Association of β₂-adrenergic receptor polymorphism with work-related symptoms in workers exposed to wheat flour

Purpose

Our previous study indicated that the presence of wheat-specific IgG1 and IgG4 antibodies was associated with work-related symptoms in workers exposed to wheat flour. We performed this study to investigate the genetic polymorphisms of β₂-adrenergic receptors and wheat-specific antibodies in association with the clinical parameters of baker''s asthma.

Materials and Methods

In total, 379 subjects working in a single industrial bakery were enrolled in this study. The skin prick test was performed with common inhalant allergens and wheat flour extract. The presence of serum- specific IgE, IgG1, and IgG4 antibodies to wheat flour were determined by ELISA. Whole blood samples were obtained for genotype analysis. Subjects were genotyped with regard to five candidate single nucleotide polymorphisms (SNPs) of the β₂-adrenergic receptor gene (ADRB2; -47 T>C, 46 A>G, 79 C>G, 252 G>A, and 523 C>A) using a single-base extension method.

Results

No significant associations were observed between the genotype/allele frequencies of any of the SNPs tested and any clinical parameters. The haplotype of ADRB2 (GAA composed of 46 A>G, 252 G>A, and 523 C>A) was significantly associated with work-related symptoms (p<0.05). Moreover, in subjects with the AG or GG genotype at 46 A>G and haplotype [GAA] of ADRB2, the prevalence rates of wheat-specific IgG1 antibodies and lower respiratory symptoms increased significantly with exposure intensity (both p<0.05).

Conclusion

The findings of the present study suggest that ADRB2 genetic polymorphism may contribute to the development of work-related symptoms in workers exposed to wheat flour, which can lead to baker''s asthma.     

Comparison of Specific IgE Antibodies to Wheat Component Allergens in Two Phenotypes of Wheat Allergy

Specific IgE to gliadin was proposed as a marker for wheat dependent exercise induced anaphylaxis, while Tri a 14 was found to induce IgE response in baker''s asthma. We evaluated whether these components could be used for discriminating phenotypes of wheat allergy. Twenty-nine patients who were wheat-induced anaphylaxis and/or urticaria (n=21, group I) and baker''s asthma (n=8, group II) were enrolled. The prevalence of serum specific IgE to Tri a 14 was higher in group II (25%) than in group I (4.8%), while the serum specific IgE to gliadin was significantly higher in group I (70%) than in group II (12.5%). The cutoff value for predicting the baker''s asthma using the ratio of serum specific IgE to Tri a 14 to gliadin was 742.8 optical density×1,000/(kU/L) with high sensitivity and specificity. These findings suggest that Tri a 14/gliadin may be a potential marker for predicting baker''s asthma.     

Molecular Approach to Allergy Diagnosis and Therapy

Presently, allergy diagnosis and therapy procedures are undergoing a transition phase in which allergen extracts are being step-by-step replaced by molecule-based products. The new developments will allow clinicians to obtain detailed information on sensitization patterns, more accurate interpretation of allergic symptoms, and thus improved patients'' management. In this respect, recombinant technology has been applied to develop this new generation of molecule-based allergy products. The use of recombinant allergens allows full validation of identity, quantity, homogeneity, structure, aggregation, solubility, stability, IgE-binding and the biologic potency of the products. In contrast, such parameters are extremely difficult to assay and standardize for extract-based products. In addition to the possibility of bulk production of wild type molecules for diagnostic purposes, recombinant technology opened the possibility of developing safer and more efficacious products for allergy therapy. A number of molecule-based hypoallergenic preparations have already been successfully evaluated in clinical trials, bringing forward the next generation of allergy vaccines. In this contribution, we review the latest developments in allergen characterization, molecule-based allergy diagnosis, and the application of recombinant allergens in therapeutic setups. A comprehensive overview of clinical trials using recombinant allergens as well as synthetic peptides is presented.     

