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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.
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PURPOSE: Eperisone is an oral muscle relaxant used in musculoskeletal disorders causing muscle spasm and pain. For more effective pain control, eperisone is usually prescribed together with nonsteroidal anti-inflammatory drugs (NSAIDs). As such, eperisone may have been overlooked as the cause of anaphylaxis compared with NSAIDs. This study aimed to analyze the adverse drug reaction (ADR) reported in Korea and suggest an appropriate diagnostic approach for eperisone-induced anaphylaxis. METHODS: We reviewed eperisone-related pharmacovigilance data (Korea Institute of Drug Safety-Korea Adverse Event Reporting System [KIDS-KAERS]) reported in Korea from 2010 to 2015. ADRs with causal relationship were selected. Clinical manifestations, severity, outcomes, and re-exposure information were analyzed. For further investigation, 7-year ADR data reported in a single center were also reviewed. Oral provocation test (OPT), skin prick test (SPT) and basophil activation test (BAT) were performed in this center. RESULTS: During the study period, 207 patients had adverse reactions to eperisone. The most common ADRs were cutaneous hypersensitive reactions (30.4%) such as urticaria, itchiness or angioedema. Fifth common reported ADR was anaphylaxis. There were 35 patients with anaphylaxis, comprising 16.9% of the eperisone-related ADRs. In the single center study, there were 11 patients with eperisone-induced anaphylaxis. All the patients underwent OPT and all the provoked patients showed a positive reaction. Four of the 11 patients with anaphylaxis also underwent SPT and BAT, which were all negative. CONCLUSIONS: Incidence of eperisone-induced anaphylaxis calculated from the KIDS-KAERS database was 0.001%. Eperisone can cause hypersensitive reactions, including anaphylaxis, possibly by inducing non-immunoglobulin E-mediated immediate hypersensitivity.