Balloon dilatation for congenital esophageal stenosis associated with esophageal atresia.

PURPOSE: Congenital esophageal stenosis (CES) associated with esophageal atresia (EA) is rare, and no standard treatment has been established. We reviewed cases of EA-associated CES to assess the clinical characteristics and treatment outcomes, especially the feasibility of endoscopic dilatation. METHODS: We retrospectively examined patients with EA-associated CES. We also compared treatment outcomes of EA-associated CES with those of EA patients without CES who developed postoperative anastomotic stricture. RESULTS: Among 44 patients with EA, ten had CES (23%). Postoperative complications were not significantly different between EA patients with CES and those without CES but with anastomotic stricture. All CES patients underwent balloon dilatation as initial treatment. Eight of nine patients (89%) were successfully treated by dilatation only, and one patient underwent surgical resection. The median number of balloon dilatations for CES was five (2-17), which was higher than that for anastomotic stricture in patients without CES (p = 0.012). Esophageal perforation occurred in five patients with CES (5/9, 56%) after dilatation, but all perforations were successfully managed conservatively with an uneventful post-dilatation course. CONCLUSIONS: Twenty-three percent of patients with EA had CES. Although balloon dilatation for EA-associated CES required multiple treatments and carried a risk of perforation, balloon dilatation showed an 89% success rate and all perforations could be managed conservatively.

The hybrid CL-SP-D molecule has the potential to regulate xenogeneic rejection by human neutrophils more efficiently than CD47.

OBJECTIVE: Innate immunity plays a vital role in xenotransplantation. A CD47 molecule, binding to the SIRPα expressed on monocyte/macrophage cells, can suppress cytotoxicity. Particularly, the SIRPα contains ITIM, which delivers a negative signal. Our previous study demonstrated that the binding between CL-P1 and surfactant protein-D hybrid (CL-SP-D) with SIRPα regulates macrophages' phagocytic activity. In this study, we examined the effects of human CD47 and CL-SP-D expression on the inhibition of xenograft rejection by neutrophils in swine endothelial cells (SECs). METHODS: We first examined SIRPα expression on HL-60 cells, a neutrophil-like cell line, and neutrophils isolated from peripheral blood. CD47-expressing SECs or CL-SP-D-expressing SECs were generated through plasmid transfection. Subsequently, these SECs were co-cultured with HL-60 cells or neutrophils. After co-culture, the degree of cytotoxicity was calculated using the WST-8 assay. The suppressive function of CL-SP-D on neutrophils was subsequently examined, and the results were compared with those of CD47 using naïve SECs as controls. Additionally, we assessed ROS production and neutrophil NETosis. RESULTS: In initial experiments, the expression of SIRPα on HL-60 and neutrophils was confirmed. Exposure to CL-SP-D significantly suppressed the cytotoxicity in HL-60 (p = 0.0038) and neutrophils (p = 0.00003). Furthermore, engagement with CD47 showed a suppressive effect on neutrophils obtained from peripheral blood (p = 0.0236) but not on HL-60 (p = 0.4244). The results of the ROS assays also indicated a significant downregulation of SEC by CD47 (p = 0.0077) or CL-SP-D (p = 0.0018). Additionally, the suppression of NETosis was confirmed (p = 0.0125) in neutrophils co-cultured with S/CL-SP-D. CONCLUSION: These results indicate that CL-SP-D is highly effective on neutrophils in xenogeneic rejection. Furthermore, CL-SP-D was more effective than CD47 at inhibiting neutrophil-mediated xenograft rejection.

Impact of Total Parenteral Nutrition on Preoperative Management of Pediatric Living-Donor Liver Transplantation for Biliary Atresia Under 2 Years Old.

