Histamine in food: is there anything to worry about?

Molecularly Imprinting–Aptamer Techniques and Their Applications in Molecular Recognition

Molecular imprinting–aptamer techniques exhibit the advantages of molecular imprinting and aptamer technology. Hybrids of molecularly imprinted polymer–aptamer (MIP–aptamer) prepared by this technique have higher stability, binding affinity and superior selectivity than conventional molecularly imprinted polymers or aptamers. In recent years, molecular imprinting–aptamer technologies have attracted considerable interest for the selective recognition of target molecules in complex sample matrices and have been used in molecular recognition such as antibiotics, proteins, viruses and pesticides. This review introduced the development of molecular imprinting–aptamer-combining technologies and summarized the mechanism of MIP–aptamer formation. Meanwhile, we discussed the challenges in preparing MIP–aptamer. Finally, we summarized the application of MIP–aptamer to the molecular recognition in disease diagnosis, environmental analysis, food safety and other fields.

Formation of Bioactive Tyrosine Derivatives during Sprouting and Fermenting of Selected Whole Grains

Sprouting is a popular method in cereal processing because sprouted grains are accepted to have high nutritional value. The increased proteolytic activity by sprouting increases the free amino acids in grains. It was hypothesized that an increased amount of tyrosine can be utilized by microorganisms during fermentation to form higher amounts of bioactive tyrosine derivatives. Sprouting increased the tyrosine and tyramine contents considerably, but increases and decreases in l-3,4-dihydroxyphenylalanine (l-DOPA) and dopamine were specific to the cereal. More tyramine, l-DOPA, and dopamine formation was observed during sourdough fermentation than that in yeast fermentation. As a result of the combined application of sprouting (48 h at 20 °C) and sourdough fermentation (36 h at 30 °C), the amounts of dopamine, l-DOPA, and tyramine found in rye were 27, 50, and 136 mg/kg, respectively. Cereal products rich in dopamine and l-DOPA can thus be produced as functional food ingredients with their positive effects on human health and mood.

Dual-recognition molecularly imprinted aptasensor based on gold nanoparticles decorated carboxylated carbon nanotubes for highly selective and sensitive determination of histamine in different matrices

In this study, an electrochemical aptamer based sensor (aptasensor) was proposed for specific recognition of histamine (HIS). The electrochemical aptasensor based on fabrication of glassy carbon electrode (GCE) with molecular imprinted polymer (MIP) and DNA aptamers on gold nanoparticles (AuNPs) and carboxylated carbon nanotubes (cCNTs) (MIP-apta/AuNPs/cCNTs/GCE). The aptasensor exhibits high selectivity towards HIS detection as it has two recognition elements which are MIP cavities and aptamer interaction. Upon exposure of MIP-apt/AuNPs/cCNTs/GCE to HIS, the current of redox probe was decreased that depends on the template (HIS) concentration. The effects of aptamer concentration, incubation time, pH and AuNPs electro-deposition time were optimized. Differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were used to analyze HIS in complicated matrices. Favorable performance of MIP-apt/AuNPs/cCNTs/GCE was achieved with linearity ranges of 0.46-35 nmol L^-1 and 0.35-35 nmol L^-1 with limits of detection (LODs, S/N = 3) of 0.15 nmol L^-1 and 0.11 nmol L^-1 using DPV and EIS, respectively. The fabricated aptasensor displayed high selectivity, desirable reproducibility and stability. The MIP-apt/AuNPs/cCNTs/GCE was used to detect HIS in human plasma and canned tuna samples with good recoveries % and RSDs %.

Food sources and biomolecular targets of tyramine

Tyramine is a biogenic trace amine that is generated via the decarboxylation of the amino acid tyrosine. At pico- to nanomolar concentrations, it can influence a multitude of physiological mechanisms, exhibiting neuromodulatory properties as well as cardiovascular and immunological effects. In humans, the diet is the primary source of physiologically relevant tyramine concentrations, which are influenced by a large number of intrinsic and extrinsic factors. Among these factors are the availability of tyrosine in food, the presence of tyramine-producing bacteria, the environmental pH, and the salt content of food. The process of fermentation provides a particularly good source of tyramine in human nutrition. Here, the potential impact of dietary tyramine on human health was assessed by compiling quantitative data on the tyramine content in a variety of foods and then conducting a brief review of the literature on the physiological, cellular, and systemic effects of tyramine. Together, the data sets presented here may allow both the assessment of tyramine concentrations in food and the extrapolation of these concentrations to gauge the physiological and systemic effects in the context of human nutrition.

