.

Results

16 out of 197 PBC patients (8.1%) were classified as PBC-AIH OS. Compared to PBC patients, PBC-AIH OS patients were similar in age (median: 59 vs. 63, P = 0.21) and female predominance (94% vs. 89%, P = 1.00). Anti-dsDNA-by CLIFT (37.5% in PBC-AIH OS vs 9.9% in PBC alone, P <0.01) was the only autoantibody associated with PBC-AIH OS; a finding consistent with previous reports. Significant elevation in serum ALT (62 IU/L in PBC-AIH OS vs 37 IU/L in PBC alone, P < 0.01), and serum IgG (17.6 g/L in OS vs 12.1 g/L in PBC alone, P <0.01) were observed in patients with PBC-AIH OS receiving medical/immunosuppressive therapy. In a multivariate model, positive anti-dsDNA by CLIFT, ALT and IgG were significant predictors of PBC-AIH OS with an area under the receiver operator curve (AUROC) value of 0.84.

Conclusions

Consistent with previous findings, the presence of anti-dsDNA by CLIFT is associated with PBC-AIH OS. Contrary to previous reports, anti-p53 was not associated with PBC-AIH OS. Our comprehensive evaluation of various classical and novel autoantibody biomarkers including Ro52/TRIM21, anti-p53, anti-KLHL-12 and anti-HK-1 were not significantly associated with PBC-AIH OS. Our findings highlight the ongoing need for the research and development of new autoantibody biomarkers to aid in the diagnosis of PBC-AIH OS.

Invited Review/Controversial Issue: Can Duodenal Mucosa Appear Normal in Gluten-Sensitive Enteropathy (Celiac Disease)?

Increasing popularity of serologic and permeability studies in patients investigated for possible celiac disease has resulted in a growing awareness among clinicians that currently accepted histologic criteria for diagnosis of celiac disease lack sensitivity. The patients who improve on a gluten-free diet with abnormal findings from serologic and permeability studies may have normal or “almost” normal villous/crypt morphology. The population of intraepithelial lymphocytes once extensively discussed in the literature may after all prove useful in identifying the individuals who may benefit from dietary gluten withdrawal. A recently outlined spectrum of the mucosal pattern (M. N. Marsh), which may be seen in the gluten-sensitive enteropathy is valuable in assessing histomorphology of small bowel biopsies from the patients investigated for celiac disease.

Eosinophilic colitis is a sporadic self-limited disease of middle-aged people: a population-based study

AIM

Eosinophilic colitis (EC) is a rare manifestation of eosinophilic gastrointestinal disorders. Due to its rarity, little information is available on its natural history.

METHOD

From the single population-based pathology database of the Calgary Health Region (comprising a population of 1.28 million in 2008), cases of EC during the period 1996-2008 were identified. Medical records of all adults diagnosed with EC were identified and the pathology reviewed. The patients were then contacted for follow-up using a standardized questionnaire.

RESULTS

Seven cases of EC (four in women) were identified, with a median follow-up of 45 (23-79) months. The median age at diagnosis was 42 (22-70) years. Symptoms at diagnosis were abdominal pain (86%), nonbloody diarrhoea (57%), bloody diarrhoea (29%) and significant (>10%) weight loss (29%). Three patients gave a history of allergic reactions to drugs and four reported allergy to cows' milk. Endoscopic findings were nonspecific, ranging from oedema to small aphthous ulceration. An eosinophilic infiltrate was identified in the lamina propria in the initial colonic biopsy in all patients. Over the longer term, three patients experienced spontaneous resolution without treatment. Two continued to have mild diarrhoea and abdominal cramps but did not require medical therapy. Two patients required medical treatment by 5-aminosalicylic acid, with one requiring prednisone and azathioprine maintenance therapy.

CONCLUSION

Eosinophilic colitis is a rare mostly self-limiting disease affecting middle-aged adults. It usually has a mild clinical course and drug treatment is not usually necessary. When required, drug treatment follows the standard medication for other inflammatory bowel disease.

A rare cavernous hemangioma of the adrenal gland

INTRODUCTION

Cavernous hemangiomas of the adrenal gland are rare. We report a case of a cavernous hemangioma of the adrenal gland presenting as an adrenal incidentaloma suspicious for adrenal cortical carcinoma (ACC).

PRESENTATION OF CASE

A 78 year old woman was admitted after a fall. Abdominal computed tomography revealed a large right adrenal lesion with features suspicious for adrenal cortical carcinoma (5.4 cm × 3.3 cm, unilateral, tumor calcifications, average Hounsfield units 55). The tumor was removed intact by a laparoscopic approach and pathology revealed a cavernous hemangioma of the adrenal gland.

DISCUSSION

Adrenal incidentalomas are found in up to 10% of patients undergoing abdominal imaging. Differential diagnosis includes both benign and malignant lesions. Guidelines for removal of adrenal incidentalomas recommend surgery based on functional status, size, and presence of concerning features on diagnostic imaging. Cavernous hemangiomas are rare, benign vascular malformations which can be challenging to distinguish pre-operatively from malignant lesions such as ACC.

CONCLUSION

Cavernous hemangiomas of the adrenal gland are exceedingly rare. These benign tumors have imaging features which may be suggestive of adrenal cortical carcinoma. The treatment of choice is surgical excision due the difficulty of excluding malignancy.

Rituximab for the treatment of patients with autoimmune hepatitis who are refractory or intolerant to standard therapy

BACKGROUND

Although most patients with autoimmune hepatitis (AIH) respond to treatment with prednisone and⁄or azathioprine, some patients are intolerant or refractory to standard therapy. Rituximab is an anti-CD20 monoclonal antibody that depletes B cells and has demonstrated efficacy in other autoimmune conditions.

AIMS

To evaluate the safety and efficacy of rituximab in patients with refractory AIH in an open-label, single-centre pilot study.

METHODS

Six patients with definite, biopsy-proven AIH who failed prednisone and azathioprine treatment received two infusions of rituximab 1000 mg two weeks apart and were followed for 72 weeks.

RESULTS

Rituximab was well tolerated with no serious adverse events. By week 24, mean (± SD) aspartate aminotransferase (AST) levels had significantly improved (90.0±23.3 U⁄L versus 31.3±4.2 U⁄L; P=0.03) and mean immunoglobulin G levels had fallen (16.4±2.0 g⁄L versus 11.5±1.1 g⁄L; P=0.056). The prednisone dose was weaned in three of four subjects, with one subject flaring after steroid withdrawal. Inflammation grade improved in all four subjects who underwent repeat liver biopsy at week 48. Regulatory T cell levels examined by FoxP3 immunohistochemistry paralleled inflammatory activity and did not increase on follow-up biopsies. There was no significant change in serum chemokine or cytokine levels from baseline to week 24 (n=5), although interferon-gamma-induced protein 10 levels improved in three of five subjects.

CONCLUSIONS

Rituximab was safe, well tolerated and resulted in biochemical improvement in subjects with refractory AIH. These results support further investigation of rituximab as a treatment for AIH.

