Deleterious effects of electron beam radiation on allergen extracts

A review on food processing and preparation methods for altering fish allergenicity

People eat many varieties of food to satiate their hunger. Among them, a few numbers of food cause overreaction of the body's immune system, and fish holds a permanent position on that list. Processing methods, including one treatment or a combination, can have different effects on the allergenic potential of food proteins. An important point to note, however, is that not all of these methods can eliminate the potential for protein allergy. Thus, it is essential to understand the risk involved with the consumption of processed fish and its derivatives. Fish could be prepared in various ways before come to the dining plate. It has shown some of these methods can effectively manipulate the allergenicity owing to the alterations occurred in the protein conformation. This article provides an overview of the impact of fish processing methods (thermal and non-thermal) on the allergenic potential of fish along with possible causative structural modification provokes allergen stability. The article begins with current trends related to fish consumption, proceeds with the prevalence and underlying mechanism of fish allergy. Properties of clinically relevant fish proteins, projected IgE epitopes of PV, cross-reactivity of fish allergens are also addressed in this context to understand and compare the behavioral patterns of PV profiles of different species on processing methods.

Identification of major rice allergen and their clinical significance in children

Purpose

Recently, an increase in the number of patients sensitized to rice allergen with or without clinical symptoms has been reported. This study was designed to determine the major allergens in rice and their clinical significance.

Methods

Twenty-four children (15 boys and 9 girls; mean age, 16.3 months) with allergic disease, who were sensitized to rice antigen (by UniCAP) in the Pediatric Allergy Respiratory Center at Soonchunhyang University Hospital, were enrolled in this study. The allergenicity of various types of rice (raw, cooked, and heat-treated, simulated gastric fluid [SGF], and simulated intestinal fluid [SIF]) was investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoglobulin E (IgE) immunoblots. The patients' medical records, including laboratory data and allergy symptoms after ingestion of rice were reviewed.

Results

Patients were sensitized to an average of 13.5 food antigens and their mean total IgE was 6,888.7 kU/L. In SDS-PAGE, more than 16 protein bands were observed in the raw rice, whereas only 14-16 kDa and 31-35 kDa protein bands were observed in cooked rice. The common SDS-PAGE protein bands observed in SGF-, SIF-, and heat-treated rice were 9, 14, and 31 kDa. In a heated-rice IgE immunoblot, protein bands of 9, 14, and 31-33 kDa were found in 27.8%, 38.9%, and 38.9% of all sera, respectively, and in 50%, 50%, and 75%, of ser a from the 4 symptomatic patients, respectively.

Conclusion

The 9-, 14-, and 31-kDa protein bands appeared to be the major allergens responsible for rice allergy symptoms.

Compatibility of imported fire ant whole body extract with cat, ragweed, Dermatophagoides pteronyssinus, and timothy grass allergens

BACKGROUND

Recommendations regarding the administration of imported fire ant whole body extract (IFA WBE) combined with aeroallergens or environmental allergens in a single immunotherapy injection are lacking.

OBJECTIVE

To evaluate the degradative effect of IFA WBE on cat, ragweed, Dermatophagoides pteronyssinus, and timothy grass allergens.

METHODS

Imported fire ant whole body extract was combined with extracts of cat, ragweed, D pteronyssinus, and timothy grass. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed on each sample after storage for 0, 1, 3, and 6 months at 4 degrees C. In addition, cat and ragweed combinations were evaluated by radial immunodiffusion (RID); D pteronyssinus by enzyme-linked immunosorbent assay (ELISA) inhibition; and timothy grass by ELISA inhibition and Western blot.

RESULTS

Imported fire ant whole body extract combined with timothy grass demonstrated degradation of timothy grass allergens by SDS-PAGE, ELISA inhibition, and Western blot results. Cat and ragweed allergens were stable after mixing with IFA WBE, based on SDS-PAGE and RID analyses. Stability of D pteronyssinus allergens with IFA WBE was evident from SDS-PAGE and ELISA inhibition data.

CONCLUSIONS

Imported fire ant whole body extract combined with timothy grass resulted in significant and rapid timothy protein degradation. Imported fire ant whole body extract mixed with cat, ragweed, or D pteronyssinus revealed aeroallergen stability, yielding the possibility of combining these extracts in a single immunotherapy injection. Compatibilities of IFA WBE with other common aeroallergens remain undetermined and thus are not recommended for single-injection immunotherapy formulations.