BACKGROUND: Liver failure and gastrointestinal bleeding occur in the end-stage of biliary atresia (BA). Living-donor liver transplantation (LDLT) is a standard treatment in Japan. Our program actively provides pre-transplant total parenteral nutrition (TPN) for such patients, and here we report its efficiency and safety. METHODS: Patients with BA for whom LDLT was indicated were identified. Those with a long-term external central venous catheter and TPN, longer than 4 weeks before LDLT, were analyzed. Ascites was controlled with diuretics. TPN indications, efficacy, and complications were assessed along with patient growth, biochemical markers, and gastrointestinal bleeding. RESULTS: Fourteen patients were included in the study, of whom 8 were girls and 6 were boys. The median age at LDLT was 0.9 years. Body weight (BW) at TPN initiation averaged 6799 g, and the median serum total bilirubin was 9.5 mg per dL. The median catheterization duration was 54 days, and 1 patient received home TPN. Indications for TPN were gastrointestinal bleeding and/or massive esophageal varices in 4 patients and poor nutritional status in 10 patients. No complications were observed except for 1 catheter infection and 1 catheter occlusion. The median final body weight before LDLT was 7906 g. The mean rate of BW gain was significantly higher after TPN than before (149 vs 32 g/wk, respectively, P = .0002). Mean prothrombin time and levels of albumin, cholinesterase, and total bilirubin were not significantly different at the start and end of TPN. CONCLUSIONS: Pre-transplant TPN was safe and effective for patients with end-stage BA.

Plasma Concentration of Antifungal Agent Micafungin for Pediatric Living Donor Liver Transplantation.

BACKGROUND: Pediatric living-donor liver transplantation (LDLT) candidates often receive long-term antibiotic treatment. Micafungin has been used as an antifungal agent after LDLT, but the adequate dose after pediatric LDLT was unknown. Here, we report micafungin blood concentrations after pediatric LDLT and discuss its safety and adequate dosing. METHODS: Pediatric patients with data on micafungin concentrations after LDLT were identified. Those with surgical complications were excluded. All patients received standard tacrolimus-based immunosuppression. A micafungin dose of 1 mg/kg was administered once daily for 10 days starting on postoperative day (POD) 1. The trough and peak micafungin blood concentrations were evaluated on PODs 1, 4, 7, and 10. Beta D glucan levels and liver function tests were assessed to determine micafungin effectiveness and safety. RESULTS: Ten patients were enrolled, with a median age of 1.2 years. The median graft vs body weight ratio was 2.7%. The primary diseases were biliary atresia (n = 7), Alagille syndrome (n = 2), and progressive familial intrahepatic cholestasis type 2 (n = 1). Mean peak micafungin levels were 4.47, 6.27, 5.47, and 5.47 µg/mL on PODs 1, 4, 7, and 10, respectively. Mean trough levels were 2.03, 1.88, and 2.66 µg/mL on PODs 4, 7, and 10, respectively. The micafungin half-lives were 13.7, 14.7, and 14.0 hours on PODs 4, 7, and 10, respectively. Beta D glucan levels were 4.4 pg/mL and 3.7 pg/mL before and after transplantation, respectively, indicating no significant difference (P = .3). No clinical fungal infections were observed. CONCLUSION: Micafungin administration is safe and effective after pediatric LDLT.

Clinical Implications of Serum Mac-2 Binding Protein in Patients After Living Donor Liver Transplantation for Biliary Atresia.

BACKGROUND: Patients who undergo pediatric living donor liver transplantation (LDLT) sometimes develop graft fibrosis. Recently, Mac-2 binding protein glycosylation-modified isomer (M2BPGi) was developed as a new marker of hepatic fibrosis progression. We performed this study to examine the relationship between serum M2BPGi levels and liver histologic findings in patients after LDLT for biliary atresia. METHODS: Patients aged <19 years who underwent LDLT for biliary atresia at our institution and followed up for at least 1 year after LDLT were eligible. There were 56 patients in this study. Pathologic findings of the last available biopsy were assessed. Portal vein (PV) stenosis was confirmed with angiography. M2BPGi levels were compared with pathologic fibrosis scores and PV stenosis findings. RESULTS: The mean age at transplant was 4.3 years. The mean observation period was 8.6 years. In terms of the degree of liver fibrosis, F0 was observed in 7 patients, F1 in 36, and F2 in 13. The median serum M2BPGi value was 0.8 cut-off index (COI) overall and 0.60 COI for F0, 0.74 COI for F1, and 1.07 COI for F2. The mean M2BPGi value in F2 was higher than that in F0 (P = .016) and F1 (P = .012). Mean serum M2BPGi values were 1.57 COI (0.29 COI) in patients with PV complications (n = 5) and 0.72 COI in patients without PV complications (n = 51) (P = .0001). CONCLUSION: M2BPGi is a novel marker for liver fibrosis in patients after pediatric LDLT. It is especially useful for follow-up of pediatric patients after LDLT to support liver biopsy interpretation.