The rising incidence of eosinophilic oesophagitis is associated with increasing biopsy rates: a population-based study

BACKGROUND

Eosinophilic oesophagitis (EoE) has evolved from a supposedly rare entity to one whose incidence rates are approaching that of inflammatory bowel disease. The factors responsible for this apparent increase in the incidence remain obscure.

AIM

To assess various endoscopist and pathologist factors that might affect the frequency of EoE being detected in a well-defined North American population.

HYPOTHESIS

Increased endoscopist and pathologist awareness has contributed to the increased clinical recognition of EoE.

METHODS

Cases of EoE were identified systematically using population-based pathology and endoscopy databases from January 2004 to December 2008 in Calgary, Canada (population 1.25 million). EoE frequency was estimated with time trend analysis. Characteristics of individual endoscopists (n = 45) were compared with diagnostic rates.

RESULTS

Crude population incidence of EoE increased from 2.1 per 10(5) in 2004 to 11.0 per 10(5) in 2008: an annual increase of 39% (P < 0.0001). The frequency in men was 4.5 times higher than in women (95% CI: 3.51-5.76). In patients presenting with dysphagia oesophageal biopsy rates increased from 17.0% in 2004 to 41.3% of EGDs in 2008: an annual rise of 26% (P < 0.0001). On multivariate regression analysis, those endoscopists with higher biopsy rates were more likely to make the diagnosis of EoE (P = 0.008). To include or exclude the diagnosis, typical histological features of EoE were reported more often by pathologists in 2008 as compared to 2004 (P = 0.01 & P < 0.0001 respectively).

CONCLUSIONS

The incidence of eosinophilic oesophagitis continues to rise in the general population, in part due to increasing oesophageal biopsy rates and a more detailed histological evaluation of specimens. The biopsy rate of an endoscopist is an indicator for a higher diagnostic yield.

Hepatitis C virus persistence after sustained virological response to antiviral therapy in patients with or without past exposure to hepatitis B virus

Hepatitis C virus (HCV) and hepatitis B virus (HBV) frequently coinfect and persist long after clinical resolution. We assessed the incidence of low-level (occult) HCV infection (OCI) after sustained virological response (SVR) to standard anti-HCV therapy in individuals with or without past exposure to HBV to recognize whether HBV could influence the prevalence of OCI, HCV level and hepatic histology. Plasma and peripheral blood mononuclear cells (PBMC) were collected from 24 individuals at 6- to 12-month intervals for up to 72 months after SVR. Liver histology was available for nine patients. HCV and HBV genomes were detected with sensitivity <10 genome copies/mL. In individuals without HBV exposure (n = 15), comprehensive analyses of sequential plasma and PBMC samples revealed HCV RNA in all 15 cases (75% plasma and 61% PBMC). In the group with HBV exposure (n = 9), evidenced by circulating anti-HBc and/or HBV DNA detection by a highly sensitive assay, HCV RNA was identified in all cases (83% plasma and 59% PBMC), at levels similar to those in HBV nonexposed individuals. In both groups of patients, most liver biopsies included those reactive for viral genomes displayed low-grade inflammation (8 of 9) and fibrosis (7 of 9). Sequence polymorphisms at the 5`-UTR between PBMC and liver or plasma, as well as circulating HCV virion-like particles, were observed in patients with or without HBV exposure. In conclusion, the prevalence of OCI after SVR is comparable in individuals with or without past exposure to HBV. HCV loads and liver alterations in OCI appear to be unaffected by low-level HBV DNA carriage.

Percutaneous endoscopically assisted transenteric full-thickness gastric biopsy: initial experience in humans

BACKGROUND

GI neuromuscular diseases (GINMD) can cause severe dysmotility and symptoms. Full-thickness biopsy specimens may help diagnose these disorders histologically.

OBJECTIVE

To assess a novel percutaneous endoscopically assisted transenteric (PEATE) biopsy method for obtaining full-thickness gastric tissue in patients with suspected GINMD.

DESIGN

Prospective proof-of-concept case series.

SETTING

Tertiary care gastroenterology unit.

PATIENTS

Ten patients (8 women, mean [standard deviation] age 43 [10] years) with gastroparesis-like symptoms (mean [standard deviation] gastroparesis cardinal symptom index 3.28 [1.46] out of 5) and/or clinical findings suggestive of a gastric GINMD.

INTERVENTIONS

All patients underwent PEATE biopsy during standard gastroscopy as an outpatient procedure. Tissue was stained for histology and immunohistochemistry of gut wall elements. Interstitial cells of Cajal (ICC) counts were compared with archived normal gastric tissue from control gastrectomies.

MAIN OUTCOME MEASUREMENTS

Biopsy success, complications, histopathological findings according to the London Classification of GINMD.

RESULTS

Full-thickness antral tissue suitable for analysis was obtained in 9 in 10 patients (90%). PEATE biopsy was well tolerated by all patients without complications. Histology suggested GINMD in 4 of 9 cases (44%), with possible degenerative leiomyopathy in 2, probable inflammatory leiomyopathy in 1, and abnormal ICC networks (>50% reduction in ICC counts) in 1 patient.

LIMITATIONS

PEATE biopsy specimen size is smaller than a standard laparoscopic full-thickness biopsy.

CONCLUSIONS

PEATE full-thickness gastric biopsy is a simple and safe method of assessing histopathological abnormalities in gastric GINMD without the need for laparoscopy or general anesthesia.

Attenuated reovirus displays oncolysis with reduced host toxicity

BACKGROUND

Although the naturally occurring reovirus causes only mild symptoms in humans, it shows considerable potential as an oncolytic agent because of its innate ability to target cancer cells. In immunocompromised hosts, however, wild-type reovirus can target healthy tissues, including heart, liver, pancreas and neural structures.

METHODS

We characterized an attenuated form of reovirus (AV) derived from a persistently infected cell line through sequence analysis, as well as western blot and in vitro transcription and translation techniques. To examine its pathogenesis and oncolytic potential, AV reovirus was tested on healthy embryonic stem cells, various non-transformed and transformed cell lines, and in severe combined immunodeficiency (SCID) mice with tumour xenografts.

RESULTS

Sequence analysis of AV reovirus revealed a premature STOP codon in its sigma 1 attachment protein. Western blot and in vitro translation confirmed the presence of a truncated σ1. In comparison to wild-type reovirus, AV reovirus did not kill healthy stem cells or induce black tail formation in SCID mice. However, it did retain its ability to target cancer cells and reduce tumour size.

CONCLUSION

Despite containing a truncated attachment protein, AV reovirus still preferentially targets cancer cells, and compared with wild-type reovirus it shows reduced toxicity when administered to immunodeficient hosts, suggesting the potential use of AV reovirus in combination cancer therapy.

Prevalence, risk factors and causes of discordance in fibrosis staging by transient elastography and liver biopsy

BACKGROUND AND AIMS

Liver stiffness measurement (LSM) by transient elastography (TE) is widely used for the noninvasive assessment of fibrosis. Our objectives were to examine the prevalence, risk factors and causes of discordance between fibrosis estimated by TE and liver biopsy.

