Low gamma-glutamyl transpeptidase levels at presentation are associated with severity of liver illness and poor outcome in biliary atresia

Identification of Biliary Atresia in Infantile Cholestasis: Integrating Radiomics With MRCP for Unobservable Extrahepatic Biliary Systems

PURPOSE

Magnetic resonance cholangiopancreatography (MRCP) may assist in the workup of infantile cholestasis as nonvisualization of the biliary tree is seen with biliary atresia (BA). However, this finding can also be seen with other causes of infantile cholestasis. The purpose of this study is to differentiate BA from other causes of infantile cholestasis using a classification tool integrating MRCP-based radiomics and clinical signatures in patients with nonvisualization of the extrahepatic biliary tree on MRCP.

METHODS

Data from infants with cholestasis due to BA, cytomegalovirus infection, or idiopathic neonatal hepatitis (INH) from 2 sites was collected. Radiomics features from MRCP images were selected using Spearman and LASSO methods, followed by applying the optimal machine learning model to develop a radiomics signature. Clinical factors showing significant differences between BA and non-BA groups in training cohort were used to develop a clinical signature using the model. A nomogram model incorporating the signatures was developed. The nomogram model and signatures' performance were assessed using the area under the curve (AUC), accuracy, sensitivity, specificity, precision, and F1 score. The DeLong test, decision curve analysis (DCA), calibration curves, and the Hosmer-Lemeshow test were utilized to evaluate the nomogram model.

RESULTS

The training cohort consisted of 112 cases (62 BA and 50 non-BA) from site 1, while the external validation cohort included 35 cases (20 BA and 15 non-BA) from site 2. After screening, 2 clinical factors and 8 radiomics features were included. The signatures were fitted using the K-Nearest Neighbors model. The nomogram model showed an AUC of 0.981 in the training cohort and 0.913 in the external validation cohort, significantly outperforming both the signatures in the training cohort and the clinical signature in the external validation cohort, as confirmed by the DeLong test. The DCA indicated the clinical utility of the model. The Calibration curves and the Hosmer-Lemeshow test confirmed the model's adequate fit.

CONCLUSION

The nomogram model may hold clinical utility. In our cohorts, it was effective for identifying BA among cases with infantile cholestasis attributed to BA, cytomegalovirus infection, or INH in scenarios where the extrahepatic biliary system is not visualized on MRCP.

Serum bile acids early after portoenterostomy are predictive for native liver survival and portal hypertension in biliary atresia

OBJECTIVES

To compare the predictive value of serum bile acids on native liver survival (NLS) and portal hypertension (PH) at various time points early after portoenterostomy (PE) in biliary atresia (BA).

METHODS

This was a retrospective observational study. Serum bilirubin and bile acid concentrations were defined by enzymatic spectrophotometry 1, 3, and 6 months after PE. After defining optimal bilirubin and bile acids cutoffs by area under the receiver operating characteristic (AUROC) curves, cutoffs were compared with other predictors of NLS and PH in Cox regression.

RESULTS

Out of 56 patients, 42 (75%) achieved clearance of jaundice (COJ, bilirubin <20 µmol/L at 6 months). Both bilirubin and bile acids at 3 and 6 months were accurate predictors of NLS among all patients (AUROC 0.82-0.91, p < 0.001). In COJ patients, bile acids (AUROC 0.82, p = 0.003), but not bilirubin, at 1 month also predicted NLS. Among all patients, the strongest predictors of NLS were bilirubin >18.5 µmol/L and bile acids >150 µmol/L at 3 months, increasing the risk of transplantation/death seven- and eightfold, respectively (p < 0.001 for both). In COJ patients, the strongest predictor of NLS was bile acids >119 µmol/L at 3 months, increasing the risk of transplantation/death 12-fold (p = 0.014). Bile acids and bilirubin at 3 and 6 months predicted PH development in COJ patients with moderate accuracy (AUROC 0.72-0.78, p = 0.004-0.019). Bilirubin >8.5 µmol/L and bile acids >78 µmol/L at 6 months increased PH risk 13-fold (p < 0.001) and 4-fold (p = 0.006).

CONCLUSIONS

Serum bile acids offer a simple and useful additional tool to predict PE outcomes in BA, particularly after COJ.

Predictors of outcome among children with biliary atresia: a single centre trial

Objective

This study aimed to investigate the predictive role of preoperative gamma-glutamyl transpeptidase (GGT) levels on the prognosis of neonatal biliary atresia (NBA) in patients who underwent the Kasai procedure.

