AST-to-platelet ratio index in non-invasive assessment of long-term graft fibrosis following pediatric liver transplantation

A blood-based PT-LIFE (Pediatric Liver Transplantation-LIver Fibrosis Evaluation) biomarker panel for noninvasive evaluation of pediatric liver fibrosis after liver transplantation: A prospective derivation and validation study

Allograft fibrosis is increasingly detected in graft biopsies as the postoperative period extends, potentially emerging as a pivotal determinant of long-term graft function and graft survival among pediatric recipients. Currently, there is a paucity of noninvasive diagnostic tools capable of identifying allograft fibrosis in pediatric recipients of liver transplants. This study involved 507 pediatric liver transplant patients and developed a novel blood-based diagnostic assay, Pediatric Liver Transplantation-Liver Fibrosis Evaluation (PT-LIFE), to noninvasively distinguish allograft fibrosis using blood samples, clinical data, and biopsy outcomes. The PT-LIFE assay was derived from a matrix of 23 variables and validated in 2 independent cohorts. It integrates 3 biomarkers (LECT2, YKL-40, FBLN3) with an area under the receiver operating characteristic curve of 0.91. In the pooled analysis, a PT-LIFE score lower than 0.12 identified liver allograft fibrosis semiquantitative scores 0 to 2 with a sensitivity of 91.9%, whereas scores above 0.29 indicated liver allograft fibrosis semiquantitative scores 3 to 6, with a specificity of 88.4%. The PT-LIFE assay presents as a promising noninvasive diagnostic tool for the detection of allograft fibrosis in pediatric liver transplant recipients.

Metabolic-Dysfunction-Associated Steatotic Liver Disease (MASLD) after Liver Transplantation: A Narrative Review of an Emerging Issue

The development of steatotic liver disease after liver transplant (LT) is widely described, and epidemiological data have revealed an increased incidence in recent times. Its evolution runs from simple steatosis to steatohepatitis and, in a small proportion of patients, to significant fibrosis and cirrhosis. Apparently, post-LT steatotic disease has no impact on the recipient's overall survival; however, a higher cardiovascular and malignancy burden has been reported. Many donors' and recipients' risk factors have been associated with this occurrence, although the recipient-related ones seem of greater impact. Particularly, pre- and post-LT metabolic alterations are strictly associated with steatotic graft disease, sharing common pathophysiologic mechanisms that converge on insulin resistance. Other relevant risk factors include genetic variants, sex, age, baseline liver diseases, and immunosuppressive drugs. Diagnostic evaluation relies on liver biopsy, although non-invasive methods are being increasingly used to detect and monitor both steatosis and fibrosis stages. Management requires a multifaceted approach focusing on lifestyle modifications, the optimization of immunosuppressive therapy, and the management of metabolic complications. This review aims to synthesize the current knowledge of post-LT steatotic liver disease, focusing on the recent definition of metabolic-dysfunction-associated steatotic liver disease (MASLD) and its metabolic and multisystemic concerns.

Progress in the diagnosis and treatment of graft fibrosis after liver transplantation

Liver transplantation (LT) is considered one of the best treatments for patients with end‐stage liver diseases. However, some patients with no significant clinical manifestations or abnormal laboratory tests still experience graft fibrosis during postoperative follow‐up, which is often recognized by graft histopathology. Graft fibrosis can lead to graft dysfunction, thereby reducing the survival time of the recipient and even requiring re‐transplantation. Currently, noninvasive methods are widely applied in the assessment of hepatic and allograft fibrosis. Although both noninvasive diagnostic models based on laboratory examination indicators and elastography technology that can quantify liver stiffness have some value in the evaluation of fibrosis, the diagnostic accuracy and characteristics of these various methods vary and cannot replace liver biopsy completely. In recent years, some liver‐protective drugs and proprietary Chinese traditional medicines have been proven to delay or reverse chronic liver fibrosis. Nevertheless, their efficacy and safety for LT recipients need to be further verified. This article reviews the diagnosis and treatment of graft fibrosis after LT to provide a reference for improving the overall survival rate of LT recipients.

