Aflatoxin exposure and viral hepatitis in the etiology of liver cirrhosis in the Gambia, West Africa

Synergism in actions of HBV with aflatoxin in cancer development

Aflatoxin B1 (AFB1) is a fungal metabolite found in animal feeds and human foods. It is one of the most toxic and carcinogenic of aflatoxins and is classified as a Group 1 carcinogen. Dietary exposure to AFB1 and infection with chronic Hepatitis B Virus (HBV) make up two of the major risk factors for hepatocellular carcinoma (HCC). These two major risk factors raise the probability of synergism between the two agents. This review proposes some collaborative molecular mechanisms underlying the interaction between AFB1 and HBV in accelerating or magnifying the effects of HCC. The HBx viral protein is one of the main viral proteins of HBV and has many carcinogenic qualities that are involved with HCC. AFB1, when metabolized by CYP450, becomes AFB1-exo-8,9-epoxide (AFBO), an extremely toxic compound that can form adducts in DNA sequences and induce mutations. With possible synergisms that exist between HBV and AFB1 in mind, it is best to treat both agents simultaneously to reduce the risk by HCC.

Aflatoxins in food products consumed in the Kingdom of Saudi Arabia: A preliminary dietary risk assessment

Aflatoxins (AFs) are hepatotoxic, mutagenic, genotoxic, and immunosuppressive toxins. Several food commodities consumed in the Kingdom of Saudi Arabia (KSA) are susceptible to AF contamination because of improper storage practices and the warm and humid climate of the country. Therefore, the occurrence of AFs in 2388 food samples was measured and the estimated daily intake (EDI) of AFs in Saudi adults was assessed. The risks of AFB1 exposure were characterized using the margin of exposure (MoE) approach and by estimating the number of possible hepatocellular carcinoma (HCC) cases in the KSA. The results revealed that 12.1% of the analyzed samples were contaminated with AFs and the highest concentration of total AFs was observed in the nut and seed group. The mean EDI of AFB1 was estimated to be 0.21 and 0.55 ng/kg body weight (bw)/day for the lower bound (LB) and upper bound (UB) scenarios, respectively. The MoEs were estimated to be 1902.4 and 722.1, while the estimated liver cancer risk ranged from 0.002 to 0.008 cancer cases/year/100,000 persons. Based on the study's findings, contamination with AFs in the KSA is low; however, AFs are considered potent genotoxic contaminants, and therefore, exposure through food should be kept as low as possible.

Prevalence of Liver Steatosis and Fibrosis in the General Population and Various High-Risk Populations: A Nationwide Study With 5.7 Million Adults in China

BACKGROUND & AIMS

This study aimed to estimate the prevalence of liver steatosis and fibrosis in the general population and populations with potential risk factors in China, so as to inform policies for the screening and management of fatty liver disease and liver fibrosis in general and high-risk populations.

METHODS

This cross-sectional, population-based, nationwide study was based on the database of the largest health check-up chain in China. Adults from 30 provinces who underwent a check-up between 2017 and 2022 were included. Steatosis and fibrosis were assessed and graded by transient elastography. Overall and stratified prevalence was estimated among the general population and various subpopulations with demographic, cardiovascular, and chronic liver disease risk factors. A mixed effect regression model was used to examine predictors independently associated with steatosis and fibrosis.

RESULTS

In 5,757,335 participants, the prevalence of steatosis, severe steatosis, advanced fibrosis, and cirrhosis was 44.39%, 10.57%, 2.85%, and 0.87%, respectively. Participants who were male, with obesity, diabetes, hypertension, dyslipidemia, metabolic syndrome, or elevated alanine aminotransferase or aspartate aminotransferase had a significantly higher prevalence of all grades of steatosis and fibrosis, and those with fatty liver, decreased albumin or platelet count, and hepatitis B virus infection also had a significantly higher prevalence of fibrosis than their healthy counterparts. Most cardiovascular and chronic liver disease risk factors were independent predictors for steatosis and fibrosis, except for dyslipidemia for fibrosis.

CONCLUSIONS

A substantial burden of liver steatosis and fibrosis was found in China. Our study provides evidence for shaping future pathways for screening and risk stratification of liver steatosis and fibrosis in the general population. The findings of this study highlight that fatty liver and liver fibrosis should be included in disease management programs as targets for screening and regular monitoring in high-risk populations, especially in those with diabetes.

Contribution of Aflatoxin B1 Exposure to Liver Cirrhosis in Eastern Ethiopia: A Case-Control Study

Background

Liver cirrhosis is a global health problem due to a large number of disability-associated life years and mortality. However, evidence is scarce on its causes in Eastern-Ethiopia, a place where there is a high prevalence of liver cirrhosis of unknown etiology. This study attempted to identify the risk factors related to liver cirrhosis in the area.

Methods

A case-control study was conducted at a tertiary care hospital from January 2020 to July 2021. Following diagnoses using an ultrasound-based cirrhosis scale, a total of 127 cases were identified and compared with 253 control patients. A structured questionnaire and data abstraction form were used to collect demographic, lifestyle, and clinical information. A blood sample was also taken from each participant for clinical chemistry, hepatitis B virus (HBV), and hepatitis C virus tests as well as for an aflatoxin B1 (AFB1) albumin adduct (AF-alb) assay. Binary logistic regression analysis was used to determine predictors of liver cirrhosis.

Results

AF-alb levels were detected in 75% of the cases and 64% of the controls, with a median (IQR) level of 11 pg/mg (5.5-25) and 7.0 pg/mg (4.3-20.5), respectively (p<0.05). Moreover, the number of subjects with high AF-alb levels (≥8.6 pg/mg) was greater in cases (45%, p<0.05)) than controls (28%). Age ≥55 years (adjusted odds ratio (AOR)=0.4; 95% CI: 0.2, 0.8), being a farmer (AOR= 3.0; 95% CI: 1.5, 6.0), family history of liver disease (AOR= 2.9; 95% CI: 1.1, 7.9), HBV seropositivity (AOR=4.0; 95% CI: 1.9, 8.8), and exposure to high levels of AF-alb (AOR=2.0; 95% CI: 1.1, 3.7) were significantly associated with liver cirrhosis.

Conclusion

This study found a strong link between AFB1 exposure and liver cirrhosis. Mitigation of aflatoxin exposure and a better understanding of additional environmental risk factors like pesticides may be necessary to reduce the disease burden in Ethiopia.

Aflatoxin exposure in a population of HIV patients at risk of hepatocellular carcinoma North-Central, Nigeria

Background

Aflatoxin B1causes damage to the DNA by the alkylation of bases and P53 mutation. Exposure to this mycotoxin is associated with the development of liver cancer. Measures to reduce grain and cereal contamination have been a focus however, the effects of these measures are still lagging behind and exposure continues to occur even in populations at risk of developing liver cancer.

Objective

To quantify aflatoxin B1 exposure in a population of HIV infected patients with and without HCC.

Method

This was a cross-sectional study among 196 patients with HIV and or HCC. We evaluated the exposure to aflatoxin B1 using the Aflatoxin M1 metabolite by ELISA on urine samples.

Results

A total of 196 participants consisting of 163 (83.2%) HIV positive and 28 (14.3%) HCC. Mean age is 46.64±10.8 years. The median aflatoxin (IQR) aflatoxin M1level is 177.3(112.5-272) pg/ml. Only 8(4.1%) of the participant had no exposure to aflatoxin B1. The median (IQR) aflatoxin for fibrosis score ≥ 13kpa (178.7(112.9-286.8) pg/ml) VS < 13kpa (173.5(107.9-250.4)), p = 0.046.

Conclusion

There is high prevalence of aflatoxin B1 exposure in this population. Concerted efforts must be put in place to mitigate exposure because of the potential effects of short- and long-term exposure to aflatoxin.

A nationwide cross-sectional review of in-hospital hepatitis B virus testing and disease burden estimation in Ghana, 2016 - 2021

BACKGROUND AND AIMS

Data are needed to inform hepatitis B virus (HBV) testing and treatment policies in Ghana to make progress towards achieving the 2030 WHO elimination targets. This study investigated testing patterns for HBV and described the age, sex, and region-specific prevalence of HBV infection in Ghana using hospital data.

