Genetic epidemiology of cholesterol cholelithiasis among Chilean Hispanics, Amerindians, and Maoris

Cracking the silent gallstone code: Wait or operate?

The widespread availability of abdominal ultrasound has revealed the common occurrence of asymptomatic gallstones. While the treatment for symptomatic gallstones is clear, the benefits of minimally invasive laparoscopic cholecystectomy have sparked debate about the best approach to managing silent gallstones. The potential for asymptomatic gallstones to become symptomatic or lead to complications complicates the decision-making process regarding surgical intervention, as it's uncertain when or which patients might develop complications. Consequently, risk stratification appears to play a critical role in guiding decisions about silent gallstones. However, there is no definitive evidence to direct management, and a consensus-based on high-quality evidence is yet to be established.

Global, regional, and national burden and trends analysis of gallbladder and biliary tract cancer from 1990 to 2019 and predictions to 2030: a systematic analysis for the Global Burden of Disease Study 2019

Objectives

Our aim was to explore the disease burden caused by gallbladder and biliary tract cancer globally, regionally, and nationally, by age and sex.

Methods

The absolute number of cases and age-standardized rates (ASR) of incidence, prevalence, mortality, and disability-adjusted life years (DALYs) due to gallbladder and biliary tract cancer were extracted from the Global Burden of Disease (GBD) Study 2019. We estimated the trends in disease burden by calculating the percentage change in the absolute number of cases and the estimated annual percentage change (EAPC) in ASR, by social development index (SDI), region, nation, sex, and age.

Results

From 1990 to 2019, the number of incident cases, prevalent cases, deaths, and DALYs worldwide significantly increased by 1.85-fold, 1.92-fold, 1.82-fold, and 1.68-fold, respectively. However, the age-standardized rates of incidence, prevalence, mortality, and DALYs tend to decrease globally over time. Nevertheless, heterogeneous disease burden patterns exist between geographic regions due to different geographical risk factors, distinct epidemiologically predominant gallbladder and biliary tract cancer subtypes, and potential genetic predispositions or ethnicity. Additionally, socioeconomic status mediates the regional variation in disease burden, with increasing SDI or HDI scores associated with downward trends in the age-standardized rates of incidence, prevalence, mortality, and DALYs. Older individuals and females are at higher risk of gallbladder and biliary tract cancer, but the increasing burden of early-onset gallbladder and biliary tract cancer is a cause for concern, especially for those living in lower SDI areas and males. High BMI is the primary risk factors underlying gallbladder and biliary tract cancer, accounted for 15.2% of deaths and 15.7% DALYs globally in 2019.

Conclusion

Our study comprehensively elucidated the distribution and dynamic trends of gallbladder and biliary tract cancer burden over the past three decades, from multiple dimensions. These findings emphasize the importance of promoting a healthy lifestyle as a population-level cancer prevention strategy and tailoring cancer control actions based on localized risk factors and the epidemic profiles of gallbladder and biliary tract cancer by anatomical subtype.

Association between HNF4A rs1800961 polymorphisms and gallstones in a Taiwanese population

BACKGROUND AND AIM

A large genetic effect of a novel gallstone-associated genetic variant, the hepatocyte nuclear factor 4α (HNF4A) rs1800961 polymorphism, has been identified through recent genome-wide association studies. However, this effect has not been validated in Asian populations. We investigated the association between the rs1800961 variant and gallstones among a Taiwanese population.

METHODS

A total of 20 405 participants aged between 30 and 70 years voluntarily enrolled in the Taiwan Biobank. Self-report questionnaires, physical examinations, biochemical tests, and genotyping were used for analysis. The association of the HNF4A rs1800961 variant and other metabolic risks with gallstone disease was analyzed using multiple logistic regression models.

RESULTS

The minor T allele of HNF4A rs1800961 was associated with an increased risk of gallstone, and the association remained significant even after adjustment for other risk factors including age, body mass index (BMI), diabetes, hyperlipidemia, hypertension, and cigarette smoking (adjusted odds ratio [OR] = 1.90, 95% confidence interval [CI] = 1.31 to 2.75) in male participants. When further stratified by BMI and age, the lithogenic effect was the most significant in male participants with obesity (adjusted OR = 3.55, 95% CI = 1.92 to 6.56) and who were younger (adjusted OR = 2.45, 95% CI = 1.49 to 4.04).

CONCLUSION

The novel gallstone-associated HNF4A rs1800961 variant was associated with the risk of gallstone in the Taiwanese men. Screening for the rs1800961 polymorphism may be particularly useful in assessing the risk of gallstone formation in younger or obese men.

Gallbladder Cancer Risk and Indigenous South American Mapuche Ancestry: Instrumental Variable Analysis Using Ancestry-Informative Markers

A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association. Genetic markers of Mapuche ancestry were selected based on the informativeness for assignment measure, and then used as instrumental variables in two-sample Mendelian randomization analyses and complementary sensitivity analyses. Results suggested a putatively causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% per 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.7 × 10-5) and also on gallstone disease (3.6% IVW risk increase, 95% CI 3.1% to 4.0%), pointing to a mediating effect of gallstones on the association between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative effect on BMI (IVW estimate -0.006 kg/m2, 95% CI -0.009 to -0.003). The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between the individual proportion of Mapuche ancestry and GBC risk previously noted in observational studies appears to be free of confounding, primary and secondary prevention strategies that consider genetic ancestry could be particularly efficient.

Prevalence of elevated alkaline phosphatase levels among post-bariatric surgery patients

INTRODUCTION

Little is known about the prevalence of elevated alkaline phosphatase in post-bariatric surgery patients due to under-utilization of this test after surgery. Elevated alkaline phosphatase levels are caused by hepatobiliary disease or bone resorption, which can lead to gallstones and osteoporosis. Early, post-operative measurement of alkaline phosphatase can prevent complications, thus reducing morbidity and overall healthcare costs. The purpose of this study was to determine the prevalence of elevated alkaline phosphatase levels among post-operative bariatric surgery patients.

METHODS

This was a retrospective study of patients 18 years or older, who underwent laparoscopic sleeve gastrectomy (LSG) at a Midwestern Weight Management Clinic between January 1, 2002 and December 31, 2020. Alkaline phosphatase levels, weight, body mass index (BMI), gamma-glutamyl transferase (GGT), parathyroid hormone (PTH), calcitriol, and calcitonin, vitamin D and multivitamin supplementation were measured at baseline, 3, 6, and 12 months post-surgery.

RESULTS

Two hundred thirty patients with mean age of 47 years and BMI of 44.6 were included with 80.9% (n = 186) female. Alkaline phosphatase was elevated relative to baseline for 36.1% of patients (n = 52) at 3 months post-surgery, 42.4% of patients (n = 56) at 6 months, and 43.3% of patients (n = 45) at 12 months (p < 0.001). There were six cases of documented cholelithiasis post-surgery.

CONCLUSION

A significant proportion of participants experienced elevations in alkaline phosphatase following surgery, indicating that the prevalence of gallbladder pathology and bone resorption may be higher than previously thought. This merits additional investigation into these complications post-operatively to determine prevalence and avoid excess morbidity.

Colorectal cancer trends in Chile: A Latin-American country with marked socioeconomic inequities

Introduction

Colorectal cancer (CRC) is the third most frequent malignant disease in the world. In some countries with established screening programs, its incidence and mortality have decreased, and survival has improved.

Aims

To obtain reliable data about the epidemiology of CRC in Chile, we analyzed the trends in the last ten years and the influence of observable factors on survival, including a nationwide health program for CRC treatment access (GES program).

Methods

Publicly available data published by the Ministry of Health and National Institute of Statistics were used. Data were obtained from registries of mortality and hospital discharges, making follow-up of the individuals possible. Crude and age-standardized incidence and mortality rates were calculated, and individual survival was studied by constructing Kaplan–Meier curves. Finally, a Cox statistical model was established to estimate the impact of the observable factors.