METHODS

Two hundred and fifty-one patients with hepatitis B, C and nonalcoholic fatty liver disease underwent LSM by TE and liver biopsy. Predictors of discordance (≥2 fibrosis stages) between measures, which occurred in 14% of patients (n=35), were identified by comparing patient, TE and biopsy characteristics of discordant and nondiscordant cases.

RESULTS

According to predefined criteria, 40% of discordances were attributed to TE error and 23% to biopsy error; 37% were indeterminate. In multivariate analysis, mild fibrosis (F0-2 vs. F3-4), and higher body mass index (BMI), ALT and LSM variability [assessed by the ratio of the interquartile range to median LSM (IQR/M)] were independently associated with discordance. Discordance was three-fold more common in patients with obesity (28 vs. 9%), ALT ≥60 U/L (20 vs. 7%) and IQR/M ≥0.17 (22 vs. 7%; all P<0.005). Based on these variables, a discordance risk score assigning 1 point to each factor was developed. The prevalence of discordance in patients with 0, 1, 2 and 3 factors were 2, 7, 20, and 55% respectively (P<0.0005).

CONCLUSIONS

Discordance between liver fibrosis estimated by TE and biopsy occurs in one in seven patients. In assessing the validity of TE results, clinicians must recognize risk factors for discordance and in at-risk patients, consider alternative measures including biomarkers and possibly biopsy.

A novel method of full-thickness gastric biopsy via a percutaneous, endoscopically assisted, transenteric approach

BACKGROUND

Pathologic changes of the enteric nervous system of the stomach have been described in gastroparesis. Because the enteric nervous system lies within the myenteric plexus between the muscle layers of the stomach, it is not accessible by standard biopsy forceps. Thus, tissue must be obtained by laparoscopy or laparotomy. Obtaining full-thickness biopsies with a less-invasive method would be an ideal alternative.

OBJECTIVE

To assess the safety and feasibility of a novel method of gastric, full-thickness biopsy by using a percutaneous, endoscopically assisted, transenteric approach.

DESIGN

Experimental pilot study in 3 dogs, approved by the animal care committee.

INTERVENTION

Under general anesthesia, dogs underwent gastroscopy, and a suitable biopsy area was chosen, based on indentation of the anterior stomach wall by external finger pressure on the abdominal skin and by endoscope transillumination. Using sterile technique, we made a 3-mm incision through the abdominal skin, and a spring-loaded, 14-gauge biopsy needle was used to take 4 separate antral biopsies from each dog, with no mucosal or abdominal closure intervention.

MAIN OUTCOME MEASUREMENTS

Feasibility of obtaining enteric nervous system tissue; morbidity and mortality at 4 weeks; gross pathology at necropsy.

RESULTS

The procedure was well tolerated by the dogs, with no morbidity or mortality at any time, up to 4 weeks after the procedure. Adequate tissue specimens were obtained for histologic analysis of all layers of the stomach, including enteric nervous system elements.

LIMITATIONS

Biopsy size was smaller than a surgical biopsy size.

CONCLUSION

The percutaneous, endoscopically assisted, transenteric approach, full-thickness biopsy technique is safe and obtains enteric nervous tissue in a simple, minimally invasive manner.

Diverticular disease of the vermiform appendix: a diagnostic clue to underlying appendiceal neoplasm

Acquired diverticula of the vermiform appendix are rare and arise as a result of different pathogenetic mechanisms. One of the etiologies includes proximally located, often unsuspected small neoplasms. Although the association of appendiceal diverticulosis and neoplasia is known, it remains underemphasized in the teaching and practice of surgical pathology. To investigate the frequency of appendiceal neoplasms with acquired diverticulosis, we conducted a retrospective analysis of all appendectomy specimens received in our institution for a 55-month period (January 2002-July 2006). A total of 1361 appendectomy specimens were identified. Diverticulosis was diagnosed in 23 (1.7%) of all cases. Eleven (48%) appendectomy specimens with diverticulosis also harbored an appendiceal neoplasm. The association of appendiceal neoplasms with diverticulosis was statistically significant (P < .0001, 2-sided Fisher exact test). Neoplastic processes included 5 well-differentiated neuroendocrine tumors (carcinoids), 3 mucinous adenomas, 1 tubular adenoma, and 2 adenocarcinomas. In one case, routine representative sections sampled only a small focus of carcinoma, which originally went undiagnosed. We stress the need for meticulous gross assessment with histologic examination of the entire appendectomy specimen in cases of appendiceal diverticulosis. Thorough examination is required to rule out an underlying neoplasm as a cause of diverticulosis. As acquired diverticula represent a rare finding, examination of the entire appendix in this setting does not create a significant impact on the workload within the pathologic laboratory.

Changing epidemiology and risk factors for gastrointestinal non-Hodgkin's lymphoma in a North American population: population-based study

OBJECTIVES

To assess the incidence, risk factors, and endoscopic presentation of gastrointestinal non-Hodgkin's lymphoma (GI NHL) in a large predominantly urban adult population sample.

METHODS

A comprehensive database review of all diagnoses of GI NHL in the Calgary Health Region over a 5-yr period (1999-2003) was undertaken. Longer-term data from a population-based HIV database (1985-2004) were also reviewed. A regional pathology database was used to corroborate case identification. All patients 18 yr of age or older were included. Age- and gender-adjusted incidence rates were calculated. Within the HIV-positive population, incidence rates were compared over time. Endoscopic appearances were assessed and compared.

RESULTS

Fifty-six GI NHL cases occurred during the study period. The age- and gender-adjusted annual incidence of GI NHL was 1.73 per 100,000 in the study population. The majority were diffuse large B-cell histology (54%), followed by lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) (29%). Increasing age, history of kidney transplant, and H. pylori positivity in MALT lymphoma were identified as risk factors. Within the HIV-positive population, a highly significant drop in GI NHL was seen over time, with an incidence of 3.86 per 1,000 patient-years in 1985-1989 compared to zero cases in 2000-2004, despite a greater prevalence of HIV disease (P < 0.0001 for trend). MALT lymphoma was less likely to manifest as a mass on endoscopy versus other presentations (P < 0.05).

CONCLUSIONS

Population-based GI NHL incidence rates in Calgary are higher than those described elsewhere in North America or in Britain. The incidence of GI NHL within the HIV population has virtually disappeared, presumably due to the advent of highly active retroviral therapy.

Colorectal liver metastases contract centripetally with a response to chemotherapy: a histomorphologic study

BACKGROUND

Recently, there has been considerable interest in neoadjuvant chemotherapy for colorectal liver metastases. However, there is little information that defines how much liver should be removed after a favorable response.

METHODS

Liver metastases from 2 groups of patients were analyzed: 25 metastases were evaluated from a group that did not receive chemotherapy and 26 lesions were studied from patients who had received systemic chemotherapy before resection. All patients except for 1 had 5-fluorouracil (5-FU), leucovorin (LV), and irinotecan (CPT-11); 1 had 5-FU and LV alone. The average duration of chemotherapy was 2.9+/-0.7 months. Separate assessments of the histopathologic features of the central and peripheral portions of each tumor were made. The pathologist was blinded to all clinical information.

