Small intestinal enteropathy in non-obese diabetic mice fed a diet containing wheat

AIMS/HYPOTHESIS

A deranged mucosal immune response and dietary factors may play an important role in the pathogenesis of type 1 diabetes. The aims of our work were to look for the presence of small intestinal enteropathy in non-obese diabetic (NOD) mice in relation to the presence of wheat proteins in the diet, and to assess their role in the risk of developing diabetes.

METHODS

Female NOD mice were fed a standard or gluten-free diet or a gluten-free diet with the addition of wheat proteins (MGFD). Small intestine architecture, intraepithelial CD3(+) infiltration, epithelial expression of H2-IA, mRNA for IFN-gamma and IL-4 were assessed.

RESULTS

NOD mice fed a standard diet showed reduced villous height, increased intraepithelial infiltration by CD3(+) cells and enhanced expression of H2-IA and IFN-gamma mRNA when compared with mice on the gluten-free diet. The cumulative diabetes incidence at 43 weeks of age was 65% in the latter and 97% in the former (p<0.01). Mice on MGFD also showed increased epithelial infiltration and a higher incidence of diabetes.

CONCLUSIONS/INTERPRETATION

Mice fed a wheat-containing diet showed a higher incidence of diabetes, signs of small intestinal enteropathy and higher mucosal levels of proinflammatory cytokines.

Which cereal is a suitable substitute for wheat in children with wheat allergy?

Wheat is one of the main food allergens. It is among widely used cereals and there is an extensive cross-reaction between cereals. The aim of this study is to evaluate the extent to which cereals cross-react and to find the best substitute for wheat. Eighteen patients with definite diagnosis of type I hypersensitivity reactions to wheat enrolled in this study. Measurement of serum-specific IgE and skin prick test (SPT) for cereals flour (wheat, barley, oat, rye, rice and corn) and wheat bran was carried out. Also, open food challenge tests with available and conventional cereals in Iranian food culture (wheat, corn, rice and barley) were carried out. The SPTs were positive in 44.4% of patients for barley, 94.5% for wheat and 44-77% for other cereals. Positive serum-specific IgE was remarkable for wheat and barley and there was correlation between wheat and barley-specific IgE concentrations (r = 0.773 and p < 0.01). Corn serum-specific IgE was measured in 10 patients, which were positive in six of them. Of the patients, 55.5% had positive barley challenge tests, but all corn and rice challenge tests were negative. The best substitutes for wheat in wheat allergic patients are rice and corn. Regarding the correlation of wheat and barley serum-specific IgEs, there might be a high antigenic cross-reaction, therefore barley is not a good substitute for wheat and consuming barley needs a careful challenge test. Considering concordance of positive SPT to wheat flour and wheat bran, avoiding both of them is necessary in patients with wheat allergy.

A woman with daily headaches

Headache, and migraine in particular, is the main neurological reason for consultation. We present the case of a 48–year–old woman who experienced a transformation of her episodic migraine attacks into daily headache episodes due to the ingestion of biscuits containing wheat as their main ingredient. This experience emphasises that a good clinical interview remains the most important point in the diagnosis and management of headache.

Assessment of exposure to wheat flour and the shape of its relationship with specific sensitization

OBJECTIVES

Dust and wheat-allergen exposure were assessed among bakers, flour millers, and bakery-ingredient producers, and the risk for sensitization was studied.

METHODS

About 520 inhalable dust and wheat-allergen measurements were made among 270 Dutch workers. Data on sensitization to wheat and common allergens (atopy) were also available. Exposure was estimated according to the sector of industry, job title, and tasks. The shape of the relationship between sensitization and exposure was studied using a two-stage modeling approach: semi-parametric generalized additive modeling and, consequently, a simple description of the relationship using a parametric logistic model. To reduce the effect of exposure measurement errors (attenuation), a combination of the actual measured exposure and variance-weighted estimates of exposure was used. Results The effect of exposure to both inhalable dust and wheat allergens on sensitization was described best by a linear relationship in three industries and a quadratic relationship in one industry. The relation for the whole study population was best described as quadratic, and the probability of sensitization increased with exposure up to -2.7 mg/m3 for inhalable dust and approximately 25.7 microg EQ/m3 for wheat allergens. The risk decreased at higher exposures (P = 0.0121 and P = 0.0731 for dust and wheat, respectively). Atopy and sector of industry modified the sensitization risk significantly in all the analyses. Using a variant-weighted estimator to calculate exposures corrected for the bias and resulted in almost the same point risk estimators. Conclusions Exposure-response relationships for allergens may be nonlinear and differ between industries. A threshold is not indicated on which to base occupational exposure standards; alternatively, other approaches, such as benchmarking, seem warranted.

