SARS-CoV-2 BA.2 (Omicron) variant infection in pediatric liver transplanted recipients and cohabitants during 2022 Shanghai outbreak: a prospective cohort.

BACKGROUND: The Omicron variant BA.2 was the dominant variant in the COVID-19 outbreak in Shanghai since March 2022. We aim to investigate the characteristics of SARS-CoV-2 Omicron variant infection in pediatric liver-transplanted recipients. METHODS: We conducted a single-center, prospective, observational, single-arm study. We enrolled pediatric liver-transplanted patients infected with the Omicron variant BA.2 from March 19th to October 1st, 2022 and analyzed their demographic, clinical, laboratory, and outcome data. The management of COVID-19 was conducted according to the 9th trial edition of the Chinese guideline. The immunosuppressive therapy was tailored considering the patients' infection developments and liver functions. RESULTS: Five children were included. The primary diseases included Niemann-Pick disease, propionic acidemia, decompensated cirrhosis, biliary atresia, and Crigler-Najjar syndrome type I. All of the patients were onset with fever before or when getting RNA-positive results at the age of 3 (Range: 1-13) years. The infection duration was 29 (Range: 18-40) days. Three and two children were diagnosed with mild and moderate COVID-19 respectively. Two patients were tested RNA-positive within 14 days after having been tested negative. The immunosuppressants were paused or extenuated in four patients. Eight of all nine cohabitants were injected with at least two doses of inactivated SARS-CoV-2 vaccine. The disease courses were significantly longer than the patients (P < 0.05). CONCLUSIONS: Post-transplant immunosuppression slows down the virus clearance and increases the risk of relapse but does not affect symptom duration or infection severity in pediatric patients. Patients can usually gain a favorable outcome and prognosis by extenuating immunosuppressants.

Postoperative Risk Factors and Outcome of Patients With Liver Transplantation Who Were Admitted to Pediatric Intensive Care Unit: A 10-Year Single-Center Review in China.

INTRODUCTION: The aim of this study was to present our 10-year experience of pediatric intensive care unit (PICU) management with pediatric liver recipients and to understand the importance of close interdisciplinary cooperation in 2 hospitals. METHODS: A retrospective chart review study was performed according to our hospital's medical records and the pediatric liver transplant database of Renji hospital. RESULTS: A total of 767 patients received liver transplantation (LT) performed in Renji hospital between October 2006 and December 2016, of which 97 of them were admitted to PICU in our center for various complications developed after transplantation. 8.8% (16/208) and 14.4% (81/559) of patients were transferred to PICU in stages I and II, respectively, and was comparable in the 2 stages (P = .017). The majority of patients was late postoperative children (median 185 post-LT days) in stage I. More patients were transferred to PICU directly in stage II. PICU admitted more younger (median 8.2 months) and early postoperative patients in stage II. The median length of PICU stay was 11.0 (6.0-20.5) days. The median length of mechanical ventilation was 5.0 (0.0-12.0) days. The most frequent complications were pulmonary complications (52 [53.6%] patients), surgical complications (22 [22.7%] patients), sepsis (7 [7.2%]), and other miscellaneous complications (16 [16.5%] patients). The overall 28-day PICU mortality was 25.8% (n = 25) and 64.0% (n = 16) of the deaths happened in the early postoperative period. There was significant difference concerning mortality in children with surgical complications and medical problems (54.5% [12/22] vs 17.3% [13/75], P = .001). Multivariate analysis by regression showed that the pediatric risk of mortality III score was the only independent prognostic factor (P = .031). CONCLUSIONS: Multiple complications occur in children with LT. Although challenging, interdisciplinary cooperation between different hospitals is an effective mean to enable children to maximize the benefit gained from LT in China.

Hepatic artery reconstruction in pediatric liver transplantation: Experience from a single group.

BACKGROUND: The reconstruction of hepatic artery is a challenging part of the pediatric liver transplantation procedure. Hepatic artery thrombosis (HAT) and stenosis are complications which may result in ischemic biliary injury, causing early graft lost and even death. METHODS: Two hundred and fifty-nine patients underwent liver transplantation in 2017 in a single liver transplantation group. Among them, 225 patients were living donor liver transplantation (LDLT) and 34 deceased donor liver transplantation (DDLT). RESULTS: In LDLT all reconstructions of hepatic artery were microsurgical, while in DDLT either microsurgical reconstruction or traditional continuous suture technique was done depending on different conditions. There were five (1.9%) HATs: four (4/34, 11.8%) in DDLT (all whole liver grafts) and one (1/225, 0.4%) in LDLT (P = 0.001). Four HATs were managed conservatively using anticoagulation, and 1 accepted salvage surgery with re-anastomosis. Until now, 3 HAT patients remain in good condition, whereas two developed biliary complications. One of them needed to be re-transplanted, and the other patient died due to biliary complications. CONCLUSIONS: Microsurgical technique significantly improves the reconstruction of hepatic artery in pediatric liver transplantation. The risk for arterial complications is higher in DDLT. Conservative therapy can achieve good outcome in selected HAT cases.

