New data on the occurrence of ochratoxin A in human sera from patients affected or not by renal diseases in Tunisia

Mycotoxins occurrence in milk and cereals in North African countries - a review

North African countries; Algeria, Egypt, Libya, Morocco and Tunisia suffer from mycotoxin contamination. Various studies have indicated the presence of mycotoxins in raw milk and cereals (i.e. wheat, barley, maize and cereal-based products). Aflatoxins (AFs), Aflatoxin M1 (AFM1), Ochratoxin A (OTA), Fumonisin (FB1) and Zearalenone (ZEN)-mycotoxin are the most detected due to climatic change in the region. In this review, we will present the kind of foods and feeds cereals and milk based products contaminated and the level of their contaminated mycotoxin. On the other hand, researchers try to find biologic methods to remove/mitigate mycotoxins in food and feed using bio-products. But the research works concerning legislations and mycotoxin risk assessment still rare. Therefore, it appears necessary to make review on the current status of mycotoxins in North African countries in order to explore data related to contamination of basic food in this region and to highlight the problem to the policy-makers to establish a serious legislation on this matter. On the other hand, to give more information to the worldwide readers about the impact of climate change on the food and feed pollution on mycotoxins in the Mediterranean Sea region.

Human Biomonitoring of Selected Hazardous Compounds in Portugal: Part II—Lessons Learned on Mycotoxins

Human biomonitoring (HBM) data provide information on total exposure regardless of the route and sources of exposure. HBM studies have been applied to quantify human exposure to contaminants and environmental/occupational pollutants by means of determining the parent compounds, their metabolites, or even their reaction products in biological matrices. HBM studies performed among the Portuguese population are dispersed and limited. Thus, to overcome this knowledge gap, this work reviews the published Portuguese HBM information concerning mycotoxins detected in the urine, serum, milk, hair, and nails of different groups of the Portuguese population. This integrative approach to the available HBM data allows us to analyze the main determinants and patterns of exposure of the Portuguese population to the selected hazardous compounds, as well as to assess the potential health risks. We also aimed to identify the main difficulties and challenges of HBM through the analysis of the enrolled studies. Ultimately, this study aims to support national and European policies in promoting human health by summarizing the most important outcomes and lessons learned through the HBM studies carried out in Portugal.

Change of Amino Acid Residues in Idiotypic Nanobodies Enhanced the Sensitivity of Competitive Enzyme Immunoassay for Mycotoxin Ochratoxin A in Cereals

Anti-idiotypic nanobodies, usually expressed by gene engineering protocol, has been shown as a nontoxic coating antigen for toxic compound immunoassays. We here focused on how to increase immunoassay sensitivity by changing the nanobody’s primary sequence. In the experiments, two anti-idiotype nanobodies against monoclonal antibody 1H2, which is specific to ochratoxin A, were obtained and named as nontoxic coating antigen 1 (NCA1) and nontoxic coating antigen 2 (NCA2). Three differences between the nanobodies were discovered. First, there are six amino acid residues (AAR) of changes in the complementarity determining region (CDR), which compose the antigen-binding site. One of them locates in CDR1 (I–L), two of them in CDR2 (G–D, E–K), and three of them in CDR3 (Y–H, Y–W). Second, the affinity constant of NCA1 was tested as 1.20 × 10⁸ L mol⁻¹, which is about 4 times lower than that of NCA2 (5.36 × 10⁸ L mol⁻¹). Third, the sensitivity (50% inhibition concentration) of NCA1 for OTA was shown as 0.052 ng mL⁻¹, which was 3.5 times lower than that of nontoxic coating antigen 2 (0.015 ng mL⁻¹). The results indicate that the AAR changes in CDR of the anti-idiotypic nanobodies, from nonpolar to polar, increasing the affinity constant may enhance the immunoassay sensitivity. In addition, by using the nontoxic coating antigen 2 to substitute the routine synthetic toxic antigen, we established an eco-friendly and green enzyme-linked immunosorbent assay (ELISA) method for rapid detection of ochratoxin A in cereals. The half-maximal inhibitory concentration (IC₅₀) of optimized ELISA was 0.017 ng mL⁻¹ with a limit of detection (LOD) of 0.003 ng mL⁻¹. The optimized immunoassay showed that the average recoveries of spiked corn, rice, and wheat were between 80% and 114.8%, with the relative standard deviation (RSD) ranging from 3.1–12.3%. Therefore, we provided not only basic knowledge on how to improve the structure of anti-idiotype nanobody for increasing assay sensitivity, but also an available eco-friendly ELISA for ochratoxin A in cereals.

