Development and validation of machine learning model for predicting treatment responders in patients with primary biliary cholangitis.

AIMS: Ursodeoxycholic acid is the first-line treatment for primary biliary cholangitis, and treatment response is one of the factors predicting the outcome. To prescribe alternative therapies, clinicians might need additional information before deciphering the treatment response to ursodeoxycholic acid, contributing to a better patient prognosis. In this study, we developed and validated machine learning (ML) algorithms to predict treatment responses using pretreatment data. METHODS: This multicenter cohort study included collecting datasets from two data samples. Data 1 included 245 patients from 18 hospitals for ML development, and was divided into (i) training and (ii) development sets. Data 2 (iii: test set) included 51 patients from our hospital for validation. An extreme gradient boosted tree predicted the treatment response in the ML model. The area under the curve was used to evaluate the efficacy of the algorithm. RESULTS: Data 1 showed that patients complying with the Paris II treatment response had significantly lower serum alkaline phosphatase and total bilirubin levels than those who did not respond. Three factors, total bilirubin, total protein, and alanine aminotransferase levels were selected as essential variables for prediction. Data 2 showed that patients complying with the Paris II criteria had significantly high prothrombin time and low total bilirubin levels. The area under the curve of extreme gradient boosted tree was good for (ii) (0.811) and (iii) (0.856). CONCLUSIONS: We demonstrated the efficacy of ML in predicting the treatment response for patients with primary biliary cholangitis. Early identification of cases requiring additional treatment with our novel ML model may improve prognosis.

Machine learning prediction model for treatment responders in patients with primary biliary cholangitis.

Background and Aim: Treatment response to ursodeoxycholic acid may predict the prognosis of patients with primary biliary cholangitis (PBC). Recent studies have suggested the benefits of using machine learning (ML) to forecast complex medical predictions. We aimed to predict treatment response in patients with PBC using ML and pretreatment data. Methods: We conducted a single-center retrospective study and collected data from 194 patients with PBC who were followed up for at least 12 months after treatment initiation. Patient data were analyzed with five ML models, namely random forest, extreme gradient boosting (XGB), decision tree, naïve Bayes, or logistic regression, to predict treatment response using the Paris II criteria. The established models were assessed using an out-of-sample validation. The area under the curve (AUC) was used to evaluate the efficacy of each algorithm. Overall survival and liver-related deaths were analyzed using Kaplan-Meier analysis. Results: Compared to logistic regression (AUC = 0.595, P = 0.0219, 0.031 models), ML analyses showed significantly high AUC in the random forest (AUC = 0.84) and XGB (AUC = 0.83) models; however, the AUC was not significantly high for decision tree (AUC = 0.633) or naïve Bayes (AUC = 0.584) models. Kaplan-Meier analysis showed significantly improved prognoses in patients predicted to achieve the Paris II criteria by XGB (log-rank = 0.005 and 0.007). Conclusion: ML algorithms could improve treatment response prediction using pretreatment data, which could lead to better prognoses. In addition, the ML model using XGB could predict the prognosis of patients before treatment initiation.

Navitoclax improves acute-on-chronic liver failure by eliminating senescent cells in mice.