[Anaphylactic reactions after intake of products with wheat]

BACKGROUND

Food allergy is common in small children. Sensitisation to wheat is frequent, reactions to ingested wheat more seldom and mostly associated with atopic eczema and exercise-induced anaphylaxis.

MATERIAL AND METHODS

Eleven children with severe reactions after ingestion of small amounts of wheat were referred to us for further diagnostic procedures. Skin prick tests, total and specific IgE as well as oral provocation test were performed.

RESULTS

All but two children had strongly positive skin prick tests results to wheat. The same two children had specific IgE to Immunocap f4 (a-amylase) < 10 kUa/L while the nine other children had specific IgE to f4 > 29 kUa/L. All children had general reactions when provoked orally with small amounts of wheat with the need for administration of adrenalin and in most cases oral steroids.

INTERPRETATION

It is important to identify children at risk for general reactions to wheat, as cereals are staple foods in our community. Identification of the proteins involved in serious reactions is essential.

Coeliac disease in Middle Eastern countries: a challenge for the evolutionary history of this complex disorder?

About 10,000 years ago domestication and farming of wheat and other cereals developed in the 'Fertile Crescent', an area including modern Turkey, Iraq and Iran. Agriculture then slowly spread from Middle East to Europe. Coeliac disease is the permanent intolerance to dietary gluten, the major protein component of wheat. It has been until relatively recently hypothesised that wheat consumption exerted a negative selective pressure on genes predisposing to coeliac disease, eventually leading to higher coeliac disease frequency in Northeastern Europe because of lack of exposure to cereals. This theory is at variance with recent studies showing that coeliac disease is as common in Middle Eastern countries as in Europe. High prevalence of coeliac disease has been found in Iran, in both the general population and at-risk groups, e.g. patients with irritable bowel syndrome or type 1 diabetes. Clinical manifestations of coeliac disease vary markedly with the age of the patient, the duration and the extent of disease. Clinical studies showed that presentation with non-specific symptoms or no symptoms is as common in the Middle East as in Europe. Wheat represented a major component of the Iranian diet for many centuries and it may be argued that the continuous and high level of exposure to wheat proteins has induced some degree of immune tolerance, leading to milder symptoms that may be misdiagnosed as irritable bowel syndrome or unexplained gastrointestinal disorders. The gluten-free diet represents a real challenge to both patients and clinicians in this area. This is particularly difficult in the absence of any supply for gluten-free diet in Middle Eastern countries.

The occurrence of mite-containing wheat flour

Anaphylaxis after eating mite-infested wheat flour has been recently reported. This paper is to describe two cases and examine the occurrence of mite contamination in wheat flour in Japan. Packages of wheat flour from retail outlets and homes were examined microscopically for the presence of mites. Three of 176 packages from retail outlets and seven of 127 from homes were infested with mites, and it seems likely that the mite contamination takes place in most cases at homes after the packages have been opened. No mites were found in packages stored in a refrigerator, therefore, mite-sensitive patients must be advised to store wheat flour products in a refrigerator.

Natural history of cow's milk allergy. An eight-year follow-up study in 115 atopic children

BACKGROUND

Cow's milk allergy (CMA) is a disease of infancy and usually appears in the first few months of life. The evaluation of infants for possible CMA is one of the more common problems shared by pediatricians. The role of foods in determining and/or aggravating the clinical features of atopic dermatitis (AD) has been stressed in the last decades.

OBJECTIVE

The aim of the present study was to investigate, in children with food related AD, the development of tolerance to the offending food(s), clinical or laboratory data to predict the development of food tolerance, and whether there are clinical or laboratory data to predict the onset of respiratory allergy.

