Patterns of improvement in spirometry, bronchial hyperresponsiveness, and specific IgE antibody levels after cessation of exposure in occupational asthma caused by snow-crab processing.
Thirty-one workers with occupational asthma caused by snow-crab processing were assessed by a long-term follow-up on three occasions at mean +/- SD intervals of 12.8 +/- 5.4, 31.4 +/- 6.3, and 64.4 +/- 6.3 months after leaving work. The diagnosis of work-related asthma was initially confirmed in all of them by specific inhalation challenges at the workplace or by laboratory inhalation of snow-crab boiling water (n = 24) or by serial monitoring of airway caliber and bronchial responsiveness to histamine at work and off work (n = 7). Total duration of work-related exposure was 12.8 +/- 5.6 months (range, 3 to 21 months), and the duration of symptoms after onset was 6.8 +/- 4.2 months (range, 1 to 18 months). At the time of diagnosis, all 31 subjects required medication for asthma, 11 had a FEV1 less than or equal to 85% predicted, and all subjects had a PC20 less than or equal to 16 mg/ml. Twelve of 25 serum samples assessed showed high levels of specific immunoglobulin E (IgE) antibodies to crab meat and/or boiling water. At the time of the first follow-up, there was a reduction in the number of subjects still requiring medication, with a significant reduction in FEV1, and a PC20 less than or equal to 16 mg/ml. However, no further change was observed afterwards. Similarly, the mean FEV1 and FEV1/FVC improved significantly from the time of diagnosis to the first follow-up (p less than 0.01), with a plateau thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)
Malo
J L
JL
Department of Chest Medicine, Hôpital du Sacré-Coeur, Montreal, Canada.
Cartier
A
A
Ghezzo
H
H
Lafrance
M
M
McCants
M
M
Lehrer
S B
SB
D000328:Adult; D000818:Animals; D000906:Antibodies / Q000032:analysis*; D001249:Asthma / Q000209:etiology* / Q000503:physiopathology; D003386:Brachyura / Q000276:immunology; D001980:Bronchi / Q000503:physiopathology*; D004781:Environmental Exposure; D005260:Female; D005525:Food-Processing Industry; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D008297:Male; D013147:Spirometry; D014797:Vital Capacity
D000906:Antibodies; D007073:Immunoglobulin E