Urinary sulfated bile acid analysis for the early detection of biliary atresia in infants

The magnetic resonance imaging and age-adjusted matrix metalloproteinase-7 assist the diagnosis of biliary atresia

BACKGROUND

We investigated the utilities of the liver-to-psoas apparent diffusion coefficient ratios (LTPAR) yielded by diffusion-weighted magnetic resonance imaging (DWMRI) and the age-adjusted serum matrix metalloproteinase-7 (MMP-7) for the diagnosis of biliary atresia (BA) in cholestatic infants.

METHODS

In total, 170 cholestatic infants were recruited, of whom 50 (29.41%) were diagnosed with BA after cholestatic workups. The LTPAR and MMP7 levels were assessed.

RESULTS

The LTPAR was significantly lower in BA infants, and the age-adjusted MMP7 ratio was significantly higher, compared to other cholestatic infants (both p < 0.001). Receiver operating characteristic curve analysis yielded a cutoff > 0.1 ng/mL.day for the age-adjusted MMP-7 ratio, and an LTPAR < 1.01 for the optimal prediction of BA (both p < 0.001). Univariate logistic regression analysis revealed that both an age-adjusted MMP-7 ratio > 0.1 ng/mL.day and an LTPAR < 1.01 were significant predictors of BA among cholestatic infants (odds ratio = 30.98 and 13.28; p < 0.001 and < 0.001, respectively). The significance of the age-adjusted MMP-7 ratio and the LTPAR persisted on multivariate logistic regression analysis after adjusting for sex and the serum gamma-glutamyl transferase level (p < 0.001 and < 0.001, respectively). The negative predictive values (NPVs) for BA were 91.49% and 94.17%, respectively, for the LTPAR and age-adjusted MMP-7 ratio.

CONCLUSION

The age-adjusted MMP-7 ratio and the LTPAR are both significant non-invasive predictors of BA. The consideration of both serum and imaging parameters may enhance BA diagnostic performance in cholestatic infants.

Bile acid profiles in adult patients with biliary atresia who achieve native liver survival after portoenterostomy

Bile acids have received increasing attention as a marker of the long-term prognosis and a potential therapeutic target in patients with biliary atresia, which is a progressive disease of the hepatobiliary system. A detailed analysis of serum and urinary bile acid compositions was conducted to assess the characteristics of bile acid profiles and the correlation between bile acid profiles and liver fibrosis markers in adult patients with biliary atresia who achieved bilirubin normalization. Serum total bile acids and glucuronide-conjugated (glyco- and tauro-) cholic acids (GCA and TCA) and chenodeoxycholic acids (GCDCA and TCDCA) were significantly higher in patients with biliary atresia than in healthy controls, whereas unconjugated CA and CDCA showed no significant difference. There were no significant differences in CA to CDCA ratios and glycine-to-taurine-conjugated ratios. Urinary glycocholic acid 3-sulfate (GCA-3S) was significantly higher in patients with biliary atresia. Serum GCDCA showed a strong positive correlation with Mac-2 binding protein glycosylation isomer (M2BPGi). These results demonstrate that bile acid congestion persists into adulthood in patients with biliary atresia, even after cholestasis has completely improved after Kasai portoenterostomy. These fundamental data on bile acid profiles also suggest the potential value of investigating bile acid profiles in patients with biliary atresia.

Population-based screening methods in biliary atresia: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to investigate tested methods of population-based biliary atresia (BA) screening.

DESIGN

We searched 11 databases between 1 January 1975 and 12 September 2022. Data extraction was independently done by two investigators.

MAIN OUTCOME MEASURES

Our primary outcomes were: sensitivity and specificity of screening method in BA detection, age at Kasai, BA associated morbidity and mortality, cost-effectiveness of screening.

RESULTS

Six methods of BA screening were evaluated: stool colour charts (SCCs), conjugated bilirubin measurements, stool colour saturations (SCSs), measurements of urinary sulfated bile acids (USBAs), assessments of blood spot bile acids and blood carnitine measurements.In a meta-analysis, USBA was the most sensitive and specific, with a pooled sensitivity and specificity of 100.0% (95% CI 2.5% to 100.0%) and 99.5% (95% CI 98.9% to 99.8%) (based on one study). This was followed by conjugated bilirubin measurements: 100.0% (95% CI 0.0% to 100.0%) and 99.3% (95% CI 91.9% to 99.9%), SCS: 100.0% (95% CI 0.00% to 100.0%) and 92.4% (95% CI 83.4% to 96.7%), and SCC: 87.9% (95% CI 80.4% to 92.8%) and 99.9% (95% CI 99.9% to 99.9%).SCC reduced the age of Kasai to ~60 days, compared with 36 days for conjugated bilirubin. Both SCC and conjugated bilirubin improved overall and transplant-free survival. The use of SCC was considerably more cost-effective than conjugated bilirubin measurements.