AIM: Acute-on-chronic liver failure (ACLF), a disease with poor prognosis, is reportedly caused by cellular senescence due to mitochondrial dysfunction. In this study, we described and analyzed the underlying mechanism of a novel approach for ACLF using ABT263/navitoclax (Navi) that selectively eliminates senescent cells. METHODS: Irradiation-induced senescent hepatocytes were used for in vitro evaluation of the effects of Navi on ACLF (n = 6 for each group). Lipopolysaccharide- and carbon tetrachloride-induced ACLF mouse model was used for in vivo evaluation of the effects of Navi administration compared with the control using one-way or two-way analysis of variance, followed by Student's t-test or Kruskal-Wallis test. The effects on the senescence-associated secretory phenotype (n = 8 for each group) and mitochondrial functions, including adenosine triphosphate concentration and membrane potential (n = 8 for each group), were investigated using real-time polymerase chain reaction, immunohistochemistry, and enzyme analysis. RESULTS: Navi eliminated irradiation-induced senescent hepatocytes in vitro, leading to non-senescent hepatocyte proliferation. Navi eliminated senescent cells in the liver in vivo, resulting in downregulation of mRNA expression of senescence-associated secretory phenotype factors, a decrease of liver enzymes, and upregulated proliferation of non-senescent cells in the liver. Regarding mitochondrial functional assessment in the liver, adenosine triphosphate concentration and membrane potential were upregulated after Navi administration in vitro and in vivo. CONCLUSIONS: Navi may ameliorate ACLF damage by eliminating senescent cells in the liver, downregulating senescence-associated secretory phenotype factors, and upregulating mitochondrial functions. We believe that this novel approach using Navi will pave the way for ACLF treatment.

Analysis of drug-induced liver-related adverse event trend reporting between 1997 and 2019.

AIM: This study aimed to analyze the current trends of drug-induced liver-related adverse events in the Food and Drug Administration Adverse Event Reporting System (FAERS) and Japanese Adverse Drug Event Report (JADER) databases. METHODS: The characteristics of implicated drugs were investigated by analyzing big data on drug-induced liver-related adverse events over the past 20 years in FAERS, comparing drug rankings between the JADER and FAERS databases, and calculating rankings of drugs inducing liver-related adverse events using the Medical Dictionary for Regulatory Activities Terminology. RESULTS: In the 452 272 cases registered in FAERS from 1997 to 2019, warfarin, paracetamol, and adalimumab were the drugs most related to drug-induced liver injury (DILI). In the 38 919 cases registered in JADER from 2004 to 2019, sorafenib, nivolumab, and herbal extracts were the drugs most related to DILI. No associations were found between the top 30 drugs in either of the two databases. Notably, the number of drug-induced liver-related adverse event reports and total adverse events has sharply increased in recent years. CONCLUSIONS: Although liver-related adverse events are largely caused by host immunity and other constitutional factors, differences in primary diseases, countries, and historical backgrounds lead to differences in the number of reports. Securing an appropriate database and a mechanism to collect real-time information on the frequency of adverse drug reactions is warranted.

Two rare pancreatic parenchymal hemorrhagic lesions associated with acute pancreatitis in acute liver failure: a case report and literature review.

Acute pancreatitis is an uncommon occurrence in acute liver failure. Furthermore, such cases are rarely complicated by parenchymal hemorrhages. Herein, we report the case of a 69-year-old male patient with multiple pancreatic parenchymal hemorrhages concomitant with acute liver failure. The patient underwent conservative treatment for acute liver failure caused by hepatitis B virus infection. Plain computed tomography on the 30th day revealed two high-density mass lesions in the pancreatic body and tail, which were suspected to be multiple pancreatic parenchymal hemorrhages. Despite restarting gabexate mesylate, the patient died of multiple organ failure on the 49th day. The clinical information of the present case and our literature review of 61 similar cases in 43 case reports identified via a systematic keyword search of the PubMed database, which described acute pancreatitis concomitant with acute hepatitis and acute liver failure, will aid physicians in the diagnosis and treatment of this rare condition.

Cumulative risk of developing a new symptom in patients with primary biliary cholangitis and its impact on prognosis.