Accuracy of noninvasive fibrosis scores in predicting advanced fibrosis in pediatric patients after liver transplantation

BACKGROUND

Liver biopsy is the gold standard to stage fibrosis in liver disease. Several scoring systems have been studied to predict advanced fibrosis in liver disease. Those scores have not been validated in pediatric liver transplant patients.

AIM

Evaluate the performance of three fibrosis scores (FSc) in assessing the presence of advanced fibrosis (AF) in children after orthotopic liver transplantation (OLT).

METHODS

Patients < 20 years of age who underwent liver biopsy post-OLT with laboratory values within 1 month of the biopsy were included. Fibrosis was determined by an experienced pathologist (F0-4). We defined AF as F3-4. The following FSc were calculated: AST/ALT ratio, APRI, and FIB-4 index. Receiver operating characteristic curve analysis was done to assess the FSc performance in predicting AF.

RESULTS

A total of 232 biopsies were analyzed, of those 42 (18.1%) showed AF (F3-4). FIB-4 was significantly higher in patients with AF compared to those without AF [median value of 1.1 [0.7, 3.0] and 0.6 [0.2, 1.4], respectively (p = .02)]; however, FIB-4 had satisfactory accuracy to diagnose AF with significant overlap and AUC of 0.68 (CI 0.56-0.81). Cutoff points of 0.2 and 3.03 were used to rule in and rule out AF, respectively. AST/ALT and APRI were not significantly different between patients with and without AF.

CONCLUSION

Even though FIB-4 had satisfactory accuracy in detecting AF in pediatric transplant patients, noninvasive hepatic FSc developed in adults still performed poorly. Our results highlight the need to develop a reliable pediatric FSc.

Diagnostic performance of 2D-shear wave elastography and serum fibrosis markers for evaluation of hepatic graft fibrosis in pediatric liver-inclusive transplant recipients: A prospective pilot study

BACKGROUND

Liver biopsy is the gold standard for hepatic fibrosis staging, but it is invasive and has potential severe complications. We aimed to determine the diagnostic performance of 2D-SWE and serum markers to predict significant hepatic graft fibrosis (≥F2) in pediatric liver-inclusive transplant recipients.

METHODS

This prospective, cross-sectional pilot study included children younger than 19 years who had received a LT or LSBT and underwent a liver biopsy performed for clinical indications. LS was measured using 2D-SWE. The AUROC was calculated to evaluate the diagnostic performance of 2D-SWE and biomarkers (AST/ALT ratio, APRI, FIB4) for predicting significant fibrosis.

RESULTS

Twenty-two children (13 males, 8 LSBT) were included. Eighteen (81.8%) children received a whole liver graft. Thirteen (59.1%) patients had hepatic fibrosis (≥F1) and four (18.2%) had significant fibrosis. The AUROCs of AST/ALT ratio, APRI, and FIB4 for predicting significant hepatic graft fibrosis were 0.71 (p = .29), 0.85 (p = .0001), and 0.76 (p = .03), respectively. When FIB4 was calculated using the hepatic graft's age, its AUROC improved to 0.85 (p < .0001). The AUROC of 2D-SWE for predicting significant hepatic graft fibrosis was 0.80 (p = .046). When 2D-SWE was combined with APRI or FIB4, its AUROC improved to 0.82 (p = .08) and 0.87 (p = .002), respectively.

CONCLUSIONS

APRI and FIB4 can accurately predict significant hepatic graft fibrosis. 2D-SWE may serve as a valuable adjunct tool to detect significant graft fibrosis, especially when combined with these serum markers.

Fish Oil Emulsion Reduces Liver Injury and Liver Transplantation in Children with Intestinal Failure-Associated Liver Disease: A Multicenter Integrated Study

OBJECTIVE

To compare the aspartate aminotransferase to platelet ratio index, liver transplantation, and mortality rates between children with intestinal failure-associated liver disease who received fish oil lipid emulsion (FOLE) or soybean oil intravenous lipid emulsion (SOLE).

