Hypersensitivity Pneumonitis in Farmers: Improving Etiologic Diagnosis to Optimize Counselling.

In a farmer, a diagnosis of hypersensitivity pneumonitis (HP) might cause drastic changes in life, and guidance concerning future prospects within farming requires a best possible etiological diagnosis. We aimed to assess (1) if immunological analyses based on material samples from the work environment could be used to improve the etiologic diagnosis in a farmer suffering from HP, and (2) if combining a longitudinal immunological investigation of workplace material with a realistic work place inhalation challenge could be used to optimize counselling with respect to further employment within farming. A realistic workplace inhalation challenge was performed to explore potential associations between exposure, symptoms and immune responses. Material samples were collected from various places on the farm, and enzyme-linked immunosorbent assay (ELISA) was performed to identify possible IgE and IgG antibodies in patient serum towards these material samples. Electrophoresis (SDS-PAGE) and immunoblot were used to detect the specific proteins in the material samples that were recognized by ELISA. The patient's symptoms were reproduced by the workplace challenge, and more severe symptoms were associated with increased serum levels of specific IgG antibodies towards material samples from the workplace. The immunoblot detected IgG binding proteins in agreement with known allergens of the fungi Alternaria and Pullularia. Combining realistic workplace challenge with immunological analyses of workplace material may improve the basis for counselling farmers with farmer´s lung concerning future work within farming.

Effects of industrial processing on the immunogenicity of commonly ingested fish species.

BACKGROUND: Food-processing techniques may induce changes in fish protein immunogenicity. Allergens from >100 fish species have been identified, but little is known on the effects of processing on fish protein immunogenicity. METHODS: IgE binding of sera of patients allergic to fresh and processed (smoked, salted/sugar-cured, canned, lye-treated and fermented) cod, haddock, salmon, trout, tuna, mackerel and herring and of hydrolysates based on salmon and whiting was investigated using immunoblot and inhibition ELISA. RESULTS: Parvalbumin oligomers were identified using monoclonal and polyclonal antibodies. IgE binding was seen in most sera at 12-14 kDa (parvalbumin), and at 17-60 kDa for all fish except tuna. Changes in IgE binding appeared to reflect altered parvalbumin monomers and oligomers. Smoked haddock, salmon and mackerel had increased IgE binding and novel bands at 30 kDa. Chemically processed cod, salmon, trout and pickled herring had reduced or abolished IgE binding. The serum of 1 subject, however, had increased IgE binding to these products and also inhibition of binding by both fish hydrolysates to their constituent fish species. CONCLUSION: Process-induced changes in fish protein immunogenicity were more dependent on process rather than species, although individual responses varied. Changes in the allergenicity of a product may depend on the net effect of processing on parvalbumin oligomerization patterns, which may also vary in different species. Chemical processes generally caused loss in IgE-binding activity, though sensitization may occur to modified or degraded rather than intact peptides as shown by increased binding by chemically processed fish and hydrolysates in 1 subject. The clinical significance of these findings remains to be established.

Occupational allergy to Artemia fish fry feed in aquaculture.

BACKGROUND: Artemia (brine shrimp) is used as feed for fish fry and shrimp in aquaculture. Two employees in a Norwegian aquaculture research farm reported having chest symptoms when working in an Artemia hatch room. AIMS: To determine the presence and prevalence of Artemia sensitization at the farm and the extent of any Artemia-related respiratory and hand skin symptoms and to identify the allergens involved. METHODS: Participants completed a questionnaire and structured interview. Skin prick tests (SPTs) were performed, and immunoglobulin E (IgE) antibodies to Artemia, shrimp and recombinant tropomyosin were determined. Gel electrophoresis and immunoblots of Artemia extracts were also carried out. RESULTS: Thirty of 42 employees (71%) participated. Among the 24 subjects exposed to Artemia, four (17%) reported chest and/or hand skin symptoms during exposure and three of them were IgE sensitized to Artemia. Five (21%) of those exposed demonstrated IgE antibodies to Artemia and four (17%) had immediate-positive SPTs. A serum pool from these subjects exhibited IgE binding to a protein of approximately 97 kDa in the Artemia extract. CONCLUSIONS: Occupational exposure to the Artemia fish fry feed can cause IgE sensitization and allergic symptoms affecting airways and skin.