Results

We found 37,217 newly identified CRC patients between 2008 and 2019 in Chile, corresponding to 103,239 hospital discharges. In the same period, 24,217 people died of CRC. A nearly linear, steady increase in crude incidence, mortality and prevalence was observed. CRC incidence was the lowest in the North of the country, increasing toward the South and reaching a maximum value of 34.6/100,000 inhabitants/year in terms of crude incidence and 20.7/100,000 inhabitants/year in terms of crude mortality in the XII region in 2018. We found that older patients had lower survival rates, as well as men compared to women. Survival was significantly better for patients with private insurance than those under the public insurance system, and the treating hospital also played a significant role in the survival of patients. Patients in the capital region survived longer than those in almost every other part of the country. We found no significant effect on survival associated with the GES program.

Conclusions

We found important inequalities in the survival probabilities for CRC patients in Chile. Survival depends mainly on the type of insurance, access to more complex hospitals, and geographical location; all three factors correlated with socioeconomic status of the population. Our work emphasized the need to create specific programs addressing primary causes to decrease the differences in CRC survival.

A POPULATION STUDY ON GENDER AND ETHNICITY DIFFERENCES IN GALLBLADDER DISEASE IN BRAZIL

Gallbladder diseases (GBD) are one of the most common medical conditions requiring surgical intervention, both electively and urgently. It is widely accepted that sex and ethnic characteristics mighty influence both prevalence and outcomes.

Acute Cholecystitis: A Review

IMPORTANCE

Gallbladder disease affects approximately 20 million people in the US. Acute cholecystitis is diagnosed in approximately 200 000 people in the US each year.

OBSERVATIONS

Gallstone-associated cystic duct obstruction is responsible for 90% to 95% of the cases of acute cholecystitis. Approximately 5% to 10% of patients with acute cholecystitis have acalculous cholecystitis, defined as acute inflammation of the gallbladder without gallstones, typically in the setting of severe critical illness. The typical presentation of acute cholecystitis consists of acute right upper quadrant pain, fever, and nausea that may be associated with eating and physical examination findings of right upper quadrant tenderness. Ultrasonography of the right upper quadrant has a sensitivity of approximately 81% and a specificity of approximately 83% for the diagnosis of acute cholecystitis. When an ultrasound result does not provide a definitive diagnosis, hepatobiliary scintigraphy (a nuclear medicine study that includes the intravenous injection of a radiotracer excreted in the bile) is the gold standard diagnostic test. Following diagnosis, early (performed within 1-3 days) vs late (performed after 3 days) laparoscopic cholecystectomy is associated with improved patient outcomes, including fewer composite postoperative complications (11.8% for early vs 34.4% for late), a shorter length of hospital stay (5.4 days vs 10.0 days), and lower hospital costs. During pregnancy, early laparoscopic cholecystectomy, compared with delayed operative management, is associated with a lower risk of maternal-fetal complications (1.6% for early vs 18.4% for delayed) and is recommended during all trimesters. In people older than 65 years of age, laparoscopic cholecystectomy is associated with lower mortality at 2-year follow-up (15.2%) compared with nonoperative management (29.3%). A percutaneous cholecystostomy tube, in which a drainage catheter is placed in the gallbladder lumen under image guidance, is an effective therapy for patients with an exceptionally high perioperative risk. However, percutaneous cholecystostomy tube placement in a randomized trial was associated with higher rates of postprocedural complications (65%) compared with laparoscopic cholecystectomy (12%). For patients with acalculous acute cholecystitis, percutaneous cholecystostomy tube should be reserved for patients who are severely ill at the time of diagnosis; all others should undergo a laparoscopic cholecystectomy.

CONCLUSIONS AND RELEVANCE

Acute cholecystitis, typically due to gallstone obstruction of the cystic duct, affects approximately 200 000 people in the US annually. In most patient populations, laparoscopic cholecystectomy, performed within 3 days of diagnosis, is the first-line therapy for acute cholecystitis.

Evolving Paradigms in the Systemic Treatment of Advanced Gallbladder Cancer: Updates in Year 2022

Gallbladder cancer (GBC) is a biological, anatomical, and clinically distinct subset of biliary tract cancers (BTC), which also include extra- and intra-hepatic cholangiocarcinoma. The advent of next-generation sequencing (NGS) clearly shows that GBC is genetically different from cholangiocarcinoma. Although GBC is a relatively rare cancer, it is highly aggressive and carries a grave prognosis. To date, complete surgical resection remains the only path for cure but is limited to patients with early-stage disease. The majority of the patients are diagnosed at an advanced, inoperable stage when systemic treatment is administered as an attempt to enable surgery or for palliation. Gemcitabine and platinum-based chemotherapies have been the main treatment modality for unresectable, locally advanced, and metastatic gallbladder cancer. However, over the past decade, the treatment paradigm has evolved. These include the introduction of newer chemotherapeutic strategies after progression on frontline chemotherapy, incorporation of targeted therapeutics towards driver mutations of genes including HER2, FGFR, BRAF, as well as approaches to unleash host anti-tumor immunity using immune checkpoint inhibitors. Notably, due to the rarity of BTC in general, most clinical trials included both GBC and cholangiocarcinomas. Here, we provide a review on the pathogenesis of GBC, past and current systemic treatment options focusing specifically on GBC, clinical trials tailored towards its genetic mutations, and emerging treatment strategies based on promising recent clinical studies.

Health-related quality of life among patients with gallstone disease: a systematic review and meta-analysis of EQ-5D utility scores

PURPOSE

Gallstone disease or cholelithiasis is a chronic illness that usually presents with pain in the abdomen, vomiting and indigestion leading to impaired quality of life. EQ-5D utility score is a validated measure of health-related quality of life (HRQoL). We systematically reviewed the literature and synthesised EQ-5D utility scores among patients with gallstone disease and its improvement on treatment.

METHODS

We have systematically searched observational studies reporting EQ-5D utility scores of gallstone disease in PubMed, Scopus, and Embase databases, from inception until February 2021. We selected the studies adhering to the PRISMA guidelines. The selected studies were reviewed, and the EQ-5D utility values of pre and post cholecystectomy were pooled using the random-effects model.

RESULT

From identified 4,817 records of database search, eleven studies predominantly from western countries with 2,189 participants were included for systematic review and meta-analysis. The pooled EQ-5D and visual analogue scores were 0.87 (0.82 to 0.91, I² = 93.73%) and 83.30 (60.59 to 106.12, I² = 99.30%) respectively with high heterogeneity. The pooled EQ-5D and EQ-5D visual analogue scores post cholecystectomy treatment were 0.93 (0.91 to 0.95, I² = 90.17%) and 91.7 (85.99 to 96.35, I² = 97.93%) respectively. The mean difference between the baseline and post intervention were 0.05 (0.01 to 0.10, I² = 93.50%) and 10.58 (-8.63 to 29.79, I² = 98.32%) for EQ-5D and visual analogue scores respectively with high heterogeneity between the studies.

CONCLUSION

The pooled mean difference indicates improvement in HRQoL after cholecystectomy but with high heterogeneity. Further high-quality studies from Asian countries are required for globally representative quantification and precise estimates of HRQoL among gallstone diseases.

PROSPERO REGISTRATION ID

CRD42021234467.

Obesity and Gallstones

BACKGROUND

The prevalence of obesity has been increasing globally and represents the main risk factor for the development of gallstone disease (GD).

SUMMARY

Excess body weight represents the main cause for the development of GD; nevertheless, there have been described multiple risk factors for its development, among them modifiable risk factors as diet, lifestyle, physical inactivity, and non-modifiable risk factors as ethnicity, female sex, advanced age, parity, and genetic mutations. Body mass index, abdominal perimeter, and waist-hip index have been used to determine the degree of adiposity of a person. Hence, central abdominal fat has been mostly associated with insulin resistance with the consequent increase in the hepatic cholesterol secretion; contributing as one of the multiple mechanisms associated with the development of gallstones. This disease has a low mortality; however, it has been associated with multiple diseases such as cardiovascular diseases, carotid atherosclerosis, metabolic associated fatty liver disease, and gallbladder cancer, probably because they share many of the risk factors.

KEY MESSAGES

GD continues to be considered a disease with a high medical burden, in which it is sought to intervene in modifiable risk factors to reduce its development.