METHODS

A nationwide multi-centre cross-sectional study was performed where hospital-based registers were reviewed. These included review of 139,966 laboratory, 169,048 blood bank, and 83,920 delivery register entries from 22 healthcare institutions in Ghana. Frequencies and proportions, and crude and pooled estimates reported. Chi squared test was used for tests of independence. Logistic regression was used to identify factors associated with a positive test result.

RESULTS

The crude HBsAg seroprevalence was 8.48% (95%CI 8.25-8.57%) with pooled estimate of 11.40% (95%CI 10.44-12.35). HBsAg seroprevalence among children under 5 years was 1.87% (95%CI 1.07-3.27) and highest age-specific seroprevalence was in those 40-49 years. The highest region-specific seroprevalences was in the Savannah (22.7%). Predictors of a positive HBsAg RDT test included female sex (OR 0.81 95% CI 0.74-0.88), and age (OR 1.005 95%CI 1.002-1.007). The proportion of parturient women receiving HBsAg testing increased between 2017 (87.2%) and 2020 (94.3%) (p < 0.001). The crude HBsAg seroprevalence in parturient women was 6.14% (95% CI 5.97-6.31). Among blood donors the crude HBsAg seroprevalence was 5.69% (95%CI 5.58-5.80). Data from 2 teaching hospitals indicated that in 2020, although 1500 HBsAg positive tests were recorded only 746 serological profile and 804 HBV DNA tests were performed. HBV e antigen seroprevalence was 6.28% (95%CI 4.73-7.84).

CONCLUSION AND RECOMMENDATIONS

Ghana remains a country with high HBV burden. There is an unequal distribution, with higher HBsAg seroprevalence in the north of the country. Furthermore, PCR testing is not widely available outside of large teaching hospitals, which limits diagnostic work-up. Hepatitis reporting systems and registers should be improved to facilitate data capture of indicators and standardised across the country to allow for comparability. Furthermore, where gains have been made in testing among pregnant women, there is a need for linkage to appropriate care.

Mycotoxins’ Toxicological Mechanisms Involving Humans, Livestock and Their Associated Health Concerns: A Review

Mycotoxins are well established toxic metabolic entities produced when fungi invade agricultural/farm produce, and this happens especially when the conditions are favourable. Exposure to mycotoxins can directly take place via the consumption of infected foods and feeds; humans can also be indirectly exposed from consuming animals fed with infected feeds. Among the hundreds of mycotoxins known to humans, around a handful have drawn the most concern because of their occurrence in food and severe effects on human health. The increasing public health importance of mycotoxins across human and livestock environments mandates the continued review of the relevant literature, especially with regard to understanding their toxicological mechanisms. In particular, our analysis of recently conducted reviews showed that the toxicological mechanisms of mycotoxins deserve additional attention to help provide enhanced understanding regarding this subject matter. For this reason, this current work reviewed the mycotoxins’ toxicological mechanisms involving humans, livestock, and their associated health concerns. In particular, we have deepened our understanding about how the mycotoxins’ toxicological mechanisms impact on the human cellular genome. Along with the significance of mycotoxin toxicities and their toxicological mechanisms, there are associated health concerns arising from exposures to these toxins, including DNA damage, kidney damage, DNA/RNA mutations, growth impairment in children, gene modifications, and immune impairment. More needs to be done to enhance the understanding regards the mechanisms underscoring the environmental implications of mycotoxins, which can be actualized via risk assessment studies into the conditions/factors facilitating mycotoxins’ toxicities.

Aflatoxin B1 exposure and liver cirrhosis in Guatemala: a case-control study

Objective

In Guatemala, cirrhosis is among the 10 leading causes of death, and mortality rates have increased lately. The reasons for this heavy burden of disease are not clear as the prevalence of prominent risk factors, such as hepatitis B virus, hepatitis C virus and heavy alcohol consumption, appears to be low. Aflatoxin B₁ (AFB₁) exposure, however, appears to be high, and thus could be associated with the high burden of cirrhosis. Whether AFB₁ increases the risk of cirrhosis in the absence of viral infection, however, is not clear.

Design

Cirrhosis cases (n=100) from two major referral hospitals in Guatemala City were compared with controls (n=200) from a cross-sectional study. Logistic regression was used to estimate the ORs and 95% CIs of cirrhosis and quintiles of AFB₁ in crude and adjusted models. A sex-stratified analysis was also conducted.

Results

The median AFB₁ level was significantly higher among the cases (11.4 pg/mg) than controls (5.11 pg/mg). In logistic regression analyses, higher levels of AFB₁ was associated with cirrhosis (quintile 5 vs quintile 1, OR: 11.55; 95% CI 4.05 to 32.89). No attenuation was observed with adjustment by sex, ethnicity, hepatitis B virus status, and heavy alcohol consumption. A significantly increasing trend in association was observed in both models (p trend <0.01). Additionally, the cirrhosis–AFB₁ association was more prominent among men.

Conclusions

The current study found a significant positive association between AFB₁ exposure and cirrhosis. Mitigation of AFB₁ exposure and a better understanding of additional risk factors may be important to reduce the burden of cirrhosis in Guatemala.

Aflasafe SN01 is the First Biocontrol Product Approved for Aflatoxin Mitigation in Two Nations, Senegal and The Gambia

Aflatoxin contamination is caused by Aspergillus flavus and closely related fungi. In The Gambia, aflatoxin contamination of groundnut and maize, two staple and economically important crops, is common. Groundnut and maize consumers are chronically exposed to aflatoxins, sometimes at alarming levels, and this has severe consequences on their health and productivity. Aflatoxin contamination also impedes commercialization in local and international premium markets. In neighboring Senegal, an aflatoxin biocontrol product containing four atoxigenic isolates of A. flavus, Aflasafe SN01, has been registered and is approved for commercial use in groundnut and maize. We detected that the four genotypes composing Aflasafe SN01 are also native to The Gambia. The biocontrol product was tested during two years in 129 maize and groundnut fields and compared with corresponding untreated fields cropped by smallholder farmers in The Gambia. Treated crops contained up to 100% less aflatoxins than untreated crops. A large portion of the crops could have been commercialized in premium markets due to the low aflatoxin content (in many cases no detectable aflatoxins), both at harvest and after storage. Substantial aflatoxin reductions were also achieved when commercially produced groundnut received treatment. Here we report for the first time the use and effectiveness of an aflatoxin biocontrol product registered for use in two nations. With the current scale-out and -up efforts of Aflasafe SN01, a large number of farmers, consumers, and traders in The Gambia and Senegal will obtain health, income, and trade benefits.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

Urinary polycyclic aromatic hydrocarbons concentrations and hepatitis B antibody serology in the United States (NHANES, 2003-2014)

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants that are hepatotoxic and immunotoxic. PAH exposure may modulate hepatitis B immunology.

OBJECTIVE

We used data from 6 cycles of the National Health and Nutrition Examination Survey (2003-2014) to evaluate the associations between urinary PAH metabolites and hepatitis B serology.

METHODS

This analysis included individuals who self-reported receiving ≥3 doses of hepatitis B vaccine and urinary PAH metabolites (i.e. 1-napthol, 2-napthol, 3-fluorene, 2-fluorene, 1-phenanthrene, 1-pyrene, and total PAH [sum of all metabolites]). Separate logistic regression models assessed the association between hepatitis B vaccination status (i.e. individuals who were immune due to vaccination or susceptible) and tertiles of urinary PAH. Models were adjusted for age, gender, race/ethnicity, survey cycle, family income to poverty ratio, BMI, country of birth, serum cotinine, and urinary creatinine.

RESULTS

Among participants who reported receiving ≥3 doses of vaccine and had no antibodies indicating a history of hepatitis B infection and/or current hepatitis B infection, dose-response relationships were observed where individuals with the lowest odds of serology indicating a response to the hepatitis B vaccine (i.e., anti-HBs⁺, anti-HBc^-, and HBsAg^-) were in the highest tertile of 2-Napthol (adjusted Odds Ratio [aOR]: 0.70, 95% confidence interval [CI]: 0.54, 0.91), 3-Napthol (aOR: 0.68, 95% CI: 0.53, 0.87), 2-Fluorene (aOR: 0.61, 95% CI: 0.54, 0.86), 1-Phenanthrene (aOR: 0.79, 95% CI: 0.65, 0.97), 1-Pyrene (aOR): 0.68, 95% CI: 0.55, 0.83), and total PAH (aOR: 0.73, 95% CI: 0.56, 0.95) had the compared to the lowest tertile.

