Prevalence of specific IgE to the storage mite, Aleuroglyphus ovatus

Aleuroglyphus ovatus (Ao) is a storage mite that has a worldwide distribution and has been found in stored bran, wheat, chicken meal, and dried fish products. Ao was isolated from a chicken meal sample, cultured on whole wheat flour at 75% relative humidity, and 1 gm of pure Ao bodies were extracted, 1:20 wt/vol, in 0.2 mol/L of ammonium bicarbonate. Der p I, major allergen of Dermatophagoides, pteronyssinus (Dp), or Der f I major allergen to Dermatophagoides farinae (Df), was not detected in extracts of Ao. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed 25 bands (6 to 110 kd), and thin-layer isoelectric focusing revealed 19 bands (isoelectric point, 3.5 to 9.3). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis immunoblots with six different sera identified nine IgE binding bands (16 to 100 kd). Thin-layer isoelectric focusing immunoblots identified 16 IgE binding bands (isoelectric point, 4.5 to 9.3). An aliquot of the Ao extract was diluted in bicarbonate buffer (pH 9.2) and adsorbed to plastic microtiter plates. RAST to Ao and Dp were performed with sera of 163 atopic individuals (88 with allergic rhinitis and 75 with allergic asthma with or without allergic rhinitis). All individuals had appropriately positive skin tests that correlated with a history of exacerbation secondary to allergen exposure. RAST results to Dp and Ao were analyzed by regression analysis (r = 0.64; p = 0.0001). Fifty-five individuals were RAST positive to Dp alone, 32 to Ao and Dp, and three to Ao alone; 73 individuals were negative to Ao and Dp. RAST inhibition demonstrated moderate cross-reactivity between Ao and Dp.