STUDY DESIGN

In this multicenter integrated analysis, FOLE recipients (1 g/kg/d) (n = 189) were compared with historical controls administered SOLE (≤3 g/kg/d) (n = 73).

RESULTS

Compared with SOLE, FOLE recipients had a higher direct bilirubin level at baseline (5.8 mg/dL vs 3.0 mg/dL; P < .0001). Among FOLE recipients, 65% experienced cholestasis resolution vs 16% of SOLE recipients (P < .0001). The aspartate aminotransferase to platelet ratio index scores improved in FOLE recipients (1.235 vs 0.810 and 0.758, P < .02) but worsened in SOLE recipients (0.540 vs 2.564 and 2.098; P ≤ .0003) when baseline scores were compared with cholestasis resolution and end of study, respectively. Liver transplantation was reduced in FOLE vs SOLE (4% vs 12%; P = .0245). The probability of liver transplantation in relation to baseline direct or conjugated bilirubin (DB) was lower in FOLE vs SOLE recipients (1% vs 9% at DB of 2 mg/dL; 8% vs 35% at DB of 12.87 mg/dL; P = .0022 for both). Death rates were similar (FOLE vs SOLE: 10% vs 14% at DB of 2 mg/dL; 17% vs 23% at a DB of 12.87 mg/dL; P = .36 for both).

CONCLUSIONS

FOLE recipients experienced a higher rate of cholestasis resolution, lower aspartate aminotransferase to platelet ratio index, and fewer liver transplants compared with SOLE. This study demonstrates that FOLE may be the preferred parenteral lipid emulsion in children with intestinal failure-associated liver disease when DB reaches 2 mg/dL.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT00910104 and NCT00738101.

[Is the alpps procedure justified in children?]

The authors have analyzed the indications and outcomes after ALPPS procedure considering modern literature data devoted to this surgery in pediatric patients. No data on post-resection liver failure, as well as unclear future liver remnant function make it possible to question the feasibility of such procedures in children.

Utility of Mac-2 Binding Protein Glycosylation Isomer to Evaluate Graft Status After Liver Transplantation

Mac-2 binding protein glycosylation isomer (M2BPGi) is a novel liver fibrosis biomarker, but there are few studies on M2BPGi in liver transplantation (LT) recipients. This study aimed to evaluate the utility of M2BPGi measurement in LT recipients. We collected the clinicopathological data of 233 patients who underwent a liver biopsy at Kyoto University Hospital after LT between August 2015 and June 2019. The median values of M2BPGi in patients with METAVIR fibrosis stages F0, F1, F2, and ≥F3 were 0.61, 0.76, 1.16, and 1.47, respectively, whereas those in patients with METAVIR necroinflammatory indexes A0, A1, and ≥A2 were 0.53, 1.145, and 2.24, respectively. Spearman rank correlation test suggested that the necroinflammatory index had a stronger correlation to the M2BPGi value than the fibrosis stage. The area under the receiver operating characteristic curve of M2BPGi to predict ≥A1 was 0.75, which was significantly higher than that of any other liver fibrosis and inflammation marker. Patients with a rejection activity index (RAI) of ≥3 had a higher M2BPGi value than those with RAI ≤ 2 (P = 0.001). Patients with hepatitis C virus viremia had a higher M2BPGi value than sustained virological responders or those with other etiologies. In conclusion, the present study demonstrated that M2BPGi values are more strongly influenced by necroinflammatory activity and revealed M2BPGi, which has been thought to be a so-called fibrosis marker, as a disease activity marker in transplant recipients. M2BPGi measurement may be useful to detect early stage liver inflammation that cannot be detected by routine blood examination of LT recipients.

Pretransplantation and Post-Transplantation Liver Disease Assessment in Adolescents Undergoing Isolated Heart Transplantation for Fontan Failure

OBJECTIVE

To describe the assessment of Fontan-associated liver disease and determine the clinical and imaging measures that may identify hepatic morbidity risk in isolated heart transplantation candidates and trend those measures post-isolated heart transplantation.