MATERIALS AND METHODS

In this prospective study we report on 115 babies, first examined at a median age of 6 months, and followed-up for 8 years. We have investigated several factors as predictive of the outcome, as follows: early onset; widespread or not-typical (reverse pattern) skin lesions, family history positive for atopy; persisting FA, high levels of total and specific IgE antibodies, association with CMA and asthma.

RESULTS

All these parameters were significantly predictive of a long-term morbidity of AD children with CMA. The median age for tolerance to cow's milk was 7 years + 11 months, to egg 6 years + 6 months, and to wheat 7 years + 2 months. However a great number of both tolerant and intolerant children developed multiple sensitizations. Only 66 children (57%) acquired food tolerance, but there was the onset of asthma in 54% of cases.

CONCLUSION

The natural history of CMA is not well-known, since not many related studies have been done in children. The several predictive factors, all in a negative sense, may be the norm in atopic children. We suggest possible areas of intervention in children at risk due to parental atopy. Preventive measures may induce a dramatic improvement in children with food allergy, but we stress that the long-term prognosis is challenging, since asthma prevalence may increase up to 54% during a long follow-up. Therefore, the natural history of IgE-mediated AD in atopic children sensitized to several allergens may be less optimistic than generally reported.

Prevalence of respiratory symptoms among wheat flour mill workers in Ibadan, Nigeria

BACKGROUND

While investigations into occupational health problems of various groups of workers have been conducted in Nigeria, so far, very little attention has been paid to the health status of workers in the grain industry. The prevalence of respiratory symptoms among wheat flour mill workers and control groups in a medium size industrial setting in Nigeria was studied.

METHODS

The study employed a cross-sectional analytical design. Data were collected using structured interviews, work-site observations, and physical examination. Respondents consisted of 91 flour-millers, 30 matched internal controls from the maintenance unit of the same flour mill factory, and 121 matched external controls.

RESULTS

Fifty-four percent of the flour-millers reported at least one respiratory symptom compared with 30% of the internal controls (P < 0.05) and 19% of the external controls (P < 0.001). Most symptoms were significantly more prevalent among the flour-millers compared with control subjects, and this trend was more evident amongst non-smokers than ex-smokers.

CONCLUSIONS

The study concluded that wheat flour mill workers in Nigeria, like grain workers elsewhere, were at an increased risk of developing both pulmonary and non-pulmonary symptoms compared with control subjects. The result has implications for improved dust control measures in the grain industry in Nigeria.

Development and validation of challenge materials for double-blind, placebo-controlled food challenges in children

BACKGROUND

The use of double-blind, placebo-controlled food challenges (DBPCFCs) is considered the gold standard for the diagnosis of food allergy. Despite this, materials and methods used in DBPCFCs have not been standardized.

OBJECTIVE

The purpose of this study was to develop and validate recipes for use in DBPCFCs in children by using allergenic foods, preferably in their usual edible form.

METHODS

Recipes containing milk, soy, cooked egg, raw whole egg, peanut, hazelnut, and wheat were developed. For each food, placebo and active test food recipes were developed that met the requirements of acceptable taste, allowance of a challenge dose high enough to elicit reactions in an acceptable volume, optimal matrix ingredients, and good matching of sensory properties of placebo and active test food recipes. Validation was conducted on the basis of sensory tests for difference by using the triangle test and the paired comparison test. Recipes were first tested by volunteers from the hospital staff and subsequently by a professional panel of food tasters in a food laboratory designed for sensory testing. Recipes were considered to be validated if no statistically significant differences were found.

RESULTS

Twenty-seven recipes were developed and found to be valid by the volunteer panel. Of these 27 recipes, 17 could be validated by the professional panel.

CONCLUSION

Sensory testing with appropriate statistical analysis allows for objective validation of challenge materials. We recommend the use of professional tasters in the setting of a food laboratory for best results.

Comparison of wheat and rye flour skin prick test solutions for diagnosis of baker's asthma

BACKGROUND

Skin prick tests (SPTs) play an important role in the diagnosis of baker's asthma and in the investigation of sensitization frequencies in field studies. It was the aim of our study to compare different SPT solutions for wheat and rye flour sensitization and to assess the validity of test results.

METHODS

Skin prick tests with wheat and rye flour were performed in parallel with extracts from different companies and compared with the results of bronchial challenge tests with both flours (69 rye flour and 51 wheat flour challenge tests). Additionally, specific immunoglobulin E (sIgE) to wheat and rye flour were tested. SPT solutions were analysed for protein content and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).