Biogenic Amines in Alcohol-Free Beverages

Biogenic amines are ubiquitous bioactive compounds that are synthesized by living organisms and perform essential functions for their metabolism. In the human diet, their excessive intake can cause food poisoning. In food, especially in alcohol-free beverages, biogenic amines can be synthesized by enzymes, naturally present in raw materials, or by microorganisms, which may be naturally present in the matrix or be added during beverage transformation processes. For this reason, in alcohol-free beverages, biogenic amine amount can be considered, above a certain level, as undesired microorganism activity. Therefore, it is important to evaluate the biogenic amine profile of non-alcoholic beverages in order to monitor food quality and safety. Moreover, biogenic amines can be taken into account by industries in order to monitor production processes and products. This review article provides an overview on the biogenic amine profile of alcohol-free beverages (plant milk, nervine drinks, soft drinks, and fruit juices). Furthermore, the clinical and toxicological effects, the biogenic amines legislation, and biogenic amine synthesis have been evaluated in non-alcoholic beverages.

Impaired resolution of wheals in the skin prick test and low diamine oxidase blood level in allergic patients

Introduction

Histamine is the major mediator of IgE- and non-IgE-mediated allergic reactions upon allergen or hapten contact. Reduced histamine degradation capacity was associated with atopic eczema as well as with non-immunological histamine intolerance. Higher blood serum histamine level concomitant with decreased intestinal diamine oxidase activity were observed in patients with food allergy.

Aim

To evaluate the relationship between patients’ blood diamine oxidase (DAO) activity/histamine status and their reactivity to time-resolved histamine skin prick test in respect to vulnerability to allergic diseases.

Material and methods

Fifty-three patients were examined with skin prick tests (SPT) and patch tests for suspected presence of either IgE- or non-IgE-mediated allergy. All individuals were skin prick tested with histamine and the resolution of the wheal was monitored for 50 min. Blood DAO activity and histamine concentration were measured with a radio-extraction radioimmunoassay.

Results

Time-resolved histamine skin prick testing revealed presence of wheals which were 35% larger in diameter in 47% of examined subjects at 20 min of the test. These patients exhibited significantly compromised time-course wheal resolution (wheal ≥ 3 mm at 50 min) compared to a group of patients with the normal-rate of wheal resolution (wheal = 0 mm at 50 min). Within a group of subjects exhibiting impaired wheal resolution, 61% of patients were diagnosed allergic compared to 50% in a group of patients with a normal rate of wheal resolution. Finally, allergic patients were characterized by a significantly lower DAO activity and higher histamine content compared to healthy subjects.

Conclusions

The results of this study indicate that patients with IgE- or non-IgE-mediated allergy are likely to have low DAO blood activity and may concomitantly suffer from histamine intolerance. Furthermore, our results suggest that allergic patients are more likely to develop an excessive SPT reaction. Our results emphasize caution in interpretation of the SPT results in allergic patients with diagnosed histamine intolerance or histamine/DAO activity imbalance.

Polyamines in mammalian pathophysiology

Polyamines (PAs) are essential organic polycations for cell viability along the whole phylogenetic scale. In mammals, they are involved in the most important physiological processes: cell proliferation and viability, nutrition, fertility, as well as nervous and immune systems. Consequently, altered polyamine metabolism is involved in a series of pathologies. Due to their pathophysiological importance, PA metabolism has evolved to be a very robust metabolic module, interconnected with the other essential metabolic modules for gene expression and cell proliferation/differentiation. Two different PA sources exist for animals: PA coming from diet and endogenous synthesis. In the first section of this work, the molecular characteristics of PAs are presented as determinant of their roles in living organisms. In a second section, the metabolic specificities of mammalian PA metabolism are reviewed, as well as some obscure aspects on it. This second section includes information on mammalian cell/tissue-dependent PA-related gene expression and information on crosstalk with the other mammalian metabolic modules. The third section presents a synthesis of the physiological processes described as modulated by PAs in humans and/or experimental animal models, the molecular bases of these regulatory mechanisms known so far, as well as the most important gaps of information, which explain why knowledge around the specific roles of PAs in human physiology is still considered a "mysterious" subject. In spite of its robustness, PA metabolism can be altered under different exogenous and/or endogenous circumstances so leading to the loss of homeostasis and, therefore, to the promotion of a pathology. The available information will be summarized in the fourth section of this review. The different sections of this review also point out the lesser-known aspects of the topic. Finally, future prospects to advance on these still obscure gaps of knowledge on the roles on PAs on human physiopathology are discussed.

