Bile Acid Synthesis Disorders in Arabs: A 10-year Screening Study

EASL Clinical Practice Guidelines on genetic cholestatic liver diseases

Genetic cholestatic liver diseases are caused by (often rare) mutations in a multitude of different genes. While these diseases differ in pathobiology, clinical presentation and prognosis, they do have several commonalities due to their cholestatic nature. These Clinical Practice Guidelines (CPGs) offer a general approach to genetic testing and management of cholestatic pruritus, while exploring diagnostic and treatment approaches for a subset of genetic cholestatic liver diseases in depth. An expert panel appointed by the European Association for the Study of the Liver has created recommendations regarding diagnosis and treatment, based on the best evidence currently available in the fields of paediatric and adult hepatology, as well as genetics. The management of these diseases generally takes place in a tertiary referral centre, in order to provide up-to-date approaches and expertise. These CPGs are intended to support hepatologists (for paediatric and adult patients), residents and other healthcare professionals involved in the management of these patients with concrete recommendations based on currently available evidence or, if not available, on expert opinion.

Clinical and laboratory features of biliary atresia and patterns of management practices: Saudi national study (2000-2018)

BACKGROUND

We utilized the data from the Saudi national biliary atresia (BA) study (2000-2018) to describe the clinical, biochemical, imaging, and histopathological features of BA and the perioperative clinical practices among local pediatric gastroenterologists.

METHODS

This is a retrospective, multicenter, nationwide study that included 10 tertiary care governmental hospitals including the four liver transplant (LT) centers in different regions across Saudi Arabia.

RESULTS

BA was diagnosed in 204 infants (106 females; 10% preterm). The median age at referral was 65 days. Congenital anomalies were present in 68 patients (33%); 22 were splenic malformation (10.8%). The medians of laboratory investigations were total bilirubin (189 μmol/l), direct bilirubin (139 μmol/l), ALT (164 u/l), and GGT (472 u/l). The level of serum GGT was normal in 26 cases (12.7%). The ultrasound findings included hypoplastic or atrophic gall bladder (GB) (65%), normal GB (30%), and cord sign (5%). A HIDA scan was performed in 99 cases (48.52%). Magnetic resonance cholangiopancreatography (MRCP) was performed in 27 cases (13%). A total of 179 liver biopsies (88%) were obtained. The most common histopathologic findings were bile duct proliferation (92%), canalicular cholestasis (96%), bile plugs (84%), and portal fibrosis (95%). Cholangiography was performed in 139 cases (68%): operative in 122 (60%) and percutaneous in 17 (8%). A total of 143 children (70%) underwent Kasai portoenterostomy (KPE) at a median age of 70 days. After KPE, steroid was used in 37% of the cases and 100 cases (70%) were prescribed prophylactic antibiotics for variable duration (ranging between 3 and 12 months).

CONCLUSION

Our data show marked variation in the diagnostic evaluation and perioperative management of BA cases among the different tertiary centers. There is a need to establish a national BA registry in Saudi Arabia aiming to standardize pre- and postoperative clinical practices. Additionally, normal serum GGT level, normal GB size on ultrasound, and being a premature baby should not preclude the diagnostic workup for BA.

∆4-3-oxo-5β-reductase deficiency: favorable outcome in 16 patients treated with cholic acid

BACKGROUND

Oral cholic acid therapy is an effective therapy in children with primary bile acid synthesis deficiencies. Most reported patients with this treatment have 3β-hydroxy-Δ5-C27-steroid oxidoreductase deficiency. The aim of the study was the evaluation of cholic acid therapy in a cohort of patients with the rarer Δ4-3-oxosteroid 5β-reductase (Δ4-3-oxo-R) deficiency.

METHODS

Sixteen patients with Δ4-3-oxo-R deficiency confirmed by AKR1D1 gene sequencing who received oral cholic acid were retrospectively analyzed.

RESULTS

First symptoms were reported early in life (median 2 months of age), with 14 and 3 patients having cholestatic jaundice and severe bleeding respectively. Fifteen patients received ursodeoxycholic acid before diagnosis, with partial improvement in 8 patients. Four patients had liver failure at the time of cholic acid initiation. All 16 patients received cholic acid from a median age of 8.1 months (range 3.1-159) and serum liver tests normalized in all within 6-12 months of treatment. After a median cholic acid therapy of 4.5 years (range 1.1-24), all patients were alive with their native liver. Median daily cholic acid dose at last follow-up was 8.3 mg/kg of body weight. All patients, but one, had normal physical examination and all had normal serum liver tests. Fibrosis, evaluated using liver biopsy (n = 4) or liver elastography (n = 9), had stabilized or improved. Cholic acid therapy enabled a 12-fold decrease of 3-oxo-∆4 derivatives in urine. Patients had normal growth and quality of life. The treatment was well tolerated without serious adverse events and signs of hepatotoxicity.