RESULTS

All of the untreated metastases had well-circumscribed borders. Irregular borders were seen in 6 of the postchemotherapy lesions (26%), which was particularly prominent in lesions that had significantly contracted. After chemotherapy, discrete islands of viable tumor cells outside of the main tumor mass were seen in 4 patients, but all were close to the peripheral margin of the tumor mass. Viable tumor cells were more frequent in the periphery of metastases, regardless of chemotherapy exposure. Central necrosis was prominent in untreated metastases, but disappeared after chemotherapy. In lesions treated with chemotherapy, central fibrosis was greater compared with untreated lesions.

CONCLUSIONS

After a partial response to chemotherapy, liver metastases shrank in a generally concentric fashion. These findings support the practice of removing less liver after downsizing with chemotherapy.

Colorectal liver metastases contract centripetally with a response to chemotherapy: a histomorphologic study

BACKGROUND

Recently, there has been considerable interest in neoadjuvant chemotherapy for colorectal liver metastases. However, there is little information that defines how much liver should be removed after a favorable response.

METHODS

Liver metastases from 2 groups of patients were analyzed: 25 metastases were evaluated from a group that did not receive chemotherapy and 26 lesions were studied from patients who had received systemic chemotherapy before resection. All patients except for 1 had 5-fluorouracil (5-FU), leucovorin (LV), and irinotecan (CPT-11); 1 had 5-FU and LV alone. The average duration of chemotherapy was 2.9+/-0.7 months. Separate assessments of the histopathologic features of the central and peripheral portions of each tumor were made. The pathologist was blinded to all clinical information.

RESULTS

All of the untreated metastases had well-circumscribed borders. Irregular borders were seen in 6 of the postchemotherapy lesions (26%), which was particularly prominent in lesions that had significantly contracted. After chemotherapy, discrete islands of viable tumor cells outside of the main tumor mass were seen in 4 patients, but all were close to the peripheral margin of the tumor mass. Viable tumor cells were more frequent in the periphery of metastases, regardless of chemotherapy exposure. Central necrosis was prominent in untreated metastases, but disappeared after chemotherapy. In lesions treated with chemotherapy, central fibrosis was greater compared with untreated lesions.

CONCLUSIONS

After a partial response to chemotherapy, liver metastases shrank in a generally concentric fashion. These findings support the practice of removing less liver after downsizing with chemotherapy.

The risk of microscopic colitis in solid-organ transplantation patients: a population-based study

BACKGROUND

Microscopic colitis (MC) has not been recognized as a complication of transplantation because patients are on immunosuppressant medications. The objective of this work was to describe the risk of developing MC after solid-organ transplantation.

METHODS

This population-based cohort study identified all cases of MC diagnosed after kidney, kidney and pancreas, or liver transplantation using pathology and transplantation databases. The annual incidence and point prevalence of MC after transplantation was calculated. The incidence rate of MC among transplantation patients was compared with the general population and presented as a Standardized Incidence Ratio (SIR) with 95% confidence intervals.

RESULTS

Seven cases (0.9%) of MC were diagnosed in kidney (n=2), kidney and pancreas (n=1), and liver (n=4) transplantation recipients. The point prevalence of MC was 8.8 per 1000 transplantation recipients. The annual incidence rate of MC in solid-organ transplantation patients was 5.0 cases per 1000 person-years. The SIR of developing MC after transplantation was 50.5 (95% confidence interval 13.6-131.8). The average age of diagnosis of MC was 49.4+/-5.3 years, average time of onset from transplantation was 67.4+/-27.0 months, and the average latency period was 30.1+/-9.0 months. Once diagnosed, all patients responded to MC-specific therapy.

CONCLUSION

Physicians should have a low threshold to investigate for MC in solid-organ transplantation recipients who present with chronic diarrhea because this population is at an increased risk of developing MC.

Microscopic colitis-defining incidence rates and risk factors: a population-based study

BACKGROUND & AIMS

The burden and determinants of microscopic colitis (MC) in North America are inadequately defined. We determined the incidence rate of and risk factors for MC in a well-defined North American population.

METHODS

A population-based cohort study was conducted between April 1, 2002, and March 31, 2004. All adults with a pathologic diagnosis of MC were identified and comprehensive chart review was undertaken to confirm the diagnosis and identify risk factors. Category-specific risks for developing MC were reported as rate ratios (RRs) with exact 95% confidence intervals (CIs).

RESULTS

MC was identified in 164 individuals for an annual incidence rate of 10.0 per 100,000 person-years (lymphocytic colitis, 5.4; collagenous colitis, 4.6 per 100,000). Patients older than the age of 65 were more than 5 times more likely to develop MC (RR, 5.6; 95% CI, 4.0-7.7). Women were at higher risk of acquiring MC for both collagenous colitis (RR, 3.44; 95% CI, 2.07-5.97) and lymphocytic colitis (RR 6.29; 95% CI, 3.21-13.74). Elderly women with a history of malignancy were associated with a higher risk of MC (RR, 3.59; 95% CI, 1.68-7.01), as were patients with celiac disease (RR, 7.9; 95% CI, 4.0-14.2) and hypothyroidism (RR, 6.1; 95% CI, 3.5-10.0).

CONCLUSIONS

This was a large population-based cohort study of MC and our incidence rates were consistent with previously reported population-based studies in North America and Europe. An increased incidence of MC was observed in several disease states with the novel finding of an increased risk of MC with malignancy.

The risk of gastrointestinal malignancies in cystic fibrosis: case report of a patient with a near obstructing villous adenoma found on colon cancer screening and Barrett's esophagus

The life expectancy for cystic fibrosis (CF) patients has increased dramatically over the last 30 years. Although the overall cancer risk for CF patients does not appear to be increased there is a marked increased risk of gastrointestinal malignancies especially in the post lung transplant population. CF patients that do develop gastrointestinal malignancies do so at an earlier age and there is often a lag in the diagnosis and management of these individuals. We present a 39 year old male CF patient that underwent a colonoscopy for colon cancer screening and a large, near obstructing, villous adenoma of his ileum was found. The polyp was removed successfully via endoscopy without incident and there was no evidence of malignancy. An upper endoscopy revealed a long segment of Barrett's esophagus with no evidence of dysplasia. We present this case as well as a detailed review of the literature on cancer risk in CF and a discussion of the mechanisms that may be involved. We also present the risk of GI malignancies in non-CF patients as a guide on how to assess and manage the risk of GI malignancies in this ever-changing patient population.

Reovirus decreases azoxymethane-induced aberrant crypt foci and colon cancer in a rodent model

Reovirus type 3 Dearing has demonstrated oncolytic efficacy in vitro and in vivo against a variety of cancer cell lines, tumor xenografts and syngeneic cancer models. In this study, we investigated the effectiveness of reovirus against aberrant crypt foci (ACF) and colon cancer induced by the carcinogen azoxymethane (AOM) in an immunocompetent rat model. Sprague-Dawley rats received 15 mg/kg AOM intraperitoneally once per week for 4 weeks and reovirus was administered rectally once a week for 5 weeks starting 20 weeks after the last dose of AOM. Two weeks after completion of reovirus therapy, animals were examined for tumor burden in the colon and other tissues. Reovirus-treated animals showed a decrease in total ACF numbers (P=0.014), in large ACFs (P=0.0069) and in tumor number (P=0.03) compared to vehicle-treated animals. Fewer obstructing tumors in the colon (P=0.07) and duodenum (P=0.03) and reduced hepatic metastases were also noted. In addition, a tumor cell line derived from hepatic metastases was found to be susceptible to reovirus in vitro. Our results show that repeated rectal reovirus administration had some efficacy in the treatment and prevention of AOM-induced ACFs, colon cancers and metastases.

