Host factors in occupational diisocyanate asthma: a Swiss longitudinal study.

OBJECTIVE: To investigate the usefulness of surrogates for individual susceptibility to organic diisocyanates in occupational asthma. SUBJECTS: All new cases declared to the Swiss National Accident Insurance Company (SUVA) for establishment of a case for compensable occupational disease during 1993. Sixty-nine persons, of whom three were women, were suspected of having occupational asthma due to isocyanates. Of these, 47 subjects fulfilled the criteria to be accepted as an occupational disease case. METHODS: All subjects were studied clinically and gave a blood sample for the phenotyping of their alpha-antitrypsin status and for immunological studies. The subjects were also given a peroral dose of caffeine for the determination of their N-acetylation capacity. Finally, those with an occupational disease were subjected to the methacholine provocation test. RESULTS: Forty-four persons with occupational disease, out of 47, were heterozygous antitrypsin carriers and/or slow acetylators of primary amines. In the bronchial provocation with methacholine, 12 of these subjects had an unaltered response and seven had a mild reaction, 13 a moderate one and 15 a severe reaction. INTERPRETATION: The study confirms the finding that slow N-acetylators are susceptible to asthma from exposure to common diisocyanate monomers at work. The same applies to heterozygous antitrypsin-phenotype carriers. Thus, the use of these markers may reinforce the diagnostic procedure, but they cannot completely replace the immunological tests.

[Peak flow profile and expert testimony. The significance of peakflow self assessment for pneumological expert testimony]. / Peak-flow-Profil und Gutachten. Die Bedeutung der Peak-flow-Selbstmessung für das pneumologische Gutachten.

Quantitative assessment of pulmonary obstructive diseases, such as asthma, may be difficult because of variability of obstruction. This is particularly true with regard to expert evidence pulmonary physicians deliver to insurances. Severity of obstruction, degree of impairment by an obstructive ventilatory defect, and temporal relationship of bronchial obstruction to exposure, may not be detected by physiological measurements in the pulmonary function laboratory. Much of the expert's opinion on these matters will depend on the credibility he assigns to the insured individual. The insured individual, in the other hand, has no other proof available than the description of his complaints, which puts him at a disadvantage. Serial peak flow measurements can be instrumental in clarifying such issues. They add an objective dimension to the case history. Six cases in which expert evidence was commissioned by insurances are described in detail, to exemplify how the thinking of the experts was modified by peak flow profiles. The greater usefulness of serial peak flow measurements in occupational asthma is emphasized and problems that may arise with peak flow measurements are discussed.