Effects of Gamma Irradiation on Ochratoxin A Stability and Cytotoxicity in Methanolic Solutions and Potential Application in Tunisian Millet Samples

Gamma irradiation is a useful technology for degrading mycotoxins. The purpose of this study was to investigate the effect of irradiation on ochratoxin A (OTA) stability under different conditions. OTA was irradiated in methanolic solution and on millet flour at doses of 2 and 4 kGy. Residual OTA concentrations and possible degradation products in irradiated samples were analyzed by high-performance liquid chromatography with fluorescence detection and liquid chromatography coupled to mass spectrometry. The extent of in vitro cytotoxicity of OTA to HepG2 cells, with and without irradiation treatment, was assessed with an MTT assay. OTA was more sensitive to gamma radiation on Tunisian millet flour than in methanolic solutions. After irradiation of naturally contaminated millet flour, the OTA concentration was significantly reduced by 48 and 62% at a dose of 2 and 4 kGy, respectively. However, in the methanolic solution, OTA at concentrations of 1 and 5 μg mL^-1 was relatively stable even at a dose of 4 kGy, with no degradation products detected in the chemical analysis. Analytical results were confirmed by cell culture assays. The remaining cytotoxicity (MTT assay) of OTA following irradiation was not significantly affected compared with the controls. These findings indicate that gamma irradiation could offer a solution for OTA decontamination in the postharvest processing chain of millet flour. However, the associated toxicological hazard of decontaminated food matrices needs more investigation.

Ochratoxin A levels in plasma from inhabitants of northern Paraná, Brazil

Ochratoxin A (OTA), a mycotoxin produced by some fungi like Aspergillus ochraceus, Aspergillus niger, Aspergillus carbonarius and Penicillium viridicatum, is a natural contaminant of many foods worldwide. The intake of OTA is associated with deleterious effects to humans and animals, such as nephro- and hepatotoxicity. Although there are some data about food contamination, there is lack of data about human exposure to OTA in Brazil. Therefore, current research aimed to determine the level of human exposure to OTA and, additionally, identify possible associations with biomarkers of liver and kidney damage. OTA levels were evaluated in plasma samples from 149 individuals living in the state of Paraná, Brazil, by indirect competitive ELISA using monoclonal antibody anti-OTA (cell line OTA.7). Plasma levels of OTA, alanine aminotransferase, aspartate aminotransferase, urea and creatinine were submitted to Pearson's correlation test. It was possible to measure OTA levels in 54.4% of the samples (mean 734±296 pg/ml; maximum 1,585 pg/ml), with an estimated daily intake of 983-1,445 pg/kg body weight. There was no correlation between OTA plasma levels and biochemical parameters, possibly due to the low level of contamination. This is one of the first studies concerning the contamination of humans by OTA in Brazil and we conclude that the plasma levels of the evaluated population indicate an estimated weekly intake below the tolerable weekly intake derived by the EFSA Panel on Contaminants in the Food Chain. Nevertheless, additional longitudinal studies with greater regional coverage and at different seasonal periods are necessary.

Ochratoxin A: 50 Years of Research

Since ochratoxin A (OTA) was discovered, it has been ubiquitous as a natural contaminant of moldy food and feed. The multiple toxic effects of OTA are a real threat for human beings and animal health. For example, OTA can cause porcine nephropathy but can also damage poultries. Humans exposed to OTA can develop (notably by inhalation in the development of acute renal failure within 24 h) a range of chronic disorders such as upper urothelial carcinoma. OTA plays the main role in the pathogenesis of some renal diseases including Balkan endemic nephropathy, kidney tumors occurring in certain endemic regions of the Balkan Peninsula, and chronic interstitial nephropathy occurring in Northern African countries and likely in other parts of the world. OTA leads to DNA adduct formation, which is known for its genotoxicity and carcinogenicity. The present article discusses how renal carcinogenicity and nephrotoxicity cause both oxidative stress and direct genotoxicity. Careful analyses of the data show that OTA carcinogenic effects are due to combined direct and indirect mechanisms (e.g., genotoxicity, oxidative stress, epigenetic factors). Altogether this provides strong evidence that OTA carcinogenicity can also occur in humans.