Potential risks associated with laparoscopic gastrostomy in patients with the COL4A1 variant: Two case reports.

The COL4A1 (collagen Type 4 alpha1) pathogenic variant is associated with porencephaly and schizencephaly and accounts for approximately 20% of these patients. This gene variant leads to systemic microvasculopathy, which manifests as brain, ocular, renal, and muscular disorders. However, only a few patients with surgical interventions have been reported and the potential surgical risks are unknown. Here, we present the cases of two female patients between 7 and 8 years of age who were diagnosed with the COL4A1 variant and underwent laparoscopy-assisted percutaneous endoscopic gastrostomy (LAPEG) for oral dysphagia. Their primary brain lesions were caused by porencephaly and paralysis, which are caused by multiple cerebral hemorrhages and infarctions, and both patients had refractory epileptic complications. Although LAPEG was successfully performed in both patients without any intraoperative complications, one patient developed alveolar hemorrhage postoperatively and required mechanical ventilation. Thus, careful perioperative management of patients with the COL4A1 variant is important.

Stapleless thoracoscopic lobectomy for congenital pulmonary airway malformation: a simple technique in thoracoscopic surgery.

Congenital pulmonary airway malformation (CPAM) is a developmental malformation that affects the lung parenchyma, especially terminal respiratory bronchioles. This paper reports a case of an infant diagnosed with CPAM who underwent stapleless thoracoscopic lobectomy using Hem-o-Lok clips®. Computed tomography showed cystic pulmonary lesions in the left lower lobe. Thoracoscopic lobectomy was performed at the age of 1 year and 3 months. During surgery, the hilar vasculature was treated using either Hem-o-Lok® clips or a LigaSure vessel sealing system. The lower lobe bronchus was divided using double Hem-o-Lok® clips proximally. The surgery was successfully completed. The patient's postoperative course was uneventful, and there were no complications. This technique can be easily performed as a thoracoscopic lobectomy with the potential benefits of safe and effective procedures for bronchus closure and vascular sealing in the small working space of pediatric patients.

Liver-Spleen Volume Ratio as a Predictor of Native Liver Survival in Patients with Biliary Atresia.

BACKGROUND: The appropriate timing of liver transplantation (LT) in patients with biliary atresia (BA) who survived with their native livers until adolescence remains controversial. The liver-spleen volume ratio (LSR) has been reported to be efficacious in predicting the prognosis of chronic liver disease. We investigated whether LSR could predict long-term native liver prognosis and serve as an indication for LT in patients with BA. METHODS: Patients with BA who survived with their native liver until the age of 15 years were included. These patients were classified into 2 groups. The unfavorable prognosis group included patients who underwent or were awaiting LT or developed complications such as refractory cholangitis or gastrointestinal bleeding due to esophagogastric or intestinal varices. The favorable prognosis group included patients who survived with their native liver without complications. We compared the 2 groups regarding LSR, hematological, and histologic data. RESULTS: Of 19 patients, 8 were in the unfavorable prognosis group, and 11 were in the favorable prognosis group. LSR was significantly lower in the unfavorable prognosis group (P = .009). Analysis of the receiver operating characteristic curve showed that the area under the curve of the LSR was 0.891, which was higher than the area under the curve of liver fibrosis markers. The optimal LSR cut-off value for predicting poor native liver prognosis was 1.97, with a sensitivity of 75.0% and a specificity of 87.5%. CONCLUSIONS: The LSR reflects splenomegaly and liver atrophy. The LSR might be a reliable predictor of native liver prognosis and could guide decisions about LT in patients with BA.

