Factors related to the development of sensitization to green coffee and castor bean allergens among coffee workers

Background Occupational allergic respiratory symptoms in coffee workers have been frequently reported, but the ultimate cause of sensilization is still debated, castor bean being considered besides green coffee beans. Atopy and cigarette smoking have been suggested as promoting factors of sensitizalion for several occupational allergens. Objective This study was carried out to assess the prevalence of allergic respiratory symptoms and of sensitization to both green coffee beans and castor bean in the whole workforce of a coffee manufacturing plant. Furthermore we wanted to ascertain both the presence of castor bean antigens in the settled dust of the green coffee beans warehouse and the possible crossreactivity between the two beans. Meanwhile, the effect of smoking and atopy was considered. Method: Two-hundred and eleven workers were examined. A questionnaire on oculorhinitis and asthma was administered and skin-prick tests for green coffee beans, castor bean and 15 common inhalant allergens were carried out. Isoelectric focusing, isoelectric focusing immunoblot and radioallergosorbent assay (RAST) inhibition were performed on samples of settled environmental dust from the green coffee area, as well as on castor bean and green coffee beans. Results Ten per cent of the workers complained of oculorhinitis alone and 16% of asthma (nearly always associated with oculorhinitis). The overall prevalence of skin-sensitization was: 15% for green coffee beans, 22% for castor bean, 22% for common allergens. Evidence of sensitization to occupational allergens was more common in smokers, with a more than twofold increase in relative risk. The strong association between skin positivity to common and occupational allergens suggests that atopy acts as an enhancing host factor towards occupational sensitization. The analysis of the dust confirmed the presence of castor bean antigens. Conclusion Our findings indicate that castor bean is the major cause of occupational sensitization among coffee workers, whereas smoking and atopy act as enhancing factors.     

Analysis of green coffee bean and castor bean allergens using RAST inhibition

Coffee workers with occupational allergic symptoms and positive skin tests to green coffee bean and factor dust antigens have elevated serum IgE antibodies (by radioallergosorbent test–RAST) to green coffee and castor bean allergens. These antibodies were used in a RAST inhibition assay to analyse coffee and castor allergens. Bean allergens were extracted by homogenization in PBS, centrifugation and concentration of supernates by ultrafiltration. Green coffee bean allergens, fractionated by gel filtration and Pevikon block electrophoresis, were shown to be very heterogeneous with a molecular weight range of 50 000 to 500 000 daltons. Castor allergens were more homogeneous with a molecular weight of 14 000 daltons and were partially purified by Pevikon block electrophoresis, gel filtration and isoelectrofocusing. Chemical analysis showed that protein was the major component in both allergen extracts. However, proteolytic enzymes could only partially destroy allergenic activity. Such isolation and characterization of these allergens should result in better methods of diagnosis and treatment of coffee workers with occupational allergic disease.     

Diagnostic Tests in Allergy to Green Coffee

Twenty-two coffee roastery workers with work-related symptoms of various degree from the eyes, nose or bronchi were tested with partly purified water-soluble extract from dust of green coffee beans (GCB). Eighteen persons had a positive prick test, eight a positive bronchial provocation test and seven a positive nasal provocation test. Fourteen had a positive methacholine test, indicating unspecific bronchial hyperreactivity. Specific IgE antibodies to GCB extract were found in sera of 11 workers and to castor bean (CB) extract in 16. The workers measured their lung function with an air flow meter, three times a day for 1 week, and the values were lower in the second half of the week for the workers with IgE antibodies to GCB, but not for the others. It is concluded that the case history, prick test, RAST, and simple lung function tests for one or a few weeks are the best tools when investigating occupational allergy. When the allergen is unknown, but the occurrence of an IgE-mediated allergy is suspected, serial lung function measurements and determinations of total serum IgE, in addition to taking a careful case history, are valuable methods with which to start the investigation.     

