Cholesterol, non-cholesterol sterols and bile acids in paediatric gallstones

Analysis of Sphingolipids in Pediatric Patients with Cholelithiasis—A Preliminary Study

(1) Background: Disturbances in the sphingolipid profile are observed in many diseases. There are currently no data available on the evaluation of sphingolipids and ceramides in cholelithiasis in children. The aim of this study was to evaluate the concentrations of sphingolipids in the sera of pediatric patients with gallstones. We determined their relationship with anthropometric and biochemical parameters. (2) Methods: The concentrations of sphingolipids in serum samples were evaluated using a quantitative method, ultra-high-performance liquid chromatography–tandem mass spectrometry. (3) Results: The prospective study included 48 children and adolescents diagnosed with gallstones and 38 controls. Serum concentrations of total cholesterol (TC); sphinganine (SPA); ceramides—C14:0-Cer, C16:0-Cer, C18:1-Cer, C18:0-Cer, C20:0-Cer and C24:1-Cer; and lactosylceramides—C16:0-LacCer, C18:0-LacCer, C18:1-LacCer, C24:0-LacCer and C24:1-LacCer differed significantly between patients with cholelithiasis and without cholelithiasis. After adjusting for age, gender, obesity and TC and TG levels, we found the best differentiating sphingolipids for cholelithiasis in the form of decreased SPA, C14:0-Cer, C16:0-Cer, C24:1-LacCer and C24:0-LacCer concentration and increased C20:0-Cer, C24:1-Cer, C16:0-LacCer and C18:1-LacCer. The highest area under the curve (AUC), specificity and sensitivity were determined for C16:0-Cer with cholelithiasis diagnosis. (4) Conclusions: Our results suggest that serum sphingolipids may be potential biomarkers in pediatric patients with cholelithiasis.

Altered Bile Transporter Expression and Cholesterol Metabolism in Children With Cholesterol and Pigment Gallstones

OBJECTIVES

We elucidated pathophysiology of pediatric gallstone disease by assessing liver expression of bile transporters in relation to bile acids and surrogates of cholesterol absorption and synthesis in serum and gallstones.

METHODS

RNA expression of canalicular bile transporters in liver biopsies from 32 pediatric gallstone patients and from 6 liver donors (controls) was measured by qRT-PCR (quantitative real-time reverse transcription polymerase chain reaction). Concentrations of cholesterol and precursors, plant sterols and bile acids in gallstones, and in serum of the patients and 82 healthy children were measured. Primary outcomes were the difference in RNA expressions and serum sterol profiles between patients and controls.

RESULTS

Cholesterol stones (CS; n = 15) contained cholesterol >42% and pigment stones (PS; n = 17) <9% of weight. CS patients had markedly lower serum plant sterols (absorption) and higher cholesterol precursors (synthesis) than PS patients or healthy controls. CS contained several times more cholesterol precursors and less plant sterols relative to cholesterol than PS, which were enriched by primary bile acids (12-5.2-fold, P < 0.001). Liver RNA expression of ABCG5/G8 was similarly increased 2.5- to 1.8-fold (P < 0.002) in CS and PS patients, whereas PS patients had higher ABCB11 expression (P < 0.05). In PS bile acid concentration correlated with gallstone plant sterols (R = 0.83, P < 0.0001), and ABCG5 expression with ABCB11 expression (R = 0.27, P = 0.03).

CONCLUSIONS

In CS, upregulation of ABCG5/G8 expression associates with low absorption and high gallstone content of cholesterol. In PS, activation of bile acid transport by ACBC11 interconnects with hepatic upregulation of ABCG5/G8 enriching PS with bile acids and plant sterols.

Adolescent gallstones-need for early intervention in symptomatic idiopathic gallstones

BACKGROUND AND AIM

Currently, there is a paucity of the literature describing the natural history of cholelithiasis (CL) and choledocholithiasis (CDL) in adolescent children. This study aims to analyse the changing demographics of paediatric and adolescent gallstones.