Background and Aim: Symptoms of primary biliary cholangitis (PBC) frequently impair one's quality of life (QOL). Nonetheless, with improved treatment, the prognosis of PBC also improves. QOL plays an important role in patients with PBC. In this study, we aimed to reevaluate the transition of new symptom development in PBC and its predictive factors. Methods: This retrospective multicenter study enrolled 382 patients with PBC for symptom analysis. The impact of a newly developed symptom on PBC prognosis was investigated by Kaplan-Meier analysis with propensity score matching and logistic progression analysis. Results: The cumulative risk of developing a new symptom after 10 and 20 years of follow-up was 7.6 and 28.2%, and specifically that of pruritus, which was the most common symptom, was 6.7 and 23.3%, respectively. In Cox hazard risk analysis, serum Alb level (hazard ratio [HR], 1.097; 95% confidence interval [CI], 1.033-1.165; P = 0.002), the serum D-Bil level (HR, 6.262; 95% CI, 2.522-15.553, P < 0.001), and Paris II criteria (HR, 0.435; 95% CI, 0.183-1.036; P = 0.037) were significant independent predictors of a new symptom. Kaplan-Meier analysis showed that the overall survival and liver-related death were not significant between patients with and without a new symptom. Conclusion: The cumulative risk of new symptom development is roughly 30% 20 years after diagnosis and could be predicted by factors including serum albumin levels, serum D-Bil level, and Paris II criteria.

A rare case of duodenal variceal bleeding due to extrahepatic portal vein obstruction successfully treated with endoscopic injection sclerotherapy.

Primary extra-hepatic portal vein obstruction (EHPVO) is a disease that develops ectopic varices due to portal hypertension and obstruction of the portal vein. Since bleeding from ectopic varices is life-threatening, the management of ectopic varices is important for patients with primary EHPVO. Here, we report a case of duodenal variceal bleeding in a patient with primary EHPVO. A 39-year-old man was diagnosed with F2-shaped duodenal varices (DV) due to primary EHPVO and was first treated with endoscopic variceal ligation for temporary hemostasis. We then performed angiography to understand the detailed hemodynamics and subsequently conducted endoscopic injection sclerotherapy (EIS) with a sclerosing agent containing N-butyl-2-cyanoacrylate for further hemostasis. After the treatment, dynamic computed tomography and endoscopic ultrasound revealed that the blood flow to the causative DV disappeared, although the DV itself remained. The patient was discharged without any re-bleeding or adverse events. Since treatment for DV due to primary EHPVO differs depending on hemodynamics (hepatofugal or hepatopetal blood flow), evaluating detailed hemodynamics for optimal treatment selection is crucial. Although EIS for this patient was not a radical treatment, it was effective in managing acute bleeding from the DV. This case will serve as a reference for successful treatment in future cases.

Utility of autologous fecal microbiota transplantation and elucidation of microbiota in diversion colitis.

Objectives: Diversion colitis (DC) is an inflammatory disorder caused by interruption of the fecal stream and subsequent nutrient deficiency from luminal bacteria. The utility of fecal microbiota transplantation (FMT) for DC was recently investigated; however, the precise pathogenesis of this condition remains unclear. This study aimed to evaluate the utility of autologous FMT in DC and to determine the related changes in the intestinal microbiota. Methods: Autologous FMT was performed to reestablish the intestinal microbiota in five patients (average age, 64.6 ± 8.3 years) with DC. They underwent double-ended colostomy. We assessed the diverted colon by endoscopy and evaluated the microbiota before and after FMT using the 16S rRNA gene sequencing method. Results: All five patients had mild inflammation (ulcerative colitis endoscopic index of severity [UCEIS] 2-3) in the diverted colon based on the colonoscopic findings. Three patients presented with symptoms, such as tenesmus, mucoid stool, and bloody stool. With FMT treatment, all patients achieved endoscopic remission (UCEIS score of 0 or 1) and symptomatic improvement. We observed a significantly decreased α-diversity in DC patients compared to healthy controls. The frequency of aerobic bacteria, such as Enterobacteriaceae, in the diverted colon decreased after autologous FMT. Conclusions: This study was the first to show that the microbiota in the diverted colon was significantly affected by autologous FMT. Since interruption of the fecal stream is central to the development of DC, FMT can be considered a promising treatment.