CONCLUSION

This cross-sectional study supports a hypothesis that PAH exposures experienced by the general US population may modulate hepatitis B vaccine induced immunity. Given the ubiquity of PAH exposures in the US, additional research is warranted to explore the effects of chronic PAH exposures on hepatitis B related humoral immunity.

Can it be all more simple? Manufacturing aflatoxin biocontrol products using dry spores of atoxigenic isolates of Aspergillus flavus as active ingredients

Aflatoxin contamination of staple crops, commonly occurring in warm areas, negatively impacts human and animal health, and hampers trade and economic development. The fungus Aspergillus flavus is the major aflatoxin producer. However, not all A. flavus genotypes produce aflatoxins. Effective aflatoxin control is achieved using biocontrol products containing spores of atoxigenic A. flavus. In Africa, various biocontrol products under the tradename Aflasafe are available. Private and public sector licensees manufacture Aflasafe using spores freshly produced in laboratories adjacent to their factories. BAMTAARE, the licensee in Senegal, had difficulties to obtain laboratory equipment during its first year of production. To overcome this, a process was developed in Ibadan, Nigeria, for producing high‐quality dry spores. Viability and stability of the dry spores were tested and conformed to set standards. In 2019, BAMTAARE manufactured Aflasafe SN01 using dry spores produced in Ibadan and sent via courier and 19 000 ha of groundnut and maize in Senegal and The Gambia were treated. Biocontrol manufactured with dry spores was as effective as biocontrol manufactured with freshly produced spores. Treated crops contained safe and significantly (P < 0.05) less aflatoxin than untreated crops. The dry spore innovation will make biocontrol manufacturing cost‐efficient in several African countries.

Mycotoxin Occurrence, Exposure and Health Implications in Infants and Young Children in Sub-Saharan Africa: A Review

Infants and young children (IYC) remain the most vulnerable population group to environmental hazards worldwide, especially in economically developing regions such as sub-Saharan Africa (SSA). As a result, several governmental and non-governmental institutions including health, environmental and food safety networks and researchers have been proactive toward protecting this group. Mycotoxins, toxic secondary fungal metabolites, contribute largely to the health risks of this young population. In SSA, the scenario is worsened by socioeconomic status, poor agricultural and storage practices, and low level of awareness, as well as the non-establishment and lack of enforcement of regulatory limits in the region. Studies have revealed mycotoxin occurrence in breast milk and other weaning foods. Of concern is the early exposure of infants to mycotoxins through transplacental transfer and breast milk as a consequence of maternal exposure, which may result in adverse health effects. The current paper presents an overview of mycotoxin occurrence in foods intended for IYC in SSA. It discusses the imperative evidence of mycotoxin exposure of this population group in SSA, taking into account consumption data and the occurrence of mycotoxins in food, as well as biomonitoring approaches. Additionally, it discusses the health implications associated with IYC exposure to mycotoxins in SSA.

Survival advantage associated with metformin usage in hepatocellular carcinoma patients with diabetes mellitus receiving radical resection: a propensity score matching analysis

BACKGROUND

Metformin is associated with improved survival among hepatocellular carcinoma (HCC) patients with diabetes mellitus. However, the role of metformin in the survival of hepatitis B virus (HBV)-related HCC patients with diabetes mellitus after radical resection is unclear, so this study aimed to assess the effects of metformin on the clinical outcomes of patients who received radical resection for HCC.

PATIENTS AND METHODS

A total of 250 HCC patients (30-78 years old) diagnosed with diabetes mellitus were selected between 2000 and 2013 from the First Affiliated Hospital of Nanchang University and the Eastern Hepatobiliary Surgery Hospital in China. Patients were divided into the metformin group (n = 66) and the nonmetformin group (n = 184). A propensity score matching analysis was performed to evaluate the effect of metformin in patients receiving radical resection for HCC.

RESULTS

In the propensity score-matched cohort (n = 176), the overall survival (OS) in the metformin group at 1, 3, and 5 years was significantly higher than in the nonmetformin group (P = 0.002), and a similar treatment effect was observed for disease-free survival (DFS) (P = 0.030). The adjusted Cox proportional hazards model showed that metformin usage significantly improved OS [hazard ratio: 0.558, 95% confidence interval (CI): 0.385-0.810].

CONCLUSIONS

Metformin is associated with satisfactory clinical outcomes among HBV-related HCC patients with diabetes mellitus after radical resection. The use of metformin could significantly improve the OS and reduce the risk of HCC recurrence in patients after radical resection. A prospective controlled study is recommended to verify the metformin effect and explore its possible mechanisms.

Aflatoxins as a risk factor for liver cirrhosis: a systematic review and meta-analysis

Background

Liver cirrhosis is characterized by fibrosis and nodule formation in the liver, due to a chronic injury, and subsequent alteration of the normal architecture of the liver. Even though there is a huge effort to elucidate the possible etiologic factors of liver cirrhosis, a significant number of cases are cryptogenic, especially in Sub Saharan Africa, where there is a high burden of aflatoxin exposure. Aflatoxins are known to cause hepatocellular carcinoma, which share similar etiologic factors with liver cirrhosis. This study aimed to assess the association between aflatoxin exposure and the risk of liver cirrhosis.

Methods

Relevant studies were identified through systematic searches conducted in Ovid MEDLINE, PubMed and Google Scholar. Also, by searching the references of retrieved articles. The abstracts and full text were screened for eligibility and the risk of bias was assessed for each study using Joanna Briggs Institute (JBI) critical appraisal checklist for observational studies. The extracted data from included studies using Microsoft Excel were exported to Stata software version 15.0 for analyses. The overall pooled estimation of outcomes was calculated using a random-effects model of DerSimonian–Laird method at a 95% confidence level. The heterogeneity of studies was determined using I2 statistics. The presence of publication bias between studies was evaluated using the Begg’s and Egger’s tests and funnel plot. The protocol of this systematic review and meta-analysis was registered in the Prospero database with reference number ID: CRD42019148481.

Results

A total of 5 studies published between the years 2005 and 2018 that met the pre-defined inclusion and exclusion criteria were included. The meta-analysis showed that a significant increase in the risk of liver cirrhosis is associated with aflatoxin exposure (unadjusted pooled odds ratio (OR) = 3.35, 95% CI: 2.74–4.10, p = 0.000; I² = 88.3%, p = 0.000; adjusted OR = 2.5, 95% CI: 1.84–3.39, p = 0.000; I² = 0%, p = 0.429).

Conclusions

The present meta-analysis suggests that aflatoxin exposure is associated with a higher risk of liver cirrhosis.

Liver function tests and fibrosis scores in a rural population in Africa: a cross-sectional study to estimate the burden of disease and associated risk factors

OBJECTIVES

Liver disease is a major cause of morbidity and mortality in sub-Saharan Africa, but its prevalence, distribution and aetiology have not been well characterised. We therefore set out to examine liver function tests (LFTs) and liver fibrosis scores in a rural African population.

DESIGN

We undertook a cross-sectional survey of LFTs. We classified abnormal LFTs based on reference ranges set in America and in Africa. We derived fibrosis scores (aspartate aminotransferase (AST) to Platelet Ratio Index (APRI), fibrosis-4, gamma-glutamyl transferase (GGT) to platelet ratio (GPR), red cell distribution width to platelet ratio and S-index). We collected information about alcohol intake, and infection with HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV).

SETTING

We studied a population cohort in South-Western Uganda.

PARTICIPANTS

Data were available for 8099 adults (median age 30 years; 56% female).

RESULTS

The prevalence of HBV, HCV and HIV infection was 3%, 0.2% and 8%, respectively. The prevalence of abnormal LFTs was higher based on the American reference range compared with the African reference range (eg, for AST 13% vs 3%, respectively). Elevated AST/ALT ratio was significantly associated with self-reported alcohol consumption (p<0.001), and the overall prevalence of AST/ALT ratio >2 was 11% (suggesting alcoholic hepatitis). The highest prevalence of fibrosis was predicted by the GPR score, with 24% of the population falling above the threshold for fibrosis. There was an association between the presence of HIV or HBV and raised GPR (p=0.005) and S-index (p<0.001). By multivariate analysis, elevated LFTs and fibrosis scores were most consistently associated with older age, male sex, being under-weight, HIV or HBV infection and alcohol consumption.

CONCLUSIONS

Further work is required to determine normal reference ranges for LFTs in this setting, to evaluate the specificity and sensitivity of fibrosis scores and to determine the aetiology of liver disease.

