Takehisa Ueno

Complement regulation in the GalT KO era

Miyagawa S, Yamamoto A, Matsunami K, Wang D, Takama Y, Ueno T, Okabe M, Nagashima H, Fukuzawa M. Complement regulation in the GalT KO era.
Xenotransplantation 2010; 17: 11–25.

Current status of intestinal transplantation

The prognosis of short gut syndrome has improved dramatically in the past few decades through the development of total parenteral nutrition (TPN). However, TPN-related complications still produce major problems for such patients. Intestinal transplantation can significantly improve patients’ prognosis and increase their quality of life. The international intestinal transplant registry is updated every other year in an international small bowel transplant symposium. In this report we review the indications, procedures, management, and current status of intestinal transplantation based on the 11th International Small Bowel Transplant Symposium held in Bologna in 2009. The major findings of international studies have shown that optimization of the following factors may contribute to better outcomes: advancement of surgical techniques, new immunosuppressive techniques, improvement of postsurgical management, adequate timing of transplantation, and refined selection of candidates. Ideally, intestinal transplantation will be established as a standard therapy for intestinal failure and secondary multiorgan failure by improving the long-term survival and quality of life for patients receiving such transplants.

The suppression of inflammatory macrophage-mediated cytotoxicity and proinflammatory cytokine production by transgenic expression of HLA-E.

BACKGROUND Macrophages participate in xenogenic rejection and represent a major biological obstacle to successful xenotransplantation. The signal inhibitory regulatory protein α (SIRPα) receptor was reported to be a negative regulator of macrophage phagocytic activity via interaction with CD47, its ligand. Because a majority of human macrophages express the inhibitory receptor CD94/NKG2A, which binds specifically to the human leukocyte antigen (HLA)-E and contains immunoreceptor tyrosine-based inhibition motifs (ITIMs), the inhibitory function of HLA class I molecules, HLA-E, on macrophage-mediated cytolysis was examined. The suppressive effect against proinflammatory cytokine production by macrophages was also examined. METHODS Complementary DNA (cDNA) of HLA-E, and CD47 were prepared and transfected into swine endothelial cells (SEC). The expression of the modified genes was evaluated by flow cytometry and macrophage-mediated cytolysis was assessed using in vitro generated macrophages. RESULTS Transgenic expression of HLA-E significantly suppressed the macrophage-mediated cytotoxicity. HLA-E transgenic expression demonstrated a significant suppression equivalent to CD47 transgenic expression. Furthermore, transgenic HLA-E suppressed the production of pro-inflammatory cytokines by inflammatory macrophages. CONCLUSIONS These results indicate that generating transgenic HLA-E pigs might protect porcine grafts from, not only NK cytotoxicity, but also macrophage-mediated cytotoxicity.

Humoral immunity is involved in the development of pericentral fibrosis after pediatric live donor liver transplantation

Yamada H, Kondou H, Kimura T, Ikeda K, Tachibana M, Hasegawa Y, Kiyohara Y, Ueno T, Miyoshi Y, Mushiake S, Ozono K. Humoral immunity is involved in the development of pericentral fibrosis after pediatric live donor liver transplantation.

A case of tracheal agenesis surviving without mechanical ventilation after external esophageal stenting.

Tracheal agenesis is a rare and usually lethal congenital malformation of the forgut. Although some infants can be resuscitated with an intra-esophageal intubation temporarily, long-term airway management is difficult because of the collapsing airway. We report a long-term survivor with tracheal agenesis in whom a Gortex external esophageal stent using radial traction sutures was applied to prevent the esophagus from collapsing. The patient was discharged from our hospital without mechanical ventilation or oxygen inhalation at 10 months of age. Our procedure has a potential to establish a long-term steady airway in patients with tracheal agenesis. The detail of the procedure is presented and the related literature is reviewed.

Diagnosis and management of biliary cystic malformations in neonates

PURPOSE Recent advances in ultrasonography have made it possible to identify biliary atresia (BA) and choledochal cyst (CC) with biliary cystic malformations (BCM) both prenatally and neonatally. The early differential diagnosis between BA and CC is extremely important because operations must be performed as soon as possible before the livers of BA patients advance to an irreversible cirrhotic stage. The aim of this study was to differentiate patients with BCM and to determine the best course of management in the neonatal period. METHODS The medical records of patients that were diagnosed with BCM by a prenatal or neonatal ultrasound between 1997 and 2008 were reviewed. We retrospectively divided the BCM patients into the BA and CC groups and then compared the results of ultrasound, computed tomography, and laboratory tests between the 2 groups. RESULTS Ten patients were enrolled in the study. The median age at the time of corrective surgery was 74 days (range, 24-206 days). All of the BA cases received an operation by the time they were 60 days old. In the BA group (5 patients), the mean cyst size was 15 mm, the mean direct bilirubin (D-Bil) was 3.3 mg/dL, and the mean total bile acid (TBA) was 138.1 µmol/L at 30 days of age, whereas in the CC group (5 patients), cyst size, D-Bil, and TBA were 40 mm, 0.9 mg/dL, and 46.9 µmol/L, respectively. These differences between the 2 groups were statistically significant. All of the patients with CC successfully cleared their jaundice, whereas 4 patients with BA subsequently required liver transplantation for liver failure. In our study, all patients with BCM less than 21 mm, D-Bil greater than 2.5 mg/dL, and TBA greater than 111 µmol/L in the neonatal period were diagnosed with BA. CONCLUSIONS Our data suggested that patients with BCM smaller than 21 mm, D-Bil higher than 2.5 mg/dL, and TBA higher than 111 µmol/L in the neonatal period were more likely to have BA than CC. This potential diagnosis should be surgically examined and corrected as soon as possible.