The burden of large and small duct primary sclerosing cholangitis in adults and children: a population-based analysis

OBJECTIVES

The epidemiology of primary sclerosing cholangitis (PSC) has been incompletely assessed by population-based studies. We therefore conducted a population-based study to determine: (a) incidence rates of large and small duct PSC in adults and children, (b) the risk of inflammatory bowel disease on developing PSC, and (c) patterns of clinical presentation with the advent of magnetic resonance cholangiopancreatography (MRCP).

METHODS

All residents of the Calgary Health Region diagnosed with PSC between 2000 and 2005 were identified by medical records, endoscopic, diagnostic imaging, and pathology databases. Demographic and clinical information were obtained. Incidence rates were determined and risks associated with PSC were reported as rate ratios (RR) with 95% confidence intervals (CI).

RESULTS

Forty-nine PSC patients were identified for an age- and gender-adjusted annual incidence rate of 0.92 cases per 100,000 person-years. The incidence of small duct PSC was 0.15/100,000. In children the incidence rate was 0.23/100,000 compared with 1.11/100,000 in adults. PSC risk was similar in Crohn's disease (CD; RR 220.0, 95% CI 132.4-343.7) and ulcerative colitis (UC; RR 212.4, 95% CI 116.1-356.5). Autoimmune hepatitis overlap was noted in 10% of cases. MRCP diagnosed large duct PSC in one-third of cases. Delay in diagnosis was common (median 8.4 months). A minority had complications at diagnosis: cholangitis (6.1%), pancreatitis (4.1%), and cirrhosis (4.1%).

CONCLUSIONS

Pediatric cases and small duct PSC are less common than adult large duct PSC. Surprisingly, the risk of developing PSC in UC and CD was similar. Autoimmune hepatitis overlap was noted in a significant minority of cases.

Ischemic colitis during pegylated interferon-alpha and ribavirin therapy for chronic hepatitis C

Rare cases of ischemic colitis associated with interferon-alpha (IFN-alpha) treatment for chronic hepatitis C (HCV) infection and metastatic cancer have been reported. The present study describes the first case of ischemic colitis attributable to pegylated IFN-alpha and ribavirin combination therapy in an HCV-infected patient after 34 weeks of treatment. The clinical presentation, endoscopic appearance and histopathology of the colon were consistent with ischemic colitis, and the patient's symptoms rapidly resolved with cessation of therapy. The association between the therapy and the pathogenesis of ischemic colitis is unclear, but immunoregulatory, vasospastic and procoagulant mechanisms have been proposed. Physicians should be aware of this complication, and should consider it in any HCV-infected patient taking pegylated IFN-alpha and ribavirin who develops abdominal discomfort and gastrointestinal bleeding.

Acquired resistance to reoviral oncolysis in Ras-transformed fibrosarcoma cells

Reovirus shows considerable potential as an oncolytic agent for Ras-activated tumors and is currently in clinical trials. Here we ask whether such tumor cell lines can acquire resistance to reoviral oncolysis. We challenged human HT1080 fibrosarcoma cells that carry a Ras mutation by prolonged exposure to reovirus, thereby yielding highly virus-resistant HTR1 cells. These cells are persistently infected with reovirus, exhibit high Ras activity and retain the original Ras gene mutation, showing that resistance to reovirus can be displayed in cells with active Ras. The HTR1 cells also exhibit reduced cellular cathepsin B activity, which normally contributes to viral entry and activation. Persistently infected HTR1 cells were not tumorigenic in vivo, whereas immunologically cured virus-free HTR1 cells were highly tumorigenic. Thus, acquisition of resistance to reovirus may constrain therapeutic strategies. To determine whether reoviral resistance is associated with a general reduction in apoptotic potential, we challenged the HTR1 cells with apoptotic inducers and E1B-defective adenovirus, resulting in significant apoptosis and cell death following both approaches. Therefore, even if resistance to reoviral oncolysis should arise in tumor cells in vivo, other therapeutic strategies may nevertheless remain effective.

Induction of inducible nitric oxide synthase: a protective mechanism in colitis-induced adenocarcinoma

A close association between inflammatory bowel disease (IBD) and increased risk of developing adenocarcinoma exists. Moreover, chronic induction of high levels of nitric oxide (NO) produced from inducible nitric oxide synthase (iNOS) is a consistent observation in IBD. In this study we made interleukin-10/inducible nitric oxide synthase double-deficient (IL-10(-/-)/iNOS(-/-)) mice and studied the development of adenocarcinoma. Mice >6 months of age were compared with healthy wild-type (WT) controls. Inflammation was assessed using macroscopic/histological scores and myeloperoxidase activity as an indication of granulocyte infiltration. Mucosal polyps were scored macroscopically and hyperproliferation was quantified by 5-bromo-2-deoxyuridine immunohistochemistry. Dysplastic changes were assessed histologically based on cytologic and architectured atypia as well as the presence of submucosal invasion. The p53 and beta-catenin messenger RNA mRNA and protein expression were assessed using real-time polymerase chain reaction and immunohistochemistry, respectively. Inflammatory indices were significantly elevated in interleukin-10-deficient (IL-10(-/-)) over WT and not significantly different from IL-10(-/-)/iNOS(-/-) mice. The incidence of mucosal polyps was similar between IL-10(-/-) (79%) and IL-10(-/-)/iNOS(-/-) (83%) mice; however, significantly higher numbers of polyps were observed in the absence of iNOS (P < 0.05). Hyperproliferation was noted in both groups. Signs of dysplasia and submucosal invasion were significantly higher in IL-10(-/-)/iNOS(-/-) compared with IL-10(-/-) mice (P < 0.05). No significant increase in p53 and beta-catenin mRNA levels was observed in IL-10(-/-) over WT mice; however, a 2-fold (P = 0.06) and 3-fold (P < 0.05) increase, respectively, was noted in IL-10(-/-)/iNOS(-/-) mice. Our data suggest exposure to chronic NO limits abnormal p53 and beta-catenin expression and reduces incidence of adenocarcinoma in IL-10(-/-) mice.

Rofecoxib-induced hepatotoxicity: a forgotten complication of the coxibs

Rofecoxib is a member of the coxib family of nonsteroidal anti-inflammatory drugs that selectively inhibit cyclooxygenase-2. Although the coxibs are generally well-tolerated, rofecoxib was recently withdrawn from the market due to concerns regarding cardiovascular safety. Rare cases of hepatic injury attributable to the coxibs have been reported. In the present study, two additional cases of severe hepatotoxicity are described in patients with cholestatic symptoms and abnormal liver biochemistry, shortly following the initiation of rofecoxib for arthritic complaints. In both cases, liver histology was compatible with drug-induced hepatotoxicity, and rapid clinical and biochemical improvements were observed following rofecoxib discontinuation. With new coxibs and expanding indications on the horizon, physicians in all areas of practice must be aware of this disorder and consider it in any patient who develops hepatic dysfunction after taking a coxib.