Risk assessment of aflatoxins in food

EFSA was asked to deliver a scientific opinion on the risks to public health related to the presence of aflatoxins in food. The risk assessment was confined to aflatoxin B1 (AFB1), AFB2, AFG1, AFG2 and AFM1. More than 200,000 analytical results on the occurrence of aflatoxins were used in the evaluation. Grains and grain-based products made the largest contribution to the mean chronic dietary exposure to AFB1 in all age classes, while 'liquid milk' and 'fermented milk products' were the main contributors to the AFM1 mean exposure. Aflatoxins are genotoxic and AFB1 can cause hepatocellular carcinomas (HCCs) in humans. The CONTAM Panel selected a benchmark dose lower confidence limit (BMDL) for a benchmark response of 10% of 0.4 μg/kg body weight (bw) per day for the incidence of HCC in male rats following AFB1 exposure to be used in a margin of exposure (MOE) approach. The calculation of a BMDL from the human data was not appropriate; instead, the cancer potencies estimated by the Joint FAO/WHO Expert Committee on Food Additives in 2016 were used. For AFM1, a potency factor of 0.1 relative to AFB1 was used. For AFG1, AFB2 and AFG2, the in vivo data are not sufficient to derive potency factors and equal potency to AFB1 was assumed as in previous assessments. MOE values for AFB1 exposure ranged from 5,000 to 29 and for AFM1 from 100,000 to 508. The calculated MOEs are below 10,000 for AFB1 and also for AFM1 where some surveys, particularly for the younger age groups, have an MOE below 10,000. This raises a health concern. The estimated cancer risks in humans following exposure to AFB1 and AFM1 are in-line with the conclusion drawn from the MOEs. The conclusions also apply to the combined exposure to all five aflatoxins.

[Prevention of liver fibrosis and liver cancer linked to hepatitis B virus in Africa: the Prolifica study]

Despite the existence of an effective vaccine, HBV infects 257 million people worldwide and is the cause of the majority of HCC. With an annual mortality rate of 887 000 patients in 2015, this cancer is the second deadliest. Low-income countries such as ones in sub-Saharan Africa are the most at risk due to the limited access to healthcare. To overcome this and born from an international research collaboration within an EU project, the Prolifica study aimed at evaluating a screen-and-treat program to prevent HBV complications, and more particularly HCC. Based on communities, facilities and hospitals HBsAg+ detection, the study lasted from 2011 to 2016. From the "cost effectiveness" feasibility of such a program to the development of simple scores for antiviral treatment, Prolifica uncovered data of crucial importance in a region with low HBV infection awareness, transmissions modes and prevention means which could have impacts on public health policies.

Environmental Chemical Contaminants in Food: Review of a Global Problem

Contamination by chemicals from the environment is a major global food safety issue, posing a serious threat to human health. These chemicals belong to many groups, including metals/metalloids, polycyclic aromatic hydrocarbons (PAHs), persistent organic pollutants (POPs), perfluorinated compounds (PFCs), pharmaceutical and personal care products (PPCPs), radioactive elements, electronic waste, plastics, and nanoparticles. Some of these occur naturally in the environment, whilst others are produced from anthropogenic sources. They may contaminate our food-crops, livestock, and seafood-and drinking water and exert adverse effects on our health. It is important to perform assessments of the associated potential risks. Monitoring contamination levels, enactment of control measures including remediation, and consideration of sociopolitical implications are vital to provide safer food globally.

Genetic polymorphisms in ataxin-3 and liver cirrhosis risk related to aflatoxin B1

Background

Altered expression of ataxin-3 (AT3) can modify DNA repair capacity and is observed in human diseases. The genetic polymorphisms of this gene in aflatoxin B1 (AFB1)–related liver cirrhosis (LC) have not yet been elucidated.

Materials and Methods

We conducted a hospital-based case–control study, including 384 patients with LC and 851 controls without any liver diseases, to assess the association between 264 polymorphisms in AT3 and AFB1-related LC risk. Genotype were tested using TaqMan-PCR or sequencing technique.

Results

We found three differentially distributed SNPs (rs8021276, rs7158733, and rs10146249) via the screening analysis; however, only rs8021276 polymorphism was further identified to modify the risk of LC. Compared with the homozygote of rs8021276 A alleles (rs8021276-AA), the genotypes of rs8021276 G alleles (rs8021276-AG or -GG) increased LC risk (OR: 2.48 and 6.98; 95% CI: 1.84–3.33 and 4.35–11.22, respectively). Significant interactive effects between risk genotypes and AFB1 exposure status were also observed in the joint effects analysis. Additionally, rs8021276 polymorphism was also associated with down-regulation of AT3 mRNA expression and increasing AFB1-DNA adducts in liver tissues with cirrhosis.

Conclusions

These results suggest AT3 polymorphisms may be risk biomarkers of AFB1-related LC, and rs8021276 is a potential candidate.

Review of the clinical applications and technological advances of circulating tumor DNA in cancer monitoring

Circulating cell-free DNA (cfDNA) released by tumor cells, termed ctDNA, closely reflects the heterogeneity of primary cancers and their metastases. As a noninvasive, real-time monitoring biomarker, ctDNA is a promising tool for detecting driver gene mutations, assessing tumor burden and acquired resistance, and early diagnosis. However, isolation and enrichment of cfDNA is a big challenge due to the high degree of DNA fragmentation and its relatively low abundance in the bloodstream. This review aims to provide insights into the recent technological advances in acquisition of optimal quality cfDNA, the use of preservatives, isolation methods, processing timelines, and detection techniques. It also describes clinical applications of ctDNA in cancer patient management.

Aflatoxin B1 exposure increases the risk of cirrhosis and hepatocellular carcinoma in chronic hepatitis B virus carriers

The relation between aflatoxin B1 (AFB1 ) and cirrhosis in chronic carriers of hepatitis B virus (HBV) remains inconclusive. This case-control study nested in a large community-based cohort aimed to assess the effect of AFB1 exposure on cirrhosis and HCC in chronic HBV carriers. Serum AFB1 -albumin adduct levels at study entry were measured in 232 cirrhosis cases, 262 HCC cases and 577 controls. Multivariate-adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression. Among all chronic HBV carriers, the time intervals between study entry and diagnosis of HCC, cirrhosis, cirrhotic HCC, and non-cirrhotic HCC were all significantly (p < 0.0001) shorter in participants with high serum levels of AFB1 -albumin adducts than those with low/undetectable levels. There were significant dose-response relations with serum AFB1 -albumin adduct level at study entry for cirrhosis (p-trend = 0.0001) and cirrhotic HCC (p-trend < 0.0001) newly diagnosed within 9 years after entry as well as non-cirrhotic HCC (p-trend = 0.021) newly diagnosed within 4 years after entry. The aORs (95% CIs) for high versus undetectable serum AFB1 -albumin adduct levels were 2.45 (1.51-3.98) for cirrhosis (p = 0.0003), 5.47 (2.20-13.63) for cirrhotic HCC (p = 0.0003), and 5.39 (1.11-26.18) for non-cirrhotic (p = 0.0368) HCC, respectively. There remained a significant dose-response relation between serum AFB1 -albumin adduct level and HCC risk (p-trend = 0.0291) in cirrhosis patients, showing an aOR (95% CI) of 3.04 (1.11-8.30) for high versus undetectable serum levels (p = 0.0299). It is concluded that AFB1 exposure may increase the risk of cirrhosis and HCC in a dose-response manner among chronic HBV carriers.

Characterising cancer burden and quality of care at two palliative care clinics in Malawi

BACKGROUND

This paper describes cancer burden and compares characteristics of cancer patients enrolled at 2 palliative care facilities of contrasting resources and geographical locations in Malawi. It also assesses the extent of differences in service delivery and the impact these might have on outcomes.

METHODS

Data on all cancer patients registered between October 2010 and October 2015 at Tiyanjane Clinic (at Queen Elizabeth Central Hospital, Blantyre) and Mzuzu Central Hospital (MCH) palliative care clinics were extracted and analysed. Key informant in-depth interviews were carried out at both sites. Thematic analysis was used for qualitative data and Excel 2010 and Stata 12 were used for analysis of quantitative data.

