Plasma immune signatures can predict rejection-free survival in the first year after pediatric liver transplantation.

BACKGROUND & AIMS: After pediatric liver transplantation (pLT), children undergo life-long immunosuppression since reliable biomarkers for the assessment of rejection probability are scarce. In the multicentre (n=7) prospective clinical cohort "ChilSFree" study, we aimed to characterize longitudinal dynamics of soluble and cellular immune mediators during the first year after pLT and identify early biomarkers associated with outcome. METHODS: Using paired Luminex-based multiplex technique and flow cytometry, we characterized longitudinal dynamics of soluble immune mediators (SIM, n=50) and immune cells in the blood of 244 patients at 8 visits over one year: before, 7/14/21/28 days, 3/6/12 months after pLT. RESULTS: The unsupervised clustering of patients based on SIM profiles revealed 6 unique SIM signatures associated with clinical outcome. From 3 signatures linked to improved outcome, one was associated with one-year-long rejection-free survival and stable graft function and was characterized by low levels of pro-inflammatory (CXCL8/9/10/12, CCL7, SCGF-ß, sICAM-1), high levels of regenerative (SCF, TNF-ß), and pro-apoptotic (TRAIL) SIM (all, p<0.001, fold change >100). Of note, this SIM signature appeared two weeks after pLT and remained stable over the entire year, pointing towards its potential as a novel early biomarker for minimizing or weaning immunosuppression. In the blood of these patients, a higher frequency of CD56bright NK cells (p<0.01), a known hallmark also associated with operationally tolerant pLT patients, was detected. The concordance of the model for prediction of rejection based on identified SIM signatures was 0.715, and 0.795, in combination with living-related transplantation as co-variate, respectively. CONCLUSIONS: SIM blood signatures may enable the non-invasive and early assessment of rejection risks in the first year after pLT, paving the way to improved therapeutic options.

Early steroids after pediatric liver transplantation protect against T-cell-mediated rejection: Results from the ChilSFree study.

Steroid-free immunosuppression protocols gained popularity in pediatric liver transplantation (pLT) after the introduction of IL-2-receptor blockade for induction therapy. We analyzed the clinical and immunologic outcome data of the multicenter prospective observational ChilSFree study to compare the impact of steroid-free versus steroid-containing immunosuppressive therapy following pLT in a real-life scenario. Two hundred forty-six children [55.3% male, age at pLT median: 2.4 (range: 0.2-17.9) y] transplanted for biliary atresia (43%), metabolic liver disease (9%), acute liver failure (4%), hepatoblastoma (9%), and other chronic end-stage liver diseases (39%) underwent immune monitoring and clinical data documentation over the first year after pLT. Patient and graft survival at 1 year was 98.0% and 92.7%, respectively. Primary immunosuppression was basiliximab induction followed by tacrolimus (Tac) monotherapy (55%), Tac plus steroid tapering over 3 months (29%), or cyclosporine and steroid tapering (7%). One center used intraoperative steroids instead of basiliximab followed by Tac plus mycophenolate mofetil (7% of patients). N = 124 biopsy-proven T-cell-mediated rejections were documented in n = 82 (33.3%) patients. T-cell-mediated rejection occurred early (median: 41 d, range: 3-366 d) after pLT. Patients initially treated with Tac plus steroids experienced significantly fewer episodes of rejection than patients treated with Tac alone (chi-square p <0.01). The use of steroids was associated with earlier downregulation of proinflammatory cytokines interferon (IFN)-γ, Interleukin (IL)-6, CX motif chemokin ligand (CXCL)8, IL-7, and IL-12p70. Both primary immunosuppression with Tac plus steroids and living donor liver transplantation were independent predictors of rejection-free survival 1 year after pLT on logistic regression analysis. Adjunctive steroid therapy after pLT leads to earlier suppression of the post-pLT proinflammatory response and significantly reduced rejection rates during the first year after pLT (15.9%). Fifty-one percent of patients initially treated without steroids remain steroid-free over the first 12 months without rejection.