Thoracoscopic segmentectomy for congenital pulmonary airway malformation arising in a lung with an accessory fissure: A case report.

Congenital pulmonary airway malformation is a rare congenital lung lesion. This report documents the successful application of thoracoscopic segmentectomy in a 1-year-old boy prenatally diagnosed with congenital pulmonary airway malformation. Preoperative imaging studies revealed a microcystic lesion with a region of consolidation in the middle area of the right lung. Elective thoracoscopic resection was performed when the patient was aged 1 year and 4 months. Intraoperatively, the superior segment of the right lower lobe was partially separated from the normal lower lobe by a superior accessory fissure. A solid mass, fused with this segment, shared the visceral pleura. Thoracoscopic segmentectomy was successfully performed, and the patient had an uneventful postoperative course. Histological examination revealed congenital pulmonary airway malformation stocker type 2. Thoracoscopic segmentectomy is a viable surgical option that preserves the normal lung parenchyma in pediatric patients with congenital pulmonary airway malformation.

Tension-free thoracoscopic repair of congenital diaphragmatic hernia combined with a percutaneous extracorporeal closure technique: how to do it.

PURPOSE: Thoracoscopic repair (TR) of congenital diaphragmatic hernia (CDH) is associated with a higher recurrence rate than the conventional open method. We evaluated the effectiveness of our strategy for quality improvement, named "tension-free TR of CDH". METHODS: The subjects of this retrospective analysis were 11 consecutive patients with CDH who underwent TR at our hospital between 2017 and 2021. Tension-free TR of CDH included the proactive use of an oversized patch for dome-shaped reconstruction and gapless suturing. We developed a percutaneous extracorporeal closure technique for secure suturing using a commercially available needle. RESULTS: Patch repair was performed in 8 (73%) patients and none required conversion to open surgery because of technical difficulties. Recurrence developed in one patient (9%), who underwent successful reoperation via TR. All patients had an uneventful postoperative course. CONCLUSION: Tension-free TR combined with extracorporeal closure could reduce the difficulty of suturing and the risk of recurrence of CDH.

Factors reducing psychological satisfaction after the Nuss procedure in pediatric patients.

PURPOSE: We examined patient satisfaction with postoperative chest appearance after Nuss procedure and analyzed the factors for postoperative low satisfaction. METHODS: We retrospectively reviewed data of 133 patients who underwent the Nuss procedure from 2000 to 2016. Their medical records, X-rays, and computed tomography scans were evaluated. Haller index and concave rate were used as objective indices of the deformity. The questionnaires were used to evaluate satisfaction with the chest appearance by a linear scale including five markers (1: dissatisfaction, 5: satisfaction). The patients were divided into two groups: the low satisfaction (score = 1, 2) and the high satisfaction (score = 3-5). RESULTS: The median age during the Nuss procedure was 7.6 (interquartile range, 5.8-12.8) years. Out of 133, 65 patients replied, and the mean postoperative satisfaction score was 3.8 ± 0.2. Out of the 65 respondents, 16 patients (24.6%) were classified as low satisfaction group. Haller index and concave rate were significantly higher and the previous instances of chest operation history were more frequent in the low satisfaction group than in the high satisfaction group, although there was no significant intergroup difference in terms of the postoperative concave rate. CONCLUSIONS: Severe deformity and previous chest operation history were considered to be factors for low satisfaction.

Treatment and follow-up of late onset intra hepatic bile duct stones in congenital biliary dilatation.

PURPOSE: The postoperative course after surgery for congenital biliary dilatation (CBD) has some complications. Intrahepatic bile duct (IHBD) stones were known as a late complication. We report on the treatment and long-term follow-up of postoperative IHBD stones in our department. METHODS: Patients who underwent CBD surgery at age 15 years or younger in our department were identified. Those followed up for 5 years or more were enrolled. Annual blood chemistry tests and abdominal ultrasonography were performed. Each patient's surgical procedure, IHBD stone diagnosis, treatments, and outcomes were retrospectively assessed. RESULTS: Fifty-one patients were analyzed. The median age at the last visit was 24 years (range 7-45 years), and the median age at CBD surgery was 3 years. Eight patients (16%) developed late-onset IHBD stones. The median age at onset was 25 years, and the median duration after surgery was 20 years. The initial treatment was double-balloon enteroscopy (DBE) in 4 cases, which resulted in stone removal in 3 of the 4 patients (75%). CONCLUSION: Since CBD may cause late-onset IHBD stones, continuous follow-up is required even in adulthood. In this study, DBE was effective and minimally invasive, and it is recommended as the initial treatment.