STUDY DESIGN

Retrospective analysis of pre-isolated heart transplantation and post-isolated heart transplantation Fontan-associated liver disease (FALD) status using blood tests, magnetic resonance imaging (MRI), and liver biopsy analysis within 6 months before isolated heart transplantation and 12 months after isolated heart transplantation in 9 consecutive patients with Fontan. Pre- and post-isolated heart transplantation standard laboratory values; varices, ascites, splenomegaly, thrombocytopenia (VAST) score; Fontan liver MRI score; liver biopsy scores; Model for End-stage Liver Disease (MELD); MELD excluding the International Normalized Ratio (MELD-XI); AST to platelet ratio index, and cardiac catheterization data were compared.

RESULTS

Pretransplantation maximum MELD and MELD-XI was 15 and 16, respectively. Central venous pressures and VAST scores decreased significantly post-transplantation. In 5 paired studies, Fontan liver MRI score maximum was 10 pretransplantation and decreased significantly post-transplantation. Arterially enhancing nodules on MRI persisted in 2 patients post-transplantation. Pretransplantation and post-transplantation liver biopsy scores did not differ in 4 paired biopsy specimens.

CONCLUSIONS

Patients with FALD and MELD <15, MELD-XI <16, Fontan liver MRI score <10, and VAST score ≤2 can have successful short-term isolated heart transplantation outcomes. Liver MRI and VAST scores improved post-transplantation. Post-transplantation liver biopsy scores did not change significantly. Pretransplantation liver biopsy demonstrating fibrosis alone should not exclude consideration of isolated heart transplantation. The persistence of hepatic vascular remodeling and fibrosis post-isolated heart transplantation suggests that continued surveillance for hepatic complications post-transplantation for patients with Fontan is reasonable.

First-trimester aspartate aminotransferase to platelet ratio index in predicting intrahepatic cholestasis in pregnancy and its relationship with bile acids: A pilot study

OBJECTIVE

To evaluate the predictive value of the first-trimester aspartate aminotransferase (AST)/platelet count ratio [AST to platelet ratio index (APRI) score] for intrahepatic cholestasis in pregnancy (ICP).

METHODS

This study consisted of a patient group diagnosed with ICP (n = 37) and a control group (n = 66) who presented to the hospital perinatology clinic between 2018 and 2020. Laboratory tests of both groups were analysed retrospectively. Age, gravida, parity, body mass index, third-trimester laboratory tests and first-trimester APRI scores were compared between the two groups. A receiver operating characteristic (ROC) analysis of the study was performed to determine the cut-off value for APRI score that is predictive of ICP.

RESULTS

Patients with ICP had significantly higher first-trimester APRI scores compared with controls (p < 0.001). In the ROC analysis, the cut-off value for APRI score was 0.57, with 86.5 % sensitivity and 77.3 % specificity. Spearman's correlation indicated that there was a significant positive association between first-trimester APRI score and third-trimester fasting bile acid level (r = 0.641, p < 0.001). The demographic characteristics of patients in the third trimester did not differ, except for AST and alanine transferase values.

CONCLUSIONS

The APRI score calculated in the first trimester of pregnancy seems to be predictive of the development of ICP in the third trimester.

Diagnostic performance of non-invasive tests for evaluation of hepatic graft fibrosis in pediatric liver transplantation: A scoping review

BACKGROUND

Hepatic graft fibrosis is a common histologic finding of pediatric liver transplant (LT) that might affect long-term graft outcome. However, its diagnosis and staging require an invasive liver biopsy.

AIM

To review the published literature on the diagnostic accuracy of elastography and serum-based fibrosis markers for assessing hepatic graft fibrosis in pediatric LT recipients.

METHODS

A scoping review was conducted using a systematic search of published literature in PubMed (MEDLINE), EMBASE, SCOPUS, and Cochrane Library between 2002 and 2019. We included all English conference abstracts or full-text articles that examined the diagnostic accuracy of the non-invasive test(s) to assess hepatic fibrosis in LT children, using liver biopsy as the reference test.