Bile salt export pump‐reactive antibodies form a polyclonal, multi‐inhibitory response in antibody‐induced bile salt export pump deficiency

Progressive familial intrahepatic cholestasis type 2 (PFIC‐2) is caused by mutations in ABCB11, encoding the bile salt export pump (BSEP). In 2009, we described a child with PFIC‐2 who developed PFIC‐like symptoms after orthotopic liver transplantation (OLT). BSEP‐reactive antibodies were demonstrated to account for disease recurrence. Here, we characterize the nature of this antibody response in 7 more patients with antibody‐induced BSEP deficiency (AIBD). Gene sequencing and immunostaining of native liver biopsies indicated absent or strongly reduced BSEP expression in all 7 PFIC‐2 patients who suffered from phenotypic disease recurrence post‐OLT. Immunofluorescence, western blotting analysis, and transepithelial transport assays demonstrated immunoglobulin (Ig) G‐class BSEP‐reactive antibodies in these patients. In all cases, the N‐terminal half of BSEP was recognized, with reaction against its first extracellular loop (ECL1) in six sera. In five, antibodies reactive against the C‐terminal half also were found. Only the sera recognizing ECL1 showed inhibition of transepithelial taurocholate transport. In a vesicle‐based functional assay, transport inhibition by anti‐BSEP antibodies binding from the cytosolic side was functionally proven as well. Within 2 hours of perfusion with antibodies purified from 1 patient, rat liver showed canalicular IgG staining that was absent after perfusion with control IgG. Conclusions: PFIC‐2 patients carrying severe BSEP mutations are at risk of developing BSEP antibodies post‐OLT. The antibody response is polyclonal, targeting both extra‐ and intracellular BSEP domains. ECL1, a unique domain of BSEP, likely is a critical target involved in transport inhibition as demonstrated in several patients with AIBD manifest as cholestasis. (Hepatology 2016;63:524–537)

Bile Salt Export Pump‐reactive Antibodies Form a Polyclonal, Multi‐inhibitory Response in Antibody‐induced BSEP Deficiency

Progressive familial intrahepatic cholestasis type 2 (PFIC‐2) is caused by mutations in ABCB11, encoding the bile salt export pump (BSEP). In 2009, we described a child with PFIC‐2 who developed PFIC‐like symptoms after orthotopic liver transplantation (OLT). BSEP‐reactive antibodies were demonstrated to account for disease recurrence. Here, we characterize the nature of this antibody response in 7 more patients with antibody‐induced BSEP deficiency (AIBD). Gene sequencing and immunostaining of native liver biopsies indicated absent or strongly reduced BSEP expression in all 7 PFIC‐2 patients who suffered from phenotypic disease recurrence post‐OLT. Immunofluorescence, western blotting analysis, and transepithelial transport assays demonstrated immunoglobulin (Ig) G‐class BSEP‐reactive antibodies in these patients. In all cases, the N‐terminal half of BSEP was recognized, with reaction against its first extracellular loop (ECL1) in six sera. In five, antibodies reactive against the C‐terminal half also were found. Only the sera recognizing ECL1 showed inhibition of transepithelial taurocholate transport. In a vesicle‐based functional assay, transport inhibition by anti‐BSEP antibodies binding from the cytosolic side was functionally proven as well. Within 2 hours of perfusion with antibodies purified from 1 patient, rat liver showed canalicular IgG staining that was absent after perfusion with control IgG. Conclusions: PFIC‐2 patients carrying severe BSEP mutations are at risk of developing BSEP antibodies post‐OLT. The antibody response is polyclonal, targeting both extra‐ and intracellular BSEP domains. ECL1, a unique domain of BSEP, likely is a critical target involved in transport inhibition as demonstrated in several patients with AIBD manifest as cholestasis. (Hepatology 2016;63:524–537)

Clinical application of indocyanine green (ICG) fluorescent imaging of hepatoblastoma

BACKGROUND/PURPOSE Although the usefulness of intraoperative indocyanine green (ICG) fluorescent imaging for the resection of hepatocellular carcinoma has been reported, its usefulness for the resection of hepatoblastoma remains unclear. This study clarifies the feasibility of intraoperative ICG fluorescent imaging for the resection of hepatoblastoma. METHODS In three hepatoblastoma patients, a primary tumor, recurrent tumor, and lung metastatic lesions were intraoperatively examined using a near-infrared fluorescence imaging system after the preoperative administration of ICG. RESULTS ICG fluorescent imaging was useful for the surgical navigation in hepatoblastoma patients. In the first case, the primary hepatoblastoma exhibited intense fluorescence during right hepatectomy, but no fluorescence was detected in the residual liver. In the second case, a recurrent tumor exhibited fluorescence between the residual liver and diaphragm. A complete resection of the residual liver, with a partial resection of the diaphragm, followed by liver transplantation was performed. In the third case with multiple lung metastases, each metastatic lesion showed positive fluorescence, and all were completely resected. These fluorescence-positive lesions were pathologically proven to be viable hepatoblastoma cells. CONCLUSION Intraoperative ICG fluorescence imaging for patients with hepatoblastoma was feasible and useful for identifying small viable lesions and confirming that no remnant tumor remained after resection.

Graft fibrosis in patients with biliary atresia after pediatric living‐related liver transplantation

Ueno T, Tanaka N, Ihara Y, Takama Y, Yamada H, Mushiake S, Fukuzawa M. Graft fibrosis in patients with biliary atresia after pediatric living‐related liver transplantation. 
Pediatr Transplantation 2011: 15: 470–475.