Predictors of Difficult Laparoscopic Cholecystectomy on Humanitarian Missions to Peru Difficult LC in Surgical Missions

BACKGROUND

Laparoscopic cholecystectomy (LC) is the gold standard treatment of gallstone disease. On short-term surgical missions (STSMs), it is unclear what factors can predict safety of LC. This study evaluates patient risk factors of difficult LC in Northern Peru, towards optimizing outcomes.

MATERIALS AND METHODS

A retrospective review was performed of patients who underwent LC during short-term surgical missions to Peru from 2016-2019 under the International Surgical Health Initiative (ISHI). Difficult and routine LC groups were compared for: age, weight, gender, symptom duration, pain on presentation, history of abdominal or pelvic surgery, diabetes and hypertension.

RESULTS

68 of 194 patients underwent LC; 42 patients (62%) were classified as difficult with OR (operating room) time > 70 min (90%), 2 cases converted to open (5%) and 2 aborted cases (5%). Higher weight class was found to correlate with difficult LC.

CONCLUSION

Increased patient weight was correlated to longer operative time during STSMs. Patients undergoing LC must be selected carefully to mitigate risks of difficult operations on STSMs.

A Mitochondrial DNA Variant Elevates the Risk of Gallstone Disease by Altering Mitochondrial Function

BACKGROUND AND AIMS

Gallstone disease (cholelithiasis) is a cholesterol-related metabolic disorders with strong familial predisposition. Mitochondrial DNA (mtDNA) variants accumulated during human evolution are associated with some metabolic disorders related to modified mitochondrial function. The mechanistic links between mtDNA variants and gallstone formation need further exploration.

METHODS

In this study, we explored the possible associations of mtDNA variants with gallstone disease by comparing 104 probands and 300 controls in a Chinese population. We constructed corresponding cybrids using trans-mitochondrial technology to investigate the underlying mechanisms of these associations. Mitochondrial respiratory chain complex activity and function and cholesterol metabolism were assessed in the trans-mitochondrial cell models.

RESULTS

Here, we found a significant association of mtDNA 827A>G with an increased risk of familial gallstone disease in a Chinese population (odds ratio [OR]: 4.5, 95% confidence interval [CI]: 2.1-9.4, P=1.2×10-4). Compared with 827A cybrids (haplogroups B4a and B4c), 827G cybrids (haplogroups B4b and B4d) had impaired mitochondrial respiratory chain complex activity and function and activated JNK and AMPK signaling pathways. Additionally, the 827G cybrids showed disturbances in cholesterol transport and accelerated development of gallstones. Specifically, cholesterol transport through the transporter ABCG5/8 was increased via activation of the AMPK signaling pathway in 827G cybrids.

CONCLUSIONS

Our findings reveal that mtDNA 827A>G induces aberrant mitochondrial function and abnormal cholesterol transport, resulting in increased occurrence of gallstones. The results provide an important biological basis for the clinical diagnosis and prevention of gallstone disease in the future.

Funding of Hispanic/Latino Health-Related Research by the National Institutes of Health: An Analysis of the Portfolio of Research Program Grants on Six Health Topic Areas

Hispanics/Latinos are expected to constitute 25% of the U.S. population by 2060. Differences in the prevalence of health risk factors, chronic diseases, and access to and utilization of health-care services between Hispanics/Latinos and other populations in the U.S. have been documented. This study aimed to describe and analyze the landscape of Research Program Grants (RPGs) funded by the National Institutes of Health (NIH) between 2008 and 2015 involving Hispanic/Latino health research in six health condition areas-asthma, cancer, dementia, diabetes, liver/gallbladder disease, and obesity-and to identify opportunities for continued research in these areas. Using an NIH internal search engine, we identified new and renewal Hispanic/Latino health RPGs searching for specific Hispanic/Latino identifiers in the Title, Abstract, and Specific Aims. We used descriptive statistics to examine the distribution of funded RPGs by NIH disease-based classification codes for the six health condition areas of interest, and other selected characteristics. The most prominent clusters of research subtopics were identified within each health condition area, and performance sites were mapped at the city level. Within the selected time frame, 3,221 Hispanic/Latino health-related unique RPGs were funded (constituting 4.4% of all funded RPGs), and of those 625 RPGs were eligible for review and coding in the present study. Cancer and obesity were the most commonly studied health condition areas (72%), while studies on mechanisms of disease-biological and non-biological-(72.6%), behavioral research (42.1%) and epidemiological studies (38.1%) were the most common types of research. Most of the primary performance sites were in California, Texas, the northeastern U.S., and Illinois. The predominance of mechanistic, behavioral, and epidemiological studies in our analysis poses opportunities to evaluate knowledge gained and their clinical application, explore new research questions, or to update some methods or instruments. The findings of the present study suggest opportunities to expand research in understudied mechanisms of disease that could explain differences in prevalence of conditions like diabetes and cancer among different heritage groups. In addition, our findings suggest that the impact of interventions or policies designed to reduce health disparities, innovative multi-level interventions, implementation and dissemination studies, the role of health information technology on health outcomes, and the intersectionality of individual, sociocultural, geographic, and other factors on health outcomes, among others, are understudied approaches, which could potentially advance research in Hispanic/Latino health and contribute to the achievement of better health outcomes in this diverse population.

Gallbladder and extrahepatic bile duct cancers in the Americas: Incidence and mortality patterns and trends

Trends in gallbladder cancer incidence and mortality in populations across the Americas can provide insight into shifting epidemiologic patterns and the current and potential impact of preventative and curative programs. Estimates of gallbladder and extrahepatic bile duct cancer incidence and mortality for the year 2018 were extracted from International Agency for Research on Cancer (IARC) GLOBOCAN database for 185 countries. Recorded registry-based incidence from 13 countries was extracted from IARCs Cancer Incidence in Five Continents series and corresponding national deaths from the WHO mortality database. Among females, the highest estimated incidence for gallbladder and extrahepatic bile duct cancer in the Americas were found in Bolivia (21.0 per 100,000), Chile (11.7) and Peru (6.0). In the US, the highest incidence rates were observed among Hispanics (1.8). In the Chilean population, gallbladder cancer rates declined in both females and males between 1998 and 2012. Rates dropped slightly in Canada, Costa Rica, US Whites and Hispanics in Los Angeles. Gallbladder cancer mortality rates also decreased across the studied countries, although rising trends were observed in Colombia and Canada after 2010. Countries within Southern and Central America tended to have a higher proportion of unspecified biliary tract cancers. In public health terms, the decline in gallbladder cancer incidence and mortality rates is encouraging. However, the slight increase in mortality rates during recent years in Colombia and Canada warrant further attention. Higher proportions of unspecified biliary tract cancers (with correspondingly higher mortality rates) suggest more rigorous pathology procedures may be needed after surgery.

The effect of ursodeoxycholic acid on the relative expression of the lipid metabolism genes in mouse cholesterol gallstone models

BACKGROUND

Many studies indicate that gallstone formation has genetic components. The abnormal expression of lipid-related genes could be the basis for particular forms of cholesterol gallstone disease. The aim of this study was to obtain insight into lipid metabolism disorder during cholesterol gallstone formation and to evaluate the effect of ursodeoxycholic acid (UDCA) on the improvement of bile lithogenicity and its potential influence on the transcription of lipid-related genes.

METHODS

Gallstone-susceptible mouse models were induced by feeding with a lithogenic diet (LD) for 8 weeks. Bile and liver tissues were obtained from these mouse models after 0, 4 and 8 weeks. Bile lipids were measured enzymatically, and the cholesterol saturation index (CSI) was calculated to evaluate the bile lithogenicity by using Carey's critical tables. Real-time polymerase chain reaction (RT-PCR) was used to detect the mRNA expression levels of farnesoid X receptor (FXR), liver X receptor (LXR), adenosine triphosphate-binding cassette subfamily G member 5/8 (ABCG5/8), cholesterol 7-α hydroxylase (CYP7A1), oxysterol 7-α hydroxylase (CYP7B1), sterol 27-α hydroxylase (CYP27A1), peroxisome proliferator-activated receptor alpha (PPAR-α) and adenosine triphosphate-binding cassette subfamily B member 11 (ABCB11).

