Multidisciplinary management of children with acute liver failure - Report on 104 children treated in single center.

BACKGROUND: Pediatric acute liver failure (PALF) is one of the most demanding emergencies in hepatology, intensive care, and for transplant team. This report describes the clinical pattern, diagnostic and therapeutic modalities in children with ALF considered at risk of death without liver transplantation, basing on a long-term experience of the pediatric transplant center. MATERIALS AND METHODS: Between 1990 and 2022, 104 children aged 7 days-17 years (median 8 years), with body weight 3.1 to 77 kg (median 32 kg), were qualified for LT due to ALF, and finally 81 (78%) of them were transplanted (9% of all 899 LT performed in children in the same period). RESULTS: A total of 23 children were not transplanted: 15 (14.4%) died while awaiting transplantation. In 8 (7.7%) patients liver function recovered. Before transplantation 45 (43.3%) children developed circulatory failure, in 66 (63.5%) mechanical ventilation was necessary, 18 patients presented acute kidney injury (17.3%), and encephalopathy higher than stage I was present in 60 (57.7%) patients. In 63 children, various kidney/liver assist procedures were performed: CVVHD (continuous veno-venous hemodiafiltration in 22 (21.2%) patients, albumin dialysis (MARS; molecular adsorbent recirculating system) in 39 (37.5%) patients, therapeutic plasma exchange (TPE) in 13 (12.5%) patients. Twenty (24.7%) children died after LT including 15 (18.5%) in the early posttransplant period, and 5 (6.1%) in the late follow-up. CONCLUSIONS: Treatment of children with ALF in the peritransplant period is very difficult and require an experienced, multidisciplinary team. Despite continued advances in the care of children with ALF, patient survival remains lower than for elective indications for liver transplantation, and timely qualification and transplantation still are the most important factors of survival of these children.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (1) pre-transplant evaluation.

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment in end-stage liver disease. Imaging is a key element for successful organ-transplantation to assist surgical planning. So far, only limited data regarding the best radiological approach to prepare children for liver transplantation is available. OBJECTIVES: In an attempt to harmonize imaging surrounding pediatric liver transplantation, the European Society of Pediatric Radiology (ESPR) Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phase. This paper reports the responses on preoperative imaging. MATERIAL AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted and 22 institutions from 11 countries returned the survey. From 2018 to 2020, the participating centers collectively conducted 1,524 transplantations, with a median of 20 transplantations per center per annum (range, 8-60). RESULTS: Most sites (64%) consider ultrasound their preferred modality to define anatomy and to plan surgery in children before liver transplantation, and additional cross-sectional imaging is only used to answer specific questions (computed tomography [CT], 90.9%; magnetic resonance imaging [MRI], 54.5%). One-third of centers (31.8%) rely primarily on CT for pre-transplant evaluation. Imaging protocols differed substantially regarding applied CT scan ranges, number of contrast phases (range 1-4 phases), and applied MRI techniques. CONCLUSION: Diagnostic imaging is generally used in the work-up of children before liver transplantation. Substantial differences were noted regarding choice of modalities and protocols. We have identified starting points for future optimization and harmonization of the imaging approach to multicenter studies.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (2) intraoperative imaging.

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of intraoperative and postoperative complications. So far, only limited data regarding the best radiological approach to monitor children during liver transplantation is available. OBJECTIVE: To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra- and postoperative phase. This paper reports the responses related to intraoperative imaging. MATERIALS AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey. RESULTS: Intraoperative ultrasound (US) is used by all sites to assess the quality of the vascular anastomosis in order to ensure optimal perfusion of the liver transplant. Vessel depiction is commonly achieved using color Doppler (95.3%). Additional US-based techniques are employed by fewer centers (power angio mode, 28.6%; B-flow, 19%; contrast-enhanced US, 14.3%). Most centers prefer a collaborative approach, with surgeons responsible for probe handling, while radiologists operate the US machine (47.6%). Less commonly, the intraoperative US is performed by the surgeon alone (28.6%) or by the radiologist alone (23.8%). Timing of US, imaging frequency, and documentation practices vary among centers. CONCLUSION: Intraoperative US is consistently utilized across all sites during pediatric liver transplantation. However, considerable variations were observed in terms of the US setup, technique preferences, timing of controls, and documentation practices. These differences provide valuable insights for future optimization and harmonization studies.