Exposure to wheat allergen and fungal α-amylase in the homes of bakers

BACKGROUND: Few data are available on exposure to occupational allergens in dwellings occupied by inhabitants with occupational exposure to allergens. In small bakeries working and living often takes place in the same building. It is possible that allergens from the bakery can be transported into the homes of the bakers, via the clothes or shoes of the baker. OBJECTIVE: The aims of this study were to investigate exposure to occupational allergens, wheat and fungal alpha-amylase in the homes of bakers, and evaluate potential determinants of exposure. Sensitization in family members to occupational allergens was investigated in a small preliminary survey. METHODS: Floor dust samples were collected in the homes of 34 bakers. Levels of wheat and fungal alpha-amylase allergens were determined in an extract of the dust samples. Blood samples were collected from bakers and their family members to determine the prevalence of sensitization to occupational allergens. RESULTS: The concentration of wheat and alpha-amylase allergens ranged from 38.9 to 172.4 microgeq/m(2) (GM), to 10.5-76.7 ngeq/m(2) (GM). Higher levels of dust and allergens were measured when the house could be reached directly through the bakery, and in houses with textile floor covers. Higher concentrations were also measured when bakers brought their work clothes and shoes into the house and when textiles from the bakery were laundered at home. Some family members appeared to be sensitized to wheat flour and alpha-amylase, but it cannot be excluded that they became sensitized because of their incidental presence in the bakery. CONCLUSIONS: Occupational allergens can be found in house dust from the homes of bakers and levels are associated with hygienic behaviour and distance to the bakery.     

Double-blind study of tolerability and antibody production of unmodified and chemically modified allergen vaccines of Phleum pratense

BACKGROUND: The physicochemical modification of allergen extracts provides a chance for administering higher doses of allergen vaccines. OBJECTIVE: To evaluate the safety of a chemically modified (depigmented-glutaraldehyde polymerized) therapeutic vaccine of Phleum pratense administered at doses that are 10 times higher than those used in clinical practice, in comparison with conventional doses of the corresponding non-modified alum-adsorbed vaccine. MATERIALS AND METHODS: The design of the study was randomized, double-blind, parallel and included two groups of patients. Twenty-three patients were treated weekly during nine visits for the build-up phase, followed by two weekly maintenance doses (a total of 11 injections per patient). Twelve patients received a vaccine containing the standardized unmodified extract, at a maximum concentration of 308.5 mcg of freeze dried material/mL (Group A). Eleven patients received a standardized modified allergen extract (Group B). The maximum dose used was 2400 mcg/mL. Safety was evaluated recording all adverse events. Skin test results and specific antibody levels were evaluated at the beginning and at the end of the study. RESULTS: Group A patients experienced three local immediate (two clinically irrelevant and one with a diameter>5 cm) and 18 delayed reactions (15 irrelevant and three with a diameter>10 cm), while Group B experienced six local immediate and 12 delayed reactions (all clinically irrelevant). Nine Group A patients experienced 12 systemic reactions (one immediate of grade 1, one of grade 2; and one delayed of grade 1; four of grade 2 and three of grade 3), while Group B patients experienced one immediate systemic reaction of grades 1, and 1 delayed reaction of grade 1. CONCLUSIONS: The modified extract of P. pratense is safe to treat sensitive patients, even at concentrations that are 10 times higher than those regularly administered in clinical practice. The majority of the local reactions were clinically irrelevant. No systemic reactions of grade 2, 3 or 4 were reported using the modified extract.     

