Takahisa Tainaka

Gene expression profiling reveals upregulated UCA1 and BMF in gallbladder epithelia of children with pancreaticobiliary maljunction.

Background:Pancreaticobiliary maljunction is usually associated with choledochal cysts and often causes biliary carcinoma; however, the mechanism of carcinogenesis remains unknown. No study has analyzed overall changes in genetic expression beginning during childhood in gallbladder epithelia with pancreaticobiliary maljunction. Patients and Methods:The genomewide expression of gallbladder epithelia was analyzed in 6 children with pancreaticobiliary maljunction and in 4 pediatric controls. Selected genes that were expressed differentially were further analyzed by the real-time reverse transcription-polymerase chain reaction (RT-PCR). The products of upregulated genes confirmed by real-time RT-PCR were immunohistochemically analyzed using gallbladders from 19 children with pancreaticobiliary maljunction, 5 pediatric controls, and 5 children with gallstones. Results:Microarray analysis identified 188 upregulated and 160 downregulated genes. RT-PCR confirmed upregulation in 5 of 6 genes and downregulation in 1 of 5 genes, including UCA1, DUOX2, DUOXA2, ID1, BMF, and GP2. Immunohistochemistry showed a significantly higher expression of BMF in the pancreaticobiliary maljunction patients than in the controls and gallstone patients. Conclusions:This study identified several deregulated genes in the gallbladder of children with pancreaticobiliary maljunction, which may contribute to the pathophysiology. UCA1, a noncoding RNA, is an oncofetal gene, and its upregulation may be important for biliary carcinogenesis. The elevated expression of BMF may function as an apoptotic activator in proliferative gallbladder epithelia.

Pancreaticobiliary Maljunction Without Bile Duct Dilatation in Children: Distinction From Choledochal Cyst

Objectives: Pancreaticobiliary maljunction without bile duct dilatation (nondilated type) is rare in children, and its definition remains unclear. There is controversy over treatment between pediatric and adult patients. We reevaluated our previous definition of the nondilated type in children (common bile duct diameter ≤6 mm on cholangiography). Patients and Methods: Of 150 children with pancreaticobiliary maljunction, 14 fulfilled the definition of the nondilated type. Clinical and cholangiographic findings were reviewed and compared with cholangiograms of 17 children without biliary diseases (controls). The age-related normal range of the choledochal diameter was defined in combination with previous data. Results: All of the patients had symptoms and signs similar to those of choledochal cysts. Cholangiographic features of choledochal cysts were detected in all of the patients (dilated common channel, 8; distal bile duct stenosis, 5; dilated cystic duct, 4; filling defect in the common channel, 8). The choledochal diameter in control children increased with age. Only 4 patients (29%) had a choledochal caliber within the normal range. Conclusions: Most pediatric cases reported as the nondilated type are slightly dilated (forme fruste) choledochal cysts and differ from the nondilated type seen in adults. The nondilated type in children should be defined on the basis of the age-related choledochal diameter.

A New Era of Laparoscopic Revision of Kasai Portoenterostomy for the Treatment of Biliary Atresia

Purpose. Kasai portoenterostomy is the standard therapy for biliary atresia (BA). If Kasai is unsuccessful, there is controversy over whether revision of Kasai restores adequate biliary drainage. Although there are several reports of laparoscopic Kasai (Lap-Kasai), none has described laparoscopic revision (Lap-revision). The purposes of this study were to evaluate the feasibility and efficacy of Lap-revision. Methods. 65 patients underwent open Kasai between November 2001 and November 2013, and 12 patients underwent Lap-Kasai between December 2013 to January 2015. The indications for revision included bile flow cessation and recurrent cholangitis. Clinical data were compared between open and laparoscopic revisions of Kasai. Results. Open revision of Kasai was performed in 20 patients after open Kasai, and Lap-revision was performed in 4 patients after Lap-Kasai. Lap-revision was completed without conversion or major complication in any patient. The bilirubin level was normalized by Lap-revision in all four patients, and three of them were alive with their native liver. Open and laparoscopic revisions of Kasai were comparable in terms of the operation time, blood loss, and surgical outcomes. Conclusion. Lap-revision is a feasible and effective method for the treatment of BA and might herald a new era for the treatment of this disease.

Fatty acid calcium stones in patients with pancreaticobiliary maljunction/choledochal cyst as another cause of obstructive symptoms besides protein plugs

Symptoms of choledochal cysts are caused by protein plugs, which clog up in the long common channel and increase pancreaticobiliary ductal pressure. We report that fatty calcium acid stones/debris are another previously unreported cause of obstructive symptoms in 2 cases with choledochal cyst.