Methods

A retrospective analysis was conducted of patients with NBA who underwent the Kasai procedure at our hospital from 2017 to 2021. Patients were categorized into high (GGT > 300 IU/L) and GGT inadequate (GGT ≤ 300 IU/L) groups based on preoperative GGT levels. The influence of GGT levels on NBA prognosis was evaluated by comparing clinical data, age at operation, jaundice normalization, and survival outcomes between the groups.

Results

A total of 74 patients with NBA were included, with 59 in the high GGT group and 15 in the GGT inadequate group. Ages at the time of the Kasai procedure ranged from 31 to 106 days, with a median of 61 days; the average weight was 4.8 ± 1.1 kg. Two years post-procedure, 56 patients (75.7%) survived with their native liver (P < 0.0001). At 3 months post-procedure, alanine aminotransferase (ALT) levels were significantly higher in the GGT inadequate group compared to the high GGT group (3.5 times vs. 2.3 times the upper limit of normal, P = 0.0259). Significant differences in GGT levels persisted 1-month post-procedure (P = 0.0473). Jaundice clearance was significantly higher in the high GTT group (P = 0.0171) after 6 months. Multivariate logistic regression indicated a substantially higher mortality rate in the GGT inadequate group (P = 0.0452), with no significant age difference at operation (P = 0.8449). Preoperative GGT is a valuable predictor for NBA prognosis (area under the curve (AUC) 0.754, 95% confidence interval CI [0.640-0.847], P = 0.001, specificity 91.1%, and sensitivity 61.1%).

Conclusions

High preoperative GGT levels predict better prognosis in patients with NBA undergoing Kasai operation.

Human Liver Organoids to Predict the Outcome of Kasai Portoenterostomy

BACKGROUND

Kasai portoenterostomy (KPE) remains the primary intervention for biliary atresia (BA), but its outcomes are highly variable. Reliable prognostic biomarkers remain elusive, complicating the management and prediction of postoperative progression.

METHOD

Liver biopsies from BA patients taken at and after KPE (post-KPE) were used to generate organoids for RNA-sequencing analysis. Control organoids were derived from non-BA livers. Differential gene expression and enrichment analyses were performed to assess post-KPE transcriptomic changes between native liver survivors (NLS) and patients who eventually became liver transplant recipients (LTR).

RESULTS

Organoid datasets: 70 from liver biopsies at KPE (10 patients), 112 from post-KPE livers (13 livers; 12 patients), and 47 from control livers (9 patients). At KPE, BA organoids displayed mainly hepatocyte expression, a trait notably reduced in control organoids. Similarly, post-KPE organoids from NLS revealed a significant decrease in hepatocyte expression features and an overall increase in cholangiocyte expression features. A similar hepatocyte-to-cholangiocyte expression transition was evidenced in paired liver organoids (at- and post-KPE) generated from an NLS. In contrast, post-KPE organoids from LTR maintained a high level of hepatocyte expression features.

CONCLUSION

Our study demonstrated that an elevated expression of hepatocyte features in KPE organoids may indicate aberrant cholangiocyte development in BA livers. In contrast, a post-KPE hepatocyte-to-cholangiocyte expression transition in NLS may imply effective biliary recovery. The lack of this transition in LTR organoids indicates ongoing disease progression, highlighting the potential for organoid-based transcriptomic profiling to inform KPE success and guide BA management.

LEVEL OF EVIDENCE

Level III.

Predicting and optimising outcome for biliary atresia

Biliary atresia (BA) remains a disease of significant morbidity and mortality world-wide. Early and accurate diagnosis facilitates early intervention and improves outcomes. The gold standard in diagnosing BA is a liver biopsy followed by cholangiography, usually performed intra-operatively. Serum markers, like the aspartate aminotransferase-to-platelet ratio, matrix metalloproteinase-7 and several inflammatory cytokines have been recently investigated as non-invasive alternatives with varying degrees of success. Newer immunohistochemical analysis of liver biopsies, such as the expression of secretin receptors and Ki-67, from infants with BA have improved our understanding of the disease process and has shed a little light in predicting post-operative outcomes. There is little standardisation in the care of BA post operatively, though administration of steroids, prevention and treatment of cholangitis with antibiotics and anti-viral therapy for CMV+ve infants are becoming universally accepted as treatment. Experimental stem cell treatments show promise although remain in the out-of-reach future for now in routine clinical practice. This chapter aims to comprehensively describe recent knowledge on predicting the clinical outcomes of infants with BA, as well as optimising their care post operatively.