Longitudinal increase in albumin-bilirubin score is associated with non-malignancy-related mortality and quality of life in patients with liver cirrhosis.

Due to the developments in the treatment for hepatitis, it is possible to prevent the progression of liver fibrosis and improve patients' prognosis even if it has already led to liver cirrhosis (LC). Consequently, a two-step study was conducted. To begin with, a retrospective study was conducted to identify the potential predictors of non-malignancy-related mortality from LC. Then, we prospectively analyzed the validity of these parameters as well as their association with patients' quality of life. In the retrospective study, 89 cases were included, and the multivariate Cox regression analysis indicated that age (P = 0.012), model for end-stage liver disease (MELD) score (P = 0.012), and annual rate of change of the albumin-bilirubin (ALBI) score (P < 0.001) were significantly associated with LC prognosis. In the prospective study, 70 patients were included, and the patients were divided into cirrhosis progression and non-progression groups. The univariate logistic regression analysis indicated the serum procollagen type III N-terminal peptide level (P = 0.040) and MELD score (P = 0.010) were significantly associated with the annual rate of change of the ALBI score. Furthermore, the mean Chronic Liver Disease Questionnaire score worsened from 5.3 to 4.9 in the cirrhosis progression group (P = 0.034). In conclusion, a longitudinal increase in the ALBI score is closely associated with non-malignancy-related mortality and quality of life.

Novel Strategy for Diagnosis of Focal Nodular Hyperplasia Using Gadolinium Ethoxybenzyl Diethylenetriaminepentaacetic Acid: Enhanced Magnetic Resonance Imaging and Magnetic Resonance Elastography.

Focal nodular hyperplasia (FNH) is the second most frequent benign liver tumor, and it is a fiber-rich stiff lesion. Typically, FNH can be diagnosed by imaging without biopsy. However, liver biopsy and diagnostic resection may be required to differentiate atypical FNH from other liver tumors, such as hepatocellular adenoma (HCA). Therefore, improved noninvasive diagnostic methods are needed. We experienced 2 cases where combination of magnetic resonance elastography (MRE) and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) helped diagnose FNH. A 36-year-old woman and 17-year-old boy with liver tumors measuring 40 mm in diameter each showed hypointense nodule centers, indicating a central scar, surrounded by hyperintense signals during the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI. To rule out HCA, we performed MRE and liver biopsy. On MRE, the mean stiffness of the mass was 11.6 kPa (mean stiffness of the background liver was 1.7 kPa) and 11.1 kPa (mean stiffness of the background liver was 2.4 kPa) in the first and second patients, respectively. Histological examination of both specimens showed CK7-positive bile-ductular proliferations, abundant fibrous tissue, and few Ki-67-positive cells. Based on these results, we diagnosed these tumors as FNH. Combination of Gd-EOB-DTPA-enhanced MRI and MRE can evaluate the character and stiffness of lesion and help in the diagnosis of FNH.

Paris II and Rotterdam criteria are the best predictors of outcomes in patients with primary biliary cholangitis in Japan.

BACKGROUND: Biochemical response to treatment in patients with primary biliary cholangitis (PBC) reflects prognosis. However, the best predictive criteria to detect biochemical response remain undetermined. In addition, because these criteria need > 6 months until definition, parameters that can estimate its results before initiating treatment are needed. METHODS: We conducted a single-center retrospective study on 196 patients with PBC, followed up for at least 12 months after initiating treatment. RESULTS: Kaplan-Meier analysis showed that Paris II (p = 0.002) and Rotterdam criteria (p = 0.001) could estimate the overall survival of PBC patients, whereas Paris II (p = 0.001), Rotterdam (p = 0.001), and Rochester criteria (p= 0.025) could estimate liver-related deaths. Cox hazard analysis revealed Paris II and Rotterdam criteria as significantly independent predictors of overall survival (hazard ratio (HR) 3.948, 95% CI 1.293-12.054, p = 0.016 and HR 6.040, 95% CI 1.969-18.527, p = 0.002, respectively) and liver-related deaths (HR 10.461, 95% CI 1.231-88.936, p = 0.032 and HR 10.824, 95% CI 1.252-93.572, p = 0.032, respectively). The results of Paris II criteria could be estimated by serum prothrombin time (Odds ratio (OR) 1.052, 95% CI 1.008-1.098, p = 0.021) and alanine transaminase level (OR 0.954, 95% CI 0.919-0.991, p = 0.014) whereas, those of Rotterdam criteria could be estimated by serum albumin level (OR 3.649, 95% CI 1.098-12.128, p = 0.035) at the time of diagnosis. CONCLUSIONS: This study highlights the best prediction criteria and pre-treatment parameters that facilitate the prognosis of PBC patients.