Telomere length is associated with intima-media thickness in pediatric liver transplant patients: A prospective cohort study.

Leukocyte telomere length (LTL) is a marker for biological age. Pediatric liver transplant recipients show a high rate of subclinical atherosclerosis, indicated by elevated intima-media thickness (IMT). We hypothesized that atherosclerosis is associated with biological age in these patients and investigated the course of LTL over time. We measured LTL from peripheral blood leukocytes by quantitative polymerase chain reaction and IMT from 97 pediatric patients after liver transplantation in a prospective cohort study. Of the patients, 71% (n = 69) had two or more assessments (total, 228 observations; median follow-up, 1.1 years). Lower LTL was associated with higher IMT (ß = -0.701, p = 0.01) and higher aspartate aminotransferase (ß = -0.001, p = 0.02), adjusted for age, sex, and age at transplantation. Of the patients, 45% showed decreasing LTL over time, whereas 55% exhibited stable LTL. Patients with stable LTL showed a decrease in IMT (median, -0.02 mm/year) and a decrease of tacrolimus trough levels (median, -0.08 µg/L/year). LTL is associated with IMT independent of age in pediatric liver transplant patients, suggesting that early aging contributes to the high burden of subclinical cardiovascular damage and may furthermore negatively affect the graft.

Current Evidence on the Clinical Relevance of Donor-specific Antibodies in Paediatric Liver Transplantation.

ABSTRACT: The clinical impact of donor-specific antibodies (DSA) occurring before or after liver transplantation (LT) against donor-human leucocyte antigen (HLA) on graft outcome is still unclear. We aim to present the current consensus based on recent paediatric LT case series. Compared to kidney transplantation, the liver seems to be less susceptible to antibody-mediated graft damage, which is likely due to protective Kupffer cell activity. The incidence of DSA after liver transplantation is higher in children than in adults. DSA directed against HLA class II molecules, mainly DQ, occur more often. The presence of such anti-class II DSA (DQ/DR), especially of the complement-binding IgG3 subclass, may be associated with endothelial injury, T-cell-mediated rejection (TCMR), inflammation, and fibrosis. Regular DSA-posttransplant monitoring cannot as yet be recommended in routine practice but may be useful in selected cases.

Dubin-Johnson Syndrome as Differential Diagnosis for Neonatal Cholestasis.

OBJECTIVES: Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder in which multidrug-resistance-associated protein 2 (MRP2) deficiency causes an excretion disorder of conjugated bilirubin from hepatocytes into bile canaliculi. Its clinical presentation as neonatal cholestasis (NC) is rare but represents an important differential diagnosis. We aimed to define DJS-specific characteristics in NC, in particular in contrast to biliary atresia (BA) patients, and to highlight diagnostic tools that can help to avoid invasive diagnostic tests. METHODS: We performed a review of case records from 2006 to 2020 and compared 4 DJS patients to 26 patients with proven BA consecutively diagnosed from 2014 to 2017. DJS was diagnosed by urine coproporphyrin analysis (UCA) and by genetic analysis (GA) for disease-associated ABCC2 variants. RESULTS: Four male patients with NC were diagnosed with DJS by UCA and GA. DJS patients presenting as NC showed significantly lower values for aspartate aminotransferase (AST) (P < 0.001), for alanine aminotransferase (ALT) (P = 0.002) and for gamma-glutamyl transferase (GGT) (P < 0.001) compared with BA patients. Other examinations, however, could not clearly discriminate them (e.g.: stool colour, serum bile acids, total serum bilirubin). CONCLUSIONS: DJS is not only a rare differential diagnosis in NC with a suspicious phenotype (almost normal AST, ALT) but also shows overlapping features with BA. It should, therefore, be considered in every infant with NC and an atypical liver enzyme pattern to protect patients from unnecessary, invasive examinations. For this, UCA is a fast and reliable diagnostic tool. Confirmation based on GA is recommended. DJS patients have a good long-term prognosis.

Normal liver stiffness and influencing factors in healthy children: An individual participant data meta-analysis.