Extrahepatic biliary atresia and normal-range serum gamma-glutamyltranspeptidase activity: A case report

An infant with biliary atresia had normal-range ('low') serum gamma-glutamyltranspeptidase (GGT) activity, exceptional because GGT generally is elevated in biliary atresia. Mechanisms underlying low-GGT cholestasis in biliary atresia are not defined, but the phenomenon is associated with worse clinical outcome. Testing in our patient revealed no variants in genes mutated in several disorders also associated with poor prognosis and with low-GGT cholestasis; indeed, at age 14 months she has stable disease with unremarkable biomarker values. Nonetheless, we recommend extended investigations in such patients, including genetic testing, to detect coexistent disorders and to expand understanding of GGT in biliary atresia.

Primary Liver Transplant in Biliary Atresia: The Case for and Against

The role of liver transplantation as a primary procedure in biliary atresia has been argued over for at least 40 years, indeed since the coming of age of safe liver transplantation during the 1980s. Yet, it is not a common option in most series (usually ≤5%) and typically reserved for those with late presentations (arguably >100 days) with established cirrhosis. This review presents the pros and cons of primary liver transplant. The pros are based upon the observation that at best a Kasai portoenterostomy (KPE) is simply palliative in most, and at worse has no effect whatsoever on restoration of bile flow and is therefore pointless. Set against this are the cons: there is a dearth of prognostic tests (clinical, biochemical, or histological) at the time of presentation which may predict inevitable failure; the possibility of long-term native liver survival to adulthood in a proportion (albeit a minority); and the implied increased need for donor organs suitable for infants - a stressor for an already overstressed system. Improving results from KPE in terms of increasing the proportions clearing their jaundice and minimizing the effects of chronic liver fibrosis and cirrhosis would surely limit the siren calls for primary transplants but the key must be better discrimination at presentation with the use of biomarkers (circulatory or histological, individually or together) to enable better decision making.

Biliary atresia

Biliary atresia (BA) is a progressive inflammatory fibrosclerosing disease of the biliary system and a major cause of neonatal cholestasis. It affects 1:5,000-20,000 live births, with the highest incidence in Asia. The pathogenesis is still unknown, but emerging research suggests a role for ciliary dysfunction, redox stress and hypoxia. The study of the underlying mechanisms can be conceptualized along the likely prenatal timing of an initial insult and the distinction between the injury and prenatal and postnatal responses to injury. Although still speculative, these emerging concepts, new diagnostic tools and early diagnosis might enable neoadjuvant therapy (possibly aimed at oxidative stress) before a Kasai portoenterostomy (KPE). This is particularly important, as timely KPE restores bile flow in only 50-75% of patients of whom many subsequently develop cholangitis, portal hypertension and progressive fibrosis; 60-75% of patients require liver transplantation by the age of 18 years. Early diagnosis, multidisciplinary management, centralization of surgery and optimized interventions for complications after KPE lead to better survival. Postoperative corticosteroid use has shown benefits, whereas the role of other adjuvant therapies remains to be evaluated. Continued research to better understand disease mechanisms is necessary to develop innovative treatments, including adjuvant therapies targeting the immune response, regenerative medicine approaches and new clinical tests to improve patient outcomes.

Clinical Characteristics and Prognosis of Biliary Atresia with Low Serum Matrix Metalloproteinase-7 Levels

PURPOSE

Serum matrix metalloproteinase-7 (MMP-7) levels can precisely differentiate biliary atresia (BA) from non-BA cholestasis. However, serum MMP-7 levels of some BA patients were within normal range or slightly elevated. This study aimed to investigate the clinical characteristics and prognosis of biliary atresia with low serum MMP-7 levels.

METHOD

This is a retrospective cohort study. Cases of BA from July 2020 to December 2022 were consecutively enrolled. They were divided into low-MMP-7 group (MMP-7 ≤ 25 ng/ml) and high-MMP-7 group (MMP-7 > 25 ng/ml) according to serum MMP-7 levels preoperatively. The perioperative clinical characteristics, the 3-month and 6-month jaundice clearance rate post-Kasai procedure, and the native liver survival were compared between the two groups.

RESULTS

A total of 329 cases were included in this study, 40 of which were divided into the low-MMP-7 group. Preoperative GGT and direct bilirubin levels in the low-MMP-7 group were significantly lower than those in the high-MMP-7 group (258.6 U/L, interquartile range [IQR]: 160.4411.6 vs. 406.8 IU/L, IQR: 215,655.0, P = 0.0076; 103.8 μmol/L, IQR: 79.0,121.4 vs. 115.3 μmol/L, IQR: 94,138.8, P = 0.0071), while the gender, the day at surgery and preoperative ALT, AST, TBA, total bilirubin levels showed no significant differences (P > 0.05). The 3-month and 6-month jaundice clearance rate post-Kasai procedure in the low-MMP-7 group were lower than those in the high-MMP-7 group (29.73% vs. 53.09%, P = 0.049; 32.14% vs. 54.73%, P = 0.023). The 1-year native liver survival rate was 29.63% for the low-MMP-7 group and 53.02% for the high-MMP-7 group (P = 0.022).