European Society of Pediatric Radiology survey of perioperative imaging in pediatric liver transplantation: (3) postoperative imaging.

BACKGROUND: Liver transplantation is the state-of-the-art curative treatment for end-stage liver disease. Imaging is a key element in the detection of postoperative complications. So far, limited data is available regarding the best radiologic approach to monitor children after liver transplantation. OBJECTIVE: To harmonize the imaging of pediatric liver transplantation, the European Society of Pediatric Radiology Abdominal Taskforce initiated a survey addressing the current status of imaging including the pre-, intra-, and postoperative phases. This paper reports the responses related to postoperative imaging. MATERIALS AND METHODS: An online survey, initiated in 2021, asked European centers performing pediatric liver transplantation 48 questions about their imaging approach. In total, 26 centers were contacted, and 22 institutions from 11 countries returned the survey. RESULTS: All sites commence ultrasound (US) monitoring within 24 h after liver transplantation. Monitoring frequency varies across sites, ranging from every 8 h to 72 h in early, and from daily to sporadic use in late postoperative phases. Predefined US protocols are used by 73% of sites. This commonly includes gray scale, color Doppler, and quantitative flow assessment. Alternative flow imaging techniques, contrast-enhanced US, and elastography are applied at 31.8%, 18.2%, and 63.6% of sites, respectively. Computed tomography is performed at 86.4% of sites when clarification is needed. Magnetic resonance imaging is used for selected cases at 36.4% of sites, mainly for assessment of biliary abnormalities or when blood tests are abnormal. CONCLUSION: Diagnostic imaging is extensively used for postoperative surveillance of children after liver transplantation. While US is generally prioritized, substantial differences were noted in US protocol, timing, and monitoring frequency. The study highlights potential areas for future optimization and standardization of imaging, essential for conducting multicenter studies.

European Liver Transplant Registry: Donor and transplant surgery aspects of 16,641 liver transplantations in children.

BACKGROUND AND AIMS: The European Liver Transplant Registry (ELTR) has collected data on liver transplant procedures performed in Europe since 1968. APPROACH AND RESULTS: Over a 50-year period (1968-2017), clinical and laboratory data were collected from 133 transplant centers and analyzed retrospectively (16,641 liver transplants in 14,515 children). Data were analyzed according to three successive periods (A, before 2000; B, 2000-2009; and C, since 2010), studying donor and graft characteristics and graft outcome. The use of living donors steadily increased from A to C (A, n = 296 [7%]; B, n = 1131 [23%]; and C, n = 1985 [39%]; p = 0.0001). Overall, the 5-year graft survival rate has improved from 65% in group A to 75% in group B (p < 0.0001) and to 79% in group C (B versus C, p < 0.0001). Graft half-life was 31 years, overall; it was 41 years for children who survived the first year after transplant. The late annual graft loss rate in teenagers is higher than that in children aged <12 years and similar to that of young adults. No evidence for accelerated graft loss after age 18 years was found. CONCLUSIONS: Pediatric liver transplantation has reached a high efficacy as a cure or treatment for severe liver disease in infants and children. Grafts that survived the first year had a half-life similar to standard human half-life. Transplantation before or after puberty may be the pivot-point for lower long-term outcome in children. Further studies are necessary to revisit some old concepts regarding transplant benefit (survival time) for small children, the role of recipient pathophysiology versus graft aging, and risk at transition to adult age.

Pediatric transplantation in Europe during the COVID-19 pandemic: Early impact on activity and healthcare.