Ochratoxin A levels in spices and dried nuts consumed in Tunisia

A total of 112 samples of spices (24 caraway, 20 coriander, 25 curcuma, 20 black pepper and 23 red pepper) and 110 samples of dried nuts (44 almonds, 42 peanuts and 24 pistachio) purchased from popular markets in 24 regions of Tunisia were analyzed for ochratoxin A (OTA) by fluorescence HPLC. The average levels of contamination of OTA found in spice samples were 244, 206, 290, 274 and 203 µg/kg, respectively, for caraway, coriander, curcuma, black pepper and red pepper. Concerning dried nut samples, the average levels were 61, 60 and 89 µg/kg, respectively, for almonds, peanuts and pistachio. Contamination levels were higher than the usual norms (10.0 OTA µg/kg) established by the European Commission in 2005 . This survey is the first to be carried out on the natural occurrence of OTA in the main spices and dried nuts consumed by the Tunisian population.

The effects of season and gender on the serum aflatoxins and ochratoxin A levels of healthy adult subjects from the Central Anatolia Region, Turkey

PURPOSE

This study was undertaken to determine the effects of season and gender on serum aflatoxin (AF) levels (AFG1, AFB1, AFG2 and AFB2) and ochratoxin A (OTA) concentrations of healthy adult population living in Central Anatolia Region of Turkey.

METHODS

AF levels were measured by high-performance liquid chromatography (HPLC) and OTA levels were measured by enzyme-linked immunosorbent assay (ELISA) in serum samples of healthy adults (n = 233).

RESULTS

In summer and winter, total AF levels in females were 0.98 ± 0.10 and 0.94 ± 0.12 ng/ml and in males 1.35 ± 0.17 and 0.93 ± 0.11 ng/ml, respectively. Male subjects had significantly higher serum total AF levels in summer compared with females (~38%). There was no marked seasonal change in AFG1, AFB1 and AFG2 concentrations in the whole population, except AFB2. Both of the genders had significantly higher OTA levels in winter compared with summer (~60%).

CONCLUSIONS

Overall results suggest that Central Anatolia residents are continuously exposed to AFs and OTA. Besides, season and gender can be effective in mycotoxin exposure.

Mycotoxins are conventional and novel risk biomarkers for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant disease with poor prognosis. To improve the clinical outcome, early diagnosis of HCC arising from nonviral agents and hepatitis virus is important. Among several etiological factors, mycotoxins defined as carcinogens by the International Agency for Research in Cancer (IARC) might be one of the critical risk factors for nonviral HCC. Aflatoxin B1 is the most well-known carcinogenic mycotoxin for HCC, but the role of the other types of mycotoxin remains unclear. Several studies have reported that a chromatographic separation technique based on high-performance liquid chromatography can successfully detect the concentration of mycotoxins in plasma. Recently, serum level of ochratoxin A (OTA), a widely distributed mycotoxin classified as Group 2B by IARC, was evaluated in HCC patients in Egypt. The results suggested that serum OTA levels might be a good biomarker for HCC. In this article, we review recent studies of OTA, and discuss its possible significance as a biomarker of HCC.

Ochratoxin A exposure biomarkers in the Czech Republic and comparison with foreign countries

Among ochratoxins, ochratoxin A (OTA) occupies a dominant place and represents significant risk for human and animal health which also implies economic losses around the world. OTA is nephrotoxic, hepatotoxic, teratogenic and immunotoxic mycotoxin. OTA exposure may lead to formation of DNA adducts resulting to genotoxicity and carcinogenicity (human carcinogen of 2B group). Now it seems that OTA could be "a complete carcinogen" which obliges to monitor its presence in biological materials, especially using the suitable biomarkers. In this article, OTA findings in urine, blood, serum, plasma and human kidneys (target dose) in the Czech Republic and comparison with foreign countries are presented.