Mouse allergen exposure, wheeze and atopy in the first seven years of life

Background: Little is known about mouse allergen exposure in home environments and the development of wheezing, asthma and atopy in childhood. Objective: To examine the relation between mouse allergen exposure and wheezing, atopy, and asthma in the first 7 years of life. Methods: Prospective study of 498 children with parental history of allergy or asthma followed from birth to age 7 years, with longitudinal questionnaire ascertainment of reported mouse exposure and dust sample mouse urinary protein allergen levels measured at age 2–3 months. Results: Parental report of mouse exposure in the first year of life was associated with increased risk of transient wheeze and wheezing in early life. Current report of mouse exposure was also significantly associated with current wheeze throughout the first 7 years of life in the longitudinal analysis (P = 0.03 for overall relation of current mouse to current wheeze). However, early life mouse exposure did not predict asthma, eczema or allergic rhinitis at age 7 years. Exposure to detectable levels of mouse urinary protein in house dust samples collected at age 2–3 months was associated with a twofold increase in the odds of atopy (sensitization to >=1 allergen) at school age (95% confidence interval for odds ratio = 1.1–3.7; P = 0.03 in a multivariate analysis. Conclusions: Among children with parental history of asthma or allergies, current mouse exposure is associated with increased risk of wheeze during the first 7 years of life. Early mouse exposure was associated with early wheeze and atopy later in life.     

Asthma induced by inhalation of flour in adults with food allergy to wheat

Background Wheat is one of the major food allergens and it is also an inhalant allergen in workers exposed to flour dusts. Food allergy to wheat in adulthood seems to be rare and has never been reported to be associated with asthma induced by flour inhalation.
Objective The study aimed at detecting adults with food allergy to wheat and screening them for the presence of specific bronchial reactivity to inhaled wheat proteins.
Methods Adults with a history of adverse reactions to ingestion of wheat underwent skin prick test with commercial wheat extract and were assessed for the presence of specific wheat IgE in the sera. Food sensitivity to wheat was confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Specific bronchial reactivity was investigated through a specific bronchial challenge with wheat proteins.
Results In nine patients with evidence of specific IgE response to wheat, a diagnosis of food allergy was made by DBPCFC. Only two subjects had asthma as disease induced by ingestion of wheat. Seven subjects reported a history of respiratory symptoms when exposed to flour dusts. A significant reduction of forced expiratory volume in 1 s (FEV₁) was detected in these seven patients when a specific bronchial challenge with flour proteins was performed. Only three out of seven subjects with asthma induced by flour could be considered occupationally exposed to flour dusts.
Conclusion For the first time, it has been shown that specific bronchial reactivity to wheat proteins can be detected in patients with different disorders associated with food allergy to wheat. The presence of asthma induced by inhaled flour is not strictly related to occupational exposure and it may also occur in subjects not displaying asthma among symptoms induced by wheat ingestion.     

Clinical Characteristics and Management of Benign Transient Non-Organic Ileus of Neonates: A Single-Center Experience

Purpose

The term benign transient non-organic ileus of neonates (BTNIN) is applied to neonates who present symptoms and plain radiographic findings of Hirschsprung''s disease, but do not have aganglionic bowel and are managed well by conservative treatment. It can often be difficult to diagnose BTNIN because its initial symptoms are similar to those of Hirschsprung''s disease. The aim of this study is to evaluate the clinical characteristics and proper treatment of BTNIN.

Materials and Methods

A retrospective review was made on the clinical data of 19 neonates who were treated for BTNIN between January 2008 and December 2011 at a single facility.

Results

Abdominal distension occurred in every patient (19/19). Other common symptoms included emesis (5/19), explosive defecation (5/19), and constipation (4/19). The vast majority of patients (15/19) experienced the onset of symptoms between 2 and 4 weeks of age. Radiograph findings from all of the patients were similar to Hirschsprung''s disease. A barium study showed a transition zone in 33.4% (6/18) of the patients. However, rectal biopsy revealed ganglion cells in the distal rectum in 88.2% (15/17) of the patients, and anorectal manometry showed a normal rectoanal inhibitory reflex in 90% (9/10). All patients responded well to conservative treatment. Symptoms disappeared at the mean age of 4.9±1.0 months, and the abdominal radiographs normalized.

