| Popis: |
An accurate diagnosis of occupational asthma (OA) is important, since those affected are advised to reduce or eliminate any future exposure to the causative allergen. The diagnostic gold standard is the specific inhalation test, but most physicians rely on clinical history and, where available, assay of specific IgE antibodies. We investigated whether the level of flour and mouse specific IgE assay can act as a predictor for OA. We investigated subjects who attended the occupational allergy clinic at Royal Brompton Hospital, for consideration of OA due to exposures to either flour (n=238) or mouse (n=215) antigens at work. The diagnosis of OA was based on clinical history, serial peak flow measurements and specific IgE assay (ImmunoCAP) to either wheat flour or mouse urine. The diagnosis was made without reference to the level of a positive assay. The standard cut-off point (0.35 kU/l) for flour and mouse specific IgE had a specificity of 60% and 77% respectively. In each group we determined a new cut off to provide a false positive rate of ≤5%. In flour workers this threshold was reached at 10 kU/l and in mouse workers at 15 kU/l. Atopic status, age and smoking each modified these thresholds. In bakers and animal workers with work-related respiratory symptoms, high concentrations of specific IgE can act as good predictors, with high specificity, for a diagnosis of OA. |