RESULTS

The rate of gallstone formation was 100% in the 4-week group but only 30% in the UDCA-treated group. The UDCA-treated group had a significantly lower CSI compared with other groups. Of special note, the data on the effects of UDCA showed higher expression levels of ABCG8, ABCB11 and CYP27A1, as well as lower expression levels of LXR and PPAR-α, compared to the model control group.

CONCLUSIONS

UDCA exhibits tremendously potent activity in restraining lipid accumulation, thus reversing the lithogenic effect and protecting hepatocytes from serious pathological damage. The abnormal expression of ABCG8, CYP7A1, CYP27A1, LXR and PPAR-α might lead to high lithogenicity of bile. These results are helpful in exploring new lipid metabolism pathways and potential targets for the treatment of cholesterol stones and for providing some basis for the study of the pathogenesis and genetic characteristics of cholelithiasis. Research on the mechanism of UDCA in improving lipid metabolism and bile lithogenicity may be helpful for clinical treatment and for reducing the incidence of gallstones.

Transcriptomic profiles reveal differences in zinc metabolism, inflammation, and tight junction proteins in duodenum from cholesterol gallstone subjects

Cholesterol Gallstone Disease (GSD) is a common multifactorial disorder characterized by crystallization and aggregation of biliary cholesterol in the gallbladder. The global prevalence of GSD is ~10–20% in the adult population but rises to 28% in Chile (17% among men and 30% among women). The small intestine may play a role in GSD pathogenesis, but the molecular mechanisms have not been clarified. Our aim was to identify the role of the small intestine in GSD pathogenesis. Duodenal biopsy samples were obtained from patients with GSD and healthy volunteers. GSD status was defined by abdominal ultrasonography. We performed a transcriptome study in a discovery cohort using Illumina HiSeq. 2500, and qPCR, immunohistochemistry and immunofluorescence were used to validate differentially expressed genes among additional case-control cohorts. 548 differentially expressed genes between GSD and control subjects were identified. Enriched biological processes related to cellular response to zinc, and immune and antimicrobial responses were observed in GSD patients. We validated lower transcript levels of metallothionein, NPC1L1 and tight junction genes and higher transcript levels of genes involved in immune and antimicrobial pathways in GSD patients. Interestingly, serum zinc and phytosterol to cholesterol precursor ratios were lower in GSD patients. A significant association was observed between serum zinc and phytosterol levels. Our results support a model where proximal small intestine plays a key role in GSD pathogenesis. Zinc supplementation, modulation of proximal microbiota and/or intestinal barrier may be novel targets for strategies to prevent GSD.

Pathophysiological connections between gallstone disease, insulin resistance, and obesity

Obesity and cholesterol gallstone disease (GSD) are frequently coexisting diseases; therefore and considering the current worldwide obesity epidemics, a precise understanding of the pathophysiological relationships between GSD and insulin resistance (IR) is important. Classically, obesity has been understood as a risk factor for GSD and the gallbladder (GB) viewed as a simple bile reservoir, with no metabolic roles whatsoever. However, consistent evidence has showed that both GSD and cholecystectomy associates with fatty liver and IR, raising the possibility that the GB is indeed an organ with metabolic regulatory roles. Herein, we review the pathophysiological mechanisms by which GSD, IR, and obesity are interconnected, with emphasis in the actions of the GB as a regulator of bile acids kinetics and a hormone secreting organ, with metabolic actions at the systemic level. We also examine the relationships between increased hepatic lipogenic in IR states and GSD pathogenesis. We propose a model in which GSD and hepatic IR mutually interact to determine a state of dysregulated lipid and energy metabolism that potentiate the metabolic dysregulation of obesity.

Association Between Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome with Gallstone Disease, South Iran: A Population-Based Study

AIM

Gallstone disease (GSD), non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome (MetS) are common problems. The aim of this study was to investigate the association between NAFLD, MetS and its components with GSD.

MATERIALS AND METHODS

This cross-sectional study was conducted as a part of the Kavar Cohort Study (KCS) affiliated to Shiraz University of Medical Sciences, Shiraz, Iran between January 2012 and January 2018. A total of 2239 participants of the general population of the KCS were selected randomly. Ultrasonography for GSD and NAFLD diagnosis and clinical and laboratory assaying for MetS evaluation were performed for the participants. The National Cholesterol Education Program Adult Treatment Panel III (NCEP/ATP-III) and Criteria for Clinical Diagnosis of MetS in Iranian Adults (CCDMIA) were used for diagnosis of MetS.

RESULTS

Overall, 59 patients with GSD and 177 age- and sex- matched participants without gallstones as a comparison group were enrolled. According to GSD groups, NAFLD was observed in 42.4% and 22.6% of patients with and without GSD, respectively, and the difference between the two groups was statistically significant (P = 0.003). MetS was present in 33.9% and 39.0% of GSD subjects, compared with 32.8% and 33.3% of the non-GSD group, based on NCEP/ATPIII and CCDMIA, respectively. Although the mean of all components of MetS except HDL-cholesterol were higher in the GSD group than in the non-GSD group,  the difference was only significant in waist circumference (P = 0.041).

CONCLUSION

The present study found an obvious association between NAFLD and GSD. This study also showed a significant association between increasing waist circumference and risk of GSD. We recommend that patients with GSD should be evaluated for the likelihood of NAFLD and its treatment in addition to lifestyle changes to gain proper weight. However, further researches are needed to clarify the relationship between the nature of GSD, NAFLD, and obesity.

Low immune index correlates with favorable prognosis but with reduced benefit from chemotherapy in gallbladder cancer

Use of immune index is a new potential approach for cancer classification and prediction. To investigate the status and clinical effect of immune index in gallbladder cancer (GBC), 238 GBC patients from Zhongshan Hospital affiliated to Fudan University were involved in the present study, including 113 patients in a training set and 125 patients in a validation set. Five immune cells (macrophages, neutrophils, regulatory T cells, cytotoxic T cells and mast cells) were selected based on a literature review and the immune index for each patient was calculated using the LASSO regression. A low immune index (<1) was defined as immunotype A and a high immune index (≥1) was defined as immunotype B. The 5-year overall survival rate for immunotype A was higher than that for immunotype B in the training set and the validation set (70.0% vs 37.0%, P < 0.001; 68.9% vs 47.5%, P = 0.002; respectively). Moreover, the immune index showed higher prediction efficiency compared with all the single immune cells which we selected. When combined with the immune index, the areas under the curve (AUC) of the TNM staging system in both sets were elevated from 0.677 to 0.787 and from 0.631 to 0.694, respectively. Interestingly, gemcitabine-based chemotherapy only benefits stage II patients of immunotype B and stage III patients of both immunotype A and immunotype B (P = 0.015, P = 0.030, P = 0.011, respectively) but does not work in stage II patients of immunotype A (P = .307). Taken together, the immune index could effectively predict prognosis and the benefits of gemcitabine-based chemotherapy and might improve on the TNM staging system.

Copy number variants in lipid metabolism genes are associated with gallstones disease in men

Gallstones Disease (GSD) is one of the most common digestive diseases requiring hospitalization and surgical procedures in the world. GSD has a high prevalence in populations with European or Amerindian ancestry (10–20%) and the influence of genetic factors is broadly acknowledged. However, known genetic variants do not entirely explain the disease heritability suggesting that additional genetic variants remain to be identified. Here, we examined the association of copy number variants (CNVs) with GSD in a sample of 4778 individuals (1929 GSD cases and 2849 controls) including two European cohorts from Germany (n = 3702) and one admixed Latin American cohort from Chile (n = 1076). We detected 2936 large and rare CNVs events (size > 100 kb, frequency < 1%). Case-control burden analysis and generalized linear regression models revealed significant association of CNVs with GSD in men, with the strongest effect observed with CNVs overlapping lipid metabolism genes (p-value = 6.54 × 10^–4; OR = 2.76; CI 95% = 1.53–4.89). Our results indicate a clear link between CNVs and GSD in men and provides additional evidence that the genetic components of risk for GSD are complex, can be sex specific and include CNVs affecting genes involved in lipid metabolism.