Conclusion

BTNIN had an excellent outcome with conservative treatment, and must be differentiated from Hirschsprung''s disease. A rectal biopsy and anorectal manometry were useful diagnostic tools in the differential diagnosis.     

哮喘儿童AIT治疗前后血浆ET-1和血清IgE水平变化

目的:观察哮喘儿童变应原免疫治疗(AIT)前后血浆内皮素-1(ET-1)与血清IgE水平变化,以探讨二者在哮喘变应原免疫治疗中的意义和关系.方法:应用放射免疫分析检测46例哮喘儿童变应原免疫治疗前后血浆ET-1与血清IgE水平,并与32例正常对照组进行比较.结果:治疗有效组(35例)治疗前血浆ET-1与血清IgE水平分别为(59.1±11.7)pg/ml和(11.1±3.2)IU/ml,均显著高于正常对照组(P＜0.01),AIT治疗后显著降低,分别为(52.7±11.1)和(8.2±2.4)IU/ml(P＜0.01).治疗无效组(11例)治疗前后ET与IgE水平无显著性变化.结论:治疗后血浆ET-1与血清IgE水平降低可能是哮喘患儿AIT治疗有效的重要机理.     

Mattress encasings and mite allergen levels in the Prevention and Incidence of Asthma and Mite Allergy study

BACKGROUND: Reduction of allergen exposure from birth may reduce sensitization and subsequent allergic disease. OBJECTIVE: To measure the influence of mite allergen-impermeable mattress encasings and cotton placebo encasings on the amount of dust and mite allergen in beds. METHODS: A total of 810 children with allergic mothers took part in the Prevention and Incidence of Asthma and Mite Allergy (PIAMA) study. Allergen-impermeable and placebo mattress encasings were applied to the childrens' and the parents' beds before birth. Dust samples were taken from the beds of children and their parents before birth and 3 and 12 months after birth. Extracts of dust samples were analysed for mite allergens (Der p 1 and Der f 1). RESULTS: Active mattress encasings were significantly more effective in reducing dust and mite allergen levels than placebo encasings. Mite allergen levels were low in general and the treatment effect was modest. Twelve months after birth, mattresses with active mattress encasings had about half the amount of Der 1 (Der p 1 + Der f 1)/m2, compared to mattresses with placebo encasings, for the child's and the parental mattress. CONCLUSION: This study shows that mite-impermeable mattress encasings have a significant but modest effect on dust and mite allergen levels of mattresses with low initial mite allergen levels, compared to placebo.     

Predictors of indoor exposure to mouse allergen in urban and suburban homes in Boston

BACKGROUND: Mouse allergen exposure is prevalent among urban children with asthma. Little is known about mouse allergen exposure in children at risk for the development of allergic diseases. AIMS OF THE STUDY: To assess indoor mouse allergen exposure in early life among children with parental history of asthma or allergies. METHODS: Prospective birth cohort study of 498 children with a history of allergy or asthma in at least one parent living in metropolitan Boston. RESULTS: Of the 498 participating children, 357 (71.7%) resided outside the city of Boston and 439 (90.7%) lived in households with incomes > 30,000 dollars. Mouse allergen was detected in 42% of the homes of study participants. In a multivariate analysis adjusting for sex, income, and endotoxin, black race [odds ratio (OR) = 3.0; 95% confidence interval (CI) = 1.3-6.6, P = 0.009], signs of mice in the home at age 2-3 months (OR = 3.0; 95% CI = 1.6-5.6, P = 0.0006), and kitchen cockroach allergen levels > or = 0.05 to < 2 U/g (OR = 1.8; 95% CI = 1.1-3.2, P = 0.02) were associated with detectable mouse allergen in the kitchen. In this model, living in a single detached house was inversely associated with detectable kitchen mouse allergen levels (OR = 0.4; 95% CI = 0.2-0.6, P = 0.0001). CONCLUSION: Infants with a parental history of asthma or allergies are commonly exposed to mouse allergen in their homes. Among infants at high risk for atopy, predictors of increased mouse allergen levels included black race, reported mice exposure, and moderate levels of cockroach allergen.     