RESULTS

Quantitative: There were 1362 and 633 cancer patients at Tiyanjane and MCH, respectively. Overall, females predominated over males (55.8% vs 42.8%); however, Tiyanjane had more males (52.2% vs 45.8%), which was contrary to Mzuzu (77.4% females vs 22.6% males). The 35- to 54-year age group was predominant at both Tiyanjane (43.1%) and Mzuzu (40.1%).Overall, the most common cancers were Kaposi's sarcoma (26.9%), cervical cancer (26.8%), oesophageal cancer (14.2%), hepatocellular carcinoma (4.9%), and bladder cancer (3.0%). Histologically confirmed diagnoses accounted for 13% of cases at Tiyanjane, whereas all patients from MCH were diagnosed clinically. Qualitative: Palliative care services were free of charge at both facilities, and owing to the expansion of services to district hospitals, the workload at central hospitals had been reduced. Between the 2 sites, there were differences in follow-up procedures, drug availabilities, as well as human resource capacity, with Mzuzu palliative care facility facing more extensive challenges.

CONCLUSIONS

The characteristics of patients seen at each site varied according to services available. Quality of care was assessed as superior at Tiyanjane, demonstrating the importance of multiple stakeholder involvement in the delivery of palliative care services.

Liver fibrosis in treatment-naïve HIV-infected and HIV/HBV co-infected patients: Zambia and Switzerland compared

OBJECTIVE

To examine the association between hepatitis B virus (HBV) infection and liver fibrosis in HIV-infected patients in Zambia and Switzerland.

METHODS

HIV-infected adults starting antiretroviral therapy in two clinics in Zambia and Switzerland were included. Liver fibrosis was evaluated using the aspartate aminotransferase-to-platelet-ratio index (APRI), with a ratio >1.5 defining significant fibrosis and a ratio >2.0 indicating cirrhosis. The association between hepatitis B surface antigen (HBsAg) positivity, HBV replication, and liver fibrosis was examined using logistic regression.

RESULTS

In Zambia, 96 (13.0%) of 739 patients were HBsAg-positive compared to 93 (4.5%) of 2058 in Switzerland. HBsAg-positive patients were more likely to have significant liver fibrosis than HBsAg-negative ones: the adjusted odds ratio (aOR) was 3.25 (95% confidence interval (CI) 1.44-7.33) in Zambia and 2.50 (95% CI 1.19-5.25) in Switzerland. Patients with a high HBV viral load (≥20000 IU/ml) were more likely to have significant liver fibrosis compared to HBsAg-negative patients or patients with an undetectable viral load: aOR 3.85 (95% CI 1.29-11.44) in Zambia and 4.20 (95% CI 1.64-10.76) in Switzerland. In both settings, male sex was a strong risk factor for significant liver fibrosis.

CONCLUSIONS

Despite the differences in HBV natural history between Sub-Saharan Africa and Europe, the degree of liver fibrosis and the association with important risk factors were similar.

Intervention trial with calcium montmorillonite clay in a south Texas population exposed to aflatoxin

South Texas currently has the highest incidence of hepatocellular carcinoma (HCC) in the United States, a disease that disproportionately affects Latino populations in the region. Aflatoxin B1 (AFB1) is a potent liver carcinogen that has been shown to be present in a variety of foods in the United States, including corn and corn products. Importantly, it is a dietary risk factor contributing to a higher incidence of HCC in populations frequently consuming AFB1-contaminated diets. In a randomised double-blind placebo controlled trial, we evaluated the effects of a 3-month administration of ACCS100 (refined calcium montmorillonite clay) on serum AFB1-lysine adduct (AFB-Lys) level and serum biochemistry in 234 healthy men and women residing in Bexar and Medina counties, Texas. Participants recruited from 2012 to 2014 received either a placebo, 1.5 g or 3 g ACCS100 each day for 3 months, and no treatment during the fourth month. Adverse event rates were similar across treatment groups and no significant differences were observed for serum biochemistry and haematology parameters. Differences in levels of AFB-Lys at 1, 3 and 4 months were compared between placebo and active treatment groups. Although serum AFB-Lys levels were decreased by month 3 for both treatment groups, the low dose was the only treatment that was significant (p = 0.0005). In conclusion, the observed effect in the low-dose treatment group suggests that the use of ACCS100 may be a viable strategy to reduce dietary AFB1 bioavailability during aflatoxin outbreaks and potentially in populations chronically exposed to this carcinogen.

HIV infection, viral hepatitis and liver fibrosis among prison inmates in West Africa

Background

Prisoners represent a vulnerable population for blood-borne and sexually transmitted infections which can potentially lead to liver fibrosis and ultimately cirrhosis. However, little is known about the prevalence of liver fibrosis and associated risk factors among inmates in sub-Saharan Africa.

Methods

Screening of liver fibrosis was undertaken in a randomly selected sample of male inmates incarcerated in Lome, Togo and in Dakar, Senegal using transient elastography. A liver stiffness measurement ≥9.5 KPa was retained to define the presence of a severe liver fibrosis. All included inmates were also screened for HIV, Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) infection. Substances abuse including alcohol, tobacco and cannabis use were assessed during face-to-face interviews. Odds Ratio (OR) estimates were computed with their 95 % Confidence Interval (CI) to identify factors associated with severe liver fibrosis.

Results

Overall, 680 inmates were included with a median age of 30 years [interquartile range: 24–35]. The prevalence of severe fibrosis was 3.1 % (4.9 % in Lome and 1.2 % in Dakar). Infections with HIV, HBV and HCV were identified in 2.6 %, 12.5 % and 0.5 % of inmates, respectively. Factors associated with a severe liver fibrosis were HIV infection (OR = 7.6; CI 1.8–32.1), HBV infection (OR = 4.8; CI 1.8–12.8), HCV infection (OR = 52.6; CI 4.1–673.8), use of traditional medicines (OR = 3.7; CI 1.4–10.1) and being incarcerated in Lome (OR = 3.3; CI 1.1–9.8) compared to Dakar.

Conclusions

HIV infection and viral hepatitis infections were identified as important and independent determinants of severe liver fibrosis. While access to active antiviral therapies against HIV and viral hepatitis expands in Africa, adapted strategies for the monitoring of liver disease need to be explored, especially in vulnerable populations such as inmates.

Molecular characteristics of Hepatitis B and chronic liver disease in a cohort of HB carriers from Bamako, Mali

BACKGROUND

Hepatitis B (HB) infection is common in Mali. However, there is little information on molecular and biochemical characteristics of HB carriers.

METHODS

A group of 1466 adult volunteers was recruited in the district of Bamako. Confirmed HB carriers were tested for HB viral load by quantitative PCR and HBV was genotyped by sequencing of HBS. Fibrosis and hepatitis activity were measured using the Fibrotest-Actitest. A mutation of TP53 at codon 249 (R249S), specific for exposure to aflatoxin, was detected in cell-free DNA extracted from plasma.

RESULTS

Overall, 276 subjects were HBsAg-positive (18.8%). Among 152 subjects tested for HBV load, 49 (32.2%) had over 10(4) copies/mL and 16 (10.5%) had levels below the limit of detection. The E genotype was found in 91.1% of carriers. Fibrotest scores ≥ F2 were observed in 52 subjects (35.4%). Actitest scores ≥ A2 were detected in 15 subjects (10.2%) and were correlated with Fibrotest scores (p = 0.0006). Among 105 subjects tested, 60% had detectable levels of R249S copies (>40 copies/mL plasma).

CONCLUSION

Chronic HB carriage in adults in Bamako district is well over epidemic threshold. About 1/3 of carriers have moderate to severe liver fibrosis and 60% have detectable aflatoxin-related TP53 R249S mutation. These results support introduction of anti-HB therapies to reduce the progression towards severe liver disease.

