Search

Background: Pediatric cholestatic liver diseases (Ped-CLD) comprise many ultrarare disorders with a genetic basis. Pharmacologic therapy for severe cases of Ped-CLD has not been established. Species differences in bile acid (BA) metabolism between humans and rodents contribute to the lack of phenocopy of patients with Ped-CLD in rodents and hinder the development of therapeutic strategies. We aimed to establish an efficient in vivo system to understand BA-related pathogenesis, such as Ped-CLD., Methods: We generated mice that express spCas9 specifically in the liver (L-Cas9Tg/Tg [liver-specific Cas9Tg/Tg] mice) and designed recombinant adeno-associated virus serotype 8 encoding small-guide RNA (AAV8 sgRNA) targeting Abcc2, Abcb11, and Cyp2c70. In humans, ABCC2 and ABCB11 deficiencies cause constitutional hyperbilirubinemia and most severe Ped-CLD, respectively. Cyp2c70 encodes an enzyme responsible for the rodent-specific BA profile. Six-week-old L-Cas9Tg/Tg mice were injected with this AAV8 sgRNA and subjected to biochemical and histological analysis., Results: Fourteen days after the injection with AAV8 sgRNA targeting Abcc2, L-Cas9Tg/Tg mice exhibited jaundice and phenocopied patients with ABCC2 deficiency. L-Cas9Tg/Tg mice injected with AAV8 sgRNA targeting Abcb11 showed hepatomegaly and cholestasis without histological evidence of liver injury. Compared to Abcb11 alone, simultaneous injection of AAV8 sgRNA for Abcb11 and Cyp2c70 humanized the BA profile and caused higher transaminase levels and parenchymal necrosis, resembling phenotypes with ABCB11 deficiency., Conclusions: This study provides proof of concept for efficient in vivo assessment of cholestasis-related genes in humanized bile acid profiles. Our platform offers a more time- and cost-effective alternative to conventional genetically engineered mice, increasing our understanding of BA-related pathogenesis such as Ped-CLD and expanding the potential for translational research., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Association for the Study of Liver Diseases.)

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., (© 2024. The Author(s).)

Bile acids are a category of steroids biosynthesized from cholesterol in the liver. Inborn errors of their metabolism are inherited in an autosomal recessive manner, resulting in enzyme deficiencies affecting the bile acid biosynthetic pathway. These defects in the pathway cause accumulation of unusual bile acids or bile alcohols. Unusual bile acids are highly cytotoxic, causing injury to the liver. These unusual bile acids damage hepatocytes, resulting in cholestatic liver injury beginning in infancy. Except for cerebrotendinous xanthomatosis and some secondary defects, various inborn errors of bile acid metabolism (IEBAM) have been reported from Japan, affecting eight patients including three with 3β-hydroxy-Δ 5 -C 27 -steroid dehydrogenase/isomerase deficiency, three with Δ 4 -3-oxosteroid 5β-reductase deficiency, one with oxysterol 7α-hydroxylase deficiency, and one with bile acid-CoA: amino acid N-acyltransferase deficiency. Distinctive laboratory findings in patients with 3β-hydroxy-Δ 5 -C 27 -steroid dehydrogenase/isomerase deficiency, Δ 4 -3-oxosteroid 5β-reductase deficiency, and oxysterol 7α-hydroxylase deficiency include normal serum γ-glutamyltransferase and total bile acids concentrations despite presence of cholestasis (elevated serum direct bilirubin) from infancy. Pediatricians and pediatric surgeons who suspect a case of IEBAM should obtain urinary and serum bile acid analyses using gas or liquid chromatography-mass spectrometry as well as genetic analyses. Available treatments include oral cholic acid, chenodeoxycholic acid, glycocholic acid, and ursodeoxycholic acid; fat-soluble vitamin supplementation; and liver transplantation. Early diagnosis and treatment can offer a good outcome., (© 2023 Japan Pediatric Society.)