Hot biopsy forceps in the diagnosis of endobronchial lesions

Electrocoagulation bronchoscopy biopsy forceps may prevent bleeding, but could also impair the quality of the specimens obtained. Patients with endobronchial lesions during bronchoscopy underwent six endobronchial biopsies each with a hot biopsy forceps, alternating between with electrocoagulation ("hot") and without ("cold"). Bleeding was quantified on a scale of 1-4, with 1 being no bleeding. The generator was set on "soft coagulation" mode, with power settings of 40, 60, 80 and 100 W for each group of 10 patients in a sequential fashion. Clinical pathology results were recorded before samples were reviewed by a second, blinded, pulmonary pathologist. A total of 39 patients with 40 endobronchial lesions had six biopsies performed (one patient had only four samples taken), giving a total of 238 biopsy samples. Concordance between hot and cold samples was 92.5% for the clinical pathologist and 87% for the blinded pathologist. Paired analysis suggested lower average bleeding score with the use of hot forceps. Overall bleeding rates for cold and hot biopsies, respectively, were as follows: grade 1: 30.3 and 41.2%; grade 2: 62.2 and 49.6%; grade 3: 7.6 and 9.2%; and grade 4: 0 and 0%. In conclusion, the use of hot biopsy forceps for endobronchial biopsy does not appear to have a negative impact on the pathological samples. Hot biopsy forceps showed a statistically significant reduction in bleeding score, which is unlikely to be of clinical significance.

The spectrum of pulmonary mucinous cystic neoplasia : a clinicopathologic and immunohistochemical study of ten cases and review of literature

We describe 10 new cases and review 66 previously reported cases of primary pulmonary mucinous cystic neoplasia (PMCN). The 3 men and 7 women were 44 to 73 years old (mean, 60.0 years) at diagnosis. Lesions were found by chest radiograph (featuring a solitary, lobulated nodule with soft tissue density that enlarged slowly), or patients had major bronchial occlusion by mucus or hemoptysis. Tumors were well-circumscribed, lobulated soft masses with a central cavity filled with gray to greenish translucent mucus and were 1.5 to 5.5 cm in greatest dimension (mean, 3.3 cm). Microscopically, confluent lakes of mucin characterized all cases. Tumor epithelium ranged from bland to focal cytologic atypia to frankly malignant. The adjacent lung parenchyma was stretched, compressed, or showed an inflammatory reaction to dissected mucin. After 1- to 10-year follow-up (mean, 3.7 years), 3 patients died of metastasis and 1 of amitriptyline toxic effects; 6 were alive without tumor. Combined analysis of our cases and previously reported cases suggests a histologic spectrum from benign cystadenoma to mucinous cystic tumor with atypia to well-differentiated mucinous cystadenocarcinoma. The histomorphologic criteria derived from this analysis can help distinguish PMCN from other types of primary or metastatic mucinous tumors and predict outcome.

Lack of Chemokine Receptor CCR5 Promotes Murine Fulminant Liver Failure by Preventing the Apoptosis of Activated CD1d-Restricted NKT Cells

Fulminant liver failure (FLF) consists of a cascade of events beginning with a presumed uncontrolled systemic activation of the immune system. The etiology of FLF remains undefined. In this study, we demonstrate that CCR5 deficiency promotes the development of acute FLF in mice following Con A administration by preventing activated hepatic CD1d-restricted NKT cells (but not conventional T cells) from dying from activation-induced apoptosis. The resistance of CCR5-deficient NKT cells from activation-induced apoptosis following Con A administration is not due to a defective Fas-driven death pathway. Moreover, FLF in CCR5-deficient mice also correlated with hepatic CCR5-deficient NKT cells, producing more IL-4, but not IFN-gamma, relative to wild-type NKT cells. Furthermore, FLF in these mice was abolished by IL-4 mAb or NK1.1 mAb treatment. We propose that CCR5 deficiency may predispose individuals to the development of FLF by preventing hepatic NKT cell apoptosis and by regulating NKT cell function, establishing a novel role for CCR5 in the development of this catastrophic liver disease that is independent of leukocyte recruitment.

Verrucous carcinoma of the esophagus eluding multiple sets of endoscopic biopsies and endoscopic ultrasound: a case report and review of the literature

A 56-year-old woman was noted to have a 5 cm to 6 cm long, irregular narrowing of the distal esophagus on an upper gastrointestinal series. Initial endoscopy revealed a polypoid mass in the distal esophagus and concurrent endoscopic ultrasound revealed changes typical of inflammation but no evidence of an obvious neoplastic process. Repeated biopsies revealed only inflammation with no evidence of malignancy. Only after prolonged acid suppression did biopsies reveal verrucous carcinoma of the esophagus. The patient underwent a trans-hiatal esophagectomy and has remained well with no evidence of progression since. Verrucous carcinoma is a rare variant of squamous cell carcinoma, taking on a papillary or warty appearance grossly. Histological diagnosis may be difficult because this tumour typically shows no high-grade dysplasia. Therefore, diagnosis can be challenging, often requiring multiple sets of endoscopic biopsies due to the overlying hyperkeratotic layer. Of the 20 cases that have been reported, this is the second to provide an endosonographic description and the first to describe a change in endoscopic appearance with acid suppression.

Mycophenolate mofetil for the treatment of autoimmune hepatitis in patients refractory to standard therapy

There are limited therapeutic options available for patients with autoimmune hepatitis in whom conventional treatment fails. A case series of five patients unresponsive to or unable to take azathioprine, 6-mercaptopurine or corticosteroids who were treated with mycophenolate mofetil (MMF) is reported. While on MMF, alanine aminotransferase normalized or remained normal in all patients. MMF had a steroid-sparing effect and histological remission was demonstrated in one patient after seven months of MMF. One patient experienced an uncomplicated episode of pyelonephritis. In conclusion, MMF can effectively induce and maintain remission in refractory autoimmune hepatitis patients.

Aquaporin expression is downregulated in a murine model of colitis and in patients with ulcerative colitis, Crohn's disease and infectious colitis

Colitis is associated with alterations in electrolyte and water transport. These changes give rise to some of the symptoms experienced by patients with colitis. Alterations in fluid flux may also contribute to increased susceptibility to mucosal injury. Recently, endogenous water channel proteins (aquaporins; AQPs), have been identified in colonic tissue. The expression of AQP4, AQP7 and AQP8 was examined, via reverse transcription/polymerase chain reaction, Western blotting and immunohistochemistry, in a murine model of colitis and in patients with inflammatory bowel disease or infectious colitis. Colitis was induced in C57BL/6 mice by the addition of 2.5% dextran sodium sulphate (DSS) to their drinking water. AQP expression in these mice was assessed following 12 h to 7 days of DSS exposure and during the recovery phase from 1 to 15 days following cessation of DSS exposure. Colonic water transport was measured after 1 and 3 days of DSS and following 7 days of recovery. The expression of AQP4 and AQP8 mRNA was significantly decreased after 12-24 h of DSS exposure and remained depressed throughout the treatment period. Expression of AQP7 was more variable. Protein expression followed a similar pattern to that observed for AQP mRNA. Significant alteration in colonic fluid secretion was correlated with reduced expression of AQP isoforms. Significantly, patients with active ulcerative colonic, Crohn's colitis or infectious colitis had similar dramatic reductions in AQP expression that appeared to be correlated with disease activity. Thus, colonic injury in both mouse and man is associated with a downregulation in AQP expression.