Human health implications from co-exposure to aflatoxins and fumonisins in maize-based foods in Latin America: Guatemala as a case study

Co-occurrence of fumonisin B1 (FB1) and aflatoxin B1 (AFB1) in maize has been demonstrated in many surveys. Combined-exposure to FB1 and AFB1 was of concern to the Joint FAO/WHO Expert Committee on Food Additives because of the known genotoxicity of AFB1 and the ability of FB1 to induce regenerative proliferation in target tissues. Humans living where maize is a dietary staple are at high risk for exposure to both mycotoxins. Our work has focused on Guatemala, a country in Central America where maize is consumed in large amounts every day and where intake of FB1 has been shown to be potentially quite high using biomarker-based studies. In 2012 a survey was conducted which analysed maize samples for FB1 and AFB1 from all 22 departments of Guatemala. The results show that the levels of AFB1 exposure are also potentially quite high in Guatemala, and likely throughout Central America and Mexico. The implications of co-exposure for human health are numerous, but one area of particular concern is the potential of FB1 to modulate AFB1 hepatoxicity and/or hepatocarcinogenicity. Both the mechanism of action of FB1 and its ability to promote liver carcinogenicity in rats and rainbow trout is consistent with this concern. In farm and laboratory animals FB1 inhibits ceramide synthases, key enzymes in de novo ceramide biosynthesis. The inhibition of sphingolipid signalling pathways mediating programmed cell death and activation of pathways stimulating cell proliferation in livers of individuals exposed to AFB1 could contribute to the tumorigenicity of AFB1. Studies investigating the health effects of either toxin should consider the potential for co-exposure to both toxins. Also, in countries where maize-based food are prepared by alkaline treatment of the maize kernels, the effect of traditional processing on AFB1 levels and toxicity needs to be determined, especially for maize highly contaminated with AFB1.

Expression and clinical implications of HAb18G/CD147 in hepatocellular carcinoma

AIM

HAb18G/CD147 is an important factor in invasion and metastasis of hepatocellular carcinoma (HCC). However, the clinical implications of HAb18G/CD147 expression in HCC are still unclear. In this study, we clarify the clinical significance of HAb18G/CD147. We characterize the association between HAb18G/CD147 expression and presentation of fibrosis or chronic hepatitis B, as well as its effect on HCC development.

METHODS

The expression of HAb18G/CD147 in human hepatocarcinoma cell lines was analyzed by reverse transcription polymerase chain reaction and western blotting. Tumor tissues were obtained from HCC patients who underwent surgical resection between 2002 and 2006. All patients who had received previous therapy were excluded. HCC tissues were analyzed by immunohistochemistry using anti-HAb18G/CD147.

RESULTS

HAb18G/CD147 was widely expressed in Hep-G2, SMCC-7721 and BEL7402 cell lines, but not expressed in L-02, a human normal hepatic cell line. HAb18G/CD147 was mainly localized to the membrane of tumor cells in 74.0% (37/50) HCC patients. We found that higher HAb18G/CD147 expression and poor tumor differentiation were correlated with patient survival (P = 0.026 and P = 0.014, respectively). Furthermore, the distribution of HAb18G/CD147 was similar to that of hepatitis B virus (HBV) infection, but negatively related to hepatic cirrhosis.

CONCLUSION

HAb18G/CD147 has shown its potentials in HCC development and patient survival. Moreover, it may also cooperate with chronic HBV infection and cirrhosis during HCC development. Its functions in the two factors may be different. Therefore, HAb18G/CD147 may be a marker for poor prognosis in HCC patients and could be a useful therapeutic target for interfering with or reversing HCC progression.

Problem of hepatocellular carcinoma in West Africa

The incidence of hepatocellular carcinoma (HCC) is known to be high in West Africa with an approximate yearly mortality rate of 200000. Several factors are responsible for this. Early acquisition of risk factors; with vertical or horizontal transmission of hepatitis B (HBV), environmental food contaminants (aflatoxins), poor management of predisposing risk factors and poorly-managed strategies for health delivery. There has been a low uptake of childhood immunisation for hepatitis B in many West African countries. Owing to late presentations, most sufferers of HCC die within weeks of their diagnosis. Highlighted reasons for the specific disease pattern of HCC in West Africa include: (1) high rate of risk factors; (2) failure to identify at risk populations; (3) lack of effective treatment; and (4) scarce resources for timely diagnosis. This is contrasted to the developed world, which generally has sufficient resources to detect cases early for curative treatment. Provision of palliative care for HCC patients is limited by availability and affordability of potent analgesics. Regional efforts, as well as collaborative networking activities hold promise that could change the epidemiology of HCC in West Africa.

Study of liver cirrhosis over ten consecutive years in Southern China

AIM: To investigate the etiology and complications of liver cirrhosis (LC) in Southern China.

METHODS: In this retrospective, cross-sectional study, we identified cases of liver cirrhosis admitted between January 2001 to December 2010 and reviewed the medical records. Patient demographics, etiologies and complications were collected, and etiological changes were illustrated by consecutive years and within two time periods (2001-2005 and 2006-2010). All results were expressed as the mean ± SD or as a percentage. The χ² test or Student’s t-test was used to analyze the differences in age, gender, and etiological distribution, and one-way analysis of variance was applied to estimate the trends in etiological changes. We analyzed the relationship between the etiologies and complications using unconditioned logistic regression, and the risk of upper gastrointestinal bleeding (UGIB) and hepatocellular carcinoma (HCC) in the major etiological groups was evaluated as ORs. A P value less than 0.05 was considered significant. Statistical computation was performed using SPSS 17.0 software.

RESULTS: In this study, we identified 6719 (83.16%) male patients and 1361 (16.84%) female patients. The average age of all of the patients was 50.5 years at the time of diagnosis. The distribution of etiological agents was as follows: viral hepatitis, 80.62% [hepatitis B virus (HBV) 77.22%, hepatitis C virus (HCV) 2.80%, (HBV + HCV) 0.58%]; alcohol, 5.68%; mixed etiology, 4.95%; cryptogenic, 2.93%; and autoimmune hepatitis, 2.03%; whereas the other included etiologies accounted for less than 4% of the total. Infantile hepatitis syndrome LC patients were the youngest (2.5 years of age), followed by the metabolic LC group (27.2 years of age). Viral hepatitis, alcohol, and mixed etiology were more prevalent in the male group, whereas autoimmune diseases, cryptogenic cirrhosis, and metabolic diseases were more prevalent in the female group. When comparing the etiological distribution in 2001-2005 with that in 2006-2010, the proportion of viral hepatitis decreased from 84.7% to 78.3% (P < 0.001), and the proportion of HBV-induced LC also decreased from 81.9% to 74.6% (P < 0.001). The incidence of mixed etiology, cryptogenic cirrhosis, and autoimmune diseases increased by 3.1% (P < 0.001), 0.5% (P = 0.158), and 1.3% (P < 0.001), respectively. Alcohol-induced LC remained relatively steady over the 10-year period. The ORs of the development of UGIB between HBV and other major etiologies were as follows: HCV, 1.07; alcohol, 1.89; autoimmune, 0.90; mixed etiology, 0.83; and cryptogenic, 1.76. The ORs of the occurrence of HCC between HBV and other major etiologies were as follows: HCV, 0.54; alcohol, 0.16; autoimmune, 0.05; mixed etiology, 0.58; and cryptogenic, 0.60.

CONCLUSION: The major etiology of liver cirrhosis in Southern China is viral hepatitis. However, the proportions of viral hepatitis and HBV are gradually decreasing. Alcoholic LC patients exhibit a greater risk of experiencing UGIB, and HBV LC patients may have a greater risk of HCC.

An overview on mycotoxin contamination of foods in Africa

Mycotoxins are fungal secondary metabolites that contaminate various feedstuffs and agricultural crops. The contamination of food by mycotoxins can occur before production, during storage, processing, transportation or marketing of the food products. High temperature, moisture content and water activity are among the predisposing factors that facilitate the production of mycotoxins in food. Aflatoxins, ochratoxins, fumonisins, deoxynivalenol and zearalenone are all considered the major mycotoxins produced in food and feedstuffs. In Africa, mycotoxin contamination is considered to be a major problem with implications that affect human and animal health and economy. Aflatoxin-related hepatic diseases are reported in many African countries. Ochratoxin and fumonisin toxicity in humans and animals is widespread in Africa. The available, updated information on the incidence of mycotoxin contamination, decontamination and its public health importance in Africa is lacking. The aim of this review is to highlight, update and discuss the available information on the incidence of mycotoxins in African countries. The public health implications and the recommended strategies for control of mycotoxins in food and agricultural crops are also discussed.