BACKGROUND & AIMS: Although transient elastography (TE) is used to determine liver stiffness as a surrogate to hepatic fibrosis, the normal range in children is not well defined. We performed a systematic review and individual participant data (IPD) meta-analysis to determine the range of liver stiffness in healthy children and evaluate the influence of important biological parameters. METHODS: We pooled data from 10 studies that examined healthy children using TE. We divided 1702 children into two groups: ≥3 years (older group) and < 3 years of age (younger group). Univariate and multivariate linear regression models predicting liver stiffness were conducted. RESULTS: After excluding children with obesity, diabetes, or abnormal liver tests, 652 children were analysed. Among older children, mean liver stiffness was 4.45 kPa (95% confidence interval 4.34-4.56), and increased liver stiffness was associated with age, sedation status, and S probe use. In the younger group, the mean liver stiffness was 4.79 kPa (95% confidence interval 4.46-5.12), and increased liver stiffness was associated with sedation status and Caucasian race. In a subgroup analysis, hepatic steatosis on ultrasound was significantly associated with increased liver stiffness. We define a reference range for normal liver stiffness in healthy children as 2.45-5.56 kPa. CONCLUSIONS: We have established TE-derived liver stiffness ranges for healthy children and propose an upper limit of liver stiffness in healthy children to be 5.56 kPa. We have identified increasing age, use of sedation, probe size, and presence of steatosis on ultrasound as factors that can significantly increase liver stiffness.

High Burden of Subclinical Cardiovascular Target Organ Damage After Pediatric Liver Transplantation.

Cardiovascular (CV) events account for 8%-13% of deaths after liver transplantation (LT) in adulthood. Although CV risk factors (RFs) are present, little is known about the prevalence of subclinical CV target organ damage (TOD) in children after LT. The aim of this prospective observational study was to assess the prevalence of subclinical CV TOD in children after LT and to identify RFs contributing to CV damage as potential targets for clinical intervention. In this study, 104 children after LT (54% female, 46% male; aged 11.5 ± 3.8 years) underwent cross-sectional assessment of subclinical TOD by carotid-femoral pulse wave velocity (PWV), carotid intima-media thickness (IMT), and left ventricular mass index (LVMI). Results were correlated with the presence of CV RFs (obesity, hypertension, dyslipidemia, renal impairment, anemia, and microinflammation). Of the patients, 22% were exposed to 2 CV RFs, and 36% displayed 3 or more CV RFs. Pathological results for PWV, IMT, and LVMI were found in 21.9%, 57.0%, and 11.1% of patients, respectively. In the multivariate analysis, diastolic blood pressure (P = 0.01) and estimated glomerular filtration rate (eGFR; P = 0.03) were independently associated with PWV, eGFR (P = 0.005), and age at LT (P = 0.048) with IMT and body mass index with LVMI (P = 0.004). In conclusion, patients after pediatric LT carry a substantial burden of subclinical CV TOD. Identification of modifiable CV RFs opens opportunities for targeted intervention in order to reduce CV morbidity and mortality in the future.

Impact of Immunosuppression on Executive Functioning After Pediatric Liver Transplantation: An Observational Cohort Study.

OBJECTIVES: Children after liver transplantation show increased rates of impaired cognitive functioning. We aimed to assess the potential effects of immunosuppressive therapy on executive functioning measured by the Children's Color Trail Test and the cognitive functioning module of the PedsQL (cogPedsQL) in liver transplanted children to explore potential targets for intervention to improve executive functioning. METHODS: We performed a cross-sectional study in 155 children (78 girls) aged 10.4 (2-18) years at 5.0 (0.1-17) years after liver transplantation, with follow-up at 6 months in n = 114. Executive functioning was assessed by Children's Color Trail Test (ages 8-16) and by patients and parent-proxy cogPedsQL (ages 5-18/2-18, respectively). Results were correlated with clinical parameters. Stability of results over time was compared between n = 23 patients who for clinical reasons switched from twice daily calcineurin inhibitor (CNI) to once-daily slow-release tacrolimus (Tac) during the study period, and patients with unchanged CNI. RESULTS: Worse executive functioning was associated with longer stay in the intensive care unit and longer time elapsed since transplantation. No difference was found between users of cyclosporine and Tac. Children on once-daily slow-release Tac performed better than children on twice-daily Tac. In children who switched from twice-daily CNI to once-daily Tac, parent-proxy cogPedsQL improved significantly compared to stable results in the nonswitch group. CONCLUSIONS: In addition to a strong impact of disease burden around transplantation, executive functioning appears to deteriorate over time. Although there is no clear-cut advantage of any CNI, once-daily Tac appears to be advantageous compared to twice-daily Tac.