Two findings of gallstones in archaeological mummies from Colombia

Results involving the analysis of gallstones found in two pre-Hispanic Colombian mummies are presented. By applying SEM, X-ray diffraction (XRD), sectioning, and CT-scan Hounsfield Units, we were able to identify these choleliths as mainly formed by cholesterol. The number of reports on gallstones in archaeological human remains from South America is very small, making these two cases an important addition to what little is known about ancient gallstone disease on the continent.

A Single-Nucleotide Polymorphism of αVβ₃ Integrin Is Associated with the Andes Virus Infection Susceptibility

The AndesOrthohantavirus (ANDV), which causes the hantavirus cardiopulmonary syndrome, enters cells via integrins, and a change from leucine to proline at residue 33 in the PSI domain (L33P), impairs ANDV recognition. We assessed the association between this human polymorphism and ANDV infection. We defined susceptible and protective genotypes as “TT” (coding leucine) and “CC” (coding proline), respectively. TT was present at a rate of 89.2% (66/74) among the first cohort of ANDV cases and at 60% (63/105) among exposed close-household contacts, who remained uninfected (p < 0.05). The protective genotype (CC) was absent in all 85 ANDV cases, in both cohorts, and was present at 11.4% of the exposed close-household contacts who remained uninfected. Logistic regression modeling for risk of infection had an OR of 6.2–12.6 (p < 0.05) in the presence of TT and well-known ANDV risk activities. Moreover, an OR of 7.3 was obtained when the TT condition was analyzed for two groups exposed to the same environmental risk. Host genetic background was found to have an important role in ANDV infection susceptibility, in the studied population.

Whole Genome Sequence, Variant Discovery and Annotation in Mapuche-Huilliche Native South Americans

Whole human genome sequencing initiatives help us understand population history and the basis of genetic diseases. Current data mostly focuses on Old World populations, and the information of the genomic structure of Native Americans, especially those from the Southern Cone is scant. Here we present annotation and variant discovery from high-quality complete genome sequences of a cohort of 11 Mapuche-Huilliche individuals (HUI) from Southern Chile. We found approximately 3.1 × 106 single nucleotide variants (SNVs) per individual and identified 403,383 (6.9%) of novel SNVs events. Analyses of large-scale genomic events detected 680 copy number variants (CNVs) and 4,514 structural variants (SVs), including 398 and 1,910 novel events, respectively. Global ancestry composition of HUI genomes revealed that the cohort represents a sample from a marginally admixed population from the Southern Cone, whose main genetic component derives from Native American ancestors. Additionally, we found that HUI genomes contain variants in genes associated with 5 of the 6 leading causes of noncommunicable diseases in Chile, which may have an impact on the risk of prevalent diseases in Chilean and Amerindian populations. Our data represents a useful resource that can contribute to population-based studies and for the design of early diagnostics or prevention tools for Native and admixed Latin American populations.

Variants in ABCG8 and TRAF3 genes confer risk for gallstone disease in admixed Latinos with Mapuche Native American ancestry

Latin Americans and Chilean Amerindians have the highest prevalence of gallstone disease (GSD) and gallbladder cancer (GBC) in the world. A handful of loci have been associated with GSD in populations of predominantly European ancestry, however, they only explain a small portion of the genetic component of the disease. Here, we performed a genome-wide association study (GWAS) for GSD in 1,095 admixed Chilean Latinos with Mapuche Native American ancestry. Disease status was assessed by cholecystectomy or abdominal ultrasonography. Top-10 candidate variants surpassing the suggestive cutoff of P < 1 × 10⁻⁵ in the discovery cohort were genotyped in an independent replication sample composed of 1,643 individuals. Variants with positive replication were further examined in two European GSD populations and a Chilean GBC cohort. We consistently replicated the association of ABCG8 gene with GSD (rs11887534, P = 3.24 × 10⁻⁸, OR = 1.74) and identified TRAF3 (rs12882491, P = 1.11 × 10⁻⁷, OR = 1.40) as a novel candidate gene for the disease in admixed Chilean Latinos. ABCG8 and TRAF3 variants also conferred risk to GBC. Gene expression analyses indicated that TRAF3 was significantly decreased in gallbladder (P = 0.015) and duodenal mucosa (P = 0.001) of GSD individuals compared to healthy controls, where according to GTEx data in the small intestine, the presence of the risk allele contributes to the observed effect. We conclude that ABCG8 and TRAF3 genes are associated with GSD and GBC in admixed Latinos and that decreased TRAF3 levels could enhance gallbladder inflammation as is observed in GSD and GSD-associated GBC.

Incidence and Risk of Gallstone Disease in Gilbert's Syndrome Patients in Indian Population

BACKGROUND/OBJECTIVES

Individuals with Gilbert's syndrome (GS) harbor mutations in the UGT1A1 gene and are known to have elevated levels of bilirubin, which enhances the risk for gall stone formation. The aim of this study is to screen Indian patients with GS for the incidence of gall stone disease.

METHODS

Individuals with persistently elevated serum bilirubin levels were genotyped for two polymorphisms (rs8175347; rs4148323) in UGT1A1 gene to confirm GS in them. Flanking regions of the above polymorphisms were amplified followed by direct sequencing. Ultrasonography was done to detect gallstone disease. Clinical data, including assessment of liver function, circulating levels of total and direct bilirubin, as well as routine hematological parameters were obtained as per standard procedures (Autoanalyzer).

RESULTS

Of the total 1621 individuals subjected to genotyping, 1191 (1149 males of 29.6 ± 11.3 years with mean BMI of 22.1 ± 3.7 kg/m² and 42 females of 30.8 ± 14.8 years with mean BMI of 20.9 ± 3.7 kg/m²) were confirmed to have GS. Gall bladder abnormalities including cholelithiasis (n = 106/1191; 8.9%), polyps (n = 18/1191; 1.5%) and gallbladder wall thickening (n = 17/1191; 1.4%) were noted. Incidence of gall stone disease was observed in 103 males (out of 1149) and 3 females (out of 42) indicating the risk of the disease to be 9.0% and 7.1% respectively in males and females with GS.

CONCLUSION

Early recognition of GS by genetic analysis is required before these patients with intermittent episodes of jaundice run the risk of unnecessary operations on their bile ducts from the mistaken assumption ascribing the jaundice to a stone which has been left behind.

Role of the biliary microbiome in gallstone disease

Gallstone disease is caused by multiple pathogenic factors and is common worldwide. Most studies have focused on the significance of the biliary microbiome in gallstone pathogenesis. Areas covered: In this study, the epidemiology of gallstone diseases and the existence, composition, origin, and mechanisms of the biliary microbiota were reviewed. Mechanisms involved in promoting the formation of different types of gallstones were also emphasized. The antibiotic susceptibility of the biliary microbiota is briefly discussed because it may guide clinical strategies. Expert commentary: The biliary microbiome facilitates the formation of brown pigment stones. Although glycoprotein (mucin) may be pivotal for many promoting substances to coagulate and integrate relevant components, new mechanisms involving prostaglandins, oxysterols, oxygen free radicals, and lipopolysaccharides have been discovered. Furthermore, specific bacterial species such as Helicobacter and Salmonella are involved in the pathogenesis of cholesterol gallstones. Recently, metabolomics of the biliary microbiome has been used to determine the detailed mechanisms that promote gallstone formation. Previously, the bacterial effects involved in the pathogenesis of brown pigment stones have not been analyzed in detail. Whether the administration of antibiotics is related to prophylaxis for gallstone formation and gallstone-associated infections remains unclear.