Osteopontin and latent-TGF β binding-protein 2 as potential diagnostic markers for HBV-related hepatocellular carcinoma

Chronic Hepatitis B (HB) is the main risk factor for chronic liver disease (CLD) and hepatocellular carcinoma (HCC) in many low-resource countries, where diagnosis is constrained by lack of clinical, histopathological and biomarker resources. We have used proteomics to detect plasma biomarkers that outperform α-Fetoprotein (AFP), the most widely used biomarker for HCC diagnosis in low-resource contexts. Deep-plasma proteome analysis was performed in HCC patients, patients with CLD and in HB-carrier controls from Thailand (South-East Asia) and The Gambia (West-Africa). Mass spectrometry profiling identified latent-transforming growth factor β binding-protein 2 (LTBP2) and Osteopontin (OPN) as being significantly elevated in HCC versus CLD and controls. These two proteins were further analyzed by ELISA in a total of 684 plasma samples, including 183 HCC, 274 CLD and 227 asymptomatic controls. When combined, LTBP2 and OPN showed an area under the receiver operating curve of 0.85 in distinguishing HCC from CLD in subjects with AFP <20 ng/mL. In a prospective cohort of 115 CLD patients from Korea, increased plasma levels of LTBP2 and/or OPN were detected in plasma collected over 2 years prior to diagnosis in 21 subjects who developed HCC. Thus, the combination of LTBP2 and OPN outperformed AFP for diagnosis and prediction of HCC and may therefore improve biomarker-based detection of HBV-related HCC.

Aflatoxin regulations in a network of global maize trade

Worldwide, food supplies often contain unavoidable contaminants, many of which adversely affect health and hence are subject to regulations of maximum tolerable levels in food. These regulations differ from nation to nation, and may affect patterns of food trade. We soughtto determine whether there is an association between nations' food safety regulations and global food trade patterns, with implications for public health and policymaking. We developed a network model of maize trade around the world. From maize import/export data for 217 nations from 2000–2009, we calculated basic statistics on volumes of trade; then examined how regulations of aflatoxin, a common contaminant of maize, are similar or different between pairs of nations engaging in significant amounts of maize trade. Globally, market segregation appears to occur among clusters of nations. The United States is at the center of one cluster; European countries make up another cluster with hardly any maize trade with the US; and Argentina, Brazil, and China export maize all over the world. Pairs of nations trading large amounts of maize have very similar aflatoxin regulations: nations with strict standards tend to trade maize with each other, while nations with more relaxed standards tend to trade maize with each other. Rarely among the top pairs of maize-trading nations do total aflatoxin standards (standards based on the sum of the levels of aflatoxins B₁, B₂, G₁, and G₂) differ by more than 5 µg/kg. These results suggest that, globally, separate maize trading communities emerge; and nations tend to trade with other nations that have very similar food safety standards.

TP53 R249S mutation, genetic variations in HBX and risk of hepatocellular carcinoma in The Gambia

In regions with high prevalence of chronic hepatitis B virus (HBV) infection and dietary aflatoxin B(1) (AFB(1)) exposure, hepatocellular carcinomas (HCCs) often contain TP53 mutation at codon 249 (R249S). Furthermore, a C-terminal truncated HBx protein expressed from hepatocyte integrated HBV is associated with HCC development. This study evaluates the association between R249S and HBX status in relation to HCC in West African population. HBX (complete or 3'-truncated) and HBS genes were assessed by PCR in cell-free DNA (CFDNA) from plasma of subjects recruited in a hospital-based case-control study (325 controls, 78 cirrhotic patients and 198 HCC cases) conducted in The Gambia. These samples had been previously analyzed for R249S and HBV serological status. Complete HBX sequence was frequently detected in CFDNA of HCC-R249S positive (77%, 43/56) compared with HCC-R249S-negative cases (44%, 22/50). Conversely, the proportion of 3'-truncated HBX gene was significantly higher in HCC-R249S negative than positive cases (34%, 17/50, compared with 12%, 7/56) (χ(2) = 12.12; P = 0.002; distribution of R249S negative and positive according to HBX status). Occult HBV infection (detected by PCR) was present in 24% of HCC previously considered as negative by HBV serology. Moreover, HBV mutation analysis revealed that double mutation at nucleotides 1762(T)/1764(A) was associated with diagnosis of cirrhosis or HCC {cirrhosis: odds ratio (OR): 9.50 [95% confidence interval (CI) 1.50-60.11]; HCC: OR: 11.29 [95% CI 2.07-61.47]}. These findings suggest that in HCC from The Gambia, complete HBX sequences are often associated with the presence of TP53 R249S mutation.

TP53 R249S mutation, genetic variations in HBX and risk of hepatocellular carcinoma in The Gambia

In regions with high prevalence of chronic hepatitis B virus (HBV) infection and dietary aflatoxin B(1) (AFB(1)) exposure, hepatocellular carcinomas (HCCs) often contain TP53 mutation at codon 249 (R249S). Furthermore, a C-terminal truncated HBx protein expressed from hepatocyte integrated HBV is associated with HCC development. This study evaluates the association between R249S and HBX status in relation to HCC in West African population. HBX (complete or 3'-truncated) and HBS genes were assessed by PCR in cell-free DNA (CFDNA) from plasma of subjects recruited in a hospital-based case-control study (325 controls, 78 cirrhotic patients and 198 HCC cases) conducted in The Gambia. These samples had been previously analyzed for R249S and HBV serological status. Complete HBX sequence was frequently detected in CFDNA of HCC-R249S positive (77%, 43/56) compared with HCC-R249S-negative cases (44%, 22/50). Conversely, the proportion of 3'-truncated HBX gene was significantly higher in HCC-R249S negative than positive cases (34%, 17/50, compared with 12%, 7/56) (χ(2) = 12.12; P = 0.002; distribution of R249S negative and positive according to HBX status). Occult HBV infection (detected by PCR) was present in 24% of HCC previously considered as negative by HBV serology. Moreover, HBV mutation analysis revealed that double mutation at nucleotides 1762(T)/1764(A) was associated with diagnosis of cirrhosis or HCC {cirrhosis: odds ratio (OR): 9.50 [95% confidence interval (CI) 1.50-60.11]; HCC: OR: 11.29 [95% CI 2.07-61.47]}. These findings suggest that in HCC from The Gambia, complete HBX sequences are often associated with the presence of TP53 R249S mutation.

High prevalence of liver fibrosis associated with HIV infection: a study in rural Rakai, Uganda

BACKGROUND

Liver disease is a leading cause of mortality among HIV-infected persons in the United States and Europe. However, data regarding the effects of HIV and antiretroviral therapy (ART) on liver disease in Africa are sparse.

METHODS

A total of 500 HIV-infected participants in an HIV care programme in rural Rakai, Uganda were frequency-matched by age, gender and site to 500 HIV-uninfected participants in a population cohort. All participants underwent transient elastography (FibroScan(®)) to quantify liver stiffness measurements (LSM) and identify participants with significant liver fibrosis, defined as LSM≥9.3 kPa (≈ Metavir F≥2). Risk factors for liver fibrosis were identified by estimating adjusted prevalence risk ratios (adjPRR) and 95% CI using modified Poisson multivariate regression.

RESULTS

The prevalence of hepatitis B coinfection in the study population was 5%. The prevalence of significant fibrosis was 17% among HIV-infected and 11% in HIV-uninfected participants (P=0.008). HIV infection was associated with a 50% increase in liver fibrosis (adjPRR 1.5, 95% CI 1.1-2.1; P=0.010). Fibrosis was also associated with male gender (adjPRR 1.4, 95% CI 1.0-1.9; P=0.045), herbal medicine use (adjPRR 2.0, 95% CI 1.2-3.3; P=0.005), heavy alcohol consumption (adjPRR 2.3, 95% CI 1.3-3.9; P=0.005), occupational fishing (adjPRR 2.5, 95% CI 1.2-5.3; P=0.019) and chronic HBV infection (adjPRR 1.7, 95% CI 1.0-3.1; P=0.058). Among HIV-infected participants, ART reduced fibrosis risk (adjPRR 0.6, 95% CI 0.4-1.0; P=0.030).

CONCLUSIONS

The burden of liver fibrosis among HIV-infected rural Ugandans is high. These data suggest that liver disease may represent a significant cause of HIV-related morbidity and mortality in Africa.

Aetiological differences in demographical, clinical and pathological characteristics of hepatocellular carcinoma in The Gambia

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide, with a high burden in West Africa. Data evaluating aetiological differences in HCC presentation from this region are limited.

AIMS

The aim of this study was to describe the demographical, clinical and pathological characteristics of HCC by aetiology (hepatitis B or C infection, aflatoxin associated).

METHODS

One hundred and ninty-three cases of HCC diagnosed between 1997 and 2001 in The Gambia were analysed. Characteristics were compared by aetiology using χ(2)-tests, student t-test and Wilcoxon's rank sum tests as appropriate.