CD24+LCN2+ liver progenitor cells in ductular reaction contributed to macrophage inflammatory responses in chronic liver injury.

BACKGROUND: CD24+CK19+/CD24+SOX9+ resident liver cells are activated and expanded after chronic liver injury in a ductular reaction. However, the sources and functions of these cells in liver damage remain disputed. RESULTS: The current study combined genetic lineage tracing with in vitro small-molecule-based reprogramming to define liver progenitor cells (LPCs) derived from hepatic parenchymal and non-parenchymal tissues. tdTom+ hepatocytes were isolated from ROSA26tdTomato mice following AAV8-Tbg-Cre-mediated recombination, EpCAM+ biliary epithelial cells (BECs) from wild-type intrahepatic bile ducts and ALB/GFP-EpCAM- cells were isolated from AlbCreERT/R26GFP mice. A cocktail of small molecules was used to convert the isolated cells into LPCs. These in vitro cultured LPCs with CD24 and SOX9 expression regained the ability to proliferate. Transcriptional profiling showed that the in-vitro cultured LPCs derived from the resident LPCs in non-parenchymal tissues expressed Lipocalin-2 (Lcn2) at high levels. Accordingly, endogenous Cd24a+Lcn2+ LPCs were identified by integration of sc-RNA-sequencing and pathological datasets of liver dysfunction which indicates that LPCs produced by ductular reactions might also originate from the resident LPCs. Transplantation of in-vitro cultured Cd24a+Lcn2+ LPCs into CCl4-induced fibrotic livers exacerbated liver damage and dysfunction, possibly due to LCN2-dependent macrophage inflammatory response. CONCLUSIONS: CD24+LCN2+ LPCs constituted the expanding ductular reaction and contributed to macrophage-mediated inflammation in chronic liver damage. The current findings highlight the roles of LPCs from distinct origins and expose the possibility of targeting LPCs in the treatment of chronic hepatic diseases.

Profound impact of gut homeostasis on chemically-induced pro-tumorigenic inflammation and hepatocarcinogenesis in rats.

BACKGROUND & AIMS: Due to its anatomic connection, the liver is constantly exposed to gut-derived bacterial products or metabolites. Disruption of gut homeostasis is associated with many human diseases. The aim of this study was to determine the role of gut homeostasis in initiation and progression of hepatocellular carcinoma (HCC). METHODS: Disruption of intestinal homeostasis by penicillin or dextran sulfate sodium (DSS) and its restoration by probiotics were applied in a diethylnitrosamine (DEN) model of rat hepatocarcinogenesis. RESULTS: Patients with liver cirrhosis and HCC had significantly increased serum endotoxin levels. Chronic DEN treatment of rats was associated with an imbalance of subpopulations of the gut microflora including a significant suppression of Lactobacillus species, Bifidobacterium species and Enterococcus species as well as intestinal inflammation. Induction of enteric dysbacteriosis or intestinal inflammation by penicillin or DSS, respectively, significantly promoted tumor formation. Administration of probiotics dramatically mitigated enteric dysbacteriosis, ameliorated intestinal inflammation, and most importantly, decreased liver tumor growth and multiplicity. Interestingly, probiotics not only inhibited the translocation of endotoxin, which bears pathogen-associated molecular patterns (PAMPs) but also the activation of damage-associated molecular patterns (DAMPs) such as high-mobility group box 1 (HMGB1). As a result, the production of pro- and anti-inflammatory cytokines was skewed in favor of a reduced tumorigenic inflammation in the liver. CONCLUSIONS: The data highlights the importance of gut homeostasis in the pathogenesis of HCC. Modulation of the gut microbiota by probiotics may represent a new avenue for therapeutic intervention to treat or prevent HCC development.

Living-donor liver transplantation for children with tyrosinemia type I.

OBJECTIVE: To evaluate the efficacy of living-donor liver transplantation (LDLT) in children with tyrosinemia type I. METHODS: Altogether 10 patients diagnosed with tyrosinemia type I underwent LDLT between June 2013 and April 2019. Cirrhosis was the indication for LDLT in all 10 patients, and hepatocellular carcinoma (HCC) was suspected in nine. Patients' outcomes, including liver function, restoration of metabolism, quality of life and physical development, were analyzed after LDLT. RESULTS: All recipients were alive with a normal liver function after a median follow-up period of 49 months. Pathological examinations detected HCC in one patient, dysplasia in five and cirrhosis in all. Nine patients were found to have elevated alpha-fetoprotein level, and their median alpha-fetoprotein level dropped from 2520 ng/mL to a normal level after LDLT, with no recurrence of HCC detected during the follow-up. Tyrosine metabolism was restored to its normal level with normalized plasma tyrosine and succinylacetone concentrations. Moreover, urinary succinylacetone excretion decreased significantly during the follow up. LDLT improved patients' renal tubular function, as evidenced by the normalized plasma phosphate concentration and improved glomerular filtration rate. Severe rickets symptoms, including spontaneous fractures and bone pain, were also ameliorated. Improved motor function was reported by all patients' parents during the follow-up. Dietary restriction was no longer required, which was associated with a favorable catch-up in growth and improved quality of life. Complete resolution of hypertrophic cardiomyopathy was observed one year after LDLT in one patient. CONCLUSION: LDLT is an effective treatment for patients with end-stage liver disease resulting from tyrosinemia type I.