Immune monitoring after pediatric liver transplantation - the prospective ChilSFree cohort study.

BACKGROUND: Although trough levels of immunosuppressive drugs are largely used to monitor immunosuppressive therapy after solid organ transplantation, there is still no established tool that allows for a validated assessment of functional degree of immunosuppression or the identification of clinically relevant over- or under-immunosuppression, depending on graft homeostasis. Reliable non-invasive markers to predict biopsy proven acute rejection (BPAR) do not exist. Literature data suggest that longitudinal measurements of immune markers might be predictive of BPAR, but data in children are scarce. We therefore propose an observational prospective cohort study focusing on immune monitoring in children after liver transplantation. We aim to describe immune function in a cohort of children before and during the first year after liver transplantation and plan to investigate how the immune function profile is associated with clinical and laboratory findings. METHODS: In an international multicenter prospective approach, children with end-stage liver disease who undergo liver transplantation are enrolled to the study and receive extensive immune monitoring before and at 1, 2, 3, 4 weeks and 3, 6, 12 months after transplantation, and whenever a clinically indicated liver biopsy is scheduled. Blood samples are analyzed for immune cell numbers and circulating levels of cytokines, chemokines and factors of angiogenesis reflecting immune cell activation. Statistical analysis will focus on the identification of trajectorial patterns of immune reactivity predictive for systemic non-inflammatory states, infectious complications or BPAR using joint modelling approaches. DISCUSSION: The ChilSFree study will help to understand the immune response after pLTx in different states of infection or rejection. It may provide insight into response mechanisms eventually facilitating immune tolerance towards the graft. Our analysis may yield an applicable immune panel for non-invasive early detection of acute cellular rejection, with the prospect of individually tailoring immunosuppressive therapy. The international collaborative set-up of this study allows for an appropriate sample size which is otherwise difficult to achieve in the field of pediatric liver transplantation.

Quality of Life in Patients With Progressive Familial Intrahepatic Cholestasis: No Difference Between Post-liver Transplantation and Post-partial External Biliary Diversion.

OBJECTIVES: In patients with progressive familial intrahepatic cholestasis (PFIC), partial external biliary diversion (PEBD), which is associated with a permanent stoma, is recommended as first-line therapy, whereas primary liver transplantation (LTx) is restricted to those with cirrhosis. Our aim was to quantify the health-related quality of life (HRQOL) in patients with PFIC and to evaluate whether there is a difference in their HRQOL depending on the surgical approach. METHODS: A prospective HRQOL study on a consecutive series of PFIC was conducted using Pediatric Quality of Life Inventory 4.0 child-self and parent-proxy reports. Patients with PFIC after PEBD who still lived with their native livers were compared to those after LTx. Both groups were compared to healthy children. RESULTS: A total of 32 patients (53% girls) patients with a mean age of 17.7 ±â€Š7.3 years were studied. Twenty-two had undergone LTx at a mean age of 7.8 ±â€Š3.8 years and 10 had undergone PEBD at a mean age of 4.1 ±â€Š3.9 years. At the time of HRQOL assessment, the mean age was 18.9 ±â€Š7.5 years in the LTx group and 15.3 ±â€Š6.5 years in the PEBD group. Child-self and parent-proxy reports showed no significant difference in HRQOL between patients with PFIC after LTx and those after PEBD except for marginal difference in physical functioning/health (P = 0.07). Except for a lower score in patient school functioning of patients after LTx (P = 0.01), HRQOL-results showed no difference from healthy children in any group. CONCLUSIONS: The HRQOL of patients with PFIC after PEBD was similar to those after LTx. The HRQOL in both groups was also similar to that of healthy children. Thus, our data support the current policy of PEBD as primary surgical treatment for patients with PFIC without cirrhosis.