CONCLUSIONS

Oral cholic acid therapy is a safe and effective treatment for patients with Δ4-3-oxo-R deficiency.

Dried blood spot-based newborn screening for bile acid synthesis disorders, Zellweger spectrum disorder, and Niemann-Pick type C1 by detection of bile acid metabolites

OBJECTIVE

To examine whether it is possible to screen for bile acid synthesis disorders (BASDs) including peroxisome biogenesis disorder 1a (PBD1A) and Niemann-Pick type C1 (NPC1) at the time of newborn mass screening by measuring the intermediary metabolites of bile acid (BA) synthesis.

METHODS

Patients with 3β-hydroxy-ΔSuchy et al. (2021)5-C27-steroid dehydrogenase/isomerase (HSD3B7) deficiency (n = 2), 3-oxo-ΔPandak and Kakiyama (n.d.)4-steroid 5β-reductase (SRD5B1) deficiency (n = 1), oxysterol 7α-hydroxylase (CYP7B1) deficiency (n = 1), PBD1A (n = 1), and NPC1 (n = 2) with available dried blood spot (DBS) samples collected in the neonatal period were included. DBSs from healthy neonates at 4 days of age (n = 1055) were also collected for the control. Disease specific BAs were measured by newly optimized liquid chromatography-tandem mass spectrometry with short run cycle (5-min/run). The results were validated by comparing with those obtained by the conventional condition with longer run cycle (76-min/run).

RESULTS

In healthy specimens, taurocholic acid and cholic acid were the two major BAs which constituted approximately 80% in the measured BAs. The disease marker BAs presented <10%. In BASDs, the following BAs were determined for the disease specific markers: Glyco/tauro 3β,7α,12α-trihydroxy-5-cholenoic acid 3-sulfate for HSD3B7 deficiency (>70%); glyco/tauro 7α,12α-dihydroxy-3-oxo-4-cholenoic acid for SRD5B1 deficiency (54%); tauro 3β-hydroxy-5-cholenoic acid 3-sulfate for CYP7B1 deficiency (94%); 3α,7α,12α-trihydroxy-5β-cholestanoic acid for PBD1A (78%); and tauro 3β,7β-dihydroxy-5-cholenoic acid 3-sulfate for NPC1 (26%). *The % in the parenthesis indicates the portion found in the patient's specimen.

CONCLUSIONS

Early postnatal screening for BASDs, PBD1A and NPC1 is feasible with the described DBS-based method by measuring disease specific BAs. The present method is a quick and affordable test for screening for these inherited diseases.

A Current Understanding of Bile Acids in Chronic Liver Disease

Chronic liver disease (CLD) is one of the leading causes of disability-adjusted life years in many countries. A recent understanding of nuclear bile acid receptor pathways has increased focus on the impact of crosstalk between the gut, bile acids, and liver on liver pathology. While conventionally used in cholestatic disorders and to dissolve gallstones, the discovery of bile acids' influence on the gut microbiome and human metabolism offers a unique potential for their utility in early and advanced liver diseases because of diverse etiologies. Based on these findings, preclinical studies using bile acid-based molecules have shown encouraging results at addressing liver inflammation and fibrosis. Emerging data also suggest that bile acid profiles change distinctively across various causes of liver disease. We summarize the current knowledge and evidence related to bile acids in health and disease and discuss culminated and ongoing therapeutic trials of bile acid derivatives in CLD. In the near future, further evidence in this area might help clinicians better detect and manage liver diseases.

Bile Acid Synthesis Disorders in Japan: Long-Term Outcome and Chenodeoxycholic Acid Treatment

BACKGROUND

We encountered 7 Japanese patients with bile acid synthesis disorders (BASD) including 3β-hydroxy-Δ⁵-C₂₇-steroid dehydrogenase/isomerase (3β-HSD) deficiency (n = 3), Δ⁴-3-oxosteroid 5β-reductase (5β-reductase) deficiency (n = 3), and oxysterol 7α-hydroxylase deficiency (n = 1) over 21 years between 1996 and 2017.

AIM

We aimed to clarify long-term outcome in the 7 patients with BASD as well as long-term efficacy of chenodeoxycholic acid (CDCA) treatment in the 5 patients with 3β-HSD deficiency or 5β-reductase deficiency.