High prevalence of immunoglobulin E (IgE) sensitization among sisal (Agave sisalana) processing workers in Tanzania.

PURPOSE: Allergic sensitization among workers exposed to sisal is scarcely documented. We examined whether sisal processing is associated with IgE sensitization and its relationship to the prevalence of respiratory symptoms among Tanzanian processors. METHODS: 138 sisal exposed workers and 78 non-exposed controls were skin prick tested (SPT) using dry sisal extract and fresh sisal sap. Sera from a subset of 43 participants were analyzed for total and sisal specific IgE. SPT wheal size, prevalence of positive SPTs and adjusted relative risk (RR) for sisal sensitization were determined and compared between exposed and controls. Prevalences for respiratory symptoms were compared between sensitized and non-sensitized sisal workers. RESULTS: Significantly higher prevalence of positive SPTs to sisal was found among 74 % of sisal workers compared to 17 % among controls. Compared to controls, the RR of sensitization to sisal was 4 times higher (95 % CI; 2.4-6.7) among exposed workers. All exposed workers had elevated IgE levels (>100 kU/l) and 27 % of tested sera had elevated sisal specific IgE. A high prevalence of respiratory symptoms was found in both sensitized and non-sensitized sisal workers. CONCLUSION: Sisal processing is associated with increased risk of IgE sensitization, but its clinical implication is not obvious.

Nasal indices of eosinophilic and exudative inflammation in bakery-workers.

AIMS: Rhinitis symptoms frequently occur in bakery-workers. Yet, little is known about the pathophysiology of this condition. The objective of the present study was to examine nasal indices of inflammation in relation to occupational dust exposure, occupational rhinitis according to defined criteria, rhinitis symptoms associated to the workplace, and occupational sensitization in bakery-workers. METHODS: Bakery-workers (n = 197) were subjected to interviews, questionnaires, workplace dust measurements, allergy tests, and nasal lavages with and without histamine. alpha(2)-Macroglobulin and eosinophil cationic protein (ECP) were measured in saline lavages as indices of plasma exudation and eosinophilic activity, respectively. Histamine lavages were employed to explore the nasal exudative responsiveness. RESULTS: alpha(2)-Macroglobulin and ECP increased significantly by increased workplace dust exposure (P< or =0.035). Furthermore, the exudative responsiveness to histamine increased significantly by such exposure (P< or =0.016). Similar patterns were seen in workers with occupational rhinitis and in subjects with rhinitis symptoms associated to the workplace, but not in workers with occupational sensitization. CONCLUSIONS: We conclude that occupational dust exposure in bakery-workers is associated with nasal eosinophilic exudative inflammation. In contrast, occupational sensitization is not a discriminating factor with regard to indices of eosinophilic, exudative inflammation in the present material.

Allergy to fish parvalbumins: studies on the cross-reactivity of allergens from 9 commonly consumed fish.