Background: In pediatric patients with cholestasis of unknown cause, inborn errors of bile acid (BA) synthesis (IEBAS) may be considered. For the initial screening for IEBAS, clarification of the urine BA profile is essential. The transportation of urine in a frozen state via air delivery, however, is laborious and costly. This study assessed the feasibility of using dried urine spots (DUS) to establish a more convenient and affordable method of IEBAS screening., Methods: We created DUS using urine samples from patients with 3β-hydroxy-Δ5-C27-steroid dehydrogenase/isomerase deficiency (3β-HSD) and Δ4-3-oxo-steroid 5β-reductase deficiency as standard preparations. We started accepting DUS specimens by regular mail., Results: The ratio of unusual to usual BA is essential for the initial detection of IEBAS, and the recovery rates of abnormal BA were acceptable. The recovery rate of Δ4-BA on day 28 decreased to 31.8% at 25°C, and to 19.6% at 37°C. Therefore, the sending of DUS should be avoided under conditions of high temperature. Of a total of 49 children with cholestasis, eight new patients were diagnosed with IEBAS using this screening method., Conclusion: The mailing screening system is expected to facilitate the shipment, from regions outside of Japan, of samples for IEBAS screening., (© 2019 Japan Pediatric Society.)

Background and Aims: In two Japanese infants with neonatal cholestasis, 3-oxo-Δ(4)-steroid 5β-reductase deficiency was diagnosed based on mutations of the SRD5B1 gene. Unusual bile acids such as elevated 3-oxo-Δ(4) bile acids were detected in their serum and urine by gas chromatography-mass spectrometry. We studied effects of oral chenodeoxycholic acid treatment., Patients and Methods: SRD5B1 gene analysis used peripheral lymphocyte genomic DNA. Diagnosis and treatment of these two patients were investigated retrospectively and prospectively investigated., Results: With respect to SRD5B1, one patient was heterozygous (R266Q, a novel mutation) while the other was a compound heterozygote (G223E/R261C). Chenodeoxycholic acid treatment was effective in improving liver function and decreasing unusual bile acids such as 7α-hydroxy- and 7α,12α-dihydroxy-3-oxo-4-cholen-24-oic acids in serum and urine., Conclusion: Primary bile acid treatment using chenodeoxycholic acid was effective for these patients treated in early infancy before the late stage of chronic cholestatic liver dysfunction.

A method for the determination of conjugated and unconjugated 3β-hydroxy-Δ5-bile acids and related bile acids in human urine and serum has been developed using high-performance liquid chromatography electrospray ionization-tandem mass spectrometry. Calibration curves for the bile acids were linear over the range of 10 2000 pmol/mL, and the detection limit was less than 4 pmol/mL for all bile acids using selected reaction monitoring analysis. The bile acids in urine and serum samples from two patients with severe cholestatic liver disease were measured by this analytical method. Glycine-conjugated 3β-hydroxy-Δ5-bile acid 3-sulfates were determined to be the major bile acids in the urine and serum from patients with a 3β-hydroxy-Δ5-C27-steriod dehydrogenase/isomerase deficiency or dysfunction.

Background: Inborn errors of bile acid synthesis are rare genetic disorders that can present with cholestatic liver disease. Recently we encountered 3 infants with neonatal cholestasis and excessive 3β-monohydroxy-Δ⁵-C₂₄ bile acids in serum and urine. We investigated whether identification of 3β-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol in serum and urine of cholestatic patients is necessary for diagnosis of primary oxysterol 7α-hydroxylase deficiency., Methods: These 3 patients initially led us to suspected oxysterol 7α-hydroxylase deficiency. However, sequence analysis of genomic DNA resulted in diagnosis of 2 patients with oxysterol 7α-hydroxylase deficiency and 1 patient with 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase/isomerase deficiency. We examined identification of 3β-hydroxy-5-cholestenoic acid and 27-hydroxycholesterol by gas chromatography-mass spectrometry after diagnosis., Results: Interestingly, we detected a peak for 3β-hydroxy-5-cholestenoic acid in serum and 27-hydroxycholesterol of the neutral sterol in urine from 2 patients who were diagnosed with primary oxysterol 7α-hydroxylase deficiency., Conclusion: In evaluating infants with cholestasis and excessive 3β-monohydroxy-Δ⁵-C₂₄ bile acids in infancy, one needs to conduct C₂₄ bile acid analysis serially. Results can guide performance and interpretation of genomic DNA analysis. Moreover, identification of 3β-hydroxy-5-cholestenoic acid in serum and 27-hydroxycholesterol in urine is highly important for diagnosis of oxysterol 7α-hydroxylase deficiency as is genomic DNA analysis., (Copyright © 2012 Elsevier B.V. All rights reserved.)