Histological assessment of bile lake formation after hepatic portoenterostomy for biliary atresia

Bile lakes develop after hepatic portoenterostomy in some patients with biliary atresia, and have been regarded as an indication of poor prognosis. We reported that bile lakes have no epithelium of the bile duct on their wall, and are surrounded by bile ducts; however, the mechanism of bile lake formation is little known. We investigated histologically how bile ducts are formed using whole removed liver, and the characteristics of bile ducts around bile lakes. From April 1980 to July 2006, we encountered 84 patients with biliary atresia. Bile lakes were analyzed histologically in 11 patients who underwent liver transplantation in our hospital. Bile lakes had a fibrotic cyst wall and lacked epithelia. In most cases, bile stasis, calculi formation, damaged bile ducts, and invasion of inflammatory cells were observed around the bile lakes. Bile ducts around bile lakes were not stained by CD56, but bile ducts around liver lobuli were stained by CD56. The present study speculates that bile lakes would arise from original bile ducts, which are damaged, and fuse together after calculi are formed in bile ducts.

Intrahepatic cystic lesions after hepatic portoenterostomy for biliary atresia with bile lake and dilated bile ducts.

Background: Intrahepatic cystic lesions develop after hepatic portoenterostomy in some patients with biliary atresia and have been regarded as an indication of poor prognosis; however, there is confusion about the terminology and concepts of the lesions. We investigated whether the cystic lesions constituted a single entity. Patients and Methods: From 1980 to 2005, we encountered 80 patients with biliary atresia. Abdominal ultrasonography disclosed intrahepatic cystic lesions in 20 (25%) patients after hepatic portoenterostomy. The cystic lesions were analyzed morphologically with radiologic imaging studies and histologically in 13 patients who underwent liver transplantation. Results: Fifteen patients had solitary simple cystic lesions, and 5 patients had multiple continuous oval or beaded lesions. Solitary lesions had a fibrotic cyst wall and lacked epithelia. Continuous lesions had a cyst wall covered with biliary epithelia. Thirteen patients with solitary cysts died or required liver transplantation. In 2 patients with continuous lesions, surgical reboring of the porta hepatis could eliminate cystic lesions and jaundice. Conclusions: Intrahepatic cystic lesions include 2 different conditions. Solitary cysts are retention pseudocysts, which should be referred to as a bile lake, and are associated with poor prognosis. Continuous beaded cysts are dilated bile ducts, which may be reversed. This distinction is important when considering the treatment strategy.

Cytomegalovirus (CMV) Monitoring After Liver Transplantation: Comparison of CMV Pp65 Antigenemia Assay with Real-Time PCR Calibrated to WHO International Standard.

BACKGROUND Cytomegalovirus (CMV) remains a major cause of morbidity and mortality for liver transplant recipients. Although the CMV pp65 antigenemia (AG) assay has been widely used to monitor patients for CMV infection after liver transplantation, real-time PCR is becoming the standard procedure. The World Health Organization (WHO) International Reference Standard for CMV quantification has become available to standardize values diagnostic of CMV infection. MATERIAL AND METHODS Our in-house real-time PCR assay was standardized using the WHO standard reagents. Levels of CMV DNA in 1339 blood samples obtained from 190 liver transplant recipients were quantified and expressed in international units, and results were then compared with those of the CMV pp65 AG assay performed on the same blood samples. Correlation was assessed and receiver operating characteristic curves were analyzed to determine the optimal cut-off value for CMV DNA (IU/mL) PCR results. RESULTS Significant correlation was found between results of the 2 assay methods (p<0.001, r=0.715); a PCR result of ≥288 IU/mL predicted a positive result by the CMV AG assay (1 positive cells/150 000 leukocytes) with a sensitivity of 67.4% and specificity of 94.8%. CONCLUSIONS To the best of our knowledge, this is the first report to compare CMV AG and real-time PCR (calibrated to the WHO standard) results in a large number of recipients after liver transplantation. Use of this technique may provide useful information for the management of CMV infection.