Papain-induced asthma: diagnosis by skin test, RAST and bronchial provocation test

Seven out of eleven workers occupationally exposed to airborne papain developed immediate hypersensitive reactions, predominantly asthma and rhinitis. Skin tests and RAST with papain were positive in all symptomatic workers, but not in the four asymptomatic workers. Furthermore, out of forty non-exposed asthmatics, thirty-eight had negative RAST results and all had negative skin test results. Bronchial provocation tests with 0.15–0.5 mg papain performed in five patients with a positive case history showed in each case an immediate asthmatic reaction; in addition to that, one patient developed signs of a dual asthmatic reaction. Our results suggest that airborne papain is a highly immunogenic agent in humans, which induces type I allergic reactions in a large percentage of the exposed subjects.     

Aging and serum immunoglobulin E levels, immediate skin tests, RAST

The changes of the serum IgE levels, specific immediate skin-test responses, and RAST measurements with age were evaluated. A total of 331 unrelated individuals were studied, consisting of 166 subjects with ragweed allergic rhinitis and/or asthma, 67 with idiopathic (intrinsic) asthma, and 98 who appeared in good health with no clinical evidence of atopic diseases. All subjects were evaluated by history and physical examination, intradermal skin testing to the common aeroallergens, measurements of IgE antibody to common aeroallergens with the RAST, and serum IgE levels. Results demonstrated a significant decrease in serum IgE levels with aging in atopic individuals. This decline was exponential in character. In addition, a tendency for RAST and immediate type skin-test responses for selected antigens and histamine to decrease with age was observed.     

Failure of enzyme encapsulation to prevent sensitization of workers in the dry bleach industry

BDE added to dry bleach have been associated with immunologic sensitization and development of clinical allergic disease in detergent workers and occasionally in consumers. However, improved dust control and modification of the manufacturing process through encapsulation of enzyme were believed to have reduced or eliminated these problems. To determine whether or not immunologic sensitization could still develop in the detergent industry, we studied employees of a dry bleach manufacturing plant that incorporated encapsulated BDE into a consumer product. We performed air sampling for enzyme dust and total particulates, administered questionnaires, conducted physical examinations, and spirometry in 13 currently exposed, two previously exposed and nine nonexposed, employees. To assess sensitization status, RAST and ELISA were performed. Air concentrations of enzyme dust ranged from 0.002 to 1.57 micrograms/m3; all of these levels were below the TLV of 3.9 micrograms/m3. Positive BDE-specific RAST results (3.4%, 4.4%, and 8.0% binding) were obtained in three of 12 currently exposed workers. Results of personal breathing-zone air sampling indicated that these workers had high dust-exposure levels. Specificity of RAST was verified by RAST inhibition with BDE. BDE-RAST binding was not significantly elevated in the nonworkers (range: 0.6% to 1.4% binding). Positive results for specific IgG by ELISA were obtained in four of 12 currently exposed and in one of two previously exposed workers but in none of the nonexposed workers. We conclude that immunologic sensitization can develop after occupational exposure to encapsulated BDE in the dry bleach industry. We have not proved, however, that this immunologic reactivity is related to clinical sensitivity.     

Coffee Worker''s Allergy

Workers in the coffee industry were investigated. Study I comprised 50 selected cases of whom 25 had work-related symptoms and 25 had not. Prick tests and RAST investigations with different factory dust extracts were performed. Study II was a cross-sectional study comprising 129 workers who were prick-tested with one factory dust extract and with castor bean (CB). More than 40% described occupationally related asthma, rhinitis, conjunctivitis or pruritus, and in about half of these cases sensitization with one or two allergens was found. One allergen comes from coffee beans and is found in the factory dust, mainly where the raw coffee is handled. This allergen is destroyed in the roasting process. The other allergen is identical with the allergen from castor bean and its presumed to enter the plant via the sacks. Predisposing factors to developing sensitization were atopic status, degree and length of exposure, and smoking habits.     

