IgA antibodies produced by plasma cells in secretory tissues associated with mucosal surfaces represent a major host defense against infectious agents. Precursors of these IgA-producing cells originate in gut-associated lymphoid tissue and, to a lesser extent, in bronchial-associated lymphoid tissue and migrate via the blood not only to gut but also to other mucosal tissues, forming a common mucosal immune system. Oral administration of antigen leads to priming of precursor cells in the gut and subsequent occurrence of specific secretory IgA (S-IgA) antibody in saliva, milk, tears, and the respiratory and genital tracts. On the basis of a review of the world literature, it has been concluded that oral live vaccines elicit higher antibody titers in remote-site secretions and in serum than do oral killed vaccines, which usually stimulate only relatively low levels of local secretory antibody. Oral immunization induces S-IgA in children and adults (including the elderly) without detectable adverse effects. Despite a number of remaining questions, oral immunization against extraintestinal infections is a promising area for future clinical studies.

Administration, Oral↗

PubMedDate not supplied

Sensitization to different mite species in German farmers: clinical aspects.

Various mite species referred to collectively as house dust and storage mites are recognized worldwide as a cause of allergic airway disease. Our study aimed to investigate the frequency of sensitization and potential importance of mite species in farmers using a broad mite spectrum. A total of 86 German farmers with rhinitis and/or asthma were studied by skin prick testing and/or enzyme allergosorbent test (EAST) with the following mites: Blomia tjibodas, Blomia tropicalis, Blomia kulagini, Glycyphagus domesticus, Thyreophagus entomophagus, Euroglyphus maynei, Chortoglyphus arcuatus, Dermatophagoides pteronyssinus, Dermatophagoides farinae, Acarus siro, Lepidoglyphus destructor, Tyrophagus putrescentiae, Acarus farris and Cheyletus eruditus. Sensitization to at least one mite species was detected in 51 patients (59%) by skin prick testing, and in 31 patients (36%) by EAST. The most frequent sensitizations determined by skin tests were found for the three Blomia species, E. maynei and G. domesticus. Twelve patients (14%) gave a positive EAST with the predator mite C. eruditus. A total of 22 patients gave positive EAST results with the Dermatophagoides species. We were able to document sensitization to C. arcuatus, E. maynei and T. entomophagus for the first time in Germany. A considerable proportion of the German farmers tested were sensitized to storage mites. The allergological potential of various mite species has been recognized, some for the first time. It was concluded that B. tjibodas, G. domesticus, C. arcuatus and C. eruditus in particular should be included in an allergy diagnosis. Further investigations into the clinical relevance of the sensitizations and possible cross-reactivity between the mite species are necessary.

Adult↗