METHODS

Diagnoses were made from bile acid and genetic analyses. Bile acid analysis in serum and urine was performed using gas chromatography-mass spectrometry. Clinical and laboratory findings and bile acid profiles at diagnosis and most recent visit were retrospectively obtained from medical records. Long-term outcome included follow-up duration, treatments, growth, education/employment, complications of treatment, and other problems.

RESULTS

Medians with ranges of current patient ages and duration of CDCA treatment are 10 years (8 to 43) and 10 years (8 to 21), respectively. All 7 patients, who had homozygous or compound heterozygous mutations in the HSD3B7, SRD5B1, or CYP7B1 gene, are currently in good health without liver dysfunction. In the 5 patients with CDCA treatment, hepatic function gradually improved following initiation. No adverse effects were noted.

CONCLUSIONS

We concluded that CDCA treatment is effective in 3β-HSD deficiency and 5β-reductase deficiency, as cholic acid has been in other countries. BASD carry a good prognosis following early diagnosis and initiation of long-term CDCA treatment.

Genetic spectrum and clinical characteristics of 3β-hydroxy-Δ5-C27-steroid oxidoreductase (HSD3B7) deficiency in China

BACKGROUND

Biallelic variants in HSD3B7 cause 3β-hydroxy-Δ5-C27-steroid oxidoreductase (HSD3B7) deficiency, a life-threatening but treatable liver disease. The goal of this study was to obtain detailed information on the correlation between the genotype and phenotype of HSD3B7 deficiency and to report on responses to primary bile acid therapy.

METHODS

The medical records of a cohort of 39 unrelated patients with genetically and biochemically confirmed HSD3B7 deficiency were examined to determine whether there exist genotype-phenotype relationships in this bile acid synthesis disorder.

RESULTS

In all, 34 of the 44 variants identified in HSD3B7 were novel. A total of 32 patients presented early with neonatal cholestasis, and 7 presented after 1-year of age with liver failure (n = 1), liver cirrhosis (n = 3), cholestasis (n = 1), renal cysts and abnormal liver biochemistries (n = 1), and coagulopathy from vitamin K1 deficiency and abnormal liver biochemistries (n = 1). Renal lesions, including renal cysts, renal stones, calcium deposition and renal enlargement were observed in 10 of 35 patients. Thirty-three patients were treated with oral chenodeoxycholic acid (CDCA) resulting in normalization of liver biochemistries in 24, while 2 showed a significant clinical improvement, and 7 underwent liver transplantation or died. Remarkably, renal lesions in 6 patients resolved after CDCA treatment, or liver transplantation. There were no significant correlations between genotype and clinical outcomes.

CONCLUSIONS

In what is the largest cohort of patients with HSD3B7 deficiency thus far studied, renal lesions were a notable clinical feature of HSD3B7 deficiency and these were resolved with suppression of atypical bile acids by oral CDCA administration.

Liver Failure Among Young Saudi Infants: Etiology, Clinical Presentation, and Outcome

OBJECTIVES

The published data on early infantile liver failure (EILF) are scarce and limited to Caucasians. We conducted this study to describe the etiology and outcome of EILF among Arabs and identify prognostic factors.

METHODS

We retrospectively reviewed our database of 524 infants presenting with liver impairment from 2008 to 2018, and identified cases of EILF defined as presence of biochemical pattern of liver disease and INR ≥2 (unresponsive to vitamin K) with onset before 3 months of life. Primary outcomes included death or liver transplantation (LT) (poor outcome group) and survival with native liver (good outcome group).

RESULTS

Forty-two cases of EILF (22 girls) were identified (8%). The etiology was indeterminate in 14 (33.3%) and established in 27 (64.3%): galactosemia (7 cases, 16.6%), tyrosinemia (5, 12%), neonatal hemochromatosis (NH), and hemophagocytic lymphohistiocytosis (HLH) (4 each, 9.5%]) mitochondrial hepatopathy (3, 7%), and miscellaneous (5, 12%). LF resolved in 15 cases (35.7%), either spontaneously or in response to specific therapy, 23 (54.7%) died, and 4 underwent LT (9.5%). ROC analysis for the best cut-off value of serum total bilirubin for prediction of study outcomes was 120 μmol/L (sensitivity 81.5%, specificity 80%). Among the diagnostic groups, galactosemia and tyrosinemia predicted good outcome, whereas the idiopathic diagnosis predicted poor outcome (OR = 13).

CONCLUSIONS

Similar to Western countries, galactosemia, tyrosinemia, NH, HLH, and mitochondrial hepatopathy are the main players in EILF in Saudi Arabia. Galactosemia and tyrosinemia predict good prognosis and idiopathic diagnosis predicts poor prognosis.