Side effects and efficacy of renal sparing immunosuppression in pediatric liver transplantation-A single center matched cohort study.

Immunosuppressive combination therapy with MMF can reduce CNI associated nephrotoxicity. We investigated effectiveness and safety of de novo MMF-tacrolimus based immunosuppression after pLTx. Patients after pLTx receiving immunosuppression with MMF/tacrolimus (MMF/TAC) were compared to retrospectively selected age- and diagnosis-matched patients with tacrolimus monotherapy (TAC) and cyclosporine/prednisolone therapy (CSA) (19 patients each, n = 57). Effectiveness, renal function and side effects were analyzed for 1 year after pLTx. Tacrolimus reduction in combination therapy (0.7 µg/L over the year) was lower than aspired (2 µg/L). Acute BPAR occurred equally in MMF/TAC and TAC groups (31.6% each), being slightly higher in CSA group (42.1%; OR = 1.5; 95% CI = 0.42-5.44; P = .5). GFR deteriorated comparably in all 3 groups (P < .01 each) without significant differences between the groups. Septicemia was detected significantly more often in MMF/TAC (73.6%) than in TAC (31.6%) (OR 4.17; 1.07-16.27; P = .04). EBV reactivation occurred more often in CSA patients (84.2%) than in MMF/TAC (47.4%; OR 5.16; 0.98-27.19; P = .05) and TAC patients (52.6%; OR 8.16; 1.48-44.89; P = .02) the same was true for other viral infections (47.4% (CSA) vs 15.8% (TAC); OR 4.21; 0.95-18.55; P = .05). Our study does not provide additional evidence for a benefit of initial use of MMF/TAC over TAC regarding renal function, but raises concerns regarding a potentially increased risk of serious infections under MMF/TAC compared to TAC monotherapy at equivalent renal outcome; our study is, however, limited by the minor CNI reduction in combination therapy.

Human leucocyte antigens and pediatric autoimmune liver disease: diagnosis and prognosis.

UNLABELLED: An association of human leukocyte antigen (HLA) class II alleles with autoimmune conditions is increasingly being used for diagnostic purposes. The aim of our study was to examine whether HLA class II alleles in pediatric-onset autoimmune liver disease (pAILD) may serve as diagnostic markers and if they correlate with clinical outcome parameters. HLA-DRB1 alleles of 76 children with pAILD (autoimmune hepatitis [AIH], autoimmune sclerosing cholangitis [AISC], primary sclerosing cholangitis [PSC]) and of 50 healthy blood donors as control group were analyzed retrospectively. Diagnosis of these patients was confirmed by the autoimmune hepatitis score including liver histology, which has been re-evaluated by a blinded liver pathologist, and by bile duct imaging, as appropriate. Our results showed significant association of HLA-DRB1*03 with AIH1 and AISC with 82 % specificity for AIH. For pAILD (excluding AIH2), HLA-DRB1*03 homozygosity had specificity of 98 %, whereas sensitivity is low. Remission in HLA-DRB1*03-positive patients appears to be less likely. HLA-DRB1*13 is significantly associated with PSC and also with AIH1. CONCLUSION: HLA-DRB1 alleles provide supportive information for diagnostic workup in patients with liver disease, but they were not suitable for differentiation within pAILD. Their prognostic value could be helpful but needs to be evaluated further. WHAT IS KNOWN: • HLA-DRB1*03 is NOT associated with pediatric AIH in a previous national study. • In other studies, HLA-DRB1*03 is associated with AIH1. • HLA-DRB1*13 is associated with PSC. • HLA-DRB1*04 is described as protective for AILD. What is New: • HLA-DRB1 four-digit typing for all alleles and for all subgroups of pAILD combined with re-assessment of liver histology • HLA-DRB1*03:01 is associated with pediatric AIH1 and AISC. • HLA-DRB1*03:01 appears to be a prognostic marker. • HLA-DRB1*13:01 is associated with pediatric AIH1 in mixed ethnicity cohort. • HLA-DRB1*04 does not show any protective effect for pAILD.