The current pandemic SARS-CoV-2 has required an unusual allocation of resources that can negatively impact chronically ill patients and high-complexity procedures. Across the European Reference Network on Pediatric Transplantation (ERN TransplantChild), we conducted a survey to investigate the impact of the COVID-19 outbreak on pediatric transplant activity and healthcare practices in both solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT). The replies of 30 professionals from 18 centers in Europe were collected. Twelve of 18 centers (67%) showed a reduction in their usual transplant activity. Additionally, outpatient visits have been modified and restricted to selected ones, and the use of telemedicine tools has increased. Additionally, a total of 14 COVID-19 pediatric transplanted patients were identified at the time of the survey, including eight transplant recipients and six candidates for transplantation. Only two moderate-severe cases were reported, both in HSCT setting. These survey results demonstrate the limitations in healthcare resources for pediatric transplantation patients during early stages of this pandemic. COVID-19 disease is a major worldwide challenge for the field of pediatric transplantation, where there will be a need for systematic data collection, encouraging regular discussions to address the long-term consequences for pediatric transplantation candidates, recipients, and their families.

Undifferentiated sarcoma of the liver: Multicenter international experience of the Cooperative Soft-Tissue Sarcoma Group and Polish Paediatric Solid Tumor Group.

BACKGROUND: Undifferentiated embryonal sarcomas of the liver (UESL) are extremely rare and continue to pose a diagnostic and therapeutic challenge. The aim of the study was to present a multicenter experience of the German CWS and Polish PPSTG groups in the treatment of UESL in children. PROCEDURE: Twenty-five patients were treated according to the CWS-96, CWS-2002, and CYVADIC protocols. Distant metastases were observed in four cases (16%). In four cases, an initial disease presentation mimicked other entities. A pure cystic appearance of liver mass led to misdiagnosis of hydatid cyst in three cases. In one case, laparotomy was performed due to the signs of appendicitis, and bleeding from ruptured liver tumor was found. All these patients were finally diagnosed as UESL. RESULTS: Thirteen patients received preoperative chemotherapy. Partial response was observed in 10 cases. Tumor resection was performed in 20 patients (primary resections, 12; delayed resections-, 8). In five patients, the primary tumor never became operable. The macroscopically complete resection rate was 95% (19/20). Postoperative chemotherapy was given to 20 children. Local radiotherapy was used in three children. After a median follow-up time of 136 months, 17 patients (68%) were alive with no evidence of disease. All children with unresectable tumor and three out of four patients with distant metastases died. The five-year overall survival (OS) rate was 72%. CONCLUSIONS: In summary, a complete tumor excision plays the central role in the treatment of UESL. A cystic presentation of the liver lesion on imaging does not exclude the diagnosis of malignant tumor.

Predictive Factors for Survival in Children Receiving Liver Transplants for Wilson's Disease: A Cohort Study Using European Liver Transplant Registry Data.

Liver transplantation (LT) is a rescue therapy for life-threatening complications of Wilson's disease (WD). However, data on the outcome of WD patients after LT are scarce. The aim of our study was to analyze a large pediatric WD cohort with the aim of investigating the longterm outcome of pediatric WD patients after LT and to identify predictive factors for patient and transplant survival. This is a retrospective cohort study using data of all children (<18 years) transplanted for WD enrolled in the European Liver Transplant Registry from January 1968 until December 2013. In total, 338 patients (57.6% female) transplanted at 80 different European centers (1-26 patients per center) were included in this study. The median age at transplantation was 14.0 years (interquartile range [IQR], 11.2-16.1 years); patients were followed up for a median of 5.4 years (IQR, 1.0-10.9 years) after LT. Overall patient survival rates were high with 87% (1-year survival), 84% (5-year survival), and 81% (10-year survival); survival rates increased considerably with the calendar year (P < 0.001). Early age at LT, living donation, and histidine tryptophan ketoglutarate preservation liquid were identified as risk factors for poor patient survival in the multivariate analysis. LT is an excellent treatment option for pediatric patients with WD and associated end-stage liver disease. Longterm outcome in these patients is similar to other pediatric causes for LT. Overall patient and graft survival rates improved considerably over the last decades. To improve future research in the field, the vast variability of allocation strategies should be harmonized and a generally accepted definition or discrimination of acute versus chronic WD needs to be found.

Endoscopic treatment in biliary strictures after pediatric liver transplantation.