Δ4-3-oxosteroid-5β-reductase deficiency: Responses to oral bile acid therapy and long-term outcomes

BACKGROUND

Disorders of primary bile acid synthesis may be life-threatening if undiagnosed, or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of patients with Δ4-3-oxosteroid 5β-reductase (AKR1D1) deficiency. We hypothesized that a retrospective analysis of the responses to oral bile acid replacement therapy with chenodeoxycholic acid (CDCA) in patients with this bile acid synthesis disorder will increase our understanding of the disease progression and permit evaluation of this treatment regimen as an alternative to the Food and Drug Administration (FDA) approved drug cholic acid, which is currently unavailable in China.

AIM

To evaluate the therapeutic responses of patients with AKR1D1 deficiency to oral bile acid therapy, specifically CDCA.

METHODS

Twelve patients with AKR1D1 deficiency, confirmed by fast atom bombardment ionization-mass spectrometry analysis of urine and by gene sequencing for mutations in AKR1D1, were treated with differing doses of CDCA or ursodeoxycholic acid (UDCA). The clinical and biochemical responses to therapy were monitored over a period ranging 0.5-6.4 years. Dose adjustment, to optimize the therapeutic dose, was based on changes in serum biochemistry parameters, notably liver function tests, and suppression of the urinary levels of atypical hepatotoxic 3-oxo-Δ4-bile acids measured by mass spectrometry.

RESULTS

Physical examination, serum biochemistry parameters, and sonographic findings improved in all 12 patients during bile acid therapy, except one who underwent liver transplantation. Urine bile acid analysis confirmed a significant reduction in atypical hepatotoxic 3-oxo-Δ4 bile acids concomitant with clinical and biochemical improvements in those patients treated with CDCA. UDCA was ineffective in down-regulating endogenous bile acid synthesis as evidenced from the inability to suppress the urinary excretion of atypical 3-oxo-Δ4-bile acids. The dose of CDCA required for optimal clinical and biochemical responses varied from 5.5-10 mg/kg per day among patients based on maximum suppression of the atypical bile acids and improvement in serum biochemistry parameters, and careful titration of the dose was necessary to avoid side effects from CDCA.

CONCLUSION

The primary bile acid CDCA is effective in treating AKR1D1 deficiency but the therapeutic dose requires individualized optimization. UDCA is not recommended for long-term management.

Inborn Errors of Bile Acid Metabolism

Inborn errors of bile acid metabolism are rare causes of neonatal cholestasis and liver disease in older children and adults. The diagnosis should be considered in the context of hyperbilirubinemia with normal serum bile acids and made by urinary liquid secondary ionization mass spectrometry or DNA testing. Cholic acid is an effective treatment of most single-enzyme defects and patients with Zellweger spectrum disorder with liver disease.

Cholic acid for primary bile acid synthesis defects: a life-saving therapy allowing a favorable outcome in adulthood

Background

Oral cholic acid (CA) replacement has been shown to be an effective therapy in children with primary bile acid synthesis defects, which are rare and severe genetic liver diseases. To date there has been no report of the effects of this therapy in children reaching adulthood. The aim of the study was to evaluate the long-term effectiveness and safety of CA therapy.

Methods

Fifteen patients with either 3β-hydroxy-Δ⁵-C₂₇-steroid oxidoreductase (3β-HSD) (n = 13) or Δ⁴–3-oxosteroid 5β-reductase (Δ⁴–3-oxo-R) (n = 2) deficiency confirmed by mass spectrometry and gene sequencing received oral CA and were followed prospectively.

Results

The median age at last follow-up and the median time of follow-up with treatment were 24.3 years (range: 15.3–37.2) and 21.4 years (range: 14.6–24.1), respectively. At last evaluation, physical examination findings and blood laboratory test results were normal in all patients. Liver sonograms were normal in most patients. Mean daily CA dose was 6.9 mg/kg of body weight. Mass spectrometry analysis of urine showed that excretion of the atypical metabolites remained low or traces in amount with CA therapy. Liver fibrosis scored in liver biopsies or assessed by elastography in 14 patients, after 10 to 24 years with CA therapy, showed a marked improvement with disappearance of cirrhosis (median score < F1; range: F0-F2). CA was well tolerated in all patients, including five women having 10 uneventful pregnancies during treatment.

Conclusions

Oral CA therapy is a safe and effective long-term treatment of 3β-HSD and Δ⁴–3-oxo-R deficiencies and allows affected children to reach adulthood in good health condition without the need for a liver transplantation.