Personal decision-making processes for living related liver transplantation in children.

Living related liver transplantation (LRLT) is a valuable transplant option for children with end-stage liver disease who face long waiting times on regular waiting lists. The subjection of a healthy adult to a potentially life-threatening operation can raise issues of freedom of choice, fear, and family conflict for the potential donors. We examined attitudes, fears, and influencing factors in the decision-making process for living liver donation for children in order to identify factors to improve support for living liver donors in the future. In a retrospective, questionnaire-based survey of 93 adults evaluated for living liver donation between 1997 and 2010, 47 of whom actually proceeded to donation, we asked about attitudes, motivation, fears, influencing factors, and well-being during the LRLT evaluation process and during the donation period. Answers were recorded on Likert scales and compared with Pearson's rho correlation and the Mann-Whitney U test as appropriate. Although there was a strong sense of a lack of alternatives among the donors, the majority of the donors felt free in their decision to donate. Donors who were asked to donate for a relative who was not their own child appeared at higher risk of lacking support and of feeling coerced. Family and social support and good and empathic information about the donation process were identified as key factors for donor well-being. In conclusion, potential living liver donors need to have adequate, sufficient, and empathic information, and they need to be provided a supportive framework, including family support, in order to promote their well-being. Care needs to be taken in identifying and counseling potential donors at risk of feeling coerced into donation.

Spleen stiffness measurement by transient elastography to diagnose portal hypertension in children.

BACKGROUND: The development of esophageal varices is a late complication of chronic liver disease (LD) in children. The diagnosis is presently limited to invasive procedures such as endoscopy. Noninvasive tools to diagnose the presence and degree of esophageal varices would alter management decisions and support indications for invasive procedures in affected children. The aim of the study was to test the feasibility of spleen stiffness measurement (SSM) by transient elastography (TE; FibroScan) in children and compare data on its diagnostic use with established markers of liver fibrosis and parameters of portal hypertension. METHODS: A total of 99 children (62 with chronic LD, 6 after liver transplantation, 31 controls) underwent SSM by TE. Fibrotest was determined in 37 children, 45 children had an additional liver stiffness measurement, and 19 underwent upper endoscopy. RESULTS: SSM by FibroScan is feasible. Spleen size significantly determined success rate (90.5% in patients with splenomegaly vs 70.2% in patients without, P = 0.02). Spleen stiffness was significantly higher in patients with splenomegaly (62.96 vs 18.4 kPa, P < 0.001), in patients with varices (75 vs 24 kPa, P < 0.01), and in patients with a history of variceal hemorrhage (75 vs 50.25 kPa, P < 0.05). Variceal hemorrhage did not occur in patients with SSM results <60 kPa. Spleen stiffness decreased after liver transplantation, but remained elevated compared with controls (27.5 vs 16.3 kPa). Liver stiffness measurements and Fibrotest did not reflect the presence or degree of esophageal varices. CONCLUSIONS: SSM by TE is feasible in children and the results reflect the degree and occurrence of complications. A prospective follow-up study with larger patient numbers and performance of screening endoscopies appears justified and desirable.

Autophagy-enhancing drug carbamazepine diminishes hepatocellular death in fibrinogen storage disease.

