Stability of extracts from pollens of allergenic importance in Korea

Background/Aims@#Accurate diagnosis and the effects of allergen-specific immunotherapy for pollinosis are greatly dependent on the potency and stability of the extract. This study aimed to examine factors, such as temperature and storage buffer composition, that affect the stability of allergen extracts from pollens of allergenic importance in Korea. @*Methods@#We prepared four pollen allergen extracts from ragweed, mugwort, Japanese hop, and sawtooth oak, which are the most important causes of seasonal rhinitis in Korea. Changes of protein and major allergen concentration were measured over 1 year by Bradford assay, two-site enzyme-linked immunosorbent assay, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reconstitution of the lyophilized allergen extract in various buffers and stored at room temperature (RT, 18°C to 26°C) or refrigerated (4°C). @*Results@#More than 90% of the original protein concentration in all four extracts examined was detected over 1 year when 50% glycerol was added and refrigerated, whereas 57.9% to 94.5% remained in the extracts at RT. The addition of 50% glycerol to the storage buffer was found to prevent protein degradation at RT. Amb a 1, a major allergen of ragweed, was almost completely degraded in 9 weeks at RT when reconstituted in a buffer without 50% glycerol. However, 55.6% to 92.8% of Amb a 1 content was detected after 1 year of incubation at 4°C in all buffer conditions except 0.3% phenol. @*Conclusions@#Addition of 50% glycerol as well as refrigeration was found to be important in increasing the shelf-life of allergen extracts from pollens of allergenic importance.

IgE Cross-Reactivity between Humulus japonicus and Humulus lupulus

PURPOSE: Japanese hop (Humulus japonicus) is a major cause of weed pollinosis in East Asia. However, supplies of commercial allergen extract from this plant have not met clinical demand. The pollen of common hop (Humulus lupulus), a closely related species, may provide an alternative source if there is strong IgE cross-reactivity between these two species. We aimed to compare the IgE cross-reactivity and allergenicity of common hop and Japanese hop pollen. MATERIALS AND METHODS: Cross-reactivity was measured by inhibition ELISA. One- and two-dimensional (2D) gel analyses combined with IgE immunoblotting and mass spectrometry [liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS)] were performed to detect IgE-reactive pollen components. RESULTS: Up to 16.7% of IgE reactivity to Japanese hop was inhibited by common hop. A 12-kDa protein component of Japanese hop pollen that showed the most potent IgE reaction was absent from common hop. Six IgE-reactive components from Japanese hop were detected by 2D gel electrophoresis and LC-ESI-MS/MS, but showed low Mascot scores, preventing positive identification. CONCLUSION: No significant IgE cross-reaction was observed for Japanese and common hop pollen allergens. Development of allergy diagnostic and immunotherapeutic reagents based on Japanese hop pollen are urgently needed.

Comparison between Newly Developed and Commercial Inhalant Skin Prick Test Reagents Using In Vivo and In Vitro Methods

BACKGROUND: We developed skin prick test (SPT) reagents for common inhalant allergens that reflected the real exposure in Korea. The study aim was to evaluate diagnostic usefulness and allergen potency of our inhalant SPT reagents in comparison with commercial products. METHODS: We produced eight common inhalant allergen SPT reagents using total extract (Prolagen): Dermatophagoides farinae, Dermatophagoides pteronyssinus, oak, ragweed, mugwort, Humulus japonicus pollens, as well as cat and dog allergens. We compared the newly developed reagents with three commercially available SPT reagents (Allergopharma, Hollister-Stier, Lofarma). We measured total protein concentrations, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), major allergen concentration, and biological allergen potencies measured by immunoglobulin E (IgE) immunoblotting and ImmunoCAP inhibition test. RESULTS: Diagnostic values of these SPT reagents were expressed as positivity rate and concordance rate of the results from ImmunoCAP allergen-specific IgE test in 94 allergic patients. In vitro analysis showed marked differences in protein concentrations, SDS-PAGE features, major allergen concentrations, and biological allergen potencies of four different SPT reagents. In vivo analysis showed that positive rates and concordance rates of Prolagen® SPT reagents were similar compared to the three commercial SPT reagents. CONCLUSION: The newly developed Prolagen® inhalant SPT reagents are not inferior to the commercially available SPT reagents in allergy diagnosis.

Comparison of the ImmunoCAP Assay and AdvanSure™ AlloScreen Advanced Multiplex Specific IgE Detection Assay

PURPOSE: The AdvanSure™ AlloScreen assay is an advanced multiplex test that allows for simultaneous detection of specific IgE (sIgE) against multiple allergens. For precise identification of causative allergens in allergic patients, we compared this new multiplex sIgE assay with the ImmunoCAP assay, which is currently the gold-standard method for sIgE detection. MATERIALS AND METHODS: Serum samples from 218 Korean allergic disease patients were used to compare the ImmunoCAP and AlloScreen assays with respect to the following 13 allergens: Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat and dog dander, Alternaria, birch, oak, ragweed, mugwort, rye grass, and food allergens (egg white, cow's milk, peanuts). RESULTS: A total of 957 paired tests using the 13 allergens were compared. The total agreement ratio ranged from 0.74 (oak) to 0.97 (Alternaria). With respect to class association analyses, the gamma index ranged from 0.819 (rye grass) to 0.990 (Alternaria). The intra-class correlation coefficients for house dust mites, cat and dog dander, Alternaria, birch, ragweed, egg white, cow's milk, and peanut sIgE titers were >0.8. CONCLUSION: The AlloScreen and ImmunoCAP assays exhibited similar diagnostic performance. However, due to methodological differences between the two systems, careful interpretation of their results is needed in clinical applications.

Needs for Health Care Services for Active Aging of Home-Dwellers With Age

BACKGROUND: In a rapidly aging population, the importance of the quality of life of the elderly has been emphasized. The need for special care services according to an individual's physical, emotional, and social functions changes with aging. This study was conducted to analyze the needs of home dwellers in terms of health-care services for active aging. METHODS: The study subjects were 869 adults older than 40 years who lived in houses. They responded to a survey that inquired about the importance of each health-care item for active aging at home. The important items for active aging at home were graded by using a 5-point Likert scale. RESULTS: Among the items, "affection" topped the list, with 4.68 points, followed by cognitive function (4.67 points) and "social relations" (4.59 points). The top 3 items had no significant differences between the age groups. However, some items related to activities of daily living (ADL; including bathing, eating, and ambulating.) and instrumental ADL (IADL; including taking medicines and preparing meals) had significant differences between the age groups. Compared with the subjects in the older age groups, the subjects in the forties age group placed less importance on ADL and IADL. CONCLUSION: For the subjects who lived in houses, affection, cognitive function, and social relation are highly important for as active aging, regardless of age. ADL and IADL are regarded as more important in ≥50 years age groups.