Echogenic material in the fetal gallbladder: prevalence, sonographic spectrum, and perinatal outcome in an unselected third-trimester population

Objective: To determine the prevalence, sonographic spectrum, and clinical significance of echogenic material in the fetal gallbladder in our population.Methods: Sonographic visualization of the fetal gallbladder was attempted in 3894 consecutive third-trimester pregnancies (4026 fetuses). Gallbladder content was classified as clear (anechoic), containing echogenic material that was either diffuse (sludge), or presenting as a single focus or multiple foci (gallstone(s)). Information on the clinical course was obtained by reviewing the medical records or contacting the provider or the parents themselves.Results: During the three and a half-year study period from July 2014 to December 2017, 19 fetuses were identified as having echogenic material in the gallbladder (prevalence 1/211, 0.47%). Among them, echogenic biliary sludge was found in eight fetuses (42%); all eight were asymptomatic and a normal gallbladder was documented postnatally in four of them. Single (n = 3) or multiple (n = 8) echogenic foci were found in 58% of cases, which was associated with a good prognosis and subsequent resolution between 1 and 10 months of life in all cases.Conclusions: The prevalence of echogenic material in the fetal gallbladder in our population was similar to that previously reported in the literature. The prognosis appears to be favorable, with resolution and without subsequent postnatal hepatic or gastrointestinal complications in all cases.

Nonalcoholic fatty liver disease, cholesterol gallstones, and cholecystectomy: new insights on a complex relationship

PURPOSE OF REVIEW

Gallstone disease (GSD) and nonalcoholic fatty liver disease (NAFLD often coexist in a given patient and both conditions are associated to obesity and insulin resistance. The relationship between GSD and NAFLD is complex and bidirectional. In the present review, we summarize the existing information on the complex link between GSD and NAFLD and the potential implications for patient care.

RECENT FINDINGS

Several clinical studies and systematic reviews have addressed the association between NAFLD and GSD underscoring that NAFLD is an independent risk factor for GSD. Conversely, GSD has been found also to be an independent risk factor for NAFLD with GSD potentially being linked to greater disease severity. In addition to the data showing association of NAFLD and GSD, recent evidence has also showed that cholecystectomy may itself be a risk factor for NAFLD development. The complex and bidirectional relationship between these diseases is partially explained by a number of common pathogenic links but the precise underlying mechanisms of the association of GSD and NAFLD need to be better delineated. Also, although the mechanisms of the promotional effect of cholecystectomy on NAFLD development are unknown, recent findings unveiling new aspects of gallbladder physiology and endocrine actions of bile acids provide a framework to advance research in this field.

SUMMARY

In this review, we address the different aspects of the complex association between NAFLD and GSD. The potential underlying mechanisms and recent information on endocrine actions of bile acids and the gallbladder are reviewed.

Sex and ethnic/racial-specific risk factors for gallbladder disease

BACKGROUND

Gallbladder disease (GBD) is a highly prevalent condition; however, little is known about potential differences in risk factors by sex and ethnicity/race. Our aim was to evaluate dietary, reproductive and obesity-related factors and GBD in multiethnic populations.

METHODS

We performed a prospective analysis from the Multiethnic Cohort study who self-identified as non-Hispanic White (n = 32,103), African American (n = 30,209), Japanese (n = 35,987), Native Hawaiian (n = 6942) and Latino (n = 39,168). GBD cases were identified using Medicare and California hospital discharge files (1993-2012) and self-completed questionnaires. We used exposure information on the baseline questionnaire to identify exposures of interest. Associations were estimated by hazard ratios and 95% confidence intervals using Cox models adjusted for confounders.

RESULT

After a median 10.7 years of follow-up, there were 13,437 GBD cases. BMI over 25 kg/m2, diabetes, past and current smoking, red meat consumption, saturated fat and cholesterol were significant risk factors across ethnic/racial populations (p-trends < 0.01). Protective factors included vigorous physical activity, alcohol use, fruits, vegetables and foods rich in dietary fiber (p-trends < 0.01). Carbohydrates were inversely associated with GBD risk only among women and Latinos born in South America/Mexico (p-trend < 0.003). Parity was a significant risk factor among women; post-menopausal hormones use was only associated with an increased risk among White women (estrogen-only: HR = 1.24; 95% CI = 1.07-1.43 and estrogen + progesterone: HR = 1.23; 95% CI = 1.06-1.42).

CONCLUSION

Overall, dietary, reproductive and obesity-related factors are strong risk factors for GBD affecting men and women of different ethnicities/races; however some risk factors appear stronger in women and certain ethnic groups.

Estimation of life expectancy of patients diagnosed with the most common cancers in the Valparaiso Region, Chile

Background

The 1000s of people who die from cancer each year have become one of the leading causes of death among the Chilean population, placing it as the second cause of death in the region of Valparaiso between 1997 and 2003. Statistics have provided different measures regarding the life expectancy of cancer patients which have resulted in being useful to establish courses of action for prevention and treatment plans to follow.

Methods

Data was extracted from the cancer module of the Epidemiology Assistance System (SADEPI for its initials in Spanish) which stores information about cancer cases in the provinces of Valparaiso and Petorca. The survival period is defined as the difference in days between the date of occurrence and the date of death of the patient by separating the data into quartiles.

Results

The more frequent cancers in the region of Valparaiso behave similarly to global behaviours of the disease. The majority of affected patients are around 65 years of age which progressively lowers its occurrence in younger adults under the age of 45.

Conclusions

Further efforts are required for early detection and timely access to treatment for cancer patients. Statistics are an important support in achieving this.

Cancer of the gallbladder-Chilean statistics

Chile has the world's highest rate of incidence as well as death from cancer of the gallbladder and biliary ducts. The problem is most acute in the southern provinces. These areas constitute the low average income associated with low educational attainment and a high rate of obesity compared with the rest of Chile. We could also include genetic factors related to processes of lithogenesis to these elements which are more common among the Mapuche. This population sub-group could benefit from special government programmes for early diagnosis and treatment of lithiasic disease and for the management of risk factors such as obesity. In this way, we could reduce the mortality rate of gallbladder cancer.

Gallstones: new insights into an old story

Gallstones, particularly cholesterol gallstones, are common in Western populations and may cause symptoms such as biliary colic or complications such as acute cholecystitis or gallstone pancreatitis. Recent studies have allowed for a better understanding of the risk of symptoms or complications in patients with gallstones. In addition, newer data suggest an association of gallstones with overall mortality, cardiovascular disease, gastrointestinal cancers, and non-alcoholic fatty liver disease. Knowledge of appropriate indications and timing of cholecystectomy, particularly for mild biliary pancreatitis, has gradually accumulated. Lastly, there are exciting possibilities for novel agents to treat or prevent cholesterol stone disease. This review covers new advances in our understanding of the natural history, clinical associations, and management of gallstone disease.

Frequency of cholecystectomy and associated sociodemographic and clinical risk factors in the ELSA-Brasil study

CONTEXT AND OBJECTIVE

There are few data in the literature on the frequency of cholecystectomy in Brazil. The frequency of cholecystectomy and associated risk factors were evaluated in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

DESIGN AND SETTING

Cross-sectional study using baseline data on 5061 participants in São Paulo.

METHODS

The frequency of cholecystectomy and associated risk factors were evaluated over the first two years of follow-up of the study and over the course of life. A multivariate regression analysis was presented: odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

A total of 4716 individuals (93.2%) with information about cholecystectomy were included. After two years of follow-up, 56 had undergone surgery (1.2%: 1.7% of the women; 0.6% of the men). A total of 188 participants underwent cholecystectomy during their lifetime. The risk factors associated with surgery after the two-year follow-up period were female sex (OR, 2.85; 95% CI, 1.53-5.32), indigenous ethnicity (OR, 2.1; 95% CI, 2.28-15.85) and body mass index (BMI) (OR, 1.10; 95% CI, 1.01-1.19 per 1 kg/m2 increase). The risk factors associated over the lifetime were age (OR, 1.03; 95% CI, 1.02-1.05 per one year increase), diabetes (OR, 1.92; 95% CI, 1.34-2.76) and previous bariatric surgery (OR, 5.37; 95% CI, 1.53-18.82). No association was found with parity or fertile age.

CONCLUSION

Female sex and high BMI remained as associated risk factors while parity and fertile age lost significance. New factors such as bariatric surgery and indigenous ethnicity have gained importance in this country.