Mutagenicity of ochratoxin A and its hydroquinone metabolite in the SupF gene of the mutation reporter plasmid Ps189

Ochratoxin A (OTA) is a mycotoxin that enhances renal tumor formation in the outer medulla of male rat kidney. Direct DNA damage and subsequent mutagenicity may contribute to these processes. In this study we have determined whether OTA in the absence or presence of activated rat liver microsomes (RLM) or redox-active transition metals (Fe(III) or Cu(II)) causes promutagenic DNA damage in the supF gene of the mutation reporter plasmid pS189 replicating in human Ad293 cells. In addition, we have assessed the mutagenicity of the hydroquinone metabolite (OTHQ) of OTA in the absence or presence of cysteine without added cofactors. Our results show that oxidation of OTA, either by RLM or by transition metal ions, activates OTA to a directly genotoxic mutagen(s). The Fe(III)/OTA system was the most potent mutagen in our experimental system, causing a 32-fold increase in mutant fraction (MF) above the spontaneous control MF. The Cu(II)/OTA system caused a 9-fold increase in MF, while a 6-10-fold increase in MF was observed for OTA in the presence of RLM. The OTHQ metabolite is also mutagenic, especially in the presence of cysteine, in which a 6-fold increase in MF was observed. Our data provide further insight into OTA bioactivation that may account for its in vivo mutagenicity in male rat kidney.

Determinants of ochratoxin A exposure--a one year follow-up study of urine levels

Dietary exposure to the ochratoxin A (OTA) occurring in Portugal is characterized by a high frequency of contamination of the consumed foodstuffs, although at low levels. The exposure bears significance for the total food consumed, and not for a particular one. Biomonitoring studies are thus fundamental in simplifying the evaluation of exposure, with no need to examine the entire range of consumed foodstuffs. Biomonitoring studies further allow the identification of host factors as predictors of OTA exposure in epidemiologic studies, the results of which are merited for targeting intervention strategies by public health authorities and advising official regulatory decisions. Using a longitudinal approach, this study examined factors related to OTA exposure in the adult population over a one-year period. Anthropometric measures, season of the year and region were the selected factors correlated with OTA exposure biomarker. Urine samples from 95 inhabitants from six Portuguese main geographical areas were assayed through spectrofluorimetric detection. Exposure to OTA proved to markedly increase in winter, and gender differences were observed only in summer, which might be related to different dietary patterns not only between seasons, but also between genders. The same rationale may also serve the observed statistically significant differences between some regions. No other strong association upon the remaining determinants under testing was observed. These observations reinforce the need for OTA exposure evaluation, possibly specifically targeting the staple foods or dietary habits that sustain potential predictors or determinants of exposure.

Analysis of ochratoxin A blood levels in bladder cancer cases and healthy persons from Pakistan

The mycotoxin ochratoxin A (OTA), a well-known human nephrotoxic and carcinogenic agent, is a public health concern in many countries. Exposure is assessed by means of mycotoxin analysis in food commodities and by human biomonitoring of OTA in blood samples. Data available from several European countries and some studies in Africa, Asia, and the Americas indicate frequent detection of OTA. Thus far, data from developing countries that compare blood levels in healthy and diseased individuals are scarce. Thus, the aim of this investigation was to determine OTA levels in blood samples of bladder cancer patients (n = 96) and healthy controls (n = 31) from Pakistan. OTA in blood plasma was analyzed after extraction by high-performance liquid chromatography (HPLC) with fluorescence detection. Among samples of 87 cancer patients and 30 controls, 92% in total contained quantifiable amounts of OTA. In bladder cancer cases the median OTA concentration was 0.19 ng/ml (mean 0.296; range: 0.03 to 3.41 ng/ml), and in healthy controls the median OTA was 0.19 ng/ml (mean 0.3; range: 0.04 to 1.24 ng/ml). The OTA levels found in the Pakistanian cohorts were comparable to those reported previously for the general population in the European Union. In conclusion, OTA is not likely to play a major role in the etiology of bladder cancer in the Karachi cohort, at least as the sole risk factor.

Plasma ochratoxin A levels, food consumption, and risk biomarkers of a representative sample of men and women from the Molise region in Italy

BACKGROUND

Ochratoxin A (OTA) is a mycotoxin present in food that can be found in human blood, due to its long half-life. Plasma OTA detection represents a good parameter for evaluating the exposure at the population level.

PURPOSE

The relation between plasma OTA levels, dietary habits, and specific disease risk biomarkers (body mass index (BMI), C-reactive protein (CRP), and cardiovascular risk score) was investigated.