BACKGROUND: Fish-hypersensitive patients can probably tolerate some fish species while being allergic to others. OBJECTIVE: To determine the allergenic cross-reactivity between 9 commonly edible fish: cod, salmon, pollack, mackerel, tuna, herring, wolffish, halibut, and flounder. METHODS: Sera from 10 patients allergic to fish and rabbit antisera against 3 parvalbumins (Gad c 1, Sal s 1, and The c 1) were used. Cross-reactivity was investigated by SDS/PAGE and IgE immunoblotting, IgG ELISA, IgE ELISA inhibition, and skin prick test (SPT). RESULTS: Cod (Gad c 1), salmon (Sal s 1), pollack (The c 1), herring, and wolffish share antigenic and allergenic determinants as shown by immunoblots and IgE ELISA, whereas halibut, flounder, tuna, and mackerel displayed lowest cross-reactivities. The highest mean IgE ELISA inhibition percent of 10 sera was obtained by Gad c 1, followed by The c 1, herring, Sal s 1, wolffish, halibut, flounder, tuna, and mackerel with the least inhibition. Nine of the 10 patients showed positive SPT to cod, salmon, and pollack; 8 patients reacted to recombinant (r) Sal s 1. Positive SPTs to rGad c 1 and rThe c 1 were demonstrated in 1 patient. CONCLUSION: Gad c 1, Sal s 1, The c 1, herring, and wolffish contained the most potent cross-reacting allergens, whereas halibut, flounder, tuna, and mackerel were the least allergenic in the current study. The latter could probably be tolerated by some of the tested patients.

Exposure and airway effects of seafood industry workers in northern Norway.

OBJECTIVE: In this study, we explored airway symptoms and exposure to bioaerosols and exhaust gases in seafood industry plants. METHODS: The study details the results from personal and environmental exposure measurements (17 plants), a questionnaire (n = 984), and clinical examinations (n = 225). RESULTS: The workers were exposed to allergens, endotoxins, molds, and exhaust. The 1-year prevalence of work-related airway symptoms was 42.8% for production workers and 25.9% for administrative workers. Mean levels of forced expiratory volume in 1 second and forced vital capacity were less than the predicted values in all exposed nonsmoker groups. A total of 20.5% had increased levels of total IgE (>/=100 kU/L). Specific IgE-mediated reactions seemed to be relevant only in the shrimp industry. CONCLUSIONS: Seafood industry workers showed a high prevalence of work-related airway symptoms. Further research on the relationship between exposure and effects is necessary.

Characterization of parvalbumin, the major allergen in Alaska pollack, and comparison with codfish Allergen M.

Increased fish consumption has led to frequent reporting of fish allergy and adverse reactions. Alaska pollack (Theragra chalcogramma) is a globally important commercial fish species, belonging to the Gadidae family. This family of fish also includes cod whose parvalbumin, Allergen M (Gad c 1), has been thoroughly studied and considered as a reference to sensitization in fish allergy. In the present study, parvalbumin from Alaska pollack, designated The c 1, was purified by use of anion exchange chromatography. To demonstrate the homogeneity of the purified protein, reverse phase high performance liquid chromatography was performed and showed two distinct fractions which had similar IgG and IgE binding capacities. Accordingly, cDNA cloning revealed two isotypic parvalbumin transcripts in pollack muscle. Recombinant parvalbumins of pollack exhibited low IgG and IgE binding capacities, in contrast to the native counterparts, which were almost as potent as cod Gad c 1. The allergenicity of The c 1 was assayed by ELISA inhibition, and compared to cod, the concentration required for obtaining 50% ELISA inhibition (C 50%) was only 18% higher for The c 1.

The major allergen (parvalbumin) of codfish is encoded by at least two isotypic genes: cDNA cloning, expression and antibody binding of the recombinant allergens.

The major allergen (parvalbumin) from cod, designated Allergen M Gad c 1, has been intensively studied both from the structural and immunological sides. In the present study, transcripts of two isotypic parvalbumin genes in Atlantic cod were identified and characterized. Subsequently, subfragments were inserted into the expression vector pET-19b, generating plasmids with coding capacity for complete parvalbumin polypeptides fused to an N-terminal his(10) tag. Most of the recombinant products were found in the soluble fraction of the expression host Escherichia coli. The target proteins showed to react with polyclonal antibodies raised against Allergen M and demonstrated binding to specific IgE from 12 sera of patients allergic to cod in ELISA inhibition experiments. Sera with classes 4 and 5 CAP FEIA exhibited also strong binding to recombinant parvalbumins in immunoblots.