CONCLUSION

Conjugated bilirubin measurements and SCC are the most researched and demonstrate improved sensitivity and specificity in detecting BA. However, their use is expensive. Further research into conjugated bilirubin measurements, as well as alternative methods of population-based BA screening, is required.

PROSPERO REGISTRATION NUMBER

CRD42021235133.

The value of blood and urine metabolomics in differential diagnosis of cholestasis in infants

Background

Early detection of biliary atresia (BA) is a great challenge providing the main useful way to improve its clinical consequence. Promising metabolomics provides an effective method for determining innovative biomarkers and biochemical ways for improving early diagnosis. This study aimed to determine the benefit of serum and urinary potential bile acid metabolites in the differentiation of BA from non-biliary atresia (non-BA) cases using tandem mass spectrometry (MS/MS). Fourteen bile acids metabolites were measured quantitively by MS/MS in serum and urine samples from 102 cholestatic infants and 102 control infants, in addition to the assay of the total serum bile acid enzymatically.

Results

After the diagnostic clinical and laboratory workflow, cholestatic infants were divided into BA (37 infants) and non-BA (65 infants) subgroups. Remarkably on analysis of serum individual bile acid concentrations, there were significant differences between cholestatic BA and non-BA regarding serum (glycocenodeoxycholic acid (GCDCA), taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), and GCDCA/chenodeoxycholic acid (CDCA) ratio) (p < 0.001, for all), while there was no significant difference between the two groups regarding serum level of (cholic acid (CA), glycocholic (GCA), or TCDCA/CDCA ratio). There were no significant differences in either the urinary individual bile acids or urinary primary bile acids (conjugated or unconjugated) between BA and non-BA. Further principal component analysis (PCA) analysis was done and receiver operating characteristic (ROC) analysis was performed using score plots of the positive factors in the first two principal components PC1 (CA, GCA, GCDCA, TCA, TCDCA) and PC2 (CA, CDCA, lithocholic (LCA), ursodeoxycholic acid (UDCA)) for establishing the differences between the two diseased groups and revealed that the area under the curve (AUC) for PC1 was (0.770) higher than AUC for PC2 (0.583) indicating that the positive components of PC1 may be potential biomarkers for differentiation between the two cholestatic groups.

Conclusions

Metabolomics of serum bile acid levels using tandem mass spectrometry might change the paradigm differentiating BA from non-BA saving patients from unnecessary invasive procedures.

Congenital aflatoxicosis, mal-detoxification genomics & ontogeny trigger immune-mediated Kotb disease biliary atresia variant: SANRA compliant review

Biliary atresia (BA) is the most common indication for pediatric liver transplantation. We describe The BA variant: Kotb disease. Liver tissue in the Kotb disease BA is massively damaged by congenital aflatoxicosis resulting in inflammation, adhesions, fibrosis, bile duct proliferation, scarring, cholestasis, focal syncytial giant cell transformation, and typical immune response involving infiltration by CD4+, CD8+, CD68+, CD14+, neutrophil infiltration, neutrophil elastase spill, heavy loads of aflatoxin B1, accelerated cirrhosis, disruption of p53 and GSTPi, and have null glutathione S transferase M1 (GSTM1). All their mothers are heterozygous for GSTM1. This inability to detoxify aflatoxicosis results in progressive inflammatory adhesions and obliterative cholangiopathy early in life. The typical disruption of both p53 and GSTPi causes loss of fidelity of hepatic regeneration. Hence, regeneration in Kotb disease BA typically promotes accelerated cirrhosis. The immune response in Kotb disease BA is for damage control and initiation of regeneration, yet, this friendly fire incurs massive structural collateral damage. The Kotb disease BA is about actual ongoing hepatic entrapment of aflatoxins with lack of ability of safe disposal due to child detoxification-genomics disarray. The Kotb disease BA is a product of the interaction of persistent congenital aflatoxicosis, genetic lack of GSTM1 detoxification, ontogenically impaired activity of other hepatic detoxification, massive neutrophil-elastase, immune-induced damage, and disturbed regeneration. Ante-natal and neonatal screening for aflatoxicosis, avoiding cord milking, and stringent control of aflatoxicosis content of human, poultry and live-stock feeds might prove effective for prevention, prompt diagnosis and management based on our recent understanding of its patho-genomics.