Visceral Adipose Tissue Index and Hepatocellular Carcinoma Are Independent Predictors of Outcome in Patients with Cirrhosis Having Endoscopic Treatment for Esophageal Varices.

BACKGROUND: The relationship between the amount of adipose tissue and advanced-stage liver cirrhosis with esophageal varices (EV) is unknown. We aimed to reveal the prognostic significance of adipose tissues in patients with liver cirrhosis. METHODS: We enrolled 87 patients with EV who received initial endoscopic treatment and underwent scheduled treatments in our hospital. Computed tomography (CT) images were obtained of a 5-mm slice at the umbilical level. We evaluated the effect of mortality based on the visceral adipose tissue index (VATI), subcutaneous adipose tissue index (SATI), and visceral to subcutaneous adipose tissue ratio (VSR). RESULTS: Cox hazard multivariate analysis showed that the presence of hepatocellular carcinoma (HCC; hazard ratio [HR]: 4.650, 95% confidence interval [CI]: 1.750-12.353, p = 0.002), γ-GTP (HR: 1.003, 95% CI: 1.001-1.006, p = 0.026), and VATI (HR: 1.057, 95% CI: 1.030-1.085, p < 0.001) significantly affected mortality. Cox hazard multivariate analysis for liver-related death was also significantly affected by HCC (HR: 1.057, 95% CI: 1.030-1.085, p < 0.001) and VATI (HR: 1.052, 95% CI: 1.019-1.086, p = 0.002). The difference between the Child-Pugh scores 12 months after treatment and that during initial treatment were significantly positively correlated with VATI (r = 0.326, p = 0.027). Patients with high VATI had a significantly higher frequency of HCC after EV treatment by Kaplan-Meier analysis (p = 0.044). CONCLUSION: Our findings suggest that VATI measured by CT could significantly predict mortality in cirrhosis patients through decreasing liver function and increasing HCC frequency, and appropriately controlling VATI could improve their prognosis.

Changes in disease characteristics of primary biliary cholangitis: An observational retrospective study from 1982 to 2016.

AIM: Disease characteristics of primary biliary cholangitis have changed recently. However, detailed studies on the subject have been limited. Therefore, we aimed to clarify disease characteristics of patients with recent primary biliary cholangitis using the cohort from Niigata University and 21 affiliated hospitals. METHODS: Overall, 508 patients were enrolled in this study from 1982 to 2016, divided into three cohorts according to their year of diagnosis: ≤1999, 2000-2009 and ≥2010. We compared differences in clinical characteristics, response to ursodeoxycholic acid and prognosis. RESULTS: The male-to-female ratio increased incrementally from 1:16.4 (≤1999) to 1:3.8 (≥2010) (P < 0.001). In women, the median age at diagnosis increased incrementally from 54.0 years (≤1999) to 60.5 years (≥2010) (P < 0.001) and serum albumin decreased gradually (P = 0.001), which might have affected the increase in the Fibrosis-4 Index and albumin-bilirubin score. The ursodeoxycholic acid response rate according to the Barcelona criteria increased incrementally from 26.7% (≤1999) to 78.4% (≥2010) (P < 0.010), and those according to other criteria (Paris-I, Rotterdam and Toronto) were approximately ≥80% in all cohorts. Ten-year survival rate in the ≤1999 and 2000-2009 cohorts were 98.6% and 95.6%, respectively. These earlier cohorts were also characterized by a higher rate of asymptomatic state and mild histology (83.5% [≤1999] and 84.7% [2000-2009], and 93.6% [≤1999] and 91.1% [2000-2009]). CONCLUSIONS: Patients with primary biliary cholangitis were characterized by older age at diagnosis and an increase in male to female ratio as well as higher response rates of ursodeoxycholic acid and longer survival, resulting from the early recognition of primary biliary cholangitis.