BACKGROUND AND AIM: The aim of the study was to assess efficacy and safety of endoscopic treatment in BS after pediatric LTx. METHODS: We retrospectively reviewed data of patients with DDA who developed BS and underwent ERCP. RESULTS: Of 189 transplanted patients with DDA, strictures developed in 30 (16%). In this subgroup, the median age at LTx was 14.7 (1.5-17.6) and follow-up period was 3.9 (1.3-11.3). ABS were in 76% and NABS in combination with ABS in 24% of patients. Overall, 95 ERCP sessions (3.0 per patient) were performed with successful outcome in 22 (73%) cases. Duration of treatment was 9.1 (1.8-24.1) months. Five patients underwent surgical revision and three patients retransplantation (10%). Risk factors of endoscopy failure were HCV or HBV infection, prolonged CIT and treatment before 2007. The most common complications after ERCP were cholangitis (8.2%) and pancreatitis (4.2%). There were worse overall prognosis and higher risk of post-ERCP complications in NABS. CONCLUSIONS: ERCP is safe and effective in the majority of patients with post-transplant duct-to-duct BS, and it is currently recommended as the first-line treatment.

Combined and sequential liver-kidney transplantation in children.

Combined and sequential liver-kidney transplantation (CLKT and SLKT) is a definitive treatment in children with end-stage organ failure. There are two major indications: - terminal insufficiency of both organs, or - need for transplanting new liver as a source of lacking enzyme or specific regulator of the immune system in a patient with renal failure. A third (uncommon) option is secondary end-stage renal failure in liver transplant recipients. These three clinical settings use distinct qualification algorithms. The most common indications include primary hyperoxaluria type 1 (PH1) and autosomal recessive polycystic kidney disease (ARPKD), followed by liver diseases associated with occasional kidney failure. Availability of anti-C5a antibody (eculizumab) has limited the validity of CLKT in genetic atypical hemolytic uremic syndrome (aHUS). The liver coming from the same donor as renal graft (in CLKT) is immunologically protective for the kidney and this provides long-term rejection-free follow-up. No such protection is observed in SLKT, when both organs come from different donors, except uncommon cases of living donation of both organs. Overall long-term outcome in CLKT in terms of graft survival is good and not different from isolated liver or kidney transplantation, however patient survival is inferior due to complexity of this procedure.

Influence of Partial External Biliary Diversion on the Lipid Profile in Children With Progressive Familial Intrahepatic Cholestasis.

OBJECTIVES: The concentration of bile acids is highly increased in progressive familial intrahepatic cholestasis (PFIC). Bile acids are the end products of cholesterol metabolism, and aid in the absorption of fat-soluble vitamins and dietary fat. The aim of our study was to investigate lipid metabolism in patients with PFIC with focus on the effect of partial external biliary diversion (PEBD). METHODS: In 26 patients with PFIC, who underwent PEBD surgery at the median age of 2.2 years (range: 0.4-16.6), we analyzed the concentrations of lipids and apolipoproteins both before and 6 months after PEBD. Patients were split into 2 groups according to the outcome of surgery (either "good" or "poor"), and were analyzed separately. A "good" result following surgery was defined as complete relief from pruritus, and normalization of total bilirubin (<1.0 mg/dL) and bile acid concentration in serum (<12 µmol/L). RESULTS: We found abnormal lipid concentrations at baseline in all 26 patients: cholesterol was increased (>190 mg/dL) in 13 patients, phospholipids were increased (>250 mg/dL) in 5 patients, and triglyceride concentration was increased (>150 mg/dL) in 13 patients. After PEBD, the concentrations of plasma cholesterol, triglycerides, and phospholipids decreased significantly, whereas, ApoA-I and high-density lipoprotein cholesterol concentrations increased and the concentrations of apolipoprotein B, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol significantly decreased. PEBD had neither an effect on ApoE concentration nor on lecithin-cholesterol acyl transferase activity. In the group with a "poor" outcome report following PEBD, total serum cholesterol concentration decreased significantly, and no effect on the concentrations of triglycerides and phospholipids were observed. CONCLUSIONS: Patients with PFIC present with a high risk of lipid disturbances. PEBD has a beneficial effect on lipid profile in the majority of cases.