METHODOLOGY

Retrospective review of all children (Age 0-18 years) presenting with symptomatic gallstones over the last 15 years (2002-2017) at a single tertiary institution. Demographics, diagnostic and therapeutic information were collected, with a 5-year median follow-up. Statistics were accomplished by Chi-squared analysis of trend and Student t test.

RESULTS AND DISCUSSIONS

188 children were seen with symptomatic CL. In the 0-11-year-old group, there were 13 females and 16 males (0.8: female to male ratio). There were 130 females and 29 males in the 12-18-year-old group (4.5:1 female to male ratio). The mean weight at presentation was 81.78 kg and the median age was 16 years. Idiopathic gallstones were found in 131 patients (82%). 137 required cholecystectomy (86%) and ERCP was required in 32 patients (20%). 48 adolescents (30.2%) with gallstones had an associated CDL, compared to six children (20%). All of the adolescent patients with CDL had idiopathic gallstones. Gallstone pancreatitis was noted in eighteen adolescents (11%) and one child (3%). We analysed the ideal time to operate on adolescent patients with symptomatic gallstones using the relationship between the length of delay from initial diagnosis to definitive management of CDL and incidence of complications. The analysis demonstrated that for every 10 days treatment was delayed, the risk of subsequent presentations with a symptomatic episode was increased by 5% (p = 0.0004).

CONCLUSION

The current trend of gallstones in adolescent children seems to be a disease primarily of adolescent girls. Symptomatic idiopathic gallstones in adolescents are associated with high rates of common bile duct obstruction and pancreatitis and consequently warrant an early cholecystectomy for all adolescents.

LEVEL OF EVIDENCE

Level IV Treatment Study.

Prevalence of Gallstones Compared in Children With Different Intravenous Lipids

OBJECTIVE

The aetiology of biliary liver disease in children with intestinal failure treated with long-term parenteral nutrition (PN) is multifactorial. Risks include the lipid component of PN. The aim of the study was to compare prevalence and outcome of gallstones with different types of intravenous lipids.

METHODS

Liver and biliary tract imaging and relevant clinical details were reviewed in 71 patients (37, 52% boys) treated with PN for >3 months. Types of lipid infused were compared with regard to hepatobiliary abnormalities.

RESULTS

In total 369 abdominal ultrasounds were performed in 71 patients of age between 3 months and 17 years. Underlying diagnoses were short bowel syndrome in 20 (28%), small intestinal enteropathy in 34 (48%), and motility disorder in 17 (24%). A total of 67 (94%) children had 362/369 scans on lipid-containing PN. Of the total, 15 (21%) patients had gallstones, 8 (11%) had sludge, and both were detected in 7 (10%) children. The gallstones/sludge resolved in 7 patients (10%) and persisted in 10 (13%). In 6 patients, sludge progressed to form discrete gallstones, and in 9 children, gallstones led to biliary duct dilatation. Four (6%) patients underwent cholecystectomy. Fewer children had abnormalities with the newer mixed lipid emulsion (P = 0.005). There was a higher prevalence of sludge (P = 0.01) on pure soya lipid. Predictors for sludge were young age at PN (P = 0.001), lack of enteral feed (P < 0.001), and motility disorder with stoma (P = 0.002).

CONCLUSIONS

Hepatobiliary pathology is common in children on PN. The use of mixed lipid was associated with less biliary complications and should be the first choice of treatment in children.

Relation of cholesterol metabolism to pediatric gallstone disease: a retrospective controlled study

Background

Cholesterol metabolism may be involved in pediatric gallstone disease. We aimed to reveal cholesterol metabolites and phytosterols and their relation to stone composition of sterols in children having black pigment and cholesterol stones.

Methods

We performed retrospective controlled clinical study, in which we examined parameters of cholesterol metabolism and liver function values in serum (n = 28) and gallstones (n = 46) of consecutively cholecystectomized children. Serum values of age-, body mass index- and sex-matched children (n = 82) and adult gallstones (n = 187) served as controls.

