Multiple wheat flour allergens and cross-reactive carbohydrate determinants bind IgE in baker's asthma.

BACKGROUND: Several wheat flour allergens relevant to baker's asthma have been identified in the last 25 years. The aim of this study was to determine the frequency of sensitization to these allergens in German bakers. METHODS: Using recombinant DNA technology, the following wheat flour allergens were cloned, expressed in Escherichia coli and purified: five subunits of the wheat α-amylase inhibitors (WTAI-CM1, WTAI-CM2, WTAI-CM3, WDAI-0.19 and WMAI-0.28), thioredoxin, thiol reductase or 1-cys-peroxiredoxin homologues, triosephosphate-isomerase, αß-gliadin, serpin, glyceraldehyde-3-phosphate-dehydrogenase, a nonspecific lipid transfer protein (nsLTP), dehydrin, profilin and peroxidase. In addition, ImmunoCAPs with the recombinant allergen ω-5-gliadin and two cross-reactive carbohydrate determinants (CCDs), horse radish peroxidase (HRP) and the N-glycan of bromelain (MUXF), were used. Specific IgE was measured in wheat flour-positive sera from 40 German bakers with work-related asthma/rhinitis and 10 controls with pollinosis. RESULTS: Thirty bakers (75%) had IgE to at least one of the 19 single allergens. Most frequent was IgE to WDAI-0.19, HRP and MUXF (25% each), followed by WTAI-CM1 (20%), thiol reductase (16%), WTAI-CM3 (15%), WTAI-CM2 and thioredoxin (12.5%), WMAI-28, triosephosphate-isomerase, αß-gliadin (10%), 1-cys-peroxiredoxin (7.5%), dehydrin, serpin, glyceraldehyde-3-phosphate-dehydrogenase (5%), ω-5-gliadin, nsLTP and profilin (2.5%). Fifteen bakers (38%) had IgE to any α-amylase inhibitor and 12 (30%) to at least one CCD. The controls reacted exclusively to CCDs (80%), profilin (60%), thioredoxin (30%), triosephosphate isomerase and nsLTP (10%). CONCLUSIONS: The single allergen sensitization profiles obtained with 17 recombinant wheat flour allergens and two CCDs revealed no major allergen for German bakers. The highest frequencies were found for α-amylase inhibitors and CCDs.

Occupational hypersensitivity pneumonitis due to molds in an onion and potato sorter.

A 42-year-old female non-smoking onion and potato sorter developed work-related shortness of breath, cough, fatigue and flu-like symptoms. The diagnosis of hypersensitivity pneumonitis was based on patchy infiltrates in both lungs on high resolution computed tomography and lymphocytosis of 71% in a bronchoalveolar lavage sample with a CD4/CD8 ratio of 0.4. Exposure cessation and initial corticosteroid therapy resulted in complete recovery. IgG antibodies to Penicillium species and Fusarium solani cultivated from samples from the patient's workplace were detected in the patient's serum and cross-reactivity was demonstrated within Penicillium species, but also between Penicillium species and Aspergillus fumigatus. We conclude that occupational hypersensitivity pneumonitis due to molds may develop in onion and potato sorters.