Diamine oxidase (DAO) supplement reduces headache in episodic migraine patients with DAO deficiency: A randomized double-blind trial

BACKGROUND & AIMS

Histamine intolerance is a disorder in the homeostasis of histamine due to a reduced intestinal degradation of this amine, mainly caused by a deficiency in the enzyme diamine oxidase (DAO). Among histamine related symptoms, headache is one of the most recorded. Current clinical strategies for the treatment of the symptomatology related to this disorder are based on the exclusion of foods with histamine or other bioactive amines and/or exogenous DAO supplementation. The aim of this study was to assess the efficacy of a food supplement consisting of DAO enzyme as a preventive treatment of migraine in patients with DAO deficiency through a randomized double-blind trial.

METHODS

100 patients with confirmed episodic migraine according to current International Headache Society (IHS) criteria and DAO deficiency (levels below 80 HDU/ml) were randomized in two groups. One group received DAO enzyme supplementation and the other received placebo for one month. Clinical outcomes assessed were duration and number of attacks, perception of pain intensity and adverse effects during treatment. The use of triptans was also recorded.

RESULTS

Great variability was found in the duration of migraine attacks reported by placebo and DAO groups. A significant reduction (p = 0.0217) in hours of pain was achieved in patients treated with DAO supplement, with mean durations of 6.14 (±3.06) and 4.76 (±2.68) hours before and after treatment, respectively. A smaller reduction without statistical signification was also observed for this outcome in the placebo group, from 7.53 (±4.24) to 6.68 (±4.42) hours. Only in DAO group, a decrease in the percentage of patients taking triptans was observed. The number of attacks and the scores of pain intensity showed a similar reduction in both groups. No adverse effects were registered in patients treated with DAO enzyme.

CONCLUSIONS

Migrainous patients supplemented with DAO enzyme during one month significantly reduced the duration of their migraine attacks by 1.4 h. No statistically significant reduction was found in placebo group before and after treatment. The reduction of pain hours observed in placebo group (0.9 h) could explain the lack of significant differences between both study groups. One month of DAO supplementation has demonstrated a positive trend in the improvement of migraine but more studies with a longer treatment period are needed to better assess the efficacy of DAO supplementation.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN10091019; www.isrctn.org.

Biogenic amines in foods

Biogenic amines are produced by bacterial decarboxylation of corresponding amino acids in foods. Concentration of biogenic amines in fermented food products is affected by several factors in the manufacturing process, including hygienic of raw materials, microbial composition, fermentation condition, and the duration of fermentation. Intake of low amount of biogenic amines normally does not have harmful effect on human health. However, when their amount in food is too high and detoxification ability is inhibited or disturbed, biogenic amines could cause problem. To control concentration of BAs in food, decarboxylase activity for amino acids can be regulated. Levels of BAs can be reduced by several methods such as packaging, additives, hydrostatic pressure, irradiation, pasteurization, smoking, starter culture, oxidizing formed biogenic amine, and temperature. The objective of this review paper was to collect, summarize, and discuss necessary information or useful data based on previous studies in terms of BAs in various foods.

Effect of Different Cooking Methods on Histamine Levels in Selected Foods

BACKGROUND

Histamine in food is known to cause food poisoning and allergic reactions. We usually ingest histamine in cooked food, but there are few studies about the influence of cooking method on the histamine level.

OBJECTIVE

The purpose of this study was to determine the influence of cooking methods on the concentration of histamine in foods.

METHODS

The foods chosen were those kinds consumed frequently and cooked by grilling, boiling, and frying. The histamine level of the food was measured using enzyme-linked immunosorbent assay.

RESULTS

Grilled seafood had higher histamine levels than raw or boiled seafood. For meat, grilling increased the histamine level, whereas boiling decreased it. For eggs, there was not much difference in histamine level according to cooking method. Fried vegetables had higher histamine levels than raw vegetables. And fermented foods didn't show much difference in histamine level after being boiled.