Effectiveness of Endoscopic Pancreatic Stenting for Pancreatic Pseudocyst-Portal Vein Fistula.

Pancreatic pseudocyst-portal vein (PP-PV) fistula, mostly occurring after pseudocyst formation following acute/chronic pancreatitis, is a rare but life-threatening condition. The majority of treatments are based on conservative or surgical interventions. We report the case of a 70-year-old man with a PP-PV fistula and PV thrombosis. We adopted conservative treatment at first due to his mild symptoms. However, after resuming food intake, the patient had severe abdominal pain. Following endoscopic retrograde cholangiopancreatography, we found that the pseudocyst was connected with the PV through the fistula. Subsequently, an endoscopic nasopancreatic drainage (ENPD) catheter was inserted into the main pancreatic duct to establish pancreatic drainage, which resulted in a decrease in the abdominal pain. After the ENPD tube had been exchanged for endoscopic pancreatic stenting, his abdominal pain did not recur. Therefore, this case demonstrated endoscopic treatment as an effective treatment option for PP-PV fistula.

Screening and follow-up of chronic liver diseases with understanding their etiology in clinics and hospitals.

BACKGROUND AND AIM: Considering the increasing prevalence of non-alcoholic fatty liver disease and non-alcoholic steatohepatitis (NASH), the development of an effective screening and follow-up system that enables the recognition of etiological changes by primary physicians in clinics and specialists in hospitals is required. METHODS: Chronic hepatitis B (HBV) and C (HCV), NASH, and alcoholic steatohepatitis (ASH) patients who were assayed for Mac-2-binding protein glycosylation isomer (M2BPGi) (n = 272) and underwent magnetic resonance elastography (MRE) (n = 119) were enrolled. Patients who underwent MRE were also tested by ultrasound elastography (USE) (n = 80) and for M2BPGi (n = 97), autotaxin (ATX) (n = 62), and platelet count (n = 119), and their fibrosis-4 (FIB-4) index was calculated (n = 119). RESULTS: FIB-4 index >2, excluding HBV-infected patients, M2BPGi >0.5, ATX >0.5, and platelet count <20 × 104/µL were the benchmark indices, and we took into consideration other risk factors, such as diabetes mellitus and age, to recommend further examinations, such as USE, based on the local situation to avoid overlooking hepatocellular carcinoma (HCC) in the clinic. During specialty care in the hospital, MRE exhibited high diagnostic ability for fibrosis stages >F3 or F4; it could efficiently predict collateral circulation with high sensitivity, which can replace USE. We also identified etiological features and found that collateral circulation in NASH/ASH patients tended to exceed high-risk levels; moreover, these patients exhibited more variation in HCC-associated liver stiffness than the HBV and HCV patients. CONCLUSIONS: Using appropriate markers and tools, we can establish a stepwise, practical, noninvasive, and etiology-based screening and follow-up system in primary and specialty care.

Rare case of circumferential esophageal peeling.

This report highlights the easy peeling of the esophageal epithelium with Nikolsky phenomenon after swallowing the foreign body and the healing status of the esophagus only 3 days later in a patient of pemphigus vulgaris.