CONCLUSION

Preoperative clinical characteristics were similar between low-MMP-7 group and high-MMP-7 group, while patients with low serum MMP-7 levels showed worse prognosis, indicating that this might be listed as a new clinical subtype of BA which could contribute to designing new treatment strategies for BA in the future.

STUDY TYPE

Cohort Study.

LEVEL OF EVIDENCE

Level II.

Bile duct matrix metalloproteinase-7 expression: a new modality for diagnosis of biliary atresia

Background

Biliary atresia (BA) is an obliterative cholangiopathy of infancy that results in cholestasis and liver fibrosis. This fibrosis is due to an imbalance in extracellular matrix (ECM) breakdown and deposition. The mechanism by which the progressive injury occurs is not fully elucidated. Matrix metalloproteinases (MMPs) are involved in ECM turnover but also have non-ECM-related functions. Matrix metalloproteinase 7 (MMP7) has been suggested as a promising biomarker in diagnosing BA.

Objective

The aim of this study was to assess the hepatic expression of MMP-7 in infants with BA.

Patients and methods

The study was a retrospective-prospective case–control study that included 50 patients who were categorized into two groups, BA group (25 patients) and non-BA cholestatic patients as a control group (25 patients). Liver biochemistry, liver biopsy, histopathology, and immunohistochemical staining for primary antibody MMP-7 were performed for all studied patients.

Results

Bile duct MMP7 expression was significantly higher in infants with BA than in non-BA cholestasis (P = 0.003), While the hepatic MMP-7 intensity did not differ significantly between both groups (P > 0.05). Bile duct expression of MMP-7 had a significant positive correlation with the BA Score (P = 0.017), while hepatic MMP-7 intensity had a significant positive correlation with alanine transaminase levels (P = 0.007) and a significant negative correlation with γ glutamyl transferase in the BA group (P = 0. 038). There was no statistically significant difference among different stages of fibrosis as regards the median of the hepatic MMP-7 intensity score and MMP-7 bile duct expression in infants with BA. There was no statistically significant difference between infants with successful and failed Kasai as regard the hepatic MMP-7 intensity and its bile duct expression.

Conclusion

Bile duct expression of MMP-7 measured by immunohistochemistry is useful for the diagnosis of BA, but it is limited in predicting the stage of liver fibrosis and the outcome of Kasai portoenterostomy (KPE).

A convenient nomogram for predicting early death or liver transplantation after the Kasai procedure in patients with biliary atresia

PURPOSE

Many patients with biliary atresia (BA) after the Kasai procedure (KP) progress to death or require liver transplantation to achieve long-term survival; however, most cases of death/liver transplantation (D/LT) occur in the early period after KP (usually within 1 year). This study was designed to construct a convenient nomogram for predicting early D/LT in patients with BA after KP.

METHODS

A BA cohort was established in May 2017, and up to May 2023, 112 patients with 1-5 years of follow-up were enrolled in the study and randomly (ratio, 3:1) divided into a training cohort for constructing a nomogram (n = 84) and a validation cohort (n = 28) for externally validating the discrimination and calibration. The training cohort was divided into two groups: the early D/LT group (patients who died or had undergone LT within 1 year after KP [n = 35]) and the control group (patients who survived through the native liver more than 1 year after KP [n = 49]). Multivariate logistic regression and stepwise regression were applied to detect variables with the best predictive ability for the construction of the nomogram. The discrimination and calibration of the nomogram were internally and externally validated.

RESULTS

The Kaplan-Meier (K-M) curve showed an actual 1-year native liver transplantation (NLS) rate of 57.1% and an estimated 2-year NLS rate of 55.2%. By multivariate regression and stepwise regression, age at KP, jaundice clearance (JC) speed 1 month after KP, early-onset PC (initial time < 36.5 days) after KP, sex, aspartate aminotransferase-to-platelet ratio index (APRI), and weight at KP were identified as the independent variables with the best ability to predict early D/LT and were used to construct a nomogram. The developed nomogram based on these independent variables showed relatively good discrimination and calibration according to internal and external validation.

CONCLUSION

Most D/LTs were early D/LTs that occurred within 1 year after KP. The established nomogram based on predictors, including sex, weight at the KP, the APRI, age at the KP, JC speed 1 month after the KP, and early PC, may be useful for predicting early D/LT and may be helpful for counseling BA patients about patient prognosis after KP. This study was retrospectively registered at ClinicalTrials.gov (NCT05909033) in June 2023.