[Standardizaron of the biological potency of allergenic extracts from Dermatophagoides pteronyssinus for immunotherapy]. / Estandarización de la potencia biológica de extractos alergénicos de Dermatophagoides pteronyssinus para inmunoterapia.

BACKGROUND: Allergic rhinitis and asthma are the more frequent allergic diseases. Dermatophagoides pteronyssinus is one of the more clinically relevant causes of allergic diseases. OBJECTIVE: To standardize the biological potency Allergenic Bioequivalent Units (BAU) of Dermatophagoides pteronyssinus allergen extracts of three national laboratories. METHODS: This experimental, prospective, transversal, quantitative study included patients allergic to house dust mites. According to the FDA protocol, allergenic extracts of Dermatophagoides pteronyssinus from three Mexican manufacturers, were injected intradermally in threefold dilutions, until get an midpoint orthogonal diameters 50 mm erythema sum. Statistical analysis was done using logistic regression, one-way analysis of variance and Bonferroni test. RESULTS: We included 20 adult patients, 11 women and 9 men, aged between 16 and 45 years. Four patients had allergic asthma and rhinitis and 16 only had allergic rhinitis. There were no systemic anaphylactic reactions. Correlation coefficients of linear regression of the dose/response were to Allerstand r=0.55, Allergomex r=0.54 and Allerquim r=0.57(p=0.001). Dilutions calculated for 100,000 BAU/ml for each extract were Allerstand 1:26295, Allergomex 1:26341 and Allerquim 1:73993. The protein concentration (mcg/mL) was: Allergomex: 63, Allerquim 65, Allerstand 154. CONCLUSIONS: It was established the biological potency for each tested extract. We have found significant differences in the biological equivalence among the extracts from the three manufacturers. The procedure showed an adequate safety profile.

Maintenance dosing for sublingual immunotherapy by prominent European allergen manufacturers expressed in bioequivalent allergy units.

BACKGROUND: Sublingual immunotherapy (SLIT) has become established in Europe, and its efficacy is being evaluated in the United States. The doses used for SLIT in Europe today are difficult to evaluate, because each manufacturer expresses the potency of its extracts differently. OBJECTIVES: To compare in vitro European SLIT maintenance solutions against US licensed standardized allergenic extract concentrates and to determine the monthly SLIT doses delivered expressed in bioequivalent allergy units ([B]AU). METHODS: We studied Dermatophagoides pteronyssinus, timothy grass pollen, cat (hair) and short ragweed pollen allergen extracts. The SLIT maintenance solutions of 4 leading European manufacturers and standardized concentrate extracts of 3 US manufacturers were analyzed with the following assays: protein content, relative potency (immunoglobulin E [IgE]-binding enzyme-linked immunosorbent assay [ELISA] inhibition) and major allergen content. The relative monthly allergen dose in (B)AU was calculated for each recommended SLIT schedule. RESULTS: Relative potency was approximately 10 times higher for US concentrate standardized extracts-which are meant to be diluted-than for European SLIT maintenance solutions of D pteronyssinus and timothy grass pollen. For cat (hair) and short ragweed pollen, the difference was less. Measurements of relative potency and major allergen content correlated well. In our assays, European mite extracts contain a very low quantity of Der p 2 compared with US mites. CONCLUSION: Recommended SLIT doses in Europe vary widely among the manufacturers, but are consistently lower (Eur1) or higher (Eur4) over all four allergens tested. SLIT efficacy probably depends on additional factors apart from the exact dose. SLIT dose finding studies should be done for each product.