Results

Surrogate markers of cholesterol synthesis in serum (squalene/cholesterol, cholestenol/cholesterol and lathosterol/cholesterol) were 26–52 % higher in both stone subclasses compared to controls (p < 0.05 for all). Respectively, cholestanol/cholesterol and plant sterols campesterol/cholesterol and sitosterol/cholesterol (cholesterol absorption markers) had decreasing order in serum: black pigment stone group > controls > cholesterol stone group (p < 0.05 for all). In black pigment stone group, stone cholestanol/cholesterol was associated with serum bile acids (r = 0.620, p = 0.018). In cholesterol stone group, surrogate markers of cholesterol synthesis in serum (e.g., lathosterol/cholesterol) inversely reflected those of absorption (r-range -0.633–-0.706, p-range 0.036–0.015). In cholesterol stone group, serum and stone lathosterol/cholesterol and cholestanol/cholesterol were positively interrelated (r-range 0.727–0.847, p < 0.05 for both).

Conclusions

Gallstone subclasses shared enhanced cholesterol synthesis. Cholesterol stone children were low cholesterol absorbers with intact homeostasis of cholesterol metabolism. Black pigment stone group was characterized by deteriorated cholesterol metabolism, and accumulation of cholestanol, campesterol and sitosterol in serum and stones suggesting their participation in pathogenesis.

Phytosterol and cholesterol precursor levels indicate increased cholesterol excretion and biosynthesis in gallstone disease

In hepatocytes and enterocytes sterol uptake and secretion is mediated by Niemann-Pick C1-like 1 (NPC1L1) and ATP-binding cassette (ABC)G5/8 proteins, respectively. Whereas serum levels of phytosterols represent surrogate markers for intestinal cholesterol absorption, cholesterol precursors reflect cholesterol biosynthesis. Here we compare serum and biliary sterol levels in ethnically different populations of patients with gallstone disease (GSD) and stone-free controls to identify differences in cholesterol transport and synthesis between these groups. In this case-control study four cohorts were analyzed: 112 German patients with GSD and 152 controls; two distinct Chilean ethnic groups: Hispanics (100 GSD, 100 controls), and Amerindians (20 GSD, 20 controls); additionally an 8-year follow-up of 70 Hispanics was performed. Serum sterols were measured by gas chromatography / mass spectrometry. Gallbladder bile sterol levels were analyzed in cholesterol GSD and controls. Common ABCG5/8 variants were genotyped. Comparison of serum sterols showed lower levels of phytosterols and higher levels of cholesterol precursors in GSD patients than in controls. The ratios of phytosterols to cholesterol precursors were lower in GSD patients, whereas biliary phytosterol and cholesterol concentrations were elevated as compared with controls. In the follow-up study, serum phytosterol levels were significantly lower even before GSD was detectable by ultrasound. An ethnic gradient in the ratios of phytosterols to cholesterol precursors was apparent (Germans > Hispanics > Amerindians). ABCG5/8 variants did not fully explain the sterol metabolic trait of GSD in any of the cohorts.

CONCLUSION

Individuals predisposed to GSD display increased biliary output of cholesterol in the setting of relatively low intestinal cholesterol absorption, indicating enhanced whole-body sterol clearance. This metabolic trait precedes gallstone formation and is a feature of ethnic groups at higher risk of cholesterol GSD.

Clinical characteristics and risk factors for symptomatic pediatric gallbladder disease

OBJECTIVE

Our center previously reported its experience with pediatric gallbladder disease and cholecystectomies from 1980 to 1996. We aimed to determine the current clinical characteristics and risk factors for symptomatic pediatric gallbladder disease and cholecystectomies and compare these findings with our historical series.

STUDY DESIGN

Retrospective, cross-sectional study of children, 0 to 18 years of age, who underwent a cholecystectomy from January 2005 to October 2008.

