cellulase and Hypersensitivity

Aspergillus-derived enzymes are used in dough improvers in bakeries. Some of these enzymes are identified as causing IgE-mediated sensitization in up to 25% of bakers with workplace-related symptoms.. The aim of this study was to compare the frequency of sensitization to Aspergillus xylanase, cellulase, and glucoamylase with the sensitization to alpha-amylase (Asp o 2) and to identify IgE-reactive proteins in enzyme preparations.. Sensitization to Aspergillus-derived enzymes and cross-reactivity were retrospectively studied by enzyme allergosorbent test (EAST) and EAST-inhibition experiments. IgE-reactive proteins were detected by electrophoretic separation and immunoblotting. Liquid chromatography with electrospray ionization mass spectrometry and Edman degradation of tryptic protein fragments were used for the biochemical identification of an unknown IgE-binding protein.. Twenty-three percent of 171 tested bakers had specific IgE to alpha-amylase, 8% reacted to glucoamylase, 13% reacted to cellulase, and 11% reacted to xylanase. Xylanase and cellulase preparations, each containing at least 6 different proteins, showed cross-reactivity in the range of 80%. The main IgE-binding protein in the xylanase preparation recognized in 7 of 8 xylanase-positive subjects was a protein of about 105 kd. This protein was identified as beta-xylosidase by peptide mass spectrometric fingerprinting. The identification was confirmed by matching 12 peptide sequences obtained by N-terminal and mass spectrometric sequencing to this protein.. Beta-Xylosidase from Aspergillus niger is an occupational allergen present in currently used baking additives, which causes sensitization in at least 4% of symptomatic bakers. According to the International Union of Immunological Societies nomenclature, we suggest the term Asp n 14 for this allergen.

Topics: Adult; Allergens; alpha-Amylases; Amino Acid Sequence; Antigens, Fungal; Antigens, Plant; Aspergillus niger; Cellulase; Cross Reactions; Electrophoresis, Gel, Two-Dimensional; Electrophoresis, Polyacrylamide Gel; Female; Food Handling; Glucan 1,4-alpha-Glucosidase; Humans; Hypersensitivity; Immunoblotting; Immunoglobulin E; Male; Middle Aged; Molecular Sequence Data; Occupational Diseases; Retrospective Studies; Sodium Dodecyl Sulfate; Xylan Endo-1,3-beta-Xylosidase; Xylosidases

Modern biotechnical methods have enabled production of many new types of potentially allergenic proteins. Enzymes have long been known to be respiratory allergens, but relatively few cases of skin allergy have been reported. Here we describe four patients who developed occupational allergic respiratory symptoms, three with bronchial asthma and one with allergic rhinitis, caused by cellulase and/or xylanase enzymes. Each patient also had urticarial symptoms after skin contact with these enzymes. In addition, one of the patients had allergic contact dermatitis from cellulase, and one from xylanase. Allergic contact dermatitis was verified by positive patch tests with the enzymes, and the immediate allergy was revealed by skin prick tests, specific IgE determinations (RAST) and RAST-inhibition tests. All patients had positive RASTs to both cellulase and xylanase. In the RAST inhibition test 20 microliters of cellulase brought about a 94% inhibition, indicating the specificity of the RAST. Xylanase (20 microliters, 5% w/v) gave an 92% inhibition of cellulase RAST, indicating cross-reactivity between cellulase and xylanase. Three patients have been able to continue at their previous places of work, but at different worksites. One of the patients requires continuous medication for asthma and had to change her job because of persistent symptoms.

Topics: Adult; Allergens; Asthma; Biotechnology; Cellulase; Dermatitis, Contact; Female; Glycoside Hydrolases; Humans; Hypersensitivity; Immunoglobulin E; Male; Middle Aged; Occupational Diseases; Radioallergosorbent Test; Skin Tests; Urticaria; Xylan Endo-1,3-beta-Xylosidase

We report a case of rhinitis and asthma resulting from exposure to enzymes used in an experimental plant pathology laboratory. Immediate skin-test responses were elicited to both "Cellulase" and "Macerozyme" products, and a large late onset skin reaction occurred at the Cellulase site beginning in 6 hr. Special radioallergosorbent test (RAST) substrates were prepared that showed a strong positive response to Cellulase. By the RAST method other laboratory workers were screened and another symptomatic individual was found who also showed evidence of type I hypersensitivity to both enzymes. Skin biopsy and immunodiffusion data are presented. We conclude that enzymes used to digest cell wall structures of plants are capable of eliciting both immediate and late onset skin-test reactions and positive RAST responses in susceptible persons. These reactions are thought to be mediated by IgE antibodies and can be associated with symptoms of rhinitis and asthma.

Topics: Adult; Cellulase; Clone Cells; Humans; Hypersensitivity; Hypersensitivity, Immediate; Male; Plants; Radioallergosorbent Test; Skin Tests