Gallstones

Gallstones grow inside the gallbladder or biliary tract. These stones can be asymptomatic or symptomatic; only gallstones with symptoms or complications are defined as gallstone disease. Based on their composition, gallstones are classified into cholesterol gallstones, which represent the predominant entity, and bilirubin ('pigment') stones. Black pigment stones can be caused by chronic haemolysis; brown pigment stones typically develop in obstructed and infected bile ducts. For treatment, localization of the gallstones in the biliary tract is more relevant than composition. Overall, up to 20% of adults develop gallstones and >20% of those develop symptoms or complications. Risk factors for gallstones are female sex, age, pregnancy, physical inactivity, obesity and overnutrition. Factors involved in metabolic syndrome increase the risk of developing gallstones and form the basis of primary prevention by lifestyle changes. Common mutations in the hepatic cholesterol transporter ABCG8 confer most of the genetic risk of developing gallstones, which accounts for ∼25% of the total risk. Diagnosis is mainly based on clinical symptoms, abdominal ultrasonography and liver biochemistry tests. Symptoms often precede the onset of the three common and potentially life-threatening complications of gallstones (acute cholecystitis, acute cholangitis and biliary pancreatitis). Although our knowledge on the genetics and pathophysiology of gallstones has expanded recently, current treatment algorithms remain predominantly invasive and are based on surgery. Hence, our future efforts should focus on novel preventive strategies to overcome the onset of gallstones in at-risk patients in particular, but also in the population in general.

Frequency of Cholelithiasis and Biliary Pathology in the Easter Island Rapanui and Non-Rapanui Populations

BACKGROUND

Chile is one of the countries with the highest prevalence of cholelithiasis worldwide, considering the Mapuche ethnicity as a risk factor for developing this pathology. Moreover, cholelithiasis is the main risk factor for developing gallbladder cancer, being the fifth cause of cancer death in Chile. The purpose of this study was to compare the frequency of cholelithiasis and biliary pathology among the population belonging to Rapanui ethnicity and non-Rapanui population living on Easter Island.

MATERIALS AND METHODS

In this retrospective case-control study, a total of 609 abdominal ultrasonographs performed consecutively in Hanga Roa Hospital during the period August 2012 to January 2015 were analyzed. Multiple logistic regression was used to obtain odds ratio (OR) and 95% confidence intervals (95% CI) of cholelithiasis and biliary pathology, adjusting for age, gender and referral diagnostic hypothesis.

RESULTS

In the Rapanui population the frequency for cholelithiasis and biliary pathology was 6.4% and 13%, meanwhile for the non-Rapanui population it was 13% and 22% respectively. Compared to the non-Rapanui Chilean population, the Rapanui ethnicity presented an OR of 0.53 (95% CI: 0.29-0.95) for cholelithiasis and OR of 0.52 (95% CI: 0.33-0.82) for biliary pathology.

CONCLUSIONS

We found statistically significant ethnic differences in the frequency of cholelithiasis and biliary disease among the population of Rapanui and non-Rapanui ethnicity, so that this could be a protective factor for the development of biliary pathology, given the Chilean population context. Other studies including community population to determine the real prevalence of cholelithiasis and analyze the protective role of Rapanui ethnicity on this disease are necessary.

Association of Single-Nucleotide Polymorphisms in IL28B, but Not TNF-α, With Severity of Disease Caused by Andes Virus

BACKGROUND

Andes virus (ANDV) is the sole etiologic agent of hantavirus cardiopulmonary syndrome (HCPS) in Chile, with a fatality rate of about 35%. Individual host factors affecting ANDV infection outcome are poorly understood. In this case-control genetic association analysis, we explored the link between single-nucleotide polymorphisms (SNPs) rs12979860, rs8099917 and rs1800629 and the clinical outcome of ANDV-induced disease. The SNPs rs12979860 and rs8099917 are known to play a role in the differential expression of the interleukin 28B gene (IL28B), whereas SNP rs1800629 is implicated in the expression of tumor necrosis factor α gene (TNF-α).

METHODS

A total of 238 samples from confirmed ANDV-infected patients collected between 2006 and 2014, and categorized according to the severity of the disease, were genotyped for SNPs rs12979860, rs8099917, and rs1800629.

RESULTS

Analysis of IL28B SNPs rs12979860 and rs8099917 revealed a link between homozygosity of the minor alleles (TT and GG, respectively), displaying a mild disease progression, whereas heterozygosity or homozygosity for the major alleles (CT/CC and TG/TT, respectively) in both IL28B SNPs is associated with severe disease. No association with the clinical outcome of HCPS was observed for TNF-α SNP rs1800629 (TNF -308G>A).

CONCLUSIONS

The IL28B SNPs rs12979860 and rs8099917, but not TNF-α SNP rs1800629, are associated with the clinical outcome of ANDV-induced disease, suggesting a possible link between IL28B expression and ANDV pathogenesis.

Clinical effectiveness and cost-effectiveness of cholecystectomy compared with observation/conservative management for preventing recurrent symptoms and complications in adults presenting with uncomplicated symptomatic gallstones or cholecystitis: a systematic review and economic evaluation

BACKGROUND

Approximately 10-15% of the adult population suffer from gallstone disease, cholelithiasis, with more women than men being affected. Cholecystectomy is the treatment of choice for people who present with biliary pain or acute cholecystitis and evidence of gallstones. However, some people do not experience a recurrence after an initial episode of biliary pain or cholecystitis. As most of the current research focuses on the surgical management of the disease, less attention has been dedicated to the consequences of conservative management.

OBJECTIVES

To determine the clinical effectiveness and cost-effectiveness of cholecystectomy compared with observation/conservative management in people presenting with uncomplicated symptomatic gallstones (biliary pain) or cholecystitis.

DATA SOURCES

We searched all major electronic databases (e.g. MEDLINE, EMBASE, Science Citation Index, Bioscience Information Service, Cochrane Central Register of Controlled Trials) from 1980 to September 2012 and we contacted experts in the field.

REVIEW METHODS

Evidence was considered from randomised controlled trials (RCTs) and non-randomised comparative studies that enrolled people with symptomatic gallstone disease (pain attacks only and/or acute cholecystitis). Two reviewers independently extracted data and assessed the risk of bias of included studies. Standard meta-analysis techniques were used to combine results from included studies. A de novo Markov model was developed to assess the cost-effectiveness of the interventions.

RESULTS

Two Norwegian RCTs involving 201 participants were included. Eighty-eight per cent of people randomised to surgery and 45% of people randomised to observation underwent cholecystectomy during the 14-year follow-up period. Participants randomised to observation were significantly more likely to experience gallstone-related complications [risk ratio = 6.69; 95% confidence interval (CI) 1.57 to 28.51; p = 0.01], in particular acute cholecystitis (risk ratio = 9.55; 95% CI 1.25 to 73.27; p = 0.03), and less likely to undergo surgery (risk ratio = 0.50; 95% CI 0.34 to 0.73; p = 0.0004), experience surgery-related complications (risk ratio = 0.36; 95% CI 0.16 to 0.81; p = 0.01) or, more specifically, minor surgery-related complications (risk ratio = 0.11; 95% CI 0.02 to 0.56; p = 0.008) than those randomised to surgery. Fifty-five per cent of people randomised to observation did not require an operation during the 14-year follow-up period and 12% of people randomised to cholecystectomy did not undergo the scheduled operation. The results of the economic evaluation suggest that, on average, the surgery strategy costs £1236 more per patient than the conservative management strategy but was, on average, more effective. An increase in the number of people requiring surgery while treated conservatively corresponded to a reduction in the cost-effectiveness of the conservative strategy. There was uncertainty around some of the parameters used in the economic model.

CONCLUSIONS

The results of this assessment indicate that cholecystectomy is still the treatment of choice for many symptomatic people. However, approximately half of the people in the observation group did not require surgery or suffer complications in the long term indicating that a conservative therapeutic approach may represent a valid alternative to surgery in this group of people. Owing to the dearth of current evidence in the UK setting a large, well-designed, multicentre trial is needed.