Occupational asthma in poultry workers

Sixteen poultry workers with poultry house--related rhinitis and/or asthma underwent clinical and laboratory evaluation that included history and physical examination, skin tests with common inhalant and PAg, total- and specific-IgE levels, and pulmonary-function studies. Sixteen age- and sex-matched atopic subjects who were not occupationally exposed to poultry and 12 asymptomatic veterinarians with occupational exposure to poultry served as controls. Rhinitis and asthma developed only in symptomatic poultry workers after exposure to poultry; only in these individuals could immediate wheal-and-flare reactions to poultry antigens be detected (p less than 0.001). The elapsed time between the initial poultry exposure and the onset of poultry house--related symptoms averaged 10 yr. In the symptomatic poultry workers, immediate skin test reactivity and RAST reactions were most frequently associated with NFM. The association between respiratory symptoms temporally related to poultry house exposure and the demonstrable IgE antibody-mediated reaction suggests a relationship between the two.     

An approach to fungal antigen relationships by radioallergosorbent test inhibition

Antigenic relationships among three species of Aspergillus (A. fumigatus, A. glaucus, and A. flavus) were examined by paired cross-radioallergosorbent test (RAST) inhibition analysis, an in vitro technique based on human IgE antibody specificity. Alternaria tenuis was found to be antigenically unrelated to each of the three species of Aspergillus and was used as a negative control. A single test serum yielded uninhibited RAST indices of 6, 7.4, 8.1, and 7.8 for A. fumigatus, A. glaucus, A. flavus, and Alternaria tenuis, respectively. At a concentration of 10 mg/ml, A. fumigatus inhibited A. glaucus RAST by 63% and A. flavus RAST by 62%. A. glaucus inhibited A. fumigatus RAST by 36% and A. flavus RAST by 63%. A. flavus inhibited A. fumigatus RAST by 44% and A. glaucus RAST by 81%. Each species of Aspergillus produced significant but only partial inhibition of RAST to each of the other two species analyzed. Results indicate the existence of both shared and unique antigens among these three species of Aspergillus. Paired cross-RAST inhibition may be used as an approach to study species relationships among genera of several classes of clinically relevant fungi. Unless many strains are employed, data obtained do not represent a definitive analysis of species, because of possible different degrees of inhibition by various strains of a particular species. They do, however, allow for the antigenic comparison of two or more crude, poorly characterized preparations thought to be important in human allergic disease.     

Widespread immunoglobulin E-mediated hypersensitivity in the Sudan to the “green nimitti” midge,Cladotanytarsus lewisi (diptera: Chironomidae): I. Diagnosis by radioallergosorbent test

A radioallergosorbent test (RAST) has been developed for the diagnosis of hypersensitivity to “green nimitti” chironomid midges of the species Cladotanytarsus lewisi. There was a high percentage binding of ¹²⁵I-anti-IgE to the allergen particle complex by serum from subjects who were clinically hypersensitive, and the RAST was inhibited following incubations of allergic sera with an extract of the allergen. In 104 hypersensitive subjects (i.e., those with a positive skin test or clinical history of bronchial asthma, with or without rhinitis) and 21 controls, the RAST appeared to be specific and of diagnostic value: (1) The percentage binding was appreciably higher in 38 symptomatic individuals (group I) with strongly positive skin tests as compared with 36 patients with moderate skin reactivity (group II). (2) Seven symptomatic subjects with negative skin tests (group III) had a positive (>6% binding) green nimitti RAST. (3) Positive RASTs were demonstrable in 16 and of 17 patients with positive skin tests in whom the history was equivocal (group IV). (4) Six asymptomatic individuals with positive skin tests (group V) had low RAST values. (5) Six asymptomatic Sudanese controls with negative skin tests gave similar values to those of the group V subjects. (6) All of the sera from 15 nonatopic United Kingdom controls gave less than 6% binding of ¹²⁵I-anti-IgE. There was no statistical correlation between the concentrations of total IgE and the green nimitti RAST values. These results suggest that the RAST may be useful diagnostic test in green nimitti hypersensitivity and may also be of value in studies on the epidemiology and in the monitoring of treatment of this important and widespread allergy problem in the Sudan.     

