Occupational sensitivity to Tenebrio molitor Linnaeus (yellow mealworm).

Tenebrio molitor is an abundant stored-grain pest in the northern United States. We evaluated an individual with work-related symptoms of rhinoconjunctivitis on exposure to this insect. Prick skin tests with extracts prepared from the larval, pupal, and adult-life stages were positive for the patient and for another individual with allergy to a closely related species of beetle, Alphitobius diaperinus. Specific IgE antibodies to the extracts were demonstrated by RAST. RAST inhibition demonstrated immunologic cross-reactivity between the life stages of T. molitor and also between T. molitor and A. diaperinus, as well as slight cross-reactivity with blowfly. The proteins in the extracts of each life stage were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More than 15 protein bands were detected in each of the extracts, although the patterns of separation were different for each life stage. After immunoblotting and autoradiography, six different IgE-binding proteins were identified in the larval extract, five in the pupal extract, and seven in the adult extract, with similar IgE-binding patterns noted for the larval and adult extracts. We conclude that this patient developed IgE-mediated sensitivity to T. molitor antigens as the result of occupational exposure. This study confirms the fact that beetles of the Tenebrionid family are potentially significant allergens for workers exposed to grains or grain products.

Allergens involved in occupational asthma caused by baby's breath (Gypsophila paniculata).

Although the floral industry deals with many potential allergens, few examples of occupational asthma exist in this industry. A 22-year-old florist experienced symptoms of rhinitis, conjunctivitis, and asthma on exposure to baby's breath. To determine the contribution of baby's breath to the patient's symptoms, an extract of baby's breath was prepared. Prick skin tests with a 1:10(-5) wt/vol concentration of the extract produced an immediate response, whereas nonexposed atopic and normal control subjects did not react. The patient's asthmatic response to baby's breath was confirmed by bronchial challenge that caused an immediate fall in FEV1 of 26.2% from baseline after inhalation of 88 breath units of the extract. With a direct RAST, the patient's serum bound 38 times the amount of IgE bound by the negative control. IgE binding in the RAST was inhibited by the baby's breath extract but not by unrelated inhibitors (ragweed and tree pollens). Immunoblotting demonstrated IgE binding to 13 protein bands in the extract with molecular weights ranging from 11.5 to 68 kd. Serum from a patient previously reported to have sensitivity to baby's breath recognized five protein bands. Three proteins with molecular weights of 27, 31, and 37 kd were recognized by both patients' sera. We conclude that this patient developed IgE-mediated sensitivity to multiple allergens in baby's breath. This study confirms the importance of this plant as a potential cause of occupational asthma in the floral industry.

Occupational sensitivity to Alphitobius diaperinus (Panzer) (lesser mealworm).

Alphitobius diaperinus is an important beetle in the grain and poultry industries. We evaluated three individuals with work-related symptoms of asthma, rhinitis, conjunctivitis, urticaria, and angioedema on exposure to the insect. Prick skin tests with extracts prepared from the larval, pupal, and adult life stages were positive in all three patients. Specific IgE antibodies to these extracts were demonstrated by RAST or radioimmunoassay. RAST and radioimmunoassay inhibition confirmed the specificity of IgE binding and further demonstrated immunologic cross-reactivity between the three life stages. Peripheral blood leukocytes from two of the individuals demonstrated significant histamine release when they were compared with cells from nonexposed atopic and normal control subjects. The proteins in the extracts of each life stage were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. More than 30 protein bands were detected in each of the extracts; however, the patterns of separation were different for each life stage. After immunoblotting and autoradiography, IgE-binding proteins were recognized by sera from all three individuals in the larval extract at 90 kilodaltons (kd), in the pupal extract at 90, 64, and 38 kd, and in the adult extract at 84 kd. Additionally, several other proteins were identified as being allergenic in some of the patients. We conclude that these three patients developed IgE-mediated sensitivity to A. diaperinus antigens as the result of occupational exposure. To our knowledge, this is the first description of sensitivity to this grain beetle.

Twelve-hour bronchodilation in asthma with a single aerosol dose of the anticholinergic compound glycopyrrolate.

Anticholinergic aerosols provide effective bronchodilation in some patients with obstructive lung disease. Glycopyrrolate is a quaternary ammonium anticholinergic compound that is poorly absorbed from mucus membranes, thus reducing anticholinergic side effects. In 20 adult patients with asthma, we evaluated bronchodilation to a single administration of metered-dose glycopyrrolate aerosol (GA) to ascertain its onset and duration of action along with evaluation of safety. In this randomized, double-blind, placebo-controlled, single-dose, crossover trial, bronchodilation was evaluated on five separate occasions to either placebo or a GA dose of 80, 240, 480, or 960 micrograms. Baseline spirometry for each patient on each visit was similar (mean FEV1 +/- SD of 62.2 +/- 13.6% predicted). After aerosol dosing, spirometry was measured at 30 minutes and then at hourly intervals up to 12 hours. Compared to placebo, metered-dose aerosols of 240, 480 and 960 micrograms elicited significantly greater bronchodilation at each test time. Furthermore, significant bronchodilation was noted within 30 minutes of dosing and was sustained for at least 12 hours. Bronchodilation with the 480 and 960 micrograms dose was equal, and both were greater than 240 micrograms. A subset of four asthma patients with baseline FEV1 values less than 50% predicted did not have a bronchodilating response with GA. No notable side effects occurred. Thus, a single aerosol dose of GA provides clinically significant, safe 12-hour bronchodilation in patients with asthma without severe airway obstruction (i.e., FEV1 greater than 50% predicted).

Viral "bronchitis" in childhood: relationship to asthma and obstructive lung disease.

Lower respiratory tract infections in children, including group, bronchiolitis, and bronchitis are frequently associated with recurrent episodes of wheezing. Different respiratory viruses assume greater importance at different ages of children. Respiratory syncytial virus is the most prevalent viral respiratory infection in preschool children, while rhinovirus is of increasing importance in older children. Asymptomatic virus shedding and mild respiratory infections do not provoke asthma symptoms nor do bacteria, except in association with sinusitis. Furthermore, epidemiologic studies strongly suggest that viral lower respiratory tract illness in early childhood is associated with pulmonary abnormalities, including bronchial hyperreactivity and peripheral airway obstruction that may persist for many years, and is possibly a cause of chronic airway obstruction in adulthood. Several different mechanisms have been identified by which respiratory viruses provoke asthma. No one single mechanism, however, adequately explains virus-induced asthma. Nonetheless, a common thread to these various proposed mechanisms is the ability of respiratory viruses to cause airway inflammation, either directly, through cytopathic effects, or indirectly, by increasing the inflammatory processes of respiratory cells. The consequence of these effects causes increased airway responsiveness and asthma.