STUDY REGISTRATION

The study was registered as PROSPERO CRD42012002817.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Epidemiological, clinical and biochemical characterization of the p.(Ala359Asp) SMPD1 variant causing Niemann-Pick disease type B

Niemann-Pick disease type B (NPDB) is a rare, inherited lysosomal storage disorder that occurs due to variants in the sphingomyelin phosphodiesterase 1 (SMPD1) gene and the resultant deficiency of acid sphingomyelinase (ASM) activity. While numerous variants causing NPDB have been described, only a small number have been studied in any detail. Herein, we describe the frequency of the p.(Ala359Asp) variant in the healthy Chilean population, and determine the haplotype background of homozygous patients to establish if this variant originated from a common founder. Genomic DNA samples from 1691 healthy individuals were analyzed for the p.(Ala359Asp) variant. The frequency of p.(Ala359Asp) was found to be 1/105.7, predicting a disease incidence of 1/44 960 in Chile, higher than the incidence estimated by the number of confirmed NPDB cases. We also describe the clinical characteristics of 13 patients homozygous for p.(Ala359Asp) and all of them had moderate to severe NPDB disease. In addition, a conserved haplotype and shared 280 Kb region around the SMPD1 gene was observed in the patients analyzed, indicating that the variant originated from a common ancestor. The haplotype frequency and mitochondrial DNA analysis suggest an Amerindian origin for the variant. To assess the effect of the p.(Ala359Asp) variant, we transfected cells with the ASM-p.(Ala359Asp) cDNA and the activity was only 4.2% compared with the wild-type cDNA, definitively demonstrating the causative effect of the variant on ASM function. Information on common variants such as p.(Ala359Asp) is essential to guide the successful implementation for future therapies and benefit to patients.

Gallbladder cancer: epidemiology and outcome

Gallbladder cancer, though generally considered rare, is the most common malignancy of the biliary tract, accounting for 80%-95% of biliary tract cancers. An early diagnosis is essential as this malignancy progresses silently with a late diagnosis, often proving fatal. Its carcinogenesis follows a progression through a metaplasia-dysplasia-carcinoma sequence. This comprehensive review focuses on and explores the risks, management, and outcomes for primary gallbladder carcinoma. Epidemiological studies have identified striking geographic and ethnic disparities - inordinately high occurrence in American Indians, elevated in Southeast Asia, yet quite low elsewhere in the Americas and the world. Age, female sex, congenital biliary tract anomalies, and a genetic predisposition represent important risk factors that are immutable. Environmental triggers play a critical role in eliciting cancer developing in the gallbladder, best exemplified by cholelithiasis and chronic inflammation from biliary tract and parasitic infections. Mortality rates closely follow incidence; those countries with the highest prevalence of gallstones experience the greatest mortality from gallbladder cancer. Vague symptoms often delay the diagnosis of gallbladder cancer, contributing to its overall progression and poor outcome. Surgery represents the only potential for cure. Some individuals are fortunate to be incidentally found to have gallbladder cancer at the time of cholecystectomy being performed for cholelithiasis. Such an early diagnosis is imperative as a late presentation connotes advanced staging, nodal involvement, and possible recurrence following attempted resection. Overall mean survival is a mere 6 months, while 5-year survival rate is only 5%. The dismal prognosis, in part, relates to the gallbladder lacking a serosal layer adjacent to the liver, enabling hepatic invasion and metastatic progression. Improved imaging modalities are helping to diagnose patients at an earlier stage. The last decade has witnessed improved outcomes as aggressive surgical management and preoperative adjuvant therapy has helped prolong survival in patients with gallbladder cancer. In the future, the development of potential diagnostic markers for disease will yield screening opportunities for those at risk either with ethnic susceptibility or known anatomic anomalies of the biliary tract. Meanwhile, clarification of the value of prophylactic cholecystectomy should provide an opportunity for secondary prevention. Primary prevention will arrive once the predictive biomarkers and environmental risk factors are more clearly identified.

Gallbladder cancer: epidemiology and outcome

Gallbladder cancer, though generally considered rare, is the most common malignancy of the biliary tract, accounting for 80%-95% of biliary tract cancers. An early diagnosis is essential as this malignancy progresses silently with a late diagnosis, often proving fatal. Its carcinogenesis follows a progression through a metaplasia-dysplasia-carcinoma sequence. This comprehensive review focuses on and explores the risks, management, and outcomes for primary gallbladder carcinoma. Epidemiological studies have identified striking geographic and ethnic disparities - inordinately high occurrence in American Indians, elevated in Southeast Asia, yet quite low elsewhere in the Americas and the world. Age, female sex, congenital biliary tract anomalies, and a genetic predisposition represent important risk factors that are immutable. Environmental triggers play a critical role in eliciting cancer developing in the gallbladder, best exemplified by cholelithiasis and chronic inflammation from biliary tract and parasitic infections. Mortality rates closely follow incidence; those countries with the highest prevalence of gallstones experience the greatest mortality from gallbladder cancer. Vague symptoms often delay the diagnosis of gallbladder cancer, contributing to its overall progression and poor outcome. Surgery represents the only potential for cure. Some individuals are fortunate to be incidentally found to have gallbladder cancer at the time of cholecystectomy being performed for cholelithiasis. Such an early diagnosis is imperative as a late presentation connotes advanced staging, nodal involvement, and possible recurrence following attempted resection. Overall mean survival is a mere 6 months, while 5-year survival rate is only 5%. The dismal prognosis, in part, relates to the gallbladder lacking a serosal layer adjacent to the liver, enabling hepatic invasion and metastatic progression. Improved imaging modalities are helping to diagnose patients at an earlier stage. The last decade has witnessed improved outcomes as aggressive surgical management and preoperative adjuvant therapy has helped prolong survival in patients with gallbladder cancer. In the future, the development of potential diagnostic markers for disease will yield screening opportunities for those at risk either with ethnic susceptibility or known anatomic anomalies of the biliary tract. Meanwhile, clarification of the value of prophylactic cholecystectomy should provide an opportunity for secondary prevention. Primary prevention will arrive once the predictive biomarkers and environmental risk factors are more clearly identified.

Gallbladder cancer: epidemiology and outcome

Gallbladder cancer, though generally considered rare, is the most common malignancy of the biliary tract, accounting for 80%–95% of biliary tract cancers. An early diagnosis is essential as this malignancy progresses silently with a late diagnosis, often proving fatal. Its carcinogenesis follows a progression through a metaplasia–dysplasia–carcinoma sequence. This comprehensive review focuses on and explores the risks, management, and outcomes for primary gallbladder carcinoma. Epidemiological studies have identified striking geographic and ethnic disparities – inordinately high occurrence in American Indians, elevated in Southeast Asia, yet quite low elsewhere in the Americas and the world. Age, female sex, congenital biliary tract anomalies, and a genetic predisposition represent important risk factors that are immutable. Environmental triggers play a critical role in eliciting cancer developing in the gallbladder, best exemplified by cholelithiasis and chronic inflammation from biliary tract and parasitic infections. Mortality rates closely follow incidence; those countries with the highest prevalence of gallstones experience the greatest mortality from gallbladder cancer. Vague symptoms often delay the diagnosis of gallbladder cancer, contributing to its overall progression and poor outcome. Surgery represents the only potential for cure. Some individuals are fortunate to be incidentally found to have gallbladder cancer at the time of cholecystectomy being performed for cholelithiasis. Such an early diagnosis is imperative as a late presentation connotes advanced staging, nodal involvement, and possible recurrence following attempted resection. Overall mean survival is a mere 6 months, while 5-year survival rate is only 5%. The dismal prognosis, in part, relates to the gallbladder lacking a serosal layer adjacent to the liver, enabling hepatic invasion and metastatic progression. Improved imaging modalities are helping to diagnose patients at an earlier stage. The last decade has witnessed improved outcomes as aggressive surgical management and preoperative adjuvant therapy has helped prolong survival in patients with gallbladder cancer. In the future, the development of potential diagnostic markers for disease will yield screening opportunities for those at risk either with ethnic susceptibility or known anatomic anomalies of the biliary tract. Meanwhile, clarification of the value of prophylactic cholecystectomy should provide an opportunity for secondary prevention. Primary prevention will arrive once the predictive biomarkers and environmental risk factors are more clearly identified.