Stability of standardized grass, dust mite, cat, and short ragweed allergens after mixing with mold or cockroach extracts

BACKGROUND

Limited data are available on the immunochemical compatibilities of standardized and nonstandardized allergen extracts in immunotherapy vaccines. Extract combinations recommended in immunotherapy practice parameters are based primarily on theoretical considerations rather than on actual product compatibilities.

OBJECTIVES

To determine the stabilities of standardized grass, short ragweed, dust mite, and cat extracts after mixing with fungal and cockroach extracts at final product concentrations similar to those recommended for maintenance immunotherapy injections.

METHODS

Mixtures were prepared using individual products from multiple sources at variable glycerin concentrations and were analyzed after storage for up to 1 year at 2 degrees C to 8 degrees C. Quantitative analyses included radial immunodiffusion assays for cat Fel d 1 and short ragweed Amb a 1 and human IgE enzyme-linked immunosorbent assay inhibitions for meadow fescue grass and dust mite allergens. Immunoblot analyses provided qualitative patterns of IgE binding.

RESULTS

Meadow fescue grass allergens were unstable after mixing with fungal or cockroach extracts but were highly compatible with dust mite extracts from numerous commercial sources. Fescue and dust mite allergen recoveries varied considerably when mixed with different mold extracts. The presence of cockroach extracts reduced dust mite allergen potencies but retained moderate levels of cat and short ragweed allergen activities. In all cases examined, glycerin provided concentration-dependent improvements in allergen recoveries.

CONCLUSIONS

Several allergen extract combinations generally regarded as unstable by current practice parameters seem to possess considerable biochemical compatibilities. Use of these mixtures in immunotherapy vaccines is supported for practitioners seeking to optimize formulations, doses, and treatment regimens for their patients.

Change of an egg allergen in a white layer cake containing gamma-irradiated egg white

This study was conducted to evaluate the reduction of an egg allergen in a cake containing gamma-irradiated egg white. A white layer cake was manufactured by a commercial formula with 10- or 20-kGy-irradiated egg white. Enzyme-linked immunosorbent assays (ELISAs) with immunoglobulin (Ig) E from egg-allergic patients and with rabbit anti-ovalbumin IgG were used to identify and quantify ovalbumin (OVA) in the samples. Concentrations of native OVA detected by IgE and IgG in the control were 432.88 and 375.46 microg/g sample, respectively. However, native OVA in samples with 10- and 20-kGy-irradiated egg white was detected at low concentrations (14.27 and 8.78 microg/g, respectively) by IgE (P < 0.05); IgG recognized OVA more often in 10- and 20-kGy samples than in controls. Conformational cleavage of OVA by irradiation could explain the IgG result. The results appear to suggest that irradiating egg white might reduce its allergenicity, which could be used in the production of baked goods of reduced allergenicity.

Biological sample collection and processing for molecular epidemiological studies

Molecular epidemiology uses biomarkers and advanced technology to refine the investigation of the relationship between environmental exposures and diseases in humans. It requires careful handling and storage of precious biological samples with the goals of obtaining a large amount of information from limited samples, and minimizing future research costs by use of banked samples. Many factors, such as tissue type, time of collection, containers used, preservatives and other additives, transport means and length of transit time, affect the quality of the samples and the stability of biomarkers and must be considered at the initial collection stage. An efficient study design includes provisions for further processing of the original samples, such as cryopreservation of isolated cells, purification of DNA and RNA, and preparation of specimens for cytogenetic, immunological and biochemical analyses. Given the multiple uses of the samples in molecular epidemiology studies, appropriate informed consent must be obtained from the study subjects prior to sample collection. Use of barcoding and electronic databases allow more efficient management of large sample banks. Development of standard operating procedures and quality control plans is a safeguard of the samples' quality and of the validity of the analyses results. Finally, specific state, federal and international regulations are in place regarding research with human samples, governing areas including custody, safety of handling, and transport of human samples, as well as communication of study results.Here, we focus on the factors affecting the quality and the potential future use of biological samples and some of the provisions that must be made during collection, processing, and storage of samples, based on our experience in the Superfund Basic Research Program and Children's Environmental Health Center, at the University of California, Berkeley.