METHODS

The study involved 327 subjects (150 men and 177 women) aged between 38 and 48 years. Food consumption was evaluated by means of the EPIC questionnaire; plasma OTA was measured by HPLC; CRP was determined in fresh serum samples by a latex particle-enhanced immunoturbidimetric assay.

RESULTS

OTA was detected in 99.1% of plasma samples (LOD 25 ng/L); the mean ± SD value was 0.229 ± 0.238 ng/mL. However, only 5.2% of samples exceeded 500 ng/L, considered the threshold for a possible pathogenic activity. The estimated mean daily dietary intake of OTA resulted 0.452 ± 0.468 ng/kg body weight (bw)/day, markedly lower than the tolerable daily intake set by EFSA (17.1 ng/kg bw/day). Processed and mutton/lamb meat were found to contribute most to plasma OTA variance. Nevertheless, cereals, wine, beer, and jam/honey consumption correlated positively with OTA levels. Plasma OTA showed a significant positive association with CRP and cardiovascular risk score (β = 0.20 ± 0.08; P = 0.015 and β = 0.25 ± 0.08; P = 0.001, respectively); however, the association was present in men but not in women.

CONCLUSIONS

Even if the hypothesis of a possible hepatic toxicity of OTA in humans is yet to be verified, the positive association between plasma OTA and CRP may indicate a possible role of OTA in inflammation status and consequently in the genesis of cardiovascular diseases and cancer.

Human ochratoxin a biomarkers--from exposure to effect

Ochratoxin A (OTA) is a nephrotoxic mycotoxin that has received particular attention because of the toxic effects, widespread occurrence in contaminated food and feed chain, suspected causal effect on nephropathies, and, more recently, possibility of exposure by inhalation in domicile and occupational settings. Biomarkers have been used not only to ascertain the role of OTA in inducing chronic renal failure diseases, but also as a means to portray general populations' risk to the mycotoxin. Biomonitoring can thus be used to assess internal OTA exposure, with no need to recognize the main source of exposure. And so it presents undeniable advantages over the monitoring of external dose. With a just right understanding of biomarkers, it is possible to follow the trail from exposure right to effect, and so contribute both to surveillance plans and etiological studies. In recognition of the long serum half-life and the renal elimination of OTA, most of the studies present serum/plasma and/or urine analyses as markers of exposure. In this review and for each of these main matrices, a comparison over the advantages and disadvantages is offered. Although currently limited, an overview of the current knowledge on OTA biomarkers and the influential role of the individual characteristics, namely gender and age, along with season and geographical location is given. Attention is also given to the ongoing debate over the existence of OTA-DNA adducts, a biomarker of effective dose regarded as an alternative to biomarkers of internal dose. Although unspecific, OTA effect biomarkers are also reviewed.

Polyaniline Langmuir-Blodgett film based aptasensor for ochratoxin A detection

Ochratoxin A (OTA) produced by Aspergillus Ochraceus and Penicillium verrucosum is a very dangerous toxin due to its toxic effects in human beings and its presence in a wide range of food products and cereals. A Langmuir-Blodgett (polyaniline (PANI)-stearic acid (SA)) film based highly sensitive and robust impedimetric aptasensor has been developed for ochratoxin A (OTA) detection. DNA Aptamer (Apt-DNA) specific to OTA has been covalently immobilized onto mixed Langmuir-Blodgett (LB) monolayer comprising of PANI-SA deposited onto indium tin-oxide (ITO) coated glass plates. This Apt-DNA/PANI-SA/ITO aptaelectrode has been characterized using scanning electron microscopy, Fourier transform-infrared spectroscopy, contact angle measurements, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The Apt-DNA/PANI-SA/ITO aptasensor shows detection of OTA by electrochemical impedance spectroscopy in the linear range of 0.0001 μg/ml (0.1 ng/ml) to 0.01 μg/ml (10 ng/ml) and 1 μg/ml-25 μg/ml with detection limit of 0.1 ng/ml in 15 min. The Apt-DNA/PANI-SA/ITO aptasensor can be reused ∼13 times. The binding or affinity constant (K(a)) of aptamer with OTA, calculated using Langmuir adsorption isotherm, is found be 1.21×10(7) M(-1).

Ochratoxin A levels in human serum and foods from nephropathy patients in Tunisia: where are you now?