Delta Neutrophil Index as an Early Marker for Differential Diagnosis of Adult-Onset Still's Disease and Sepsis

Purpose

To investigate clinical implications of delta neutrophil index (DNI) to discriminate adult onset Still''s disease (AOSD) from sepsis.

Materials and Methods

We reviewed the medical records of 13 patients with AOSD and 33 gender and age-matched patients with sepsis. In all subjects, microbial tests were performed to exclude or confirm sepsis. All laboratory data were measured two or three times during the first 3 days and represented by their mean levels. DNI was measured automatically by ADVIA 2120 for the first 3 days.

Results

There were no significant differences in white blood cell counts, neutrophil proportion, erythrocyte sedimentation rate and C-reactive protein between two groups. AOSD patients had notably lower DNI than sepsis patients regardless of the presence of bacteremia or not. However, both DNI and ferritin were not significant independent factors for predicting sepsis in the multivariate logistic regression analysis. Meanwhile, the area under the receiver operating characteristic curve (AUROC) of DNI was slightly higher than that of ferritin. When we set DNI of 2.75% as the cut-off value for predicting sepsis, 11 (84.6%) of AOSD patients had a DNI value below 2.75% and 2 (15.4%) of them had a DNI over 2.75% (relative risk for sepsis 176).

Conclusion

We suggest that DNI may be a useful marker for differential diagnosis of AOSD from sepsis in the early phase as supplementary to ferritin.     

Attenuation of neuropsychiatric symptoms and caregiver burden in Alzheimer's disease by motor intervention: a controlled trial

OBJECTIVE:

To analyze the effects of motor intervention on the neuropsychiatric symptoms of Alzheimer''s disease and on the caregivers'' burden.

DESIGN:

This is a controlled trial evaluating the effects of a motor intervention program on the neuropsychiatric symptoms.

SETTING:

The intervention was performed on community patients from two university centers specializing in physical exercise for the elderly.

SUBJECTS:

Patients with Alzheimer''s disease were divided into two groups: sixteen received the motor intervention and sixteen controls (five controls were excluded because of clinical intercurrences).

INTERVENTIONS:

Aerobic exercises (flexibility, strength, and agility) and functional balance exercises were conducted over six months for 60 minutes three times per week.

MAIN MEASURES:

Psychopathological features of patients were evaluated with the Neuropsychiatric Inventory and Cornell Scale for Depression in Dementia. Caregivers were evaluated using the Neuropsychiatric Inventory-Distress and Burden Interview. A two-way analysis of variance (ANOVA) was applied to observe interactions (pre- vs. post-intervention; participants vs. controls).

RESULTS:

Patients from the intervention presented a significant reduction in neuropsychiatric conditions when compared to controls (Neuropsychiatric Inventory: F∶11.12; p = 0.01; Cornell Depression scale: F∶11.97; p = 0.01). The burden and stress of caregivers responsible for patients who participated in the intervention significantly decreased when compared to caregivers responsible for controls (Neuropsychiatric Inventory-Distress: F: 9.37; p = 0.01; Burden Interview: F: 11.28; p = 0.01).

CONCLUSIONS:

Aerobic exercise was associated with a reduction in the neuropsychiatric symptoms and contributed to attenuate the caregivers'' burden. However, the researchers were not blinded to the patient''s intervention status, which constitutes an important limitation of this study.     

