D2.116 - Occupational asthma due to Chinese yeast, Yeast and Peptone
Case report
BACKGROUND
The production of cultive medium requires a mixture of nutrients and agents for the growth and differentiation of micro-organisms, such as various yeasts.
Occupational asthma is caused by exposure to an agent specific to the workplace. Occupational asthma due to cultive medium is unusual.
We present a 27-year-old man, allergic pet epithelium (cat and dog), working in a laboratory manufacturing cultive medium, who reported dry cough and wheezing when handling powdered raw material for the manufacture of these media. He works with a mask and barrier measures and he is symptom-free during holidays and weekends.
METHODS
We performed Skin prick tests (SPT) with a standard battery of common aeroallergens (pet-epithelium, house-dust mite, molds and various pollen) and Prick-prick tests with various powdered raw materials provided by the patient: Tartaric acid, sodium chloride, sodium carbonate, magnesium sulphate, dextrose, casein peptone, yeast extract, american agar and Chinese yeast extract). Respiratory function tests (spirometry, bronchodilation test and FeNO measurement) were carried out.
SDS-PAGE immunoblotting was performed to study the molecular mass of the IgE binding proteins with the prick-positive samples.
RESULTS
SPT with common aeroallergen were positive to: epithelium (dog and cat), pollens (Birch, Arizonian, Platanus acerifolia, Olive, Grasses, Plantago, Chenopodium, Salsola, Artemisia) and panallergens (LTP and profilin)
Prick-prick results were positive for casein peptone, yeast extract and chinese yeast extract.
SDS-PAGE immunoblotting with yeast extract, chinese yeast extract and casein peptone showed a similar IgE binding profile: bands were detected at 28.5-26, 26-16 and 60 kDa respectively.
As the peptone sample is derived from casein hydrolysate and the patient is allergic to pet-epithelium (dog and cat), the band detected at 60 kDa could correspond to bovine albumin.
Respiratory function tests showed improvement after cessation of occupational exposure, despite treatment with inhaled budesonide/formoterol: FEV1 baseline 4.43 (102%) FEV1 after exposure cessation: 5.56 (128%)
CONCLUSION
We report a case of occupational asthma due to IgE-mediated allergy to yeast and casein peptone.
It is likely that there is cross-reactivity between different mammalian animal proteins, however, further research is needed to validate these findings.