Ochratoxin A is a natural mycotoxin with nephrotoxic properties that can contaminate food products. It has been detected in high amount in human serum collected from nephropathy patients, especially those categorized as having a chronic interstitial nephropathy of unknown etiology. In the present study, ochratoxin A levels were measured in commonly consumed food items and in serum samples from nephropathy and healthy subjects in Tunisia. To assess ochratoxin A, a high performance liquid chromatography method was optimized. The ochratoxin A assay showed very different scales of ochratoxin A serum and food contamination from 0.12 to 1.5 ng/mL and 0.11 to 6.1 ng/g respectively, and in healthy subjects and 0.11 to 33.8 ng/g for food and 0.12 to 3.8 ng/mL for serum in nephropathy patients suffering from chronic interstitial nephropathy of unknown etiology. The disease seems related to ochratoxin A serum levels and food contaminations, since the healthy group was significantly different from the nephropathy group (P<0.001) for both food and serum ochratoxin A contamination. Those results combined with data published already, emphasize the likely endemic aspect of ochratoxin A-related nephropathy occurring in Tunisia.

The presence of ochratoxin A in cord serum and in human milk and its correspondence with maternal dietary habits

BACKGROUND

Ochratoxin A (OTA) is a mycotoxin present in food that can be found in human blood and milk.

PURPOSE

The link between the nutritional habits of pregnant women both of Italian and foreign nationality resident in Italy and the presence of ochratoxin A in cord blood and in maternal milk was investigated.

METHODS

The study involved 130 pregnant women. Food consumption during pregnancy was evaluated by means of the EPIC questionnaire; OTA content was determined in cord serum and maternal milk by HPLC.

RESULTS

The mean daily dietary intake of OTA was 1.02 ± 1.20 and 0.87 ± 0.78 ng/kg of bodyweight for Italian and non-Italian women, respectively, but this difference was not statistically significant. The incidence of positive milk samples was 73.0 and 85.0% among the Italian and non-Italian mothers, respectively. Pork meat, soft drinks, sweets and red wine showed a significant relationship with OTA level in serum. As far as milk is concerned, a positive relationship resulted for pork meat, sweets, soft drinks and seed oils. A positive relationship between serum OTA level and the ratio serum/milk OTA was found. The intake of OTA had no effect on the cord blood creatinine level.

CONCLUSIONS

This study confirms that OTA is widely present in human milk and therefore could pose a risk for the newborn.

Ochratoxin a in Portugal: a review to assess human exposure

In Portugal, the climate, dietary habits, and food contamination levels present the characteristics for higher population susceptibility to ochratoxin A (OTA), one of the known mycotoxins with the greatest public health and agro-economic importance. In this review, following a brief historical insight on OTA research, a summary of the available data on OTA occurrence in food (cereals, bread, wine, meat) and biological fluids (blood, urine) is made. With this data, an estimation of intake is made to ascertain and update the risk exposure estimation of the Portuguese population, in comparison to previous studies and other populations.

Ochratoxin A in Moroccan foods: occurrence and legislation

Ochratoxin A (OTA) is secondary metabolite naturally produced in food and feed by toxigenic fungi, especially some Aspergillus species and Penicillium verucosum. OTA is one of the most studied mycotoxins and is of great interest due to its toxic effects on human and animals. OTA is produced in different food and feed matrices and contaminates a large range of base foods including cereals and derivatives, spices, dried fruits, wine and coffee, etc. Morocco, a North African country, has a climate characterized by high humidity and temperature, which probably favors the growth of molds. This contribution gives an overview of principal investigations about the presence of OTA in foods available in Morocco. Due to its toxicity, OTA presence is increasingly regulated worldwide, especially in countries of the European Union. However, up until now, no regulation limits were in force in Morocco, probably due to the ignorance of the health and economic problems resulting from OTA contamination. Finally, recommendations and future research directions are given required to assess the situation completely.