We report definitive diagnosis and effective chenodeoxycholic acid (CDCA) treatment of two Japanese children with 3[beta]-hydroxy-[DELTA]5-C27-steroid dehydrogenase/isomerase deficiency. Findings of cholestasis with normal serum [gamma]-glutamyltransferase activity and total bile acid concentration indicated the need for definitive bile acid analysis. Large amounts of 3[beta]-hydroxy-[DELTA]5 bile acids were detected by gas chromatography-mass spectrometry. HSD3B7 gene analysis using peripheral lymphocyte genomic DNA from the patients and their parents identified four novel mutations of the HSD3B7 gene in the patients. One had a homozygous mutation, 314delA; the other had compound heterozygous mutations: V132F, T149I, and 973_974insCCTGC. Interestingly, the second patient's mother had V132F and T149I mutations in one allele. Excessive 3[beta]-hydroxy-[DELTA]5-bile acids such as 3[beta],7[alpha]-dihydroxy- and 3[beta],7[alpha],12[alpha]-trihydroxy-5-cholenoic acids were detected in the first patient's urine; the second patient's urine contained large amounts of 3[beta]-hydroxy-5-cholenoic acid. Liver dysfunction in both patients decreased with ursodeoxycholic acid treatment, but unusual bile acids were still detected. Normalization of the patients' liver function and improvement of bile acid profiles occurred with CDCA treatment. Thus, we found mutations in the HSD3B7 gene accounting for autosomal recessive neonatal cholestasis caused by 3[beta]-hydroxy-[DELTA]5-C27-steroid dehydrogenase/isomerase deficiency. Early neonatal diagnosis permits initiation of CDCA treatment at this critical time, before the late cholestatic stage.

Background: Some patients with cholestasis of unknown cause may have inborn errors of bile acid metabolism (IEBAM) thus causing abnormalities of bile acid biosynthesis. Although seven types of bile acid synthetic defects have thus far been reported for this disorder, no detailed information on its incidence and so on in Japan is yet available. In order to elucidate the current status of IEBAM in Japan, in July 1996 a diagnostic determination system was established for high-risk screening for IEBAM., Methods: Urinary bile acids were analyzed on gas chromatography-mass spectrometry (GC-MS) and quantitative analysis was done using selected ion monitoring (SIM)., Results and Conclusions: In a total of 576 samples analyzed over the 10 year period prior to June 2005, 159 patients were found with cholestasis of unknown etiology. Of these patients, 10 (6.3%) were found to have IEBAM by this system, while 91 (61.1%) had cholestasis without a definitive diagnosis. This diagnostic determination system with GC-MS of urinary bile acids is therefore considered useful for detecting IEBAM.

We report a premature infant with severe hypoglycemia (serum glucose: 6 mg/dl) and cholestasis (serum total bile acids: 211.55 mumol/L) caused by hypoplasia of the interlobular bile ducts. This patient had developed intracranial hemorrhage and sepsis while undergoing treatment for hypoglycemia. As a result of endocrine evaluation, we made a diagnosis of idiopathic panhypopituitarism, congenital absence or hypoplasia of the pituitary gland. Moreover, we found abnormal bile acid profiles: The ratio of cholic acid to chenodeoxycholic acid was abnormally low in serum (0.04) and in biliary bile (0.33). However, 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestan-26-oic acid and bile alcohols were not detected. We therefore suspected that the severe cholestasis and abnormal bile acid profiles in the serum and biliary bile in this patient were related to physiologic immaturity of the enterohepatic circulation of bile acids and immaturity of hepatic 12 alpha-hydroxylation.

Serum concentrations of nonglucuronidated-nonsulfated, glucuronidated, and sulfated bile acids in 9 control children and 16 children with cholestasis were quantitated by mass fragmentography. Total bile acid levels in control children were 19.55 +/- 2.78 mumol/liter (mean +/- SEM), and glucuronidated and sulfated bile acids comprised 2.6 +/- 0.5 and 17 +/- 3.1%, respectively. In 9 patients with congenital biliary atrasia, total bile acid levels were 167.34 +/- 11.18 mumole/liter of which 2.1 +/- 0.3% were glucuronidated and 15 +/- 1.4% were sulfated. Lithocholic and 3 beta-hydroxy-5-cholenoic acids, which have hepatotoxic effects, were presented in only small amounts in cholestatic children, and they were almost all glucuronidated or sulfated. The percentages of glucuronidated bile acids in control and cholestatic children were lower than in healthy and cholestatic adults, which may be explained by the lower activity of UDP-glucuronyltransferase in neonatal liver.