Early detection of liver fibrosis with serum Mac-2 binding protein glycosylation-modified isomer (M2BPGi) during follow-up intestinal failure patients without intestinal failure-associated liver disease (IFALD).

PURPOSE: Mac-2 binding protein glycosylation-modified isomer (M2BPGi) is a new marker for hepatic fibrosis progression. We examined the relationship between serum M2BPGi levels and liver histological findings in intestinal failure (IF) patients without IF-associated liver disease (IFALD). METHODS: This study included IF patients without IFALD followed at our hospital. All patients underwent routine liver biopsies per protocol every 1-2 years. We examined M2BPGi levels and histological findings in relation to aspartate aminotransferase (AST) to platelet ratio index, fibrosis-4 index, and AST/ALT ratio. Liver fibrosis was evaluated based on the METAVIR score. RESULTS: Total 18 liver biopsies out of eight patients were included. The median age was 11.5 years. Mean M2BPGi was 0.44 cutoff index (COI) in patients with F0 fibrosis, 0.78 COI in patients with F1 fibrosis and 1.63 COI in patients with F2 fibrosis. Mean M2BPGi was significantly higher in patients with F2 versus F1 or F0 fibrosis (P < 0.016 and P < 0.028, respectively). M2BPGi levels were more strongly correlated with fibrosis stage than with other conventional fibrosis markers. CONCLUSION: Serum M2BPGi is a novel marker of liver fibrosis in patients with IF. It is useful for follow-up prior to IFALD. Serum M2BPGi levels can support the interpretation of liver status.

Suppression of xenogeneic innate immune response by a membrane-type human surfactant protein-A.

Macrophage-mediated xenogeneic rejection is a major immunological obstacle. We recently reported that membrane-type surfactant protein-D (SP-D) on swine endothelial cells (SECs) suppressed macrophage-mediated rejection. Similar to SP-D, the carbohydrate recognition domain of surfactant protein-A (SP-A) can induce inhibitory signals in effector cells. The present study aimed to examine the suppressive effect of SP-A on macrophage-mediated xenogeneic rejection. Naive SECs and SPA-transfected SECs (SEC/SP-A) were co-cultured with THP-1 cells and cytotoxicity was evaluated. To investigate the effect of SP-A on phagocytosis, human macrophages were co-cultured with SEC or SEC/SP-A, and the extent of phagocytosis and production of reactive oxygen species were assessed via flow cytometry. The mRNA expression levels of inflammatory cytokines in macrophages were determined using reverse transcription-PCR. Additionally, the effects of THP-1-Lucia NF-κB cells on transcription factors were evaluated. The cytotoxicity and phagocytosis of SEC/SP-A were significantly decreased compared with those of naive SEC. Furthermore, the co-culture of human macrophages with SEC/SP-A decreased reactive oxygen species production, and the mRNA expression levels of TNFα were decreased in macrophages, whereas those of IL-10 were increased. In addition, NF-κB transcription was decreased in SEC/SP-A compared with that in SEC. In conclusion, the ectopic expression of human SP-A in porcine cells represents an attractive method for suppressing macrophage-mediated cytotoxicity.

Ileocecal valve-sparing surgery for duplication cysts in the terminal ileum: two case reports and literature review.