Therapeutic potential of mesenchymal stem cells and their exosomes in severe novel coronavirus disease 2019 (COVID-19) cases.

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19) and the ensuing worldwide pandemic. The spread of the virus has had global effects such as activity restriction, economic stagnation, and collapse of healthcare infrastructure. Severe SARS-CoV-2 infection induces a cytokine storm, leading to acute respiratory distress syndrome (ARDS) and multiple organ failure, which are very serious health conditions and must be mitigated or resolved as soon as possible. Mesenchymal stem cells (MSCs) and their exosomes can affect immune cells by inducing anti-inflammatory macrophages, regulatory T and B cells, and regulatory dendritic cells, and can inactivate T cells. Hence, they are potential candidate agents for treatment of severe cases of COVID-19. In this review, we report the background of severe cases of COVID-19, basic aspects and mechanisms of action of MSCs and their exosomes, and discuss basic and clinical studies based on MSCs and exosomes for influenza-induced ARDS. Finally, we report the potential of MSC and exosome therapy in severe cases of COVID-19 in recently initiated or planned clinical trials of MSCs (33 trials) and exosomes (1 trial) registered in 13 countries on ClinicalTrials.gov.

Portal Vein Thrombosis Associated with Trousseau Syndrome due to Urinary Bladder Squamous Cell Carcinoma in a Liver Cirrhosis Patient.

A 75-year-old woman with liver cirrhosis was admitted for treatment of portal vein thrombosis (PVT). Computed tomography (CT) showed PVT, massive ascites, and multiple abdominal organ embolism. Blood tests revealed a decreased liver function (Child-Pugh grade C). Language impairment followed by progressive left hemi-paralysis was subsequently detected. Magnetic resonance imaging revealed multiple small acute cerebral infarctions and, on CT, a 30-mm bladder tumour; a biopsy specimen examination showed squamous cell carcinoma. Her general condition worsened rapidly, and the best supportive care was chosen. Our findings suggest that, in patients with PVT, Trousseau syndrome should be considered, even in cases of liver cirrhosis.

Esophageal Ulcers Associated with Ulcerative Colitis: A Case Series and Literature Review.

Ulcerative colitis, a chronic and recurrent inflammatory disease, is localized to the colonic mucosa but can affect other organs and lead to various complications. Gastroduodenitis associated with ulcerative colitis has been reported. However, little is known about esophageal ulcers. We herein report two rare cases of esophageal ulcers associated with ulcerative colitis. Furthermore, the clinical and histological characteristics of 18 previously reported cases are summarized. This case series and literature review will encourage the accurate diagnosis and treatment of esophageal ulcers associated with ulcerative colitis.

Different distribution of mucosal-associated invariant T cells within the human cecum and colon.

INTRODUCTION: Mucosal-associated invariant T (MAIT) cells are innate-like T cells that are involved in anti-bacterial immunity. MAIT cells are found in the intestines, but their role and distribution within the large intestine have not been fully elucidated. Therefore, we investigated the distribution of MAIT cells within the cecum and colon. MATERIAL AND METHODS: Surgically resected tissues of the cecum and colon were obtained from 4 patients with cecal appendix cancer and 8 patients with colorectal cancer, respectively. Lymphocytes were isolated from the intestinal epithelium (intraepithelial lymphocytes - IELs) and the underlying lamina propria (lamina propria lymphocytes - LPLs), and then, MAIT cells were analyzed by flow cytometry. RESULTS: Compared with the colon, the cecum showed a significantly increased frequency of MAIT cells among IELs (p < 0.01). CD69 expression on MAIT cells was significantly increased in the cecum and colon compared with that in the blood, and the frequency of natural killer group 2, member A+ cells among MAIT cells was significantly increased in the cecum. CONCLUSIONS: These results suggest that the distribution of MAIT cells was different between the cecum and colon and that MAIT cells were more likely to be activated, especially in the intestinal epithelium of the cecum than in the colon and blood.