Review. Ochratoxin A: Presence in Human Plasma and Intake Estimation

Ochratoxin A (OTA) is a fungal toxic secondary metabolite that can be found in several foodstuffs and thereby ingested by humans. One way to assess exposure of humans to OTA is the determination of the levels of this mycotoxin in blood plasma from a certain population. Such studies have been done in many countries, both in healthy people and nephropathy patients. Relationships with individual characteristics were investigated in several cases. Thus, most studies found no correlation with age, either with gender. However, the few studies that found correlation between OTA plasma levels and gender showed that men presented the highest values. When sampling was done over more than one season, the highest OTA plasma levels were found mostly in summer. Differences within regions of a country were related to dietary habits of each area. OTA levels of group populations showed variations from year to year, whereas intraindividual repetitions showed no specific trend. Daily intake of the toxin can be estimated from OTA plasma concentrations by the Klaassen equation. OTA toxicokinetics are considered in this review. Calculated daily intake of OTA by different studies did not overpass the proposed tolerable daily intakes of OTA.

Ochratoxin A and β2-microglobulin in BEN patients and controls

Ochratoxin A (OTA) is a mycotoxin naturally occurring in different foods. OTA is arguably a risk factor for Balkan endemic nephropathy (BEN). The aims of this study are to (1) test the OTA-BEN association in BEN-groups and controls and (2) determine whether urine β2-microglobulin, a marker of impaired ability of the kidneys to re-absorb, is related to OTA. BEN patients had significantly higher OTA serum levels. Within the offspring, OTA was significantly related to higher β2-microglobulin excretion. OTA (2005/2006) was related to a higher incidence of BEN after 2008, providing further evidence that OTA is a risk factor for BEN.

A review on ochratoxin A occurrence and effects of processing of cereal and cereal derived food products

Ochratoxin A (OTA) continues to grab global attention and concern for the hazard and impact that embody for both human and animals, based on its toxicity and occurrence. Despite OTA has been described in a myriad of foodstuffs, cereal and its derivatives remain the major contributors to OTA exposure. For that reason, a critical review on OTA occurrence reported by recent studies worldwide focusing on unprocessed and processed cereal foodstuffs is made in this work. Special attention is drawn to the major cereal derived products, namely flour, bread, breakfast cereals, baby/infant foods and the inherently involved technological food processing methods and its influence on the redistribution and chemical modification of OTA. The paper further examines the factors that influence the OTA content of cereal and its derived products, explicitly the different ecological niches of the ochratoxigenic mycobiota -Aspergillus spp. and Penicillium verrucosum, the agricultural practice involved, harvest procedures and storage conditions, the type of grain, and the nature and extent of technological processing as well as the ultimate stages of analytical quality level of the sampling and analysis of the suspected ingredients or foods.

Mycotoxic and aristolochic acid theories of the development of endemic nephropathy

Despite many efforts of scientists and epidemiologists, the aetiology of endemic nephropathy (EN) is still unknown. This disease occurs in the rural population of geographically limited areas of Bulgaria, Bosnia and Herzegovina, Croatia, Romania, and Serbia, and a number of theories have been proposed about its aetiology. The mycotoxin theory has prevailed until now, based on the studies of nephrotoxic mycotoxin ochratoxin A (OTA) that revealed higher frequency of OTA-positive food and blood samples in endemic than in non-endemic areas.However, a new aristolochic acid (AA) theory of EN origin has been proposed recently, due to the histological similarities in kidney lesions between patients suffering from EN and patients suffering from Chinese herbs nephropathy caused by AA. Until now it has not been unequivocally proved that the inhabitants of EN areas are exposed to higher concentration of AA than in other regions and the exposure pathways are rather uncertain. This paper presents most important studies supporting both theories, indicating also the inconsistencies of each.

Balkan endemic nephropathy and associated urothelial cancer

Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial disease described only in some rural parts of southeastern Europe. One of its most peculiar characteristics is a strong association with upper urothelial cancer (UUC). BEN-related UUC has the same histological features as other forms of UUC in general, but is more frequently bilateral, less frequently affects the bladder and has a sex ratio close to 1. BEN and BEN-associated UUC share the same etiology. Over time, incidence of these conditions has been declining. Since BEN was first described, around half a century ago, socioeconomic changes (in housing, farming, living standards, etc.) have been profound and have obscured the factors responsible for the observed reduction in incidence. Whatever the causes of BEN, the disease might not be restricted only to southeastern Europe. Rather, the intensity of exposure to risk factors for BEN and, consequently, clustering of cases has more likely determined our knowledge of topographical distribution of an etiological entity that is much more widespread, or that might even be ubiquitous in its sporadic form.