Octreotide in Intestinal Lymphangiectasia: Lack of a Clinical Response and Failure to Alter Lymphatic Function in a Guinea Pig Model

Intestinal lymphangiectasia, which can be classified as primary or secondary, is an unusual cause of protein-losing enteropathy. The main clinical features include edema, fat malabsorption, lymphopenia and hypoalbuminemia. Clinical management generally includes a low-fat diet and supplementation with medium chain triglycerides. A small number of recent reports advocate the use of octreotide in intestinal lymphangiectasia. It is unclear why octreotide was used in these studies; although octreotide can alter splanchnic blood flow and intestinal motility, its actions on lymphatic function has never been investigated. A case of a patient with intestinal lymphangiectasia who required a shunt procedure after failing medium chain triglycerides and octreotide therapy is presented. During the management of this case, all existing literature on intestinal lymphangiectasia and all the known actions of octreotide were reviewed. Because some of the case reports suggested that octreotide may improve the clinical course of intestinal lymphangiectasia by altering lymphatic function, a series of experiments were undertaken to assess this. In an established guinea pig model, the role of octreotide in lymphatic function was examined. In this model system, the mesenteric lymphatic vessels responded to 5-hydroxytryptamine with a decrease in constriction frequency, while histamine administration markedly increased lymphatic constriction frequency. Octreotide failed to produce any change in lymphatic function when a wide range of concentrations were applied to the mesenteric lymphatic vessel preparation. In conclusion, in this case, octreotide failed to induce a clinical response and laboratory studies showed that octreotide did not alter lymphatic function. Thus, the mechanisms by which octreotide induced clinical responses in the cases reported elsewhere in the literature remain unclear, but the present study suggests that it does not appear to act via increasing lymphatic pumping.

Lymphomas and Oncolytic Virus Therapy

There are several well-documented cases in medical literature of the remission of leukemias and malignant lymphomas following natural human viral infections. In the hope of being able to reproduce these spontaneous tumor regressions, investigators have studied various viruses with distinct oncolytic properties. The first attempts to treat patients with oncolytic viruses took place > 80 years ago; however, it achieved little success. With modern technologies and current knowledge of viruses and cancer, there is an expectation for the discovery of efficient oncolytic viral therapies. This article will review the current knowledge of oncolytic viruses in relation to the treatment of lymphoma.

Lymphocytic and collagenous colitis: the emerging entity of microscopic colitis. An update on pathophysiology, diagnosis and management

Microscopic colitis (MC) encompasses the two morphologically distinct entities of collagenous colitis (CC) and lymphocytic colitis (LC). MC was first described less than 30 years ago but is presently recognized as a relatively common cause of chronic diarrhea in the adult population. Remarkably, up to 10% of adults who have a colonoscopy for the investigation of chronic diarrhea, and have endoscopically normal appearing mucosa, may have MC. Patients with MC generally present with chronic diarrhea, which can be associated with cramping and bloating. Endoscopic and radiological examinations are usually normal. Histological assessment reveals inflammation consisting predominantly of lymphocytic infiltration, and a thickened subepithelial collagen band is diagnostic of CC. Both LC and CC can be associated with autoimmune diseases such as celiac disease, diabetes, arthritis and thyroiditis, yet the mechanisms involved in the pathogenesis remain unclear. Emerging studies suggest that a stepwise approach be taken in the medical management of MC. This approach includes antidiarrheal agents and stopping of any offending agents; budesonide or bismuth subsalicylate; and cholestyramine or 5-acetylsalicylic acid agents. In resistant cases, oral corticosteroids and other immune modulatory therapy have been used.

Reovirus therapy of lymphoid malignancies

Reoviruses infect cells that manifest an activated Ras-signaling pathway, and have been shown to effectively destroy many different types of neoplastic cells, including those derived from brain, breast, colon, ovaries, and prostate. In this study, we investigated the reovirus as a potential therapeutic agent against lymphoid malignancies. A total of 9 lymphoid cell lines and 27 primary human lymphoid malignancies, as well as normal lymphocytes and hematopoietic stem/progenitor cells, were tested for susceptibility to reovirus infection. For in vitro studies, the cells were challenged with reovirus (serotype 3 Dearing), and viral infection was assessed by cytopathic effects, viability, viral protein synthesis, and progeny virus production. We present evidence of efficient reovirus infection and cell lysis in the diffuse large B-cell lymphoma cell lines and Burkitt lymphoma cell lines Raji and CA46 but not Daudi, Ramos, or ST486. Moreover, when Raji and Daudi cell lines were grown subcutaneously in severe combined immunodeficient/nonobese diabetic (SCID/NOD) mice and subsequently injected with reovirus intratumorally or intravenously, significant regression was observed in the Raji-induced, but not the Daudi-induced, tumors, which is consistent with the in vitro results. Susceptibility to reovirus infection was also detected in 21 of the 27 primary lymphoid neoplasias tested but not in the normal lymphocytes or hematopoietic stem/progenitor cells. Our results suggest that reovirus may be an effective agent against several types of human lymphoid malignancies.

Role of ICAM-1 in chronic hepatic allograft rejection in the rat

The pathogenesis of hepatic allograft rejection remains unclear. We aimed to clarify the early role of intercellular adhesion molecule-1 (ICAM-1)-mediated cell recruitment in chronic hepatic rejection. Liver transplantation was performed from Lewis to Lewis rats (isograft controls) and from Lewis to Brown Norway rats (allograft rejection group). The allografted rats were treated with either ICAM-1 antisense oligonucleotides (10 mg. kg(-1). day(-1) x 6 days ip) or a control preparation (either ICAM-1 missense oligonucleotide or normal saline). Hepatic leukocyte recruitment in vivo was studied on day 6 by using intravital microscopy. Liver histology, biochemistry, and survival rates were also examined. Leukocyte adhesion in terminal hepatic venules was significantly increased in the rejection group compared with isograft controls. Antisense ICAM-1 in the allografted group effectively reduced leukocyte adhesion. Histology and liver chemistry were less deranged in the antisense-treated groups compared with control-treated allografted rats. In the allograft groups, survival was significantly prolonged in the antisense-treated rats (42.3 +/- 1.2 days) compared with the controls (25.2 +/- 2.7 days). These results showed that early leukocyte recruitment in the hepatic microvasculature of rejecting allografts is ICAM-1 dependent and suggest that impacting on early cell recruitment can significantly ameliorate chronic rejection.