Clinical presentation,allergens, and management of wheat allergy

IgE-mediated allergy to wheat proteins can be caused by exposure through ingestion, inhalation, or skin/mucosal contact, and can affect various populations and age groups. Respiratory allergy to wheat proteins is commonly observed in adult patients occupationally exposed to flour, whereas wheat food allergy is more common in children. Wheat allergy is of growing importance for patients with recurrent anaphylaxis, especially when exercise related. The diagnosis of wheat allergy relies on a consistent clinical history, skin prick testing with well-characterized extracts and specific IgE tests. The accuracy of wheat allergy diagnosis may be improved by measuring IgE responses to several wheat components. However, a high degree of heterogeneity has been found in the recognition pattern of allergens among patient groups with different clinical profiles, as well as within each group. Thus, oral provocation with wheat or the implicated cereal is the reference test for the definitive diagnosis of ingested wheat/cereal allergy.     

Wheat antigen exposure assessment for epidemiological studies in bakeries using personal dust sampling and inhibition ELISA

Background Asthma in bakery workers caused by exposure to wheat flour proteins is an important occupational health problem. Until recently, gravimetric dust measurements were the only available technique for quantitative exposure assessment in bakeries. However, it is questionable whether dust levels are a good exposure parameter or only give a crude approximation of the actual flour allergen concentration. Objective In the present study we have investigated a method to measure wheat flour antigens with immunochemical methods. Methods Wheat flour antigens were measured in 449 personal dust samples taken in bakeries, using enzyme-linked immunosorbent assay (ELISA) inhibition and an anti-wheat lgG4 serum pool. Western-blotting was performed to compare the wheat flour proteins detected by IgE and IgG4. Results Electrophoresis and immunoblotting showed that many wheat flour proteins can bind lgG4 and IgE, but also a reasonable similarity in major allergens detected by our lgG4-serum pool and IgE-positive sera. Inhibition tests showed some cross-reactivity with some cereal species, but not with other ingredients used in bakeries. In bakeries, large differences in personal airborne flour levels were found between occupational titles. Eor several groups clear differences in wheat antigen exposure levels existed, where no difierences in dust exposure levels could be found. The relationship between dust and wheat antigen exposure varied considerably, depending on the specific bakery occupation, the size of the bakery, and the type of product produced by the bakery. This study also shows that personal sampling of wheat antigens is possible on a large scale and can be used for epidemiological field studies. Conclusion Measurement of airborne wheat antigens in bakeries is a more specific and sensitive measurement tool than measuring dust samples, and will probably be essential for epidemiologic field studies focusing on exposure-response relationships.     

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.     

Airborne exposure to wheat allergens: measurement by human immunoglobulin G4 and rabbit immunoglobulin G immunoassays

BACKGROUND: Exposure to airborne wheat allergens in the bakery trade is associated with a high risk of occupational allergy and asthma. Control and reduction of allergen exposure require relatively simple but reliable monitoring techniques. We developed new rabbit IgG-based enzyme immunoassays (EIA) for wheat allergens, which might be a convenient alternative for the thus far used human IgG4 inhibition assay. METHODS: The reactivity and specificity of rabbit antibodies were assessed by EIA and immunoblotting, and compared with those of IgE from wheat-sensitized bakers, and with the antibodies used in the IgG4 inhibition EIA. An IgG inhibition and a sandwich EIA were developed for analysis of airborne dust samples. RESULTS: Human IgG4 and rabbit IgG inhibition EIAs had comparable sensitivities, with limits of detection (LOD) between 18 and 88 ng/mL, while the sandwich EIA was much more sensitive (LOD<0.2 ng/mL). Human IgG4 and rabbit IgG reacted in immunoblotting with most of the IgE-binding wheat proteins, although with quantitative differences. All three assays showed a strong reaction with wheat proteins, and some cross-reactivity with rye and barley, but were further highly specific for cereal flour proteins. Concentrations measured with the three EIAs in 432 airborne dust samples were highly correlated (r>0.95) and their absolute values showed less than 10-20% differences. CONCLUSION: The rabbit IgG EIAs are valid substitutes for the human IgG4 inhibition EIA, with important practical advantages. The inhibition EIA is recommended for routine wheat allergen measurements. The sandwich EIA may be used to measure low allergen levels, as in short task-related exposure measurements or in subfractions of airborne dust samples.