ALLERGENICITY OF THE MITE, BLOMIA-TROPICALIS

Background: Blomia tropicalis (BT) occurs in a significant percentage of homes in tropical and subtropical geographic regions of the United States and Europe and in countries in South America and Asia along wit h the pyroglyphid mites, Euroglyphus maynei (EM), Dermatophagoides pte ronyssinus, and D. farinae. Blomia species may be major sources of all ergens in house dust in addition to Dermatophagoides species and E. ma ynei. Methods: Crossed immunoelectrophoresis and crossed radioimmunoel ectrophoresis were used to identify the antigens and allergens of BT a nd to determine the cross-reactivity between BT and the house dust mit es, D. farinae, D. pteronyssinus, and the stored product mite, Tyropha gus putrescentiae. Results: Homologous crossed immunoelectrophoresis o f BT resulted in 27 antigen-antibody complexes. Crossed radioimmunoele ctrophoresis of these gels showed 21 different immunoglobulin E bindin g antigens when they were incubated in the sera from 14 patients with asthma whose radioallergosorbent test and skin test results were posit ive. Heterologous crossed immunoelectrophoresis reactions with BT and rabbit D. farinae body and feces, D. pteronyssinus body and feces, and T. putrescentiae body and feces antisera resulted in one to four prec ipitin lines. BT extract, reacted with rabbit antisera produced agains t the bodies of D. farinae, D. pteronyssinus, and T. putrescentiae, pr oduced 3, 2, and 4 antigenic peaks, respectively; whereas crossed radi oimmunoelectrophoresis of these gels with the sera of the 14 patients with asthma resulted in immunoglobulin E binding to 2, 2, and 4 peaks, respectively. Conclusions: The results of this study indicated that B T contained multiple allergens of which most were species-specific. Th ere was a limited amount of cross-reactivity between BT and the two co mmon house dust mite species and the stored product mite. The amount o f cross-reactivity appears to parallel the phylogenetic relatedness.