RESULTS

Eight studies were included, of which 6 examined transient elastography (TE), one investigated acoustic radiation force impulse elastography, and 5 examined serum-based fibrosis markers (AST/ALT ratio, AST-to-platelet ratio index, FibroTest, enhanced liver fibrosis test). TE reportedly had a good AUROC (range: 0.82-0.92) to distinguish children with hepatic graft fibrosis (≥F1) from those with no fibrosis. However, there was considerable overlap of liver stiffness cutoffs in the mild to significant fibrosis groups (≥F1 and ≥F2). Current serum-based fibrosis markers reportedly had an unsatisfactory diagnostic accuracy.

CONCLUSIONS

TE in LT children has similar diagnostic value and limitations as in the non-transplant setting. Prospective studies are warranted to validate an optimal liver stiffness cutoff for predicting significant hepatic graft fibrosis (≥F2) and to determine if a meaningful change in liver stiffness from baseline could identify patients at risk for fibrosis progression.

Assessing the Validity of Adult-derived Prognostic Models for Primary Sclerosing Cholangitis Outcomes in Children

BACKGROUND

Natural history models for primary sclerosing cholangitis (PSC) are derived from adult patient data, but have never been validated in children. It is unclear how accurate such models are for children with PSC.

METHODS

We utilized the pediatric PSC consortium database to assess the Revised Mayo Clinic, Amsterdam-Oxford, and Boberg models. We calculated the risk stratum and predicted survival for each patient within each model using patient data at PSC diagnosis, and compared it with observed survival. We evaluated model fit using the c-statistic.

RESULTS

Model fit was good at 1 year (c-statistics 0.93, 0.87, 0.82) and fair at 10 years (0.78, 0.75, 0.69) in the Mayo, Boberg, and Amsterdam-Oxford models, respectively. The Mayo model correctly classified most children as low risk, whereas the Amsterdam-Oxford model incorrectly classified most as high risk. All of the models underestimated survival of patients classified as high risk. Albumin, bilirubin, AST, and platelets were most associated with outcomes. Autoimmune hepatitis was more prevalent in higher risk groups, and over-weighting of AST in these patients accounted for the observed versus predicted survival discrepancy.

CONCLUSIONS

All 3 models offered good short-term discrimination of outcomes but only fair long-term discrimination. None of the models account for the high prevalence of features of autoimmune hepatitis overlap in children and the associated elevated aminotransferases. A pediatric-specific model is needed. AST, bilirubin, albumin, and platelets will be important predictors, but must be weighted to account for the unique features of PSC in children.

Tissue inhibitor of metalloproteinase 1 and AST-to-Platelet Ratio Index as noninvasive biomarkers predict allograft fibrosis after pediatric liver transplantation

BACKGROUND

Assessing liver fibrosis in patients after liver transplantation is still largely dependent on liver biopsy. Especially in children, noninvasive methods are of utmost importance. We evaluated tissue inhibitor of metalloproteinase 1 (TIMP1) and AST-to-Platelet Ratio Index (APRI) and their potential as serum biomarkers to predict liver allograft fibrosis (LAF) in a pediatric cohort.

METHODS

In this retrospective, observational study, we analyzed 91 protocol liver biopsy specimens from 73 children after pediatric liver transplantation (PLT) and compared histological stage of liver fibrosis using LAF Score (LAFSc) and Ishak Score (IshakSc) to TIMP1-serum concentration and APRI using ROC analysis.

RESULTS

In our cohort, TIMP1 and APRI reliably predict LAF. Depending on the histological scoring system, cutoff values for TIMP1 were 328 ng/mL (IshakSc ≥ IV) and 351 ng/mL (LAFSc ≥ 5) with AUC of 0.86 and 0.98. The cutoff for APRI was 0.8 with AUC of 0.87 (IshakSc ≥ IV) and 0.94 (LAFSc ≥ 5). Using LAFSc, TIMP1 and APRI showed excellent diagnostic accuracy to detect severe LAF (LAFSc ≥ 5) with PPV of ≥ 90% and NPV of 100%.