Castor Bean Allergy Among Workers in the Felt Industry

We describe occupational allergy to castor bean in workers in a felt manufacturing plant. Twenty-six (37%) of the workers complained they were affected by the felt and were examined by us. Of these, 12 were considered to have occupational allergy. These 12 subjects had raised specific IgE levels to both felt and castor bean extracts. In addition, three subjects without occupational allergy had raised specific IgE. The presence of castor bean allergens in the felt was suggested by the correlation between the RAST scores to the felt and castor bean and confirmed by RAST inhibition experiments. The RAST results correlated well with the results of skin prick tests to felt and castor bean extracts. In addition it was found that atopy did not predispose the workers to castor bean allergy.     

Allergic reactions, including asthma, to the pineapple protease bromelain following occupational exposure

A 58-year-old pharmaceutical worker regularly developed asthma and rhinitis when handling bromelain, a purified protease of pineapple (Ananas comosus), at her workplace, where she had been employed for about 10 years. RAST and prick test showed strong positive reactions to bromelain. Both inhalation test with 0.03 mg bromelain and peroral challenge by ingestion of 190 g pineapple resulted in asthmatic reactions; the latter challenge was accompanied by gastrointestinal symptoms. Five of six workers sensitized to papain, showed positive RAST and skin test results to bromelain, two of them also showed immediate asthmatic reactions after bronchial challenge with bromelain. Out of sixty asthmatics not exposed to airborne proteases but probably to these as constituents of foods, two had positive skin test results and eight had positive RAST results to bromelain; but in no case was there clear evidence for clinical sensitization. The presented data prove conclusively that bromelain is capable of inducing IgE mediated respiratory and gastrointestinal allergic reactions. Furthermore, there is evidence for immunological cross-reaction between the two plant proteases bromelain and papain in human subjects.     

The relationship of total serum IgE and blocking antibody in trimellitic anhydride-induced occupational asthma

Clinical and immunologic evaluations were performed on workers who manufacture trimellitic anhydride (TMA), a chemical used widely in the plastics industry. Serum samples of 29 workers exposed to TMA dust and fumes were assayed for total IgE, as well as specific IgE and total antibody binding to radiolabeled trimellityl human serum albumin (TM-HSA). Fifteen workers were determined to have significant specific IgE to TM-HSA (≥ I ng of ¹²⁵I-TM-HSA bound per milliliter). Of these 15 individuals, seven workers had immediate asthma and rhinitis and positive cutaneous prick tests and eight were nonasthmatic and skin test negative. Mean peak total serum IgE was significantly higher in the prick test positive group (p < 0.02) and higher than in 12 exposed asymptomatic IgE antibody-negative workers (p < 0.001). Total serum IgE followed rises and falls in TM-HSA-specific IgE binding, correlating to the onset of allergic symptoms in all seven workers. Total antibody binding of ¹²⁵I—TM-HSA, as determined by the ammonium sulfate precipitation technique, was higher in the skin test-negative group of eight (mean 12,062 ng per milliliter ¹²⁵I—TM-HSA bound) than in the seven symptomatic skin test-positive workers (mean 2930, p < 0.004). Determinations of total antibody divided by specific IgE (both in nanograms of ¹²⁵I-TM-HSA bound per milliliter) or blocking ratios clearly discriminated the seven skin test-positive workers with TMA-induced asthma (range 10 to 666) from the eight skin test-negative workers (range 1580 to 16,000). Thus total serum IgE, blocking ratios, and specific IgE to TM-HSA were found to be useful indices for serologic diagnosis of TMA-induced immediate asthma and rhinitis.     

IgE antibodies against piperazine and N-methyl-piperazine in two asthmatic subjects

The presence of specific IgE antibodies against conjugates between human serum albumin and piperazine, a compound previously known to cause occupational asthma, and N-methyl-piperazine, respectively, was demonstrated by RAST, RAST inhibition and skin prick tests in 2 asthmatic subjects occupationally exposed to these agents.     