BACKGROUND: Duplication cysts close to the ileocecal valve are usually treated with ileocecal resection. However, loss of the ileocecal valve will lead to problems, especially in infants. Mucosectomy of the cyst would be a better alternative that preserves the ileocecal valve. We report two cases of duplication cyst in the terminal ileum successfully treated with mucosectomy. CASE PRESENTATION: Case 1. A 3-month-old boy with bilious emesis and abdominal distention was referred to our hospital with a diagnosis of small bowel obstruction caused by an abdominal cyst. Computed tomography revealed a cystic mass compressing the terminal ileum and causing mechanical small bowel obstruction. His general condition deteriorated quickly; emergency laparotomy was performed. Although the small intestines were dilated and partially twisted, there was no necrosis. Following intestinal decompression, a cystic mass adjacent to the terminal ileum was confirmed on the mesenteric side. Cyst mucosectomy was performed to preserve the ileocecal valve. CASE 2: A 5-month-old boy with sudden onset of hematochezia was referred to our hospital with a diagnosis of intussusception. Following unsuccessful contrast enemas, emergency surgery was performed. A cystic mass adjacent to the terminal ileum was confirmed; there was no intussusception. Cyst mucosectomy was performed. Both patients had an uneventful postoperative course. CONCLUSIONS: Cyst mucosectomy, which preserves the ileocecal valve, is safe and effective for treating duplication cysts in the terminal ileum.

Laparoscopic Percutaneous Extraperitoneal Closure for Hydrocele of the Canal of Nuck in Children.

Background: Hydrocele of the canal of Nuck (HCN) is a rare cause of inguinal swelling in women. The optimal surgical procedure for HCN in children remains unclear. To assess the safety and efficacy of laparoscopic percutaneous extraperitoneal closure (LPEC) for HCN in a pediatric population, a retrospective study was conducted. In addition, to clarify the pathogenesis of HCN, we assessed the morphological findings of the internal inguinal ring (IIR). Materials and Methods: We retrospectively analyzed 10 consecutive female patients with HCN who underwent LPEC at our hospital between January 2010 and May 2020. Age, operative time, and complications were recorded. Concerning the findings of the IIR, we classified the morphological features as follows: Type 1 (flat), Type 2 (narrow patent processus vaginalis [PPV] with a peritoneal veil), and Type 3 (widely opening PPV). Results: The median age of patients who underwent LPEC was 3 (1-12) years. Although 2 patients showed contralateral inguinal hernia (IH), there were no cases of ipsilateral IH. All patients showed ipsilateral PPV, and the morphological features of the IIR were mostly classified as Type 3 (70%). In total, 6 of 8 HCN cases without preoperatively diagnosed contralateral IH had contralateral PPV (75%), and all were closed by LPEC. All operations were accomplished laparoscopically, and the postoperative course was uncomplicated, with no recurrences observed during the study period. Conclusions: LPEC is a safe and simple surgical approach to repair the HCN in children with minimal complications.

Suppression of macrophage-mediated xenogeneic rejection by the ectopic expression of human CD177.

Cellular xenogeneic rejection by the innate immune system is a major immunological obstruction that needs to be overcome for the successful clinical use of xenografts. Our focus has been on macrophage-mediated xenogeneic rejection, since suppressing macrophage function has considerable potential for practical applications in the area of xenotransplantation. We report herein on an investigation of the suppressive effect of human CD177 (hCD177) against macrophage-mediated xenogeneic rejection. Wild type swine aortic endothelial cell (SEC) and an SEC transfectant with hCD177 (SEC/hCD177) were co-cultured with macrophages, and the degree of cytotoxicity was evaluated by WST-8 assays, and phagocytosis was examined using Calcein-AM labeling methods. The expression of anti/pro-inflammatory cytokines was evaluated by RT-qPCR and the phosphorylation of SHP-1 on macrophages in co-culture was evaluated by Western blotting. The result of cytotoxicity assays indicated that hCD177 suppressed M1 macrophage-mediated xenogeneic rejection (vs. SEC, p < 0.0001). Similarly, the result of phagocytosis assays indicated that hCD177 suppressed it (vs. SEC, p < 0.05). In addition, hCD177 significantly suppressed the expression of IL-1ß, a pro-inflammatory cytokine, in M1 macrophages (vs. SEC, p < 0.01). Luciferase assays using THP1-Lucia NF-kB also showed a significant difference in NF-kB activation (vs. SEC, p < 0.001). In addition, hCD177 was found to induce the phosphorylation of SHP-1 in M1 macrophages (vs. SEC, p < 0.05). These findings indicate that hCD177 suppresses M1 macrophage-mediated xenogeneic rejection, at least in part via in the phosphorylation of SHP-1.