RESULTS

The prevalence of hepatitis B surface antigen, hepatitis C antibody and aflatoxin-associated 249(ser) TP53 mutations among HCC patients was 60, 20 and 38% respectively. The typical HCC patient was a 49-year-old male positive for hepatitis B surface antigen presenting with hepatomegaly (93%), abdominal pain (94%) and weight loss (95%) 8 weeks after symptom onset. Most patients had multifocal lesions with background cirrhosis. The median largest tumour was 10.3 cm and the median α-fetoprotein level was 500 ng/ml. Eighty-four per cent of patients had advanced HCC (patients not meeting the Milan criteria) at presentation.

CONCLUSIONS

Irrespective of aetiological agent, HCC among West Africans presents at very advanced stages. Few clinical or pathological differences exist by aetiology. More studies are needed to understand the mechanisms of hepatocarcinogenesis among these patients as well as identify high-risk populations in which early detection through screening will be beneficial.

FOXP3 expression and clinical characteristics of hepatocellular carcinoma

AIM: To study the biological and clinical characteristics of transcription factor forkhead box protein 3 (FOXP3) in hepatocellular carcinoma (HCC).

METHODS: We analyzed the expression and localization of FOXP3 in HCC tissues and cell lines to evaluate its biological features. The relationship between FOXP3 staining and clinical risk factors of HCC was assessed to identify the clinical characteristics of FOXP3 in HCC.

RESULTS: The mRNA and protein expression of FOXP3 were found in some hepatoma cell lines. Immunohistochemical (IHC) analysis of HCC sections revealed that 48% of HCC displayed FOXP3 staining, but we did not find any FOXP3 staining in normal liver tissues and para-tumor tissues. IHC and Confocal analysis showed that the expressions of FOXP3 were mainly present in the nucleus and cytoplasm of tumor cells in tissues or cell lines. In HCC, the distribution of FOXP3 was similar to that of the cirrhosis, but not to the hepatitis B virus. Those findings implicate that FOXP3 staining seems to be associated with the high risk of HCC.

CONCLUSION: The clinical characteristics of FOXP3 in HCC warrants further studies to explore its functions and roles in the cirrhosis and development of HCC.

Clinical outcomes and correlates of TP53 mutations and cancer

The initial observation that p53 accumulation might serve as a surrogate biomarker for TP53 mutation has been the cornerstone for vast translational efforts aimed at validating its clinical use for the diagnosis, prognosis, and treatment of cancer. Early on, it was realized that accurate evaluation of p53 status and function could not be achieved through protein-expression analysis only. As our understanding of the p53 pathway has evolved and more sophisticated methods for assessment of p53 functional integrity have become available, the clinical and molecular epidemiological implications of p53 abnormalities in cancers are being revealed. They include diagnostic testing for germline p53 mutations, and the assessment of selected p53 mutations as biomarkers of carcinogen exposure and cancer risk and prognosis. Here, we describe the strengths and limitations of the most frequently used techniques for determination of p53 status in tumors, as well as the most remarkable latest findings relating to its clinical and epidemiological value.

Evaluating the technical feasibility of aflatoxin risk reduction strategies in Africa

Public health interventions must be readily accepted by their target populations to have any meaningful impact and must have financial and infrastructural support to be feasible in the parts of the world where they are most needed. At the same time, these interventions must be assessed for potential unintended consequences, either to the environment or to human health. In this paper, we evaluate the technical feasibility of interventions to control aflatoxin risk, to be potentially deployed in parts of Africa where aflatoxin exposure poses a significant public health concern. We have applied a conceptual framework for feasibility to four interventions, one associated with each of four different stages of aflatoxin risk: biocontrol (pre-harvest), a post-harvest intervention package (post-harvest), NovaSil clay (dietary), and hepatitis B vaccination (clinical). For each intervention, we have assessed the following four components of technical feasibility: (1) characteristics of the basic intervention, (2) characteristics of delivery, (3) requirements on government capacity, and (4) usage characteristics. We propose ways in which feasibility of each intervention is currently high or low from the perspective of adoption in Africa, how public education is crucial for each of these interventions to succeed, and how to align economic incentives to make the interventions more suitable for less developed countries.

Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis

Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The association between chronic HBV infection and the development of the tumor is thus even closer than was originally thought. HBV viral load was found to be significantly higher in patients with HCC than in Black African controls. As in other populations, HBV e antigen-positive patients with hepatocellular carcinoma had significantly higher viral loads than patients negative for this antigen. The significance of this finding is discussed. The risk for HCC development with genotype A of HBV, the predominant genotype in African isolates, has not been investigated. Genotype A was shown to be 4.5 times more likely than other genotypes to cause HCC in Black Africans, and tumours occurred at a significantly younger age. Increasing numbers of patients with human immunodeficiency virus (HIV) and HBV co-infection are being reported to develop HCC. A preliminary case/control comparison supports the belief that HIV co-infection enhances the hepatocarcinogenic potential of HBV. A study from The Gambia provides the first evidence that dietary exposure to aflatoxin B(1) may cause cirrhosis and that this may play a contributory role in the pathogenesis of aflatoxin-induced HCC. An animal model has provided experimental support for the clinical evidence that dietary iron overload in the African is directly hepatocarcinogenic, in addition to causing the tumor indirectly through the development of cirrhosis.

Hepatitis B viral load and risk for liver cirrhosis and hepatocellular carcinoma in The Gambia, West Africa

The main objectives of this study were to define the occurrence and levels of hepatitis B virus (HBV) DNA in asymptomatic HBV carriers, cirrhosis patients and hepatocellular carcinoma (HCC) cases from The Gambia, and to evaluate the risk for cirrhosis or HCC associated with HBV viremia. We used sensitive real-time quantitative PCR assays to measure HBV DNA in samples from a case-control study consisting of 60 asymptomatic HBV carriers, 53 cirrhotic patients and 129 HCC cases. Logistic regression was used to estimate the risks of cirrhosis and HCC associated with HBV-DNA levels and HBV e antigenemia (HBeAg) detection (a surrogate marker for viral replication). Detectable HBV viremia and HBeAg positivity were both significantly associated with cirrhosis (increasing risk by fourfold and 11-fold respectively) and with HCC (increasing risk by sixfold and threefold respectively). HBV-DNA levels were significantly higher in both HCC cases and cirrhotic patients compared to asymptomatic carriers (P < 0.01 for both). High-level HBV DNA (>10,000 copies/mL) was strongly associated with both HCC and cirrhosis (17- and 39-fold increased risk). Lower level HBV viremia (200-10,000 copies/mL) conferred a significant risk of HCC, although the association with cirrhosis was not significant. In conclusion, we find that high HBV-DNA levels are strongly associated with the serious sequelae of HBV infection, independent of HBeAg status. While risk for cirrhosis and for HCC notably increases at HBV-DNA levels >or=10,000 copies/mL, low-level viremia was also associated with significant risk for HCC.

Mycotoxins and human disease: a largely ignored global health issue

Aflatoxins and fumonisins (FB) are mycotoxins contaminating a large fraction of the world's food, including maize, cereals, groundnuts and tree nuts. The toxins frequently co-occur in maize. Where these commodities are dietary staples, for example, in parts of Africa, Asia and Latin America, the contamination translates to high-level chronic exposure. This is particularly true in subsistence farming communities where regulations to control exposure are either non-existent or practically unenforceable. Aflatoxins are hepatocarcinogenic in humans, particularly in conjunction with chronic hepatitis B virus infection, and cause aflatoxicosis in episodic poisoning outbreaks. In animals, these toxins also impair growth and are immunosuppressive; the latter effects are of increasing interest in human populations. FB have been reported to induce liver and kidney tumours in rodents and are classified as Group 2B 'possibly carcinogenic to humans', with ecological studies implying a possible link to increased oesophageal cancer. Recent studies also suggest that the FB may cause neural tube defects in some maize-consuming populations. There is a plausible mechanism for this effect via a disruption of ceramide synthase and sphingolipid biosynthesis. Notwithstanding the need for a better evidence-base on mycotoxins and human health, supported by better biomarkers of exposure and effect in epidemiological studies, the existing data are sufficient to prioritize exposure reduction in vulnerable populations. For both toxins, there are a number of practical primary and secondary prevention strategies which could be beneficial if the political will and financial investment can be applied to what remains a largely and rather shamefully ignored global health issue.