A Japanese prospective multicenter study of urinary oxysterols in biliary atresia

Diagnosis of biliary atresia (BA) can involve uncertainties. In the present prospective multicenter study, we considered whether urinary oxysterols represent a useful marker for diagnosis of BA in Japanese children. Subjects under 6 months old at 7 pediatric centers in Japan were prospectively enrolled, including patients with cholestasis and healthy controls (HC) without liver disease. Patients with cholestasis constituted 2 groups representing BA patients and others with cholestasis from other causes (non-BA). We quantitatively analyzed 7 oxysterols including 4β-, 20(S)-, 22(S)-, 22(R)-, 24(S)-, 25-, and 27-hydroxycholesterol by liquid chromatography/electrospray ionization-tandem mass spectrometry. Enrolled subjects included 14 with BA (median age 68 days; range 26-170) and 10 non-BA cholestatic controls (59; 14-162), as well as 10 HC (57; 25-120). Total urinary oxysterols were significantly greater in BA (median, 153.0 μmol/mol creatinine; range 24.1-486.7; P < 0.001) and non-BA (36.2; 5.8-411.3; P < 0.05) than in HC (2.7; 0.8-7.6). In patients with BA, urinary 27-hydroxycholesterol (3.61; 0.42-11.09; P < 0.01) was significantly greater than in non-BA (0.71; 0-5.62). In receiver operating characteristic (ROC) curve analysis for distinguishing BA from non-BA, the area under the ROC curve for urinary 27-hydroxycholesterol was 0.83. In conclusion, this first report of urinary oxysterol analysis in patients with BA indicated that 27-hydroxycholesterol may be a useful marker for distinguishing BA from other causes of neonatal cholestasis.

Targeted metabolomics of sulfated bile acids in urine for the diagnosis and grading of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is related to cholestatic disorder in pregnancy. Total urinary sulfated bile acids (SBAs) were found increased in ICP. We distinguished the metabolic profiling of urinary SBAs in ICP to find potential biomarkers for the diagnosis and grading of ICP. The targeted metabolomics based on high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to analyze urinary SBAs profiling in mild and severe ICP cases, as well as healthy controls. 16 kinds of urinary SBAs were determined by HPLC-MS/MS. Sulfated dihydroxy glycine bile acid (di-GBA-S), glycine cholic acid 3-sulfate (GCA-3S), sulfated dihydroxy taurine bile acid (di-TBA-S) and taurine cholic acid 3-sulfate (TCA-3S) increased significantly in ICP group compared with the control group. Seven kinds of SBAs were significantly different (p < 0.05) between the ICP group and the control group, with the variable importance in the projection (VIP) value more than one by the orthogonal partial least squares discriminant analysis (OPLS-DA). GCA-3S was well-suited to be used as the biomarker for the diagnosis of ICP with the sensitivity of 100% and specificity of 95.5%. A multi-variable logistic regression containing GCA-3S and di-GBA-S-1 was constructed to distinguish severe ICP from mild ICP, with the sensitivity of 94.4% and specificity of 100%. The developed HPLC-MS/MS method is suitable for the measurement of urinary SBAs profiling. Moreover, the urinary SBAs in the metabolomic profiling have the potential to be used as non-intrusive biomarkers for the diagnosis and grading of ICP.

Screening for biliary atresia

Early diagnosis followed by proper KP is essential for the improvement of long-term prognosis for patients with BA. It is increasingly accepted that KP at ≤ 30 days of age significantly improves native liver survival rate. Published analyses in English and Japanese indicate that screening by SCC and DB/CB is potentially feasible. Screening with SCC has been implemented in Tochigi Prefecture, Japan, since 1994. The concept of SCC was introduced from Japan to Taiwan and resulted in nationwide screening with SCC for the first time in Taiwan in 2004, followed by Japan in 2012. Home-based screening using SCC is easy and cost-effective; however, it may cause some difficulties for families in case of stools with intermediate colors. Laboratory-based screening using DB/CB may detect the suspected cases earlier, resulting in an increase in the number of patients with BA who undergo KP at ≤ 30 days of age; however, the recall rate is 1% and may be beyond an acceptable range. Further studies are needed to assess the feasibility and cost-effectiveness of both home-based (SCC) and laboratory-based (DB/CB) screening for BA.