CONCLUSION

TIMP1 and APRI are accurate biomarkers to predict severe LAF in children. The use of TIMP1 and APRI will not replace but complement liver biopsies after PLT to further improve our understanding of each individual patient.

Minimally invasive assessment of hepatic function in children with indocyanine green elimination: a validation study

Objectives: Pediatric liver disease (PLD) covers a variety of etiologies and severities, from mild temporary illness to diseases with fatal outcomes. There is a demand for minimally invasive and reliable measures for assessment of the severity of PLD. Indocyanine green (ICG) elimination kinetics to estimate hepatic function has been used in adults for decades, however, due to invasiveness, the use in PLD is still limited. The aim of the present study was to evaluate minimally invasive estimation of ICG elimination by pulse spectrophotometry (ICGLi), in comparison with traditional spectrophotometry using serial blood samples (ICGbs). Methods: One hundred children aged 0-18 years were included in the study. ICG elimination kinetics was measured with ICGLi and ICGbs, and results compared by failure rates, mean difference, limits of agreement, Bland Altman plots and linear regression analysis. Plasma disappearance rates (PDRLi and PDRbs) were used for comparison. Results: One hundred and twelve simultaneous measurements in 87 patients were performed successfully. Mean difference for PDR (%/min) was 3.58 (95% CI 2.69; 4.47). Limits of agreement were -5.06; 12.22. A linear correlation between the two methods with a regression coefficient of 0.83 (SE 0.02 95% CI 0.80; 0.87) was found. For conversion we computed the following equation; PDRbs = 0.83 × PDRLi. Conclusions: The present study shows that ICG PDR can be obtained by a minimally invasive method and thus replace measures by serial blood samples in children with liver disease of different etiologies and severities. However, a systematic relative difference between the two methods exists. Our proposed correction factor needs to be validated in larger cohorts.

Association between urinary thiodiglycolic acid level and hepatic function or fibrosis index in school-aged children living near a petrochemical complex

The effect of exposure to vinyl chloride monomer (VCM) on susceptibility to hepatotoxicity in children is unknown, although experimental studies have demonstrated a significantly increased risk of hepatocellular carcinoma in rodents exposed to VCM in early life. Epidemiological studies have revealed a high prevalence of liver fibrosis and abnormal liver function in workers exposed to high VCM levels. We aimed to assess the association among urinary thiodiglycolic acid (TDGA) level, abnormal liver function, and hepatic fibrosis in school-aged children living near a petrochemical complex. A total of 303 school-aged (6-13 years) children within 10 km nearly a petrochemical complex was recruited in central Taiwan. First-morning urine and blood samples were collected from each subject, and urinary TDGA level was analyzed through liquid chromatography-tandem mass spectrometry. Liver function was determined by serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels. Hepatic fibrosis was assessed using the AST to platelet ratio index (APRI) and fibrosis-4 score (FIB-4). Risk of hepatotoxicity induced by TDGA exposure was estimated using multivariate logistic regression. The median (range, subclinically abnormal %) AST and ALT levels of all subjects were 26.0 (17.0-99.0, 25.7%) and 15.0 (7.0-211.0, 5.9%) IU/L, respectively. Children in the highest urinary TDGA quartile (≥160.0 μg/g creatinine) exhibited significantly elevated median AST levels compared with those in the lowest quartiles (<35.4 μg/g creatinine, p = 0.033). After adjustment for potential confounding factors, children in the highest quartiles (Q4) of TDGA level had significantly increased odds ratio (OR) of subclinically abnormal AST (OR = 3.86; 95% confidence interval: 1.54-9.67) compared with those in the lowest quartile. A dose-response trend (p = 0.004) was observed. Our findings support the hypothesis that elevated urinary TDGA level in children living near petrochemical complex is associated with susceptibility to hepatotoxicity.