Ileal exclusion in children with progressive familial intrahepatic cholestasis.

OBJECTIVES: Children with progressive familial intrahepatic cholestasis (PFIC) rarely benefit from medical treatment and most patients require surgical intervention. Partial external biliary diversion (PEBD) is presently the treatment of choice but for those who cannot benefit from PEBD, an alternative surgical procedure--ileal exclusion (IE)--was introduced. The aim of this study was to analyze our experience with IE in children with PFIC. METHODS: This procedure was performed in 9 patients (6 girls, 3 boys) at the median age of 11 years (range 8-21). In 4 children, it was the primary operation (group 1), and in 5, IE was performed after PEBD (group 2). All of the patients were screened for ABCB11 and ATP8B1 mutations, and in 3 cases, PFIC type 2 was confirmed. RESULTS: Median follow-up after IE surgery was 8.5 years (range 3-14). In group 1, 1 patient had to be converted to PEBD and the remaining 3 children experienced alleviation in pruritus and decrease in bilirubin and bile acids concentrations 2 and 5 years after IE. After 10 years, only 2 children were still accessible for follow-up. In both, pruritus varied and elevated serum bile acids were observed. Of the 5 patients who underwent IE after PEBD, 1 eventually required liver transplantation, 1 developed varying degree of pruritus, and 3 female patients, operated on because of aesthetic reasons, had excellent outcomes. CONCLUSIONS: IE is an alternative rescue option to PEBD and should be offered cautiously, only to patients who cannot benefit from PEBD.

Candidaemia in a Polish tertiary paediatric hospital, 2000 to 2010.

Data on the epidemiology of invasive Candida infections in paediatric patients in Europe are still limited. The aim of this retrospective study was to analyse the epidemiology of candidaemia in a tertiary paediatric hospital in Poland from 2000 to 2010. Using microbiological records, a total of 118 episodes of candidaemia were identified in 114 children, with an annual incidence of 0.35 episodes/1000 discharges. The highest incidences were found in the medical intensive care unit (5.28), and in neonatal intensive care (1.47). The mortality rate was 8.5%. Candida albicans and C. parapsilosis were the most prevalent species (39.8% and 35.6% respectively). The prevalence of non-albicans species increased from 12.5% in 2000 to 70% in 2010. No differences were found between C. albicans and C. non-albicans episodes in terms of demographics, risk factors or mortality. The highest resistance rates (overall 7.6%) were observed for fluconazole (4.3% in C. albicans, 7.1% in C. parapsilosis and 13.8% in other Candida species). Resistance to amphotericin B (2.5%) was limited to non-albicans isolates. The dynamic changes in species distribution and increasing resistance of fungal pathogens confirm the importance of epidemiological surveillance.

Risk for Recurrence in Long-Term Follow-Up of Children after Liver Transplantation for Hepatoblastoma or Hepatocellular Carcinoma.

The aim of this study was to assess the long-term results of liver transplantation (LT) in pediatric patients with unresectable hepatoblastoma (HB) or hepatocellular carcinoma (HCC) with special reference to the risk of tumor recurrence. We retrospectively analyzed data from 46 HB and 26 HCC patients who underwent LT between 1990 and 2022. In HCC patients, we compared outcomes depending on donor type. We evaluated the impact of a number of risk factors on recurrence-free survival after LT. Estimated patient survival after 5, 10, and 15 years was 82%, 73%, and 73% in the HB group and 79%, 75%, and 75% in the HCC group, respectively (p = 0.76). In the HCC group, living donor LT (LDLT) and deceased donor LT (DDLT) provided similar patient survival (p = 0.09). Estimated recurrence-free survival in patients who had three or fewer risk factors was significantly better than in patients with more than three risk factors (p = 0.0001). Adequate patient selection is necessary when considering LT for primary liver tumors in children. The presence of more than three risk factors is associated with a very high risk of recurrence and indicates poor prognosis, whereas extrahepatic disease may be considered a contraindication for transplantation.