Fibrinogen storage disease (FSD) is a rare autosomal-dominant hereditary disorder characterized by hypofibrinogenemia and accumulation of fibrinogen aggregates within the hepatocellular endoplasmatic reticulum (ER). Some FSD patients present with elevated amino-transferases and fibrosis/cirrhosis similar to alpha-1-antitrypsin deficiency (ATD), also an ER storage disease. Pharmacological stimulation of autophagy has been shown to mediate clearance of protein aggregates and halt progression of liver fibrosis in in vivo models of ATD. Our aim was to evaluate the presence of autophagy and a possible response to autophagy-enhancing therapy in patients with FSD. Hepatic fibrosis was assessed by transient elastography in 2 newly identified FSD families with fibrinogen Aguadilla and Brescia mutations, encompassing 8 affected members. Available liver biopsies were assessed for autophagy. Two patients, who had had elevated alanine amino-transaminase levels (2-5 above upper limit of normal), were treated with the autophagy enhancer carbamazepine (CBZ). Transient elastography did not show evidence of significant fibrosis in any affected family members. Quantitative electron microscopy of one patient showed a 5.15-fold increase of late stage autophagocytic vacuoles compared to control livers. CBZ at low anticonvulsive treatment levels led to rapid normalization of alanine-aminotransferase and decrease of caspase-cleaved and uncleaved cytokeratin-18 fragments (M30 and M65). These effects reversed after discontinuation of treatment. Response to CBZ may be mediated by pharmacologically enhanced autophagy resulting in reduction of aggregate-related toxicity in FSD. These results suggest clinical applicability of pharmacological stimulation of autophagy in FSD, but potentially also in other related disorders.

Application and limitations of transient liver elastography in children.

OBJECTIVES: Transient elastography (TE) using the FibroScan has gained popularity recently for the noninvasive diagnosis of hepatic fibrosis. Data on its use in children younger than 6 years are still scarce, and the influence of technical aspects such as probe choice and site of measurement on FibroScan results is not clear. Our study aims to clarify some technical issues concerning the use of the FibroScan in children and to deliver normal FibroScan values for reference. METHODS: TE was performed in 527 children (229 girls, ages 0.1-17.8 [median 6.0] years, including 400 healthy controls). Feasibility of different sites of measurements, paired comparison of probe settings, and pre- and postprandial measurements were systematically performed. Sedated versus unsedated measurements were compared in age- and sex-matched cohorts. RESULTS: Success rate of TE in our population was 90%, but decreased to 83% in children younger than 24 months even in ideal conditions. General anesthesia significantly increased liver stiffness in healthy children (5.4 [3-9.5] vs 4.2 [2.8-8.15] kPa; P < 0.01). Probe choice equally influenced results in paired comparisons (S1 5.5 [3.5-17.9] vs S2 4.8 [2.1-15.4] kPa; P < 0.01), as did food intake (5.9 [3.6-75] vs 5.4 [3.6-63.9] kPa; P = 0.015). Inter- and intraobserver agreements were good. Normal liver stiffness was 4.5 (2.5-8.9) kPa and did not vary significantly with age or sex. CONCLUSIONS: TE is feasible even in extremely young children, but confounding influences on test results such as probe choice, sedation, or food intake need to be taken into account when interpreting results.

Results of single-center screening for chronic hepatitis E in children after liver transplantation and report on successful treatment with ribavirin.

RNA screening for HEV in 22 liver-transplanted children with chronic graft hepatitis out of a cohort of 267 liver-transplanted children detected a single patient with chronic HEV infection. Although this patient remained viremic for 33 months, anti-HEV-IgG was not detectable with MP assay but with Wantai assay. We present the first case of successful ribavirin therapy in an immunosuppressed child with chronic HEV infection. In conclusion, chronic HEV infection in immunosuppressed children may not be detectable employing serological assays. Therefore, the most reliably screening method is screening for HEV-RNA. Chronic HEV infection in children can successfully be treated with ribavirin.

The use of transient elastography and non-invasive serum markers of fibrosis in pediatric liver transplant recipients.