RESULTS

Skin prick test solutions for diagnosis of wheat and rye flour sensitization from three companies differed in protein concentrations and composition with the consequence of widely differing SPT results. Sensitivity of SPTs in comparison with allergen-specific bronchial challenge as a gold standard was between 40 and 67%, specificity was between 86 and 100%, the positive predictive value (PPV) ranged from 81 to 100% and the negative predictive value (NPV) from 44 to 70%. These numbers were only marginally affected by using a combination of challenge test result and sIgE value as a more specific gold standard.

CONCLUSION

Improvement and standardization of SPT extracts for wheat and rye flour is highly recommended.

The production of hypoallergenic wheat flour and the analysis of its allergy suppressive effects

We propose a novel method to produce hypoallergenic wheat flour suitable for patients allergic to wheat by using enzymatic fragmentation with cellulase and actinase. The hypoallergenic flour displayed potent inhibitory activity against allergen absorption and actively suppressed allergic reactions, probably inducing oral tolerance. The results suggest that hypoallergenic wheat flour has allergy-suppressive effects without inducing side effects.

Occupational allergy to wheat flour. Nasal response to specific inhalative challenge in asthma and rhinitis vs. isolated rhinitis: a comparative study

OBJECTIVES

The purpose of the study was to compare cytological and biochemical changes in nasal lavage fluid induced by wheat flour inhalatory challenge in bakers with allergic rhinitis and with asthma accompanied by rhinitis.

MATERIALS AND METHODS

A single-blind, placebo controlled study was conducted in 64 bakers with allergic rhinitis (n = 17), bronchial asthma and rhinitis (n = 24) and without occupational allergy (n = 23). Nasal washings were examined before, 30 min, 4 and 24 h after the specific provocation, wheras non-specific bronchial hyperreactivity (PC20) before and after 24 h.

RESULTS

A significant decrease in PC20 after the challenge test was observed only in patients with asthma and rhinitis. Eosinophil count and percentage, basophil count and the permeability index induced by specific provocation were significantly increased in both rhinitis patients and asthmatics. Moreover, the increase especially in total count and proportion of eosinophils as well as in the permeability index was more pronounced in subjects suffering from asthma and rhinitis than in those with rhinitis alone, although the changes were not statistically significant.

CONCLUSIONS

The results indicate the applicability of the "nasal pool" technique as a simple diagnostic procedure in flour-induced airway allergy. However, the evaluation of nasal lavage fluid, although a very sensitive and specific method of diagnosing respiratory allergic disease, cannot be used to distinguish patients with upper and lower airway allergy.

Mulberry (Morus alba) leaves as human food: a new dimension of sericulture

Mulberry leaf is commonly used for sericulture in almost every part of the world but its potential to be utilized for human consumption is not well recognized. This paper deals with development of mulberry leaf powder and its use with wheat flour to develop paratha, the most common food item of breakfast and dinner in the Indian diet. The optimum ratio of the mulberry leaf powder and wheat flour (MLP-WF) mix for preparation of paratha on the basis of sensory quality was found to be 1:4. The protein quality of the MLP-WF mix was estimated by measuring the Protein Efficiency Ratio, and was found to be 1.82 against a casein diet for which a value of 2.44 was observed. The in vivo toxic effect of mix was studied and no adverse effect on the growth of internal organs of rats (heart, liver, kidney and testes) was found. The storage stability of the mix was estimated for a period of 2 months in polyethylene bags at room temperature. A non-significant difference was observed between paratha prepared from fresh and stored mix. This indicated that mix can be stored for a period of 2 months at room temperature without loss of quality.

Characterization of cereal toxicity for celiac disease patients based on protein homology in grains

BACKGROUND AND AIMS

Celiac disease is caused by T-cell responses to wheat gluten-derived peptides. The presence of such peptides in other widely consumed grains, however, has hardly been studied.

METHODS

We have performed homology searches to identify regions with sequence similarity to T-cell stimulatory gluten peptides in the available gluten sequences: the hordeins of barley, secalins of rye, and avenins of oats. The identified peptides were tested for T-cell stimulatory properties.

