Sensitization to Blomia tropicalis and Lepidoglyphus destructor in Dermatophagoides spp-allergic individuals

Serum was collected from 77 atopic subjects from Cartagena, Colombia, who had a positive skin test (≥3 mm) to either Dermatophagoides farinae (Df) (73) or D. pteronyssinus (Dp) (70). Twenty-nine healthy volunteers with negative allergy histories and negative skin tests were used as control subjects. RAST and RAST-inhibition assays were used to study the prevalence of specific IgE to Blomia tropicalis (Bt), Lepidoglyphus destructor (Ld), and Df. RAST results were considered positive when a serum bound ≥1% of the total counts added; 69 atopic subjects (89.6%) were positive to Df, 66 (85.5%) to Bt, and 46 subjects (59.7%) were positive to Ld. RAST results, analyzed by regression analysis, revealed the following correlation coefficients: Df versus Bt, r = 0.59; Df versus Ld, r = 0.44; and Bt versus Ld, r = 0.52. RAST-inhibition assays with a serum pool of 11 individuals highly allergic to all three mites (mean specific IgE to all mites, ≥18.2 percent total counts bound) demonstrated considerable cross-reactivity between Bt and Ld and moderate cross-reactivity between Df and Bt and Ld. Bt, Df, and Ld possess unique, as well as common, allergens. Sensitization to Bt and Ld is very common in mite-allergic individuals in Cartagena, Colombia.