Pregnancy in Liver and Kidney Female Recipient: A Case Report.

Deterioration of kidney function after orthotopic liver transplantation is a common complication that may occur after perioperative acute kidney injury (AKI) and preexisting or developing chronic kidney disease (CKD). AKI is described in the early postoperative period in more than half of recipients, whereas the main cause of CKD is pharmacotherapy. When end-stage renal failure occurs, patients may be qualified for additional transplantations. We present a rare case of a 27-year-old woman who, as a teenager, underwent 2 liver transplantations due to Wilson's disease. Surgeries were complicated by systemic infection and multiple organ failure. The kidneys did not regain their function, and therefore, after 6 months of dialysis, the organ was transplanted. Three organ transplantations were performed. Due to the patient's willingness and good graft functions, the patient started trying to conceive. Three months before successful conception, immunosuppressive therapy was changed to tacrolimus and azathioprine. Pregnancy was complicated by pregnancy-induced hypertension, and its course was closely monitored. Organ functions and immunosuppressive therapy were regularly assessed. Due to the pre-eclampsia developed in the 35th week of gestation, a Cesarean delivery was performed, and she gave birth to a daughter weighing 2350 g (Apgar 7-7-8). The patient decided to breastfeed. There were no obstetric complications or graft function deterioration in the early postpartum period. Mother and daughter left home after 7 days of hospitalization. The presented clinical situation proves that multiorgan transplantation recipients can have a successful pregnancy without impairing graft functions. Therefore, the pregnancy requires adequate preparation and increased care.

Choledochal Cyst Excision in Infants-A Retrospective Study.

A choledochal cyst is a rare malformation primarily diagnosed in children. The only effective therapy remains surgical cyst resection followed by Roux-en-Y hepaticojejunostomy. Treating asymptomatic neonates remains a point of discussion. Between 1984 and 2021, we performed choledochal cyst (CC) excision in 256 children at our center. Out of this group, we retrospectively reviewed the medical records of 59 patients who were operated on under one year of age. Follow-up ranged from 0.3 to 18 years (median 3.9 years). The preoperative course was asymptomatic in 22 (38%), while 37 patients (62%) had symptoms before surgery. The late postoperative course was uneventful in 45 patients (76%). In symptomatic patients, 16% had late complications, while in asymptomatic patients, only 4%. Late complications were observed in the laparotomy group in seven patients (17%). We did not observe late complications in the laparoscopy group. Early surgical intervention is not followed by a high risk of complications and may prevent the onset of preoperative complications, giving excellent early and long-term results, especially after minimally invasive laparoscopic surgery.

Tissue Expression of Programmed Cell Death 1 Ligand1 (PD-L1) in Biopsies of Transplant Livers of Pediatric Patients as a Possible Marker of Acute Cellular Rejection.

INTRODUCTION: Preclinical models have demonstrated that PD-1 and its ligand programmed death ligand1 (PD-L1) play significant roles in both graft induction and the maintenance of immune tolerance. It has also been suggested that PD-L1 tissue expression may predict graft rejection; however, the available data are sparse and inconclusive. Some studies were conducted on patients with cancer; most of them do not concern the liver, especially within the context of the use of immunohistochemical tests. Therefore, the aim of our study was to assess the relationship between tissue expression of PD-L1 in a unique material, i.e., in the liver biopsies of pediatric patients after transplantation with the presence of acute cellular rejection (ACR). MATERIAL AND METHODS: This retrospective study enrolled 55 biopsies from 55 patients who underwent protocol liver biopsies. The control group consisted of 19 biopsies from 13 patients diagnosed with acute cellular rejection (rejection activity index/RAI/ from 2 to 8). An immunohistochemical (IHC) staining for PD-L1 was performed in all of the liver specimens; its expression was analyzed in different regions of liver tissue (in inflammatory infiltrates and within the endothelium and hepatocytes). The following changes were re-evaluated in each specimen: features of any kind of rejection (acute cellular, antibody-mediated, chronic); the presence and severity of fibrosis (Ishak scale); and the presence of cholestasis and steatosis. Clinical parameters were also evaluated, including tests of liver function (AST, ALT, GGT, bilirubin). RESULTS: The age of patients in the study group ranged from 2.37 to 18.9 years (median 13.87 years), with the time after transplantation being 1-17 years (median 8.36 years). The age of patients in the control group ranged from 1.48 to 17.51 years (median 7.93 years), with their biopsies being taken 0.62-14.39 years (median 1.33 years) after transplantation. We found a statistically significant relationship between PD-L1 expression on inflammatory infiltrates and ACR; however, there was no statistically significant relationship between PD-L1 endothelial expression and ACR. PD-L1 was not positive in the hepatocytes regardless of if it was the study or control group that was under observation. CONCLUSION: PD-L1 appears to be a promising marker to predict graft rejection.