Leukocyte elastase in murine and human non-Hodgkin lymphomas

Extracellular proteases play a crucial role in the invasive behavior of normal and transformed leukocytes. Thus far, however, most of the attention has been focused on members of the family of matrix metalloproteinases. In this work, we show that lymphoma cells can express leukocyte elastase (LE) and recruit the enzyme at their surface via ICAM-1. The expression of LE by lymphoma cells was augmented significantly by stimulation with IL-6 and IL-13, both of which also induced the expression of MMP-9. Although LE and IL-13 transcripts were detected in several non-Hodgkin's lymphomas, immunohistochemical analysis of lymphoma tissues also showed that LE was strongly expressed in infiltrating leukocytes. Given the spectrum of key molecules that can be cleaved by LE and that LE and MMP-9 are involved in the invasive behavior of normal or transformed leukocytes, our results raise the hypothesis that LE plays a crucial role in the multistep processes of inflammation and lymphoma metastasis.

A case of coexisting primary biliary cirrhosis and primary sclerosing cholangitis: a new overlap of autoimmune liver diseases

Although the etiology of AIH, PBC, and PSC remains unknown, it is apparent that these autoimmune liver diseases share many common features and can coexist in the same patient. Our patient had features of PBC and later clearly developed a picture of PSC. This case suggests that PBC, PSC, AIH, and autoimmune cholangitis are part of a spectrum of chronic autoimmune liver disease that develop in response to some yet unidentified antigen.

Reactivation of hepatitis B e antigen-negative chronic hepatitis B in a bone marrow transplant recipient following lamivudine withdrawal

Reactivation of hepatitis B virus (HBV) is a recognized complication of bone marrow transplantation (BMT). Lamivudine is a nucleoside analogue with potent antiviral activity that has been used in the prophylaxis of HBV reactivation in at-risk BMT recipients. Currently, no data exist regarding the safety of nucleoside analogue withdrawal in these patients. A 32-year-old BMT recipient with hepatitis B e antigen (HBeAg)-negative, chronic HBV who developed a serious flare of hepatic inflammation due to a rebound in viral replication within 12 weeks of discontinuing lamivudine therapy is described. The patient remained HBeAg-negative despite high level viremia, suggesting the emergence of a mutant viral strain. The patient's acute hepatitis resolved promptly with the reinstitution of lamivudine therapy. Further studies are necessary to define the safety and efficacy of nucleoside analogues in the prevention of HBV reactivation in at-risk BMT recipients. Clinicians should consider the risk of inducing serious flares of hepatic inflammation due to abrupt nucleoside analogue withdrawal in these patients.

Glut-1 expression in dysplastic and regenerative lesions of the colon

Monosaccaride transporter proteins are responsible for transmembrane transport of monosaccarides into cells. Glucose transporter protein 1 (Glut-1) is most prevalent in the cell membranes of erythrocytes and facilitates transport of glucose in tissues with barrier functions, i.e. blood brain barrier. Expression of Glut-1 in malignant tumors is increased due to increased metabolic need of the proliferating cell populations. In colorectal adenomas and carcinomas, membranous expression of Glut-1 has been associated with higher grade of tumors and decreased survival time. We studied the expression of Glut-1 in dysplastic proliferations of the colon which included sporadic adenomas and dysplasia associated lesions (DALM) in patients with ulcerative colitis and reactive/regenerative proliferations of the colon, including non-dysplastic chronic colitis, acute colitis and ischemia. Two patterns of Glut-1 expression were detected. Most adenomas and DALMs showed at least focal membranous expression of Glut-1. In addition a second staining pattern was recognized which consisted of prominent supranuclear dots. This pattern of staining was not only seen in adenomas and DALM but also in non-dysplastic areas immediately surrounding sporadic adenomas, in regenerative chronic colitis and in areas surrounding acute inflammation. Areas away from dysplasia did not show any positive staining for Glut-1. We conclude that two distinct patterns of Glut-1 expression may be found in colonic epithelial proliferation: membranous staining, associated with dysplasia, and, heretofore not described, supranuclear staining which may be related to Glut-1 expression secondary to expression of specific growth factors and not necessarily related to dysplasia.

Expression of survivin, YB-1, and KI-67 in sporadic adenomas and dysplasia-associated lesions or masses in ulcerative colitis

Sporadic adenomas are said to exhibit an orderly growth pattern with a reversal of proliferative and apoptotic cell distribution as compared with normal colonic crypts. Dysplastic polyps of patients with ulcerative colitis (UC) may represent dysplasia-associated lesions or masses (DALM) with a high associated cancer risk, or, alternatively, may represent sporadic adenomas. Histologic criteria to differentiate between sporadic adenomas and DALM have not focused on the balance between cell renewal and cell loss. The expression of the novel anti-apoptosis gene product, survivin, and the proliferation markers, Ki-67 and Y-box binding protein (YB-1), were investigated by immunohistochemical localization in sporadic adenomas and DALM lesions of patients with UC. In adenomas, KI-67 was expressed preponderantly at the luminal aspect of the polyp, whereas its expression was diffuse in DALM. Survivin was detected diffusely in both adenomas and DALM. YB-1 showed positive staining in the deep aspect of adenomatous glands but only to a minor degree at the surface, whereas both deep and diffuse expression patterns of YB-1 were seen in DALM. The authors conclude that DALM and sporadic adenomas exhibit different patterns of cellular proliferation and that molecular markers of cell proliferation, Ki-67 and YB-1, may be useful to distinguish sporadic adenomas from DALM. However, the similar expression of survivin suggests that the underlying mechanisms that regulate apoptotic cell death are uniform in these lesions.

Matrix metalloproteinases and their tissue inhibitors - expression, role and regulation in human malignant non-Hodgkin's lymphomas

Human malignant non-Hodgkin's lymphomas (NHL) represent a heterogeneous group of neoplasms, which vary in their clinical behavior and pathophysiology. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) have been shown to play a role in the pathophysiology and clinical aggressiveness of human NHL. In this setting, MMP-9 and TIMP-1 appear to be the most important members of the MMP and TIMP families, and overexpression of both correlates with a poor clinical outcome of patients with NHL. MMP-9 and TIMP-1, however, act through different mechanisms and are produced by different cell types. Expression of both is upregulated by interleukin-6 (IL-6), a cytokine that is known as one of the factors involved in the pathophysiology of human NHL. In this review we summarize the complex regulation of MMP and TIMP expression in human NHL and propose a mechanism by which MMP-9, TIMP-1 and IL-6 may influence the biology of these tumors.

Gastrointestinal complications in bone marrow transplant patients

Complications of bone marrow transplantation are numerous, multifactorial and may affect any organ in the body. The involvement of the gastrointestinal system represents one of dominant sites of complications. Clinical management of gastrointestinal complications can be challenging in these patients. This overview summarizes common bone marrow transplantation related conditions affecting esophagus, stomach, small and large intestine as well as liver. These are discussed primarily from the clinical point of view with emphasis on the differential diagnosis. The histomorphologic features of these conditions are discussed as well.