A comparison of in vitro potency between European and Mexican allergen extracts and US (CBER/FDA) reference extracts

Background: The most important allergen manufacturers are based in Europe and in the US. In some countries local products are also sold. No comparison between European, US and local products has been made until now. Aim of the study: To determine total protein content and total specific IgE binding capacity or major allergen content of diagnostic extracts from European, US and Mexican origins relative to the CBER/FDA reference extracts for Dermatophagoides pteronyssinus (Dpt), Bermuda grass and cat (10,000 (B) AU/mL). Methods: Diagnostic extracts were purchased from various manufacturers, blinded and shipped to the analysing laboratory, where the following assays were conducted: total protein concentration (Bradford), specific IgE competition ELISA (Dpt and Bermuda grass) and determination of Fel d 1U/mL. When available, CBER/FDA recommended tests and reagents were used. Results: Total protein content of US reference extracts was higher than all other extracts. Relative potency of European and US-bought Dpt extracts 3,300–4,400 AU/mL, Bermuda grass 800–2,500 BAU/mL and cat 2.1–4.4 Fel d IU/mL (Ref. 19U/mL), with one exception. Locally produced Mexican products were almost all below 1,000 (B) AU/mL. Conclusions: Three diagnostic extracts from European manufacturers and from Mexican providers which obtain extracts in US have a <50% relative potency compared to 10,000 (B) AU/mL US extracts. Locally produced Mexican extracts have much lower total protein content and specific IgE binding capacity. These in vitro results must be complemented with other in vitro and in vivo skin prick tests to obtain a more complete picture of comparison of potency. Nevertheless results are quite consistent for the allergens tested here

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A comparison of in vitro potency between European and Mexican allergen extracts and US (CBER/FDA) reference extracts.

BACKGROUND: The most important allergen manufacturers are based in Europe and in the US. In some countries local products are also sold. No comparison between European, US and local products has been made until now. AIM OF THE STUDY: To determine total protein content and total specific IgE binding capacity or major allergen content of diagnostic extracts from European, US and Mexican origins relative to the CBER/FDA reference extracts for Dermatophagoides pteronyssinus (Dpt), Bermuda grass and cat (10,000(B) AU/mL). METHODS: Diagnostic extracts were purchased from various manufacturers, blinded and shipped to the analysing laboratory, where the following assays were conducted: total protein concentration (Bradford), specific IgE competition ELISA (Dpt and Bermuda grass) and determination of Fel d 1 U/mL. When available, CBER/FDA recommended tests and reagents were used. RESULTS: Total protein content of US reference extracts was higher than all other extracts. Relative potency of European and US-bought Dpt extracts 3,300-4,400 AU/mL, Bermuda grass 800-2,500 BAU/mL and cat 2.1-4.4 Fel d IU/mL (Ref. 19 U/mL), with one exception. Locally produced Mexican products were almost all below 1,000 (B)AU/mL. CONCLUSIONS: Three diagnostic extracts from European manufacturers and from Mexican providers which obtain extracts in US have a <50% relative potency compared to 10,000 (B)AU/mL US extracts. Locally produced Mexican extracts have much lower total protein content and specific IgE binding capacity. These in vitro results must be complemented with other in vitro and in vivo skin prick tests to obtain a more complete picture of comparison of potency. Nevertheless results are quite consistent for the allergens tested here.

[Montelukast: new therapeutic option in patients with nasal polyps associated to respiratory allergic disease]. / Montelukast: nueva opción terapéutica en pacientes con poliposis nasal asociada a enfermedad alérgica respiratoria.

BACKGROUND: The physiopathogenic mechanism of nasal polyposis is unknown. Chemical mediators found in nasal polyposis are: histamine, serotonin, leukotrienes (LTC4, LTD4, LTE4, LTB4), norepinephrine and possibly prostaglandin D2. Leukotrienes that mediate bronchoconstriction as well as chemical mediators of inflammation are observed in the nasal disease associated to polyposis. HYPOTHESIS: Antileukotrienes might play a significant role in controlling polyposis and symptoms due to sinonasal disease. They represent an alternative to conventional treatments with oral steroids as well as to operations in the long-term control. OBJECTIVE: This study is a one year investigation that evaluates the important role of leukotriene receptor antagonists on nasal polyposis, with or without association to any allergic disease. Likewise, it compares its use with the conventional therapy used in the above mentioned disease. PATIENTS AND METHODS: We included 30 patients, 12 men (40%) and 18 women (60%), with ages between 16-45 years old. The mean age was of 20.7 years. Systematic assessments were made at the beginning of the study, as well as in the third, sixth, ninth, and twelfth month. Objective assessments, computed axial tomography of paranasal sinuses, allergological tests, nasal and bronchial symptoms evaluation, and interleukines, eosinophils, and immunoglobulin determinations were made. RESULTS: There was an improvement of nasal symptoms in the patients of group 1 (montelukast plus beclomethasone). They included the respiratory ones (p < 0.05), the nasal washing cells (p < 0.05), and the peak flow (p < 0.05) at the third, sixth, and twelfth months, respectively. There was no significant difference with the improvement obtained in the patients of group 3 (surgery-montelukast-beclomethasone) (p < 0.05). There was no significant change in group 2 regarding the baseline in the studied variables (p > 0.05).