Pediatric living donor liver transplantation decade progress in Shanghai: Characteristics and risks factors of mortality.

BACKGROUND: Pediatric living donor liver transplantation (LDLT) has become the gold standard for patients with end-stage liver disease. With improvements in organ preservation, immunosuppression, surgical and anesthesia techniques, the survival rates and long-term outcomes of patients after LDLT have significantly improved worldwide. However, data on anesthetic management and postoperative survival rate of pediatric LDLT in China are rare. AIM: To review the status of pediatric LDLT in Shanghai and investigate the factors related to anesthetic management and survival rate in pediatric LDLT. METHODS: We conducted a retrospective observational study to investigate the status of pediatric LDLT in Shanghai by reviewing 544 records of patients who underwent pediatric LDLT since the first operation on October 21, 2006 until August 10, 2016 at Renji Hospital and Huashan Hospital. RESULTS: The 30-d, 90-d, 1-year, and 2-year survival rates were 95.22%, 93.38%, 91.36%, and 89.34%, respectively. The 2-year patient survival rate after January 1, 2011 significantly improved compared with the previous period (74.47% vs 90.74%; hazard ratio: 2.92; 95% confidence interval (CI): 2.16-14.14; P = 0.0004). Median duration of mechanical ventilation in the intensive care unit (ICU) was 18 h [interquartile range (IQR), 15.25-20.25], median ICU length of stay was 6 d (IQR: 4.80-9.00), and median postoperative length of stay was 24 d (IQR: 18.00-34.00). Forty-seven (8.60%) of 544 patients did not receive red blood cell transfusion during the operation. CONCLUSION: Pediatric end-stage liver disease (PELD) score, anesthesia duration, operation duration, intraoperative blood loss, and ICU length of stay were independent predictive factors of in-hospital patient survival. Pediatric end-stage liver disease score, operation duration, and ICU length of stay were independent predictive factors of 1-year and 3-year patient survival.

Isolation of cancer-associated fibroblasts and its promotion to the progression of intrahepatic cholangiocarcinoma.

Intrahepatic cholangiocarcinoma is a highly fatal tumor characterized by an abundant stromal environment. Cancer-associated fibroblasts play key roles in tumor growth and invasiveness and have been regarded as a potential therapeutic target. This study was designed to isolate human primary cancer-associated fibroblasts of intrahepatic cholangiocarcinoma to study tumor-stroma interactions and to analyze the clinical relevance of alpha-smooth muscle actin -positive cancer-associated fibroblasts in patients with intrahepatic cholangiocarcinoma. The isolated cancer-associated fibroblasts were positive for alpha-smooth actin, fibroblast-specific protein-1, fibroblast activation protein, and PDGFR-ß. In addition, cancer-associated fibroblasts were found to increase proliferation, migration, and invasion of cholangiocarcinoma cells in vitro and promote tumor growth of mice in vivo. Moreover, alpha-smooth muscle actin-positive expression of cancer-associated fibroblasts predicted unfavorable prognosis in patients with intrahepatic cholangiocarcinoma and showed correlation with presence of lymph node metastasis. This study may provide a useful tool to investigate further effect of cancer-associated fibroblasts on the molecular mechanism of cholangiocarcinoma cells as well as contribution of cancer-associated fibroblasts in lymphangiogenesis and lymph node metastasis.

A splicing variant of Merlin promotes metastasis in hepatocellular carcinoma.

Merlin, which is encoded by the tumour suppressor gene Nf2, plays a crucial role in tumorigenesis and metastasis. However, little is known about the functional importance of Merlin splicing forms. In this study, we show that Merlin is present at low levels in human hepatocellular carcinoma (HCC), particularly in metastatic tumours, where it is associated with a poor prognosis. Surprisingly, a splicing variant of Merlin that lacks exons 2, 3 and 4 ((Δ2-4)Merlin) is amplified in HCC and portal vein tumour thrombus (PVTT) specimens and in the CSQT2 cell line derived from PVTT. Our studies show that (Δ2-4)Merlin interferes with the capacity of wild-type Merlin to bind ß-catenin and ERM, and it is expressed in the cytoplasm rather than at the cell surface. Furthermore, (Δ2-4)Merlin overexpression increases the expression levels of ß-catenin and stemness-related genes, induces the epithelium-mesenchymal-transition phenotype promoting cell migration in vitro and the formation of lung metastasis in vivo. Our results indicate that the (Δ2-4)Merlin variant disrupts the normal function of Merlin and promotes tumour metastasis.