RESULTS

We evaluated 404 patients: 73% girls; 39% Hispanic and 35% white. The mean age was 13.10 ± 0.91 years. The primary indications for surgery in patients 3 years or older were symptomatic cholelithiasis (53%), obstructive disease (28%), and biliary dyskinesia (16%). The median BMI percentile was 89%; 39% were classified as obese. Of the patients with nonhemolytic gallstone disease, 35% were obese and 18% were severely obese; BMI percentile was 99% or higher. Gallstone disease was associated with hemolytic disease in 23% (73/324) of patients and with obesity in 39% (126/324). Logistic regression demonstrated older age (P = .019) and Hispanic ethnicity (P < .0001) as independent risk factors for nonhemolytic gallstone disease. Compared with our historical series, children undergoing cholecystectomy are more likely to be Hispanic (P = .003) and severely obese (P < .0279).

CONCLUSION

Obesity and Hispanic ethnicity are strongly correlated with symptomatic pediatric gallbladder disease. In comparison with our historical series, hemolytic disease is no longer the predominant risk factor for symptomatic gallstone disease in children.

Abundant pleiotropy in human complex diseases and traits

We present a systematic review of pleiotropy among SNPs and genes reported to show genome-wide association with common complex diseases and traits. We find abundant evidence of pleiotropy; 233 (16.9%) genes and 77 (4.6%) SNPs show pleiotropic effects. SNP pleiotropic status was associated with gene location (p = 0.024; pleiotropic SNPs more often exonic [14.5% versus 4.9% for nonpleiotropic, trait-associated SNPs] and less often intergenic [15.8% versus 23.6%]), "predicted transcript consequence" (p = 0.001; pleiotropic SNPs more often predicted to be structurally deleterious [5% versus 0.4%] but not more often in regulatory sequences), and certain disease classes. We develop a method to calculate the likelihood that pleiotropic links between traits occurred more often than expected and demonstrate that this approach can identify etiological links that are already known (such as between fetal hemoglobin and malaria risk) and those that are not yet established (e.g., between plasma campesterol levels and gallstones risk; and between immunoglobulin A and juvenile idiopathic arthritis). Examples of pleiotropy will accumulate over time, but it is already clear that pleiotropy is a common property of genes and SNPs associated with disease traits, and this will have implications for identification of molecular targets for drug development, future genetic risk-profiling, and classification of diseases.

Effects of long-term parenteral nutrition on serum lipids, plant sterols, cholesterol metabolism, and liver histology in pediatric intestinal failure

BACKGROUND AND OBJECTIVE

Plant sterols (PS) in parenteral nutrition (PN) may contribute to intestinal failure-associated liver disease. We investigated interrelations between serum PS, liver function and histology, cholesterol metabolism, and characteristics of PN.

PATIENTS AND METHODS

Eleven patients with intestinal failure (mean age 6.3 years) receiving long-term PN were studied prospectively (mean 254 days) and underwent repeated measurements of serum lipids, noncholesterol sterols, including PS, and liver enzymes. PS contents of PN were analyzed. Liver biopsy was obtained in 8 patients. Twenty healthy children (mean age 5.7 years) served as controls.

RESULTS

Median percentage of parenteral energy of total daily energy (PN%) was 48%, including 0.9 g · kg(-1) · day(-1) of lipids. Respective amounts of PN sitosterol, campesterol, avenasterol, and stigmasterol were 683, 71, 57, and 45 μg · kg(-1) · day(-1). Median serum concentrations of sitosterol (48 vs 7.5 μmol/L, P < 0.001), avenasterol (2.9 vs 1.9, P < 0.01), stigmasterol (1.9 vs 1.2, P < 0.005), but not that of campesterol (9.8 vs 12, P = 0.22), were increased among patients in relation to controls, and correlated with PN% (r = 0.81-0.88, P < 0.005), but not with PN fat. Serum cholesterol precursors were higher in patients than in controls. Serum liver enzymes remained close to normal range. Glutamyl transferase correlated with serum PS (r = 0.61-0.62, P < 0.05). Liver fibrosis in 5 patients reflected increased serum PS (r = 0.55-0.60, P = 0.16-0.12).

CONCLUSIONS

Serum PS moderately increase during olive oil-based PN, and correlate positively with PN% and glutamyl transferase. Despite well-preserved liver function, histology often revealed significant liver damage.