Expression, purification and functional characterization of a novel 3α-hydroxysteroid dehydrogenase from Pseudomonas aeruginosa

3α-Hydroxysteroid dehydrogenase (3α-HSD) catalyzes the oxidation of the 3-hydroxyl group of steroids. The enzymatic conversion is a critical step in the enzymatic assay of urinary sulfated bile acids (SBAs), which is a valuable diagnosis index of hepatobiliary diseases. However, the source of 3α-HSD for clinical applications is limited. In this study, an open reading frame (ORF) encoding a novel 3α-HSD was successfully cloned from Pseudomonas aeruginosa and expressed in Escherichia coli BL21 (DE3). The recombinant protein was purified by immobilized metal ion affinity chromatography. Enzyme characterization studies revealed that the protein has 3α-HSD activity and the Km value for sodium cholate is 1.06 mmol L(-1). More than 60% relative enzyme activity was observed in a wide range of pH and temperature, with an optimum pH at 8.0 and an optimum temperature at 30°C. The enzyme's good thermostability under 40°C would be favorable in clinical applications. Ion interference experiments indicated that Zn(2+) was an activating cofactor which increased the enzyme activity 1.75-fold. With the favorable characteristics mentioned above, the new 3α-HSD is a promising enzyme for clinical applications. More importantly, the present work is the first report on a 3α-HSD from P. aeruginosa.

Effects of age at Kasai portoenterostomy on the surgical outcome: a review of the literature

The efficacy of early Kasai portoenterostomy has been repeatedly reported. However, the optimal age for performing this procedure remains controversial. This article reviews the literature on the age of patients at the time of Kasai portoenterostomy and its utility as a prognostic indicator. The age at the time of surgery is a known predictor of outcome; however, its exact predictive value in this context is unclear. Multicenter studies involving large volumes of data have tended to show advantages of early Kasai portoenterostomy, and there is no clear evidence to recommend any delay in the timing of surgery. At present, a reasonable strategy would be to perform a Kasai portoenterostomy as early as possible. The stool color card system has recently been implemented in Japan as part of a nationwide screening program, and it is expected to work well based on the early reports. However, efforts to identify an optimal screening system for ensuring the earliest diagnosis of biliary atresia should continue. An early diagnosis of biliary atresia is difficult, and global efforts are required to improve the early diagnosis rates.

Elevated bile acids in newborns with Biliary Atresia (BA)

Biliary Atresia (BA), a result from inflammatory destruction of the intrahepatic and extrahepatic bile ducts, is a severe hepatobiliary disorder unique to infancy. Early diagnosis and Kasai operation greatly improve the outcome of BA patients, which encourages the development of early screening methods. Using HPLC coupled tandem mass spectrometry, we detected primary bile acids content in dried blood spots obtained from 8 BA infants, 17 neonatal jaundice and 292 comparison infants at 3–4 days of life. Taurocholate (TC) was significantly elevated in biliary atresia infants (0.98±0.62 µmol/L) compared to neonatal jaundice (0.47±0.30 µmol/L) and comparison infants (0.43±0.40 µmol/L), with p = 0.0231 and p = 0.0016 respectively. The area under receiver operating characteristic (ROC) curve for TC to discriminate BA and comparison infants was 0.82 (95% confidence interval: 0.72–0.92). A cutoff of 0.63 µmol/L produced a sensitivity of 79.1% and specificity of 62.5%. The concentrations of total bile acids were also raised significantly in BA compared to comparison infants (6.62±3.89 µmol/L vs 3.81±3.06 µmol/L, p = 0.0162), with the area under ROC curve of 0.75 (95% confidence interval: 0.61–0.89). No significant difference was found between the bile acids of neonatal jaundice and that of comparison infants. The early increase of bile acids indicates the presentation of BA in the immediate newborn period and the possibility of TC as newborn screening marker.

Early detection of biliary atresia: past, present & future

The age threshold at the time of Kasai hepatic portoenterostomy associated with a prognosis of biliary atresia (BA) is becoming clearer as 10-year native liver survival data become more frequent in the recent literature, whereas the age at diagnosis has not dramatically decreased during the last 3 decades. A stool color card screening implemented in 1994 in Japan is now expanding worldwide. However, the contribution of this modality will probably be limited because of the nature of this disease, for example, 'progressive obliterative cholangiopathy'. A cholic stool was actually observed only in 50% before diagnosis according to the Japanese BA Registry data. Thus, color card screening does not appear to be instrumental in detecting patients with BA early enough before 1 month of age. A highly sensitive, adequately specific, noninvasive and quantitative method may be expensive, but the overall cost would be lower than that of liver transplant.