No abstract

In children with persistent asthma inadequately controlled on low dose ICS alone, adding a long acting beta-2-agonist to ICS in a single inhaler was more effective than doubling the ICS dose. These results support recommendations of adding LABA to low-dose ICS as the preferred controller option for children older than 4 years with symptomatic asthma.

Occupational asthma due to platinum salts is a frequent disease in platinum refineries. The diagnosis is based upon a history of work related symptoms and a positive skin prick test with platinum salts. Bronchial provocation tests have not been performed in epidemiological studies because the skin test is believed to be highly specific and sensitive. As no reliable data about this issue currently exist, this study assesses the use of skin prick and bronchial provocation tests with methacholine and platinum salt in platinum refinery workers. Twenty seven of 35 workers, who were referred to our clinic with work related symptoms and nine control subjects with bronchial hyperreactivity underwent a skin prick test and bronchial provocation with methacholine and platinum salt. For skin prick and bronchial provocation tests with platinum salt a 102-10' mol/l hexachloroplatinic acid solution, in 10-fold dilutions was used. Four of the 27 subjects and all controls showed neither a bronchial reaction nor a skin reaction. Twenty three subjects were considered allergic to platinum salt; 22 of these showed a fall of 50% or more in specific airway conductance after inhalation of the platinum salt solution. Four workers experienced a positive bronchial reaction despite a negative skin prick test. No correlation of responsiveness to methacholine with responsiveness to platinum salt was found, but the skin prick test correlated with the bronchial reaction to platinum salt (r, = 0 50, p < 0-023, n = 22). One dual reaction was seen in bronchial provocation tests. Side effects of both skin tests and bronchial provocation tests with platinum salt were rare and were not encountered in workers without a skin reaction to platinum salt. It is concluded that bronchial provocation tests with platinum salts should be performed on workers with work related symptoms but negative skin tests with platinum salts.Occupational asthma, rhinitis, conjunctivitis, and eczema are common diseases in platinum refineries'" and catalyst production plants. 7 The prevalence of these symptoms in cross sectional studies is considerably higher than the prevalence of a positive skin prick test with platinum salt (table 1). Thus reliable diagnostic measures are necessary to establish the causal relation between symptoms and exposure to platinum salts. For longitudinal studies quantitative assessment of sensitisation is of interest.In platinum salt allergy in vitro data such as the radioallergosorbent test (RAST)69 13 14 and histamine release from basophils' lack specificity. Binding rates in RAST showed some correlation with total serum IgE activity59 and although some authors found

Interleukin 3 (IL3) is known to stimulate progenitor cell proliferation and maturation as well as differentiated cell functions, e.g. direct or anti-IgE-mediated histamine release (HR). We investigated 14 patients with malignant diseases being treated with recombinant human IL3 (rhuIL3) as a daily subcutaneous bolus injection for 15 days. For analysis, patients were combined in a ‘low-dose’ [30 (n = 1), 60 (n = 3) and 125 (n = 2) μg/m²/day] and a ‘high-dose’ [250 (n = 6) and 500 (n = 2) μg/m²/day] therapy group. In the high-dose group there was a 2-fold increase in total leukocytes, an 8-fold increase in basophils, and a 23-fold increase in eosinophils. Histamine content per basophil decreased rapidly after rhuIL3 administration. Anti-IgE-induced HR increased in a dose-dependent manner after rhuIL3 therapy (low-dose group: HR_max 47.5 vs. 53.3%; high-dose group: HR_max 57.8 vs. 75.4%, p < 0.05). In contrast to anti-IgE-induced HR, HR with ionophore (78.0 ys. 50.3%, p < 0.05), FMLP (32.3 vs. 11.4%, p < 0.05), sodium chloride (31.8 vs. 22.6%, n.s.) and mannitol (56.3 vs. 47.8%, n.s.) decreased. There was no histamine release from basophils upon in vitro stimulation with rhuIL3 alone. The kinetics of the increase in anti-IgE-induced histamine release did not parallel the rapid histamine depletion of cells. We conclude that rhuIL3 therapy may cause a rapid HR from basophils which cannot be observed after stimulation of cells in vitro. The clinical importance of this HR remains unclear as side effects could not be correlated with HR. Both the increase in basophils and eosinophils and the enhanced anti-IgE-induced HR from basophils after rhuIL3 therapy support the concept of a regulatory, probably enhancing role of IL3 in allergic diseases.

Specific IgE to proteins from Tribolium confusum (TC), a flour beetle, was detected in 9/125 sera of subjects exposed to rye and wheat flour. TC RAST was not inhibited by Dermatophagoides pteronyssinus, rye or wheat flour. Immunoblot experiments showed specific binding to three proteins from adult TC or pupae, not present in rye or wheat flour. These findings suggest that TC might act as an occupational allergen in a proportion of bakers.