Aspects of the Complement System in New Era of Xenotransplantation.

After producing triple (Gal, H-D and Sda)-KO pigs, hyperacute rejection appeared to no longer be a problem. However, the origin of xeno-rejection continues to be a controversial topic, including small amounts of antibodies and subsequent activation of the graft endothelium, the complement recognition system and the coagulation systems. The complement is activated via the classical pathway by non-Gal/H-D/Sda antigens and by ischemia-reperfusion injury (IRI), via the alternative pathway, especially on islets, and via the lectin pathway. The complement system therefore is still an important recognition and effector mechanism in xeno-rejection. All complement regulatory proteins (CRPs) regulate complement activation in different manners. Therefore, to effectively protect xenografts against xeno-rejection, it would appear reasonable to employ not only one but several CRPs including anti-complement drugs. The further assessment of antigens continues to be an important issue in the area of clinical xenotransplantation. The above conclusions suggest that the expression of sufficient levels of human CRPs on Triple-KO grafts is necessary. Moreover, multilateral inhibition on local complement activation in the graft, together with the control of signals between macrophages and lymphocytes is required.

The Innate Cellular Immune Response in Xenotransplantation.

Xenotransplantation is very attractive strategy for addressing the shortage of donors. While hyper acute rejection (HAR) caused by natural antibodies and complement has been well defined, this is not the case for innate cellular xenogeneic rejection. An increasing body of evidence suggests that innate cellular immune responses contribute to xenogeneic rejection. Various molecular incompatibilities between receptors and their ligands across different species typically have an impact on graft outcome. NK cells are activated by direct interaction as well as by antigen dependent cellular cytotoxicity (ADCC) mechanisms. Macrophages are activated through various mechanisms in xenogeneic conditions. Macrophages recognize CD47 as a "marker of self" through binding to SIRPα. A number of studies have shown that incompatibility of porcine CD47 against human SIRPα contributes to the rejection of xenogeneic target cells by macrophages. Neutrophils are an early responder cell that infiltrates xenogeneic grafts. It has also been reported that neutrophil extracellular traps (NETs) activate macrophages as damage-associated pattern molecules (DAMPs). In this review, we summarize recent insights into innate cellular xenogeneic rejection.

Clinical implications of serum autotoxin in regular follow up after pediatric living donor liver transplantation for biliary atresia.

BACKGROUND: Pediatric patients sometimes develop graft fibrosis after living donor liver transplant (LDLT). Autotaxin is a recently developed serum marker for hepatic fibrosis. We studied the relationship between serum autotaxin levels and histological findings in patients after LDLT for biliary atresia (BA). METHODS: Information on patients aged <19 years who received LDLT for BA and were followed for at least 1 year after LDLT was gathered. Autotaxin levels were compared with pathological fibrosis scores. RESULTS: The study included 52 patients, of whom 4 patients had no fibrosis (F0), 36 patients had F1 fibrosis, and 12 patients had F2. The median serum autotaxin level was 0.89 mg/L. In patients with portal vein (PV) complications such as stenosis or thrombosis (n = 7), the mean autotoxin level was 1.25 mg/L compared with 0.95 mg/L in patients without PV complications (p = 0.004). Among patients without PV complications, the mean autotaxin level was 0.90, 0.88, and 1.18 mg/L in F0, F1, and F2 fibrosis, respectively. The mean autotaxin was higher in F2 fibrosis than in F0 or F1 fibrosis (p<0.05). Autotoxin had a high area under the curve (0.86) with the cut-off level of 0.897 mg/L. CONCLUSION: Serum autotaxin is a novel marker for liver fibrosis in patients after pediatric LDLT for BA. TYPE OF STUDY: Study of Diagnostic Test. LEVEL OF EVIDENCE: Level II.