Isocyanates are the most significant cause of occupational asthma in our country. To evaluate the prevalence of work-related respiratory symptoms and immunologic sensitization to it, we performed a questionnaire survey, allergy skin test, radioallergosorbent test (RAST) to toluene diisocyanate (TDI)-human serum albumin (HSA) conjugate and methacholine bronchial challenge test on 23 isocyanate-exposed employees and 9 unexposed controls working in a zipper factory. Six employees (26.1%) complained of work-related respiratory symptoms and three symptomatic workers showed significant bronchoconstrictions on TDI-bronchoprovocation test. Three (13%) asymptomatic workers had high specific IgE antibodies to TDI-HSA and none of the TDI-sensitive asthmatic workers had specific IgE antibody. One of the TDI-sensitive asthmatic workers showed a negative result on the initial methacholine bronchial challenge test, but bronchial hyperresponsiveness developed after the TDI challenge. It was suggested that TDI-sensitive asthma was noted in three (13%) of 23 exposed workers and that asymptomatic workers could have high specific IgE antibody. Measurement of the changes in bronchial hyperresponsiveness after the TDI challenge could be helpful to diagnose TDI-sensitive asthma.
Adult ; Asthma/*chemically induced/diagnosis ; Bronchial Provocation Tests ; Humans ; Immunoglobulin E/analysis ; Occupational Diseases/*chemically induced/diagnosis ; Occupational Exposure ; Serum Albumin/immunology ; Toluene 2,4-Diisocyanate/*adverse effects/immunology

Adult ; Aspergillosis, Allergic Bronchopulmonary ; etiology ; Aspirin ; adverse effects ; Asthma ; chemically induced ; diagnosis ; Humans ; Male ; Radiography, Thoracic ; Tomography, X-Ray Computed

Current asthma is often diagnostically excluded by the presence of normal bronchial responsiveness. We report on a TDI-induced occupational asthma patient with normal bronchial responsiveness. He had suffered from shortness of breath during and after TDI exposure for several months. His initial methacholine bronchial challenge test showed a negative response. The bronchoprovacation test with TDI showed an isolated immediate bronchoconstriction. The following methacholine bronchial challenge tests revealed that the bronchial hyperresponsiveness developed seven hours after the TDI challenge (methacholine PC20:5.1 mg/ml), progressed up until 24 hours, and returned to normal on the seventh day. This case provides evidence that the response of the airway to TDI may not always be accompanied by bronchial hyperresponsiveness to methacholine. Screening programs utilizing methacholine challenges may not always identify TDI-sensitized asthmatic workers.
Adult ; Asthma/*chemically induced/diagnosis ; Bronchial Provocation Tests ; Bronchoconstriction/*drug effects ; Humans ; Male ; Methacholine Chloride/*diagnostic use ; Occupational Diseases/*chemically induced ; Skin Tests ; Time Factors ; Toluene 2,4-Diisocyanate/*adverse effects

Polyvinyl chloride (PVC) is a widely used chemical for production of plastics. However occupational asthma (OA) caused by PVC has been reported only rarely. We report a 34-yr-old male wallpaper factory worker with OA due to PVC and nickel (Ni) whose job was mixing PVC with plasticizers. He visited the emergency room due to an asthma attack with moderate airflow obstruction and markedly increased sputum eosinophil numbers. A methacholine challenge test was positive (PC20 2.5 mg/mL). Bronchoprovocation tests with both PVC and Ni showed early and late asthmatic responses, respectively. Moreover, the fractional concentration of exhaled nitric oxide (FeNO) was increased after challenge with PVC. To our knowledge, this is the first case of OA in Korea induced by exposure to both PVC and Ni. We suggest that eosinophilic inflammation may be involved in the pathogenesis of PVC-induced OA and that FeNO monitoring can be used for its diagnosis.
Adult ; Asthma, Occupational/*chemically induced/*diagnosis ; Breath Tests ; Bronchial Provocation Tests ; Environmental Exposure ; Eosinophilia/*diagnosis ; Exhalation ; Humans ; Leukocyte Count ; Male ; Nickel ; Nitric Oxide/metabolism ; Occupational Exposure ; Plasticizers ; Polyvinyl Chloride

To evaluate the clinical significance of autoantibodies to three major epithelial cytokeratins (CK) -- CK8, CK18, and CK19 -- we compared 66 patients with toluene diisocyanate (TDI)-induced asthma (group I) with three control groups: 169 asymptomatic exposed subjects (group II), 64 patients with allergic asthma (group III), and 123 unexposed healthy subjects (group IV). Serum IgG, specific for human recombinant CKs, were measured by ELISA (enzyme linked immunosorbent assay), and ELISA inhibition tests were performed. The existence of these antibodies was confirmed by IgG immunoblot analysis. Anti-TDI-HSA (human serum albumin) IgE and IgG antibodies were measured by ELISA in the same set of the patients. The prevalence of CK8, CK18, and CK19 auotantibodies in group I was significantly higher than in the other three groups. Results of the ELISA inhibition test showed significant inhibition with the addition of three CKs in a dose-dependent manner. No significant association was found between CK autoantibodies and the prevalence of anti- TDI-HSA IgG and IgE antibodies. These results suggest that autoantibodies to CK18 and CK19 can be used as serologic markers for identifying patients with TDI-induced asthma among exposed workers.
Toluene 2,4-Diisocyanate/*toxicity ; Sensitivity and Specificity ; Occupational Diseases/chemically induced/*diagnosis ; Middle Aged ; Male ; Keratins/*immunology ; Keratin-8/immunology ; Keratin-19/immunology ; Keratin-18/immunology ; Immunoblotting ; Humans ; Female ; Enzyme-Linked Immunosorbent Assay ; Biological Markers/blood ; Autoantibodies/*blood ; Asthma/chemically induced/*diagnosis ; Adult