The Impact of Hepatic Artery Thrombosis on the Outcome of Pediatric Living Donor Liver Transplantations.

The aim of our study was to assess risk factors for hepatic artery thrombosis (HAT) and to evaluate the impact of HAT management on long-term outcomes after pediatric living donor liver transplantation (LDLT). We retrospectively analyzed 400 patients who underwent primary LDLT between 1999 and 2020. We compared preoperative data, surgical factors, complications, and patient and graft survivals in patients with HAT (HAT Group) and without HAT (non-HAT Group). A total of 27 patients (6.75%) developed HAT. Acute liver failure, a hepatic artery (HA) anastomosis diameter below 2 mm, and intraoperative HA flow dysfunction were significantly more common in the HAT Group (p < 0.05, p = 0.02026, and p = 0.0019, respectively). In the HAT Group, 21 patients (77.8%) underwent urgent surgical revision. The incidence of biliary stenosis and retransplantation was significantly higher in the HAT Group (p = 0.00002 and p < 0.0001, respectively). Patient and graft survivals were significantly worse in the HAT Group (p < 0.05). The close monitoring of HA flow with Doppler ultrasound during the critical period of 2 to 3 weeks after LDLT and the immediate attempt of surgical revascularization may attenuate the elevated risk of biliary stenosis, graft loss, and the need for retransplantation due to HAT.

Is M30 staining a reliable marker predicting graft rejection and fibrosis in protocolar liver biopsies in post-liver transplant pediatric patients?

BACKGROUND: Liver transplantation is currently a treatment of choice in patients with end-stage liver disease. Acute cellular rejection (ACR), antibody-mediated rejection (AMR), and chronic rejection (ChR) are major causes of graft injury. Therefore, new markers predicting graft rejection are investigating. Apoptosis has been recently proposed as one of the mechanisms contributing to liver fibrosis in liver grafts. Coarse needle liver biopsy is still a gold standard in monitoring post-transplant pathologies. The aim of this study was to assess the utility of immunohistochemical (IHC) staining for M30 (cytokeratin 18), as a prognostic marker of rejection in pediatric recipients of liver transplant and predicting marker of liver fibrosis and worse follow-up. METHODS: The study enrolled 55 biopsies from 55 patients aged 2.37 to 18.9 years (median 13.87 years) who underwent protocolar liver biopsies taken 1-17 years after liver transplantation (median 8.36 years). The control group (positive control group) consisted of 26 biopsies from 16 patients in whom acute ACR was diagnosed. IHC staining for M30 (cytokeratin 18) and histochemical Azan staining were performed in all liver specimens. The following changes were re-evaluated in each specimen: features of ACR (the severity was assessed using RAI/Rejection Activity Index/Scale, which ranges from 3-9 points and include 3 histopathological changes suggestive of rejection), AMR or ChR; severity of fibrosis (Ishak Scale); presence of cholestasis and steatosis. Clinical parameters including laboratory tests of liver function (AST, ALT, GGTP, bilirubin) were also evaluated. RESULTS: M30 expression correlated with presence of acute cellular rejection. However, no relationship was found between M30 expression and severity of fibrosis. CONCLUSIONS: M30 staining, marker of apoptosis, seems to be a promising marker predicting acute cellular rejection.