Simultaneous Monitoring by Real-Time Polymerase Chain Reaction of Epstein-Barr Virus, Human Cytomegalovirus, and Human Herpesvirus-6 in Juvenile and Adult Liver Transplant Recipients

Cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus-6 (HHV-6) cause symptomatic diseases in liver transplant recipients. The loads of these viruses, the associations between viral DNAemia, serologic status, and acute rejection reactions were investigated in a group of 17 juvenile and 17 adult recipients of living donor liver transplantation (LDLT) for a median of 8 weeks posttransplantation. At least 1 plasma sample from 15/34 (44.1%) patients was positive for CMV DNA. For most of the CMV-positive patients, the CMV DNA appeared in the second week of LDLT, and disappeared by the eighth week. A minimum of 200 EBV DNA copies/mug peripheral blood mononuclear cell DNA (defined as positive for EBV) was detected in 5/34 (14.7%) patients, and the number of EBV-positive children was significantly greater than the number of EBV-positive adults. In most of the EBV-positive patients, the EBV loads increased after 4 weeks posttransplantation. Plasma HHV-6 was detected in 7/34 (20.6%) patients. HHV-6 DNA appeared for a short period from the second week of LDLT. In addition, 8 of the 19 virus-positive recipients carried 2 viruses, with the combination of CMV and HHV-6 being the most frequent. Serologic status seemed to be an important factor for all 3 viral infections. The rate of acute cellular rejection was not significantly higher in the CMV-, EBV-, or HHV-6-positive groups. Simultaneous monitoring for 3 herpesviruses revealed the impact of these viruses on LDLT recipients.

Two-Stage Thoracoscopic Repair of Long-Gap Esophageal Atresia Using Internal Traction Is Safe and Feasible

BACKGROUND The treatment of long-gap esophageal atresia remains an issue for pediatric surgeons. Many techniques for treating long-gap esophageal atresia have been proposed, but the optimal method has not been established. The thoracoscopic esophageal elongation technique has recently been developed. We previously reported a case in which two-stage thoracoscopic repair was performed using internal esophageal traction without esophageal tearing, and we retrospectively reviewed the outcomes of this procedure in this study. METHODS Five patients underwent thoracoscopic treatment involving internal esophageal traction for esophageal atresia involving a long gap or vascular ring over a 5-year period. RESULTS Between November 2010 and November 2015, 5 patients were treated with thoracoscopic traction. All of these patients successfully underwent thoracoscopic-delayed primary anastomosis. Conversion to open thoracotomy was not required in any case. The postoperative complications experienced by the patients included minor anastomotic leakage in 2 cases, anastomotic stenosis in 1 case, gastroesophageal reflux (GER) in 4 cases, and a hiatal hernia in 1 case. None of the patients died. CONCLUSIONS Two-stage thoracoscopic repair for esophageal atresia involving a long gap or vascular ring is a safe and feasible procedure; however, we must develop methods for treating minor anastomotic complications and GER due to esophageal traction in future.

Congenital pancreatoblastoma associated with β-catenin mutation†

To the Editor: Pancreatoblstoma (PB) is a rare primary neoplasm of childhood. Although 200 cases of PB have been reported, it is considered the most common neoplasm in early childhood pancreatic tumors [1]. Most PB cases are sporadic and the congenital cases of PB have been described in association with Beckwith–Wiedemann syndrome (BWS) [2]. PB molecular pathogenesis remains to be elucidated. Genetic alterations of the adenomatous polyposis coli (APC)/b-catenin pathway and chromosome 11p loss of heterozygosity (LOH) are the most frequent molecular events in PB [3]. In pediatric neoplasms, ß-catenin mutation frequently found in hepatoblastoma [4] and pancreatoblastoma [3]. Here, we report a case of PB presenting in a 3-day-old male without any other congenital anomalies. On examination, there was an intra-abdominal mass that was confirmed by radiographic examination. Laboratory findings included elevated serum levels for a-fetoprotein of 272,680 ng/ml and lactate dehydrogenase of 518 IU/L. Complete resection of the tumor was performed and the patient recovered after surgery without complications. HEstained sections of the resected tumor, showed the typical histopathology of PB. Immumohistochemistry showed nuclear and cytoplasmic accumulation of b-catenin (CTNB1) and cyclin D1 proteins in PB specimen. We found a novel point mutation in codon 41 (A to G) resulting in a substitution of threonine by alanine in PB tissue from which gDNA was available. A crucial effector of Wnt signaling is b-catenin, a multifunctional protein that plays important roles in intercellular adhesion and in cell growth, survival, and differentiation [5]. Koesters and von Knebel Doeberitz [6] demonstrated that mutations in codon 41/45 of b-catenin had a higher oncogenic potential than mutations affecting the codon 33/37 cluster region in rat colon tumors induced by the alkylating agent. Our report shows the isolated congenital form of PB with point mutation in codon 41 of bcatenin gene. This study supports the notion that Wnt signaling pathway plays an important role in tumorgenesis of PB. Full benefit from early diagnosis of this rare entity of neoplasm will enable us to learn more of its biology.