The use of non-invasive markers to diagnose liver allograft fibrosis is not well established in children after LTx. TE, FT, and ELF score were performed in 117 liver-transplanted children (60M, 8.9 [0.5-18.5] yr) and 336 healthy controls. Liver biopsy was available in 36 children. Results of histology and non-invasive markers were compared using correlation coefficient or Mann-Whitney U-test as appropriate. TE correlated best with histological degree of fibrosis (r = 0.85 vs. r = 0.04 [FT] or r = -0.38 [ELF]). Liver stiffness values for transplanted children without fibrosis were significantly higher than those of healthy controls (7.55 [5.4-20.4] kPa vs. 4.5 [2.5-8.9] kPa). Presence of rejection was a potent confounder for the performance of TE. Both TE and FT reflected clinical changes (acute rejection, cholestasis, increasing fibrosis) in a total of 16 patients who underwent serial measurements. TE correlates better with histological degree of fibrosis in liver-transplanted children than FT or ELF, but an individual baseline value needs to be determined for each patient. Normal or cutoff values for pathological degrees of fibrosis cannot be transferred from non-transplanted children. Follow-up studies, preferably with protocol biopsies, might help to improve the diagnostic quality of TE.

The Impact of Thrombophilic Factors on Disease Progression in Children with Biliary Atresia-A Single-Centre Cohort Study.

Epidemiological evidence suggests that thrombophilic factors, including male sex, non-O blood type, MTHFRnt677TT mutation, factor V Leiden G1691A mutation, and prothrombin G20210A polymorphism, may contribute to the progression of fibrosis and occurrence of portal vein thrombosis in liver disease. We retrospectively investigated the effect of potentially thrombophilic factors on native liver survival as a patient-relevant endpoint of disease progression in a cohort of 142 children being followed up for biliary atresia at Hannover Medical School from April 2017 to October 2019. No significant association could be determined. There was no evidence for relevant differences in native liver survival for the Factor V Leiden G1691A mutation (hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.38-1.98, p = 0.73), prothrombin G20210A polymorphism (HR = 0.96, 95%CI 0.24-3.65, p = 0.96), non-O blood type (HR = 0.79, 95%CI 0.51-1.21, p = 0.28) or MTHFRnt677TT mutation (HR = 1.24, 95%CI 0.60-2.56, p = 0.56). A certain, albeit not strong, evidence of reduced native liver survival in male patients after Kasai hepatoportoenterostomy, particularly during the first 2000 days (42%; HR = 1.41, 95%CI 0.92-2.18, p = 0.11) was found. All children with pre-transplant portal vein thrombosis (n = 7) had non-O blood types. Larger multi-centre studies are necessary to show if the male sex or other thrombophilic factors could be potentially associated with reduced native liver survival.

Native liver survival in bile salt export pump deficiency: results of a retrospective cohort study.

BACKGROUND: Bile salt export pump (ABCB11) deficiency [Progressive familial intrahepatic cholestasis (PFIC2)] is the most common genetic cause of PFIC and is associated with pruritus and progressive liver disease. Surgical biliary diversion or pharmacological [ileal bile acid transporter inhibitor (IBATi)] approaches can be used to block the recirculation of bile acids to the liver. There is a paucity of detailed data on the natural history and, in particular, the longitudinal evolution of bile acid levels to predict treatment response. Cross-sectional data from large international consortia suggested a maximum cutoff value of bile acids after the intervention to predict a successful outcome. METHODS: This retrospective, single-center, cohort study included all patients with confirmed biallelic pathogenic ABCB11 genotype PFIC2 treated at our institution with ≥2 years follow-up. The outcomes of interventions and predictors of long-term health were analyzed. RESULTS: Forty-eight cases were identified with PFIC2. Eighteen received partial external biliary diversion (PEBD) surgery, and 22 patients underwent liver transplantation. Two patients developed HCC and 2 died. Improved survival with native liver was closely associated with genotype, complete normalization of serum bile acids following PEBD, and alleviation of pruritus. Persistence of mild-to-moderate elevation of bile acids or a secondary rise following normalization was associated with liver disease progression and led to transplantation, suggesting that any prolonged elevation of bile acids worsens the chance of native liver survival. Higher-grade fibrosis at the time of PEBD was not associated with reduced long-term native liver survival. Patients with PFIC2 benefit from PEBD even at a stage of advanced fibrosis. CONCLUSION: Serum bile acid levels are an early predictor of treatment response and might serve as the gold standard in the evaluation of novel therapies including IBATi.