CONCLUSION

The histamine level in food has changed according to the cooking method used to prepare it. Frying and grilling increased histamine level in foods, whereas boiling had little influence or even decreased it. The boiling method might be helpful to control the effect of histamine in histamine-sensitive or susceptible patients, compared with frying and grilling.

Functional electrospun nanofibers for multimodal sensitive detection of biogenic amines in food via a simple dipstick assay

Electrospun nanofibers (ENFs) are promising materials for rapid diagnostic tests like lateral flow assays and dipsticks because they offer an immense surface area while excluding minimal volume, a variety of functional surface groups, and can entrap functional additives within their interior. Here, we show that ENFs on sample pads are superior in comparison to standard polymer membranes for the optical detection of biogenic amines (BAs) in food using a dipstick format. Specifically, cellulose acetate (CA) fibers doped with 2 mg/mL of the chromogenic and fluorogenic amine-reactive chameleon dye Py-1 were electrospun into uniform anionic mats. Those extract cationic BAs from real samples and Py-1 transduces BA concentrations into a change of color, reflectance, and fluorescence. Dropping a BA sample onto the nanofiber mat converts the weakly fluorescent pyrylium dye Py-1 into a strongly red emitting pyridinium dye. For the first time, a simple UV lamp excites fluorescence and a digital camera acts as detector. The intensity ratio of the red to the blue channel of the digital image is dependent on the concentration of most relevant BAs indicating food spoilage from 10 to 250 μM. This matches the permitted limits for BAs in foods and no false positive signals arise from secondary and tertiary amines. BA detection in seafood samples was also demonstrated successfully. The nanofiber mat dipsticks were up to sixfold more sensitive than those using a polymer membrane with the same dye embedded. Hence, nanofiber-based tests are not only superior to polymer-based dipstick assays, but will also improve the performance of established tests related to food safety, medical diagnostics, and environmental testing. Graphical Absract ᅟ.

Technological Factors Affecting Biogenic Amine Content in Foods: A Review

Biogenic amines (BAs) are molecules, which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine, and agmatine. The importance of preventing the excessive accumulation of BAs in foods is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BAs accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting BA content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity, and other BAs), environmental factors influencing BA formation (temperature, salt concentration, and pH). In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolizing BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances) are addressed.

Validation of a Fluorescence Sensor Microtiterplate for Biogenic Amines in Meat and Cheese

An optical sensor microtiterplate for quantitative analysis of the total content of biogenic amines (TAC) in meat and cheese was developed and validated for the first time. In the plate, a chameleon dye (Py-1) is embedded in a polymeric cocktail which is deposited on the bottom of the wells in a common microtiterplate. On reaction with biogenic amines (BAs), the fluorescence of Py-1 at 620 nm rapidly delivers a precise TAC. After 10 min incubation at 25 °C the determination of the TAC in various (real) samples is possible in high-throughput with a standard microplate reader. The optimized fluorescence method was validated for linearity, sensitivity, accuracy, precision (intraday and inter day repeatability) and recovery using histamine (HIS) as a representative BA. The sensor microtiterplate was successfully applied to quantitatively analyze the TAC in 10 real samples of cheese and meat obtained from various Egyptian markets. The TAC of these real samples obtained by the sensor microtiterplate was validated against the contents of BAs obtained by GC-MS at various times of storage. The data of the sensor microtiterplate agreed well with those of GC-MS. This demonstrates that the sensor microtiterplate is a reliable screening tool for the degradation status of food samples.

Sensitivity to food additives, vaso-active amines and salicylates: a review of the evidence

Although there is considerable literature pertaining to IgE and non IgE-mediated food allergy, there is a paucity of information on non-immune mediated reactions to foods, other than metabolic disorders such as lactose intolerance. Food additives and naturally occurring 'food chemicals' have long been reported as having the potential to provoke symptoms in those who are more sensitive to their effects. Diets low in 'food chemicals' gained prominence in the 1970s and 1980s, and their popularity remains, although the evidence of their efficacy is very limited. This review focuses on the available evidence for the role and likely adverse effects of both added and natural 'food chemicals' including benzoate, sulphite, monosodium glutamate, vaso-active or biogenic amines and salicylate. Studies assessing the efficacy of the restriction of these substances in the diet have mainly been undertaken in adults, but the paper will also touch on the use of such diets in children. The difficulty of reviewing the available evidence is that few of the studies have been controlled and, for many, considerable time has elapsed since their publication. Meanwhile dietary patterns and habits have changed hugely in the interim, so the conclusions may not be relevant for our current dietary norms. The conclusion of the review is that there may be some benefit in the removal of an additive or a group of foods high in natural food chemicals from the diet for a limited period for certain individuals, providing the diagnostic pathway is followed and the foods are reintroduced back into the diet to assess for the efficacy of removal. However diets involving the removal of multiple additives and food chemicals have the very great potential to lead to nutritional deficiency especially in the paediatric population. Any dietary intervention, whether for the purposes of diagnosis or management of food allergy or food intolerance, should be adapted to the individual's dietary habits and a suitably trained dietitian should ensure nutritional needs are met. Ultimately a healthy diet should be the aim for all patients presenting in the allergy clinic.

Pharmacological potential of biogenic amine-polyamine interactions beyond neurotransmission

Histamine, serotonin and dopamine are biogenic amines involved in intercellular communication with multiple effects on human pathophysiology. They are products of two highly homologous enzymes, histidine decarboxylase and l-aromatic amino acid decarboxylase, and transmit their signals through different receptors and signal transduction mechanisms. Polyamines derived from ornithine (putrescine, spermidine and spermine) are mainly involved in intracellular effects related to cell proliferation and death mechanisms. This review summarizes structural and functional evidence for interactions between components of all these amine metabolic and signalling networks (decarboxylases, transporters, oxidases, receptors etc.) at cellular and tissue levels, distinct from nervous and neuroendocrine systems, where the crosstalk among these amine-related components can also have important pathophysiological consequences. The discussion highlights aspects that could help to predict and discuss the effects of intervention strategies.

A new method for the determination of biogenic amines in cheese by LC with evaporative light scattering detector

This paper presents a new LC method with evaporative light scattering detection (ELSD), for the separation and determination of the biogenic amines (histamine, spermidine, spermine, tyramine, putrescine and β-phenylethylamine) which are commonly present in cheese, as their presence and relative amounts give useful information about freshness, level of maturing, quality of storage and cheese authentication. The LC-ELSD method is validated by comparison of the results with those obtained through LC-UV determination, based on a pre-column dansyl chloride derivatisation step. The obtained data demonstrate that both methods can be interchangeably used for biogenic amines determination in cheese. The new LC-ELSD method shows good precision and permits to achieve, for standard solutions, limit of detection (LOD) values ranging from 1.4 to 3.6 mg L(-1) and limit of quantitation (LOQ) values ranging from 3.6 to 9.3 mg L(-1). The whole methodology, comprehensive of the homogenization-extraction process and LC-ELSD analysis, has been applied in the analysis of a typical Calabria (Southern Italy) POD cheese, known as Caciocavallo Silano. The most aboundant amine found was histamine, followed, in decreasing order, by tyramine, spermine, putrescine, β-phenylethylamine and spermidine, for a total amount of 127 mg kg(-1). This value does not represent a possible risk for consumer health, according to the toxicity levels reported in literature and regarded as acceptable.

Histamine intolerance: lack of reproducibility of single symptoms by oral provocation with histamine: a randomised, double-blind, placebo-controlled cross-over study

OBJECTIVES

The term histamine intolerance stands for a range of symptoms involving various effector organs after the consumption of histamine-rich food. Our intention was to objectify and quantify histamine-associated symptoms and to analyse whether oral administration of the histamine-degrading enzyme diamine oxidase (DAO) caused a reduction of symptoms.

PATIENTS AND METHODS

Four Austrian centres participated. Patients suspected to be histamine intolerant were recruited. The first step consisted in the open oral provocation of these patients with 75 mg of liquid histamine. Patients who developed symptoms were tested in a randomised double blind crossover provocation protocol using histamine-containing and histamine-free tea in combination with DAO capsules or placebo. Main and secondary symptoms (strongest and weaker symptoms based on a ten-point scale) were defined, the grand total of all symptoms of the individual provocation steps was determined and changes in symptoms after administration of DAO were measured.

RESULTS

Thirty nine patients reacted to the open histamine provocation and were enrolled in the blinded part. Here, both the main and secondary symptoms were not reproducible. Subjects reacted sometimes unexpectedly and randomly. Regarding the total symptom scores, the differences between the three treatment groups were statistically significant. The intake of DAO demonstrated a statistically significant reduction of histamine-associated symptoms compared to placebo (P = 0.014).

CONCLUSIONS

Oral provocation with 75 mg of liquid histamine failed to reproduce histamine-associated single symptoms in many patients. One may suggest that histamine-intolerant subjects reacted with different organs on different occasions. As a consequence, reproducibility of single symptoms alone may not be appropriate to diagnose histamine-intolerance whereas a global symptom score could be more appropriate. The fact, that the intake of DAO capsules compared to placebo led to a statistically significant reduction of total symptom scores, may indirectly point in the same direction.

Drug interactions

Drugs for allergy are often taken in combination with other drugs, either to treat allergy or other conditions. In common with many pharmaceuticals, most such drugs are subject to metabolism by P450 enzymes and to transmembrane transport. This gives rise to considerable potential for drug-drug interactions, to which must be added consideration of drug-diet interactions. The potential for metabolism-based drug interactions is increasingly being taken into account during drug development, using a variety of in silico and in vitro approaches. Prediction of transporter-based interactions is not as advanced. The clinical importance of a drug interaction will depend upon a number of factors, and it is important to address concerns quantitatively, taking into account the therapeutic index of the compound.

A new ultra-pressure liquid chromatography method for the determination of biogenic amines in cheese

A fast and reliable ultra-performance liquid chromatography (UPLC) method for the determination of biogenic amines (ethanolamine, methylamine, agmatine, histamine, dimethylamine, ethylamine, octopamine, pyrrolidine, dopamine, isopropylamine, propylamine, tyramine, putrescine, butylamine, cadaverine, tryptamine, 2-phenylethylamine, 3-methylbutylamine, spermidine, spermine) in cheese was established. After pre-column derivatization with 6-aminoquinolyl-N-hydroxy-succinimidyl carbamate (AQC), 20 primary and secondary biogenic amines were separated on an Acquity UPLC column (BEH C(18), 1.7 microm; 2.1 mm x 50 mm) within 9 min. Limits of detection (mg/100g cheese) ranged from 0.04 (ethanolamine) to 1.62 (spermine), and limits of quantification were between 0.16 (ethanolamine) and 6.09 (spermine). The UPLC method was applied to the analysis of 58 cheese samples as retailed in Austria. About 13.8% of samples had a histamine content above 10mg/100g, and 22.4% had a tyramine content above 10mg/100g. Moreover, 8.6% of samples had a putrescine or cadaverine content higher than 10mg/100g. The total concentration of biogenic amines in two cheese samples was about 194 mg/100g. Thus, obligatory monitoring of biogenic amines should be considered to ensure quality of cheese in future.

N-acetyltransferase 2 (NAT2) polymorphism in patients with atopic asthma

BACKGROUND AND AIMS

Allergic asthma is a chronic inflammatory disorder of the airways where, on exposure to allergens, the body mounts an immune response. The etiology of asthma is complex and multifactorial. Rapid and slow acetylators reflect the genetically determined variation in the elimination of xenobiotics. Recent advances have demonstrated the importance of genetic and environmental factors in the development of atopic asthma. Hepatic arylamine N-acetyltransferase 2 (NAT2) takes part in the detoxification of some drugs and arylamine xenobiotics. The aim of the present study was to determine the NAT2 polymorphism in patients with atopic asthma.

METHODS

In the study, 184 unrelated asthmatic patients and 181 healthy controls were included. The mutations at positions 481T, 803G, 590A and 857A of the NAT2 gene were determined by a polymerase chain reaction-restriction fragment length polymorphism assay (PCR-RFLP).

RESULTS

The frequency of homozygous fast acetylators did not differ significantly between patients and controls. Compared with the control population, the significant prevalence of slow acetylators in the group of patients with atopic asthma was observed. There was a statistically significant prevalence of subjects with NAT2*5/NAT2*5 and NAT2*5/NAT2*6 genotypes. The risk of an atopic asthma development was 3.4 times greater in slow than in fast acetylators (OR = 3.3657; p <0.000001, 95% CI = 2.1282-5.3228).

CONCLUSIONS

These results suggest that NAT2 polymorphism may be involved in the pathogenesis of atopic asthma.