Occupational allergy in greenhouse workers: sensitization to Tetranychus urticae

Background Tetranychus urticae (TU) is a macroscopic mite which is found infesting a large number of plants of economic interest. It has rarely been described as a cause of occupational allergic disease in agricultural workers. Objective To describe TU sensitization in greenhouse workers attending the outpatient allergy unit and its clinical associations, and to characterize the allergens involved. Materials and