RESULTS

With 1 exception, no identical matches with T-cell stimulatory gluten peptides were found in the other grains. However, less stringent searches identified 11 homologous sequences in hordeins, secalins, and avenins located in regions similar to those in the original gluten proteins. Seven of these 11 peptides were recognized by gluten-specific T-cell lines and/or clones from patients with celiac disease. Comparison of T-cell stimulatory sequences with homologous but non-T-cell stimulatory sequences indicated key amino acids that on substitution either completely or partially abrogated the T-cell stimulatory activity of the gluten peptides. Finally, we show that single nucleotide substitutions in gluten genes will suffice to induce these effects.

CONCLUSIONS

These results show that the disease-inducing properties of barley and rye can in part be explained by T-cell cross-reactivity against gluten-, secalin-, and hordein-derived peptides. Moreover, the results provide a first step toward a rational strategy for gluten detoxification via targeted mutagenesis at the genetic level.

Review article: The diagnosis of coeliac disease

Coeliac disease is a chronic inflammatory condition associated with small intestinal injury that results in the malabsorption of different nutrients. The damaging factor is gluten present in wheat, barley and rye. The diagnosis relies on the clinical picture of the patient, serological markers for coeliac disease, characteristic findings of small intestinal biopsy and, eventually, clinical improvement on a gluten-free diet. Our strategies for the diagnosis of coeliac disease have changed dramatically within the last 10 years. The advent of serological markers with high sensitivity and specificity is changing our understanding of the disease and its prevalence. Treatment includes a life-long gluten-free diet to prevent the recurrence of symptoms and other potential consequences. Most coeliac disease remains under-diagnosed; the utilization of more accurate serological tests and a greater awareness of its many presentations will aid its identification.

Necrotic enteritis: effect of barley, wheat and corn diets on proliferation of Clostridium perfringens type A

Necrotic enteritis, caused by Clostridium perfringens type A, is more prevalent in broilers fed wheat or barley diets than in those fed a corn diet. We compared the effects of wheat, barley and corn diets on in vitro proliferation of C. perfringens type A. Bacteria were inoculated into the supernatants delivered from either digested or non-digested barley, wheat and corn diets mixed with thioglycollate medium (1:3). Colony forming units were counted following incubation for 6 h at 40 degrees C. There were no significant differences in clostridial proliferation among non-digested diets. Bacterial proliferation in the digested wheat and barley diets was significantly higher than in the digested corn diet. These findings suggest that the increased incidence of necrotic enteritis in broilers fed barley and wheat diets compared with those fed a corn diet may be due in part to increased clostridial proliferation associated with the wheat and barley diets, or to decreased proliferation associated with the corn diet.

Mitigation of the action of wheat allergen by acidic oxidative potential water

BACKGROUND

Acidic oxidative potential water (AOPW) is strongly acidic, and contains active oxygen species and thus exhibits an oxidative potential to cause biochemical alterations of wheat proteins.

METHODS

A commercial wheat allergen extract was treated with AOPW, and then analysed by means of SDS-PAGE and the skin prick test in IgE-mediated wheat allergic patients.

RESULTS

The wheat extract comprised 70 kDa, 32 kDa and 30 kDa fractions, and the protein in the 70 kDa fraction was broken down into less than 14 kDa fractions by AOPW. AOPW mitigated 39% of the wheal reaction to the wheat extract in the skin prick test.

CONCLUSION

AOPW may be useful for enhancing the digestibility and lowering the allergenicity of wheat proteins.

The neurology of gluten sensitivity: separating the wheat from the chaff

Coeliac disease is the prototypical gluten-sensitive disease. Clinico-pathological features heal on a gluten-free diet and relapse when gluten is reintroduced. An immunopathology is suspected. A number of neurological syndromes may be associated with coeliac disease but it is unclear whether these are directly or indirectly caused by gluten ingestion. It has been proposed that idiopathic ataxias and central nervous system white matter disease are gluten-sensitive syndromes. This is an exciting hypothesis because it offers new therapeutic possibilities including simple exclusion diets. However, interpretation is difficult because occult sub-clinical coeliac disease occurs commonly and background prevalence needs to be accounted for in population-based studies. This review will attempt to summarize the pertinent literature on this fascinating topic.