Study on cockroach antigen as a probable causative agent in bronchial asthma

Bronchial provocative test (BPT) with cockroach (CR) antigen was performed in 22 asthmatic subjects. Sixteen had positive reaction (CR-positive) and 6 had negative reaction (CR-negative) to CR antigen by skin test. Immediate bronchoconstrictive response was noted following the antigen inhalation in 14 of 16 CR-positive asthmatics, while none of 6 CR-negative asthmatics showed bronchospasm. Late asthmatic responses also were noted in 13 of 16 CR-positive asthmatic individuals following BPT with CR antigen. The dual asthmatic reactions in CR-positive individuals were mostly inhibited by the prior administration of cromolyn sodium. Three-fold increases in peripheral eosinophil counts were noted 24 hr following BPT with CR antigen. Results indicate that CR-induced asthmatic responses are allergen-specific and CR plays a causative role in allergic asthma in the population studied.     

Detection of allergy to nuts by the radioallergosorbent test.

The diagnosis of food allergy is often difficult to make by conventional means. Histories are frequently ambiguous, and skin testing is of dubious reliability because of the number of false-positive and false-negative reactions. We have evaluated the radioallergosorbent test (RAST) for the in vitro measurement of the specific IgE antibodies to nuts, including Brazil nut, almond, walnut, pecan, cashew, and the legume, peanut. Serums were obtained from 18 patients with a history of nut allergy and IgE level and specific IgE antibodies were measured. Thirteen of the 18 patients had significantly elevated IgE antibody (greater than twice control) to one or more of the allergens. Prausnitz-Küstner tests on selected serums in general corroborated the results of the in vitro studies. Five patients had RAST elevations to 2 or more nuts. As a group RAST-positive patients had elevated mean serum IgE levels and more severe clinical symptoms (p less than 0.01). The specificity and cross-reactivity of IgE antibodies to different nut antigens was investigated by RAST inhibition with serums from 5 patients having high levels of IgE antibody. In 4 patients no cross-reactivity between Brazil nut and peanut was found. In contrast, several nut extracts inhibited the reaction of pecan allergen with IgE antibodies. These results indicate that specific IgE antibodies can be measured by RAST in patients with nut allergy and the cross-reactivity of nut antigens can be investigated. RAST would appear to be most useful in confirming the diagnosis of nut hypersensitivity in children or in highly allergic patients in whom skin testing poses a risk of anaphylaxis.     

Influence of IgG antibody and glycopeptide allergens on the correlation between the radioallergosorbent test (RAST) and skin testing or bronchial challenge with alternaria.

The radioallergosorbent test (RAST) for alternaria was compared to skin tests and bronchial challenges in children suffering from chronic intractable asthma. In contrast to when such children were tested with a timothy grass pollen extract, the bronchial challenge and skin test results against alternaria did not correlate significantly. When alternaria allergens were coupled to cyanogen bromide-activated microcrystalline cellulose, the RAST correlated with the results of skin testing but not bronchial challenge. It was demonstrated by column immunabsorption that some allergic sera contained sufficient IgG antibody against alternaria to competitively inhibit the RAST. When Sepharose 2B was substituted for cellulose as the insoluble support, the inhibition by IgG antibody was largely overcome and then the RAST correlated with both skin test and bronchial challenge results. Glycopeptides contribute significantly to the allergenicity of alternaria, and when these materials were coupled to a Sepharose 2B conjugate by mild oxidation, the RAST correlated with bronchial challenge, but not skin test, results. It was concluded that in this group of steroid-dependent asthmatic children, the correlation of the RAST with the in vivo challenges was strongly influenced by the presence of IgG antibody in the allergic sera and the chemical nature of the mould allergens investigated.     

The comparison of allergic responses to Dermatophagoides farinae between bronchial asthma and allergic rhinitis

The allergic responses of 52 bronchial asthma patients who exhibited a positive bronchoprovocation test with house dust and 50 allergic rhinitis patients who had positive RAST results to Dermatophagoides farinae (D. farinae) were studied, including the measurement of D. farinae-specific IgE using D. farinae-RAST, total IgE and skin reactivity to D. farinae and house dust. A comparison between the allergic rhinitis group in which methacholine PC20 was more than 4.66 mg/mL and the allergic rhinitis group which presented negative results in the methacholine bronchial challenge test, indicated that there were significant differences in skin test reactivity and the ratio of specific IgE to total IgE (P less than .05). The allergic responses we observed were not different between the allergic rhinitis group in which methacholine PC20 was less than 4.66 mg/mL (asthmatic range of methacholine PC20) and the allergic rhinitis group in which methacholine PC20 was more than 4.66 mg/mL. When comparing the bronchial asthma group which showed positive results in D. farinae-RAST and the allergic rhinitis group in which methacholine PC20 was less than 4.66 mg/mL, significant differences were noted in total IgE level (P less than .05). These findings suggest that the development of bronchial asthma in patients with allergic rhinitis might be predicted by measuring the degree of bronchial hyperreactivity and their allergic responses.     

Inhibition Experiments with Solid Phase Mite or Epithelia in House Dust Hypersensitivity

The present study was undertaken to verify that mites are not the only allergens in house dust extracts and that other allergens such as cat epithelia can also be responsible for house dust hypersensitivities detected both by house dust skin tests and house dust RAST studies. In order to determine whether mite or epithelia fixed on a solid phase could remove not only the IgE antibodies reactive with the homologous allergens, but also the IgE antibodies reactive with house dust allergens, the authors have absorbed 10 sera of house dust allergic patients with solid phase mite or epithelia. The absorption procedure removed a large part of the IgE antibodies reactive with specific immunosorbent (Dermatophagoides pteronyssinus or cat epithelia) and in the same way the IgE antibodies reactive with house dust immunosorbent. The percentage of RAST inhibition varied from 65% to 92% for Dermatophagoides pteronyssinus and from 65% to 94% for house dust in patients allergic to house dust and mite; the percentage of RAST inhibition varied from 67% to 92% for cat epithelia and from 73% to 90% for house dust in patients allergic to house dust and cat epithelia. This is in accordance with the hypothesis that house dust is not an allergen per se, but rather a complex mosaic of several allergens including mite, animal epithelia, etc.     

Specific IgE antibodies to nickel in workers with known reactivity to cobalt

Twenty-one workers with hard metal asthma, including eight atopics, diagnosed on the basis of peak flow diaries and positive reaction to cobalt chloride (CoCl2) and/or nickel sulphate (NiSO4) in skin and provocation tests were studied for sensitization by detection of specific antibodies to nickel-conjugated human serum albumin (Ni-HSA), and nickel-conjugated exchange resin (Ni-resin). Their results were compared with those of sera obtained from control sera from 60 asthmatic patients and pair-matched asymptomatic control workers in the hard metal plant. In the RASTs (radioallergosorbent tests), sera from the same six subjects developed positive reactions both to Ni-HSA (RAST index greater than 2.0, P less than 0.01) and Ni-resin (RAST index greater than 2.0, P less than 0.01), while the counts measured for the others of the 15 subjects (RAST index less than 1.52) were about the same as those for control groups (RAST index less than 1.58). Subject HSA RAST and resin RAST results (378 +/- 52 c.p.m. in HSA RAST and 324 +/- 56 in the resin RAST) were about the same as those of the control sera (388 +/- 65 c.p.m. and 398 +/- 59 c.p.m., respectively). There was no difference in the prevalence of smoking habit and high IgE between Ni-RAST positive and negative subjects. However, subjects with simultaneous sensitivity to nickel and/or cobalt still developed asthmatic attacks following medications, while those without sensitivity to these metals were almost symptom free. The positive sera had simultaneous sensitivity to both cobalt and nickel, suggesting the presence in them of specific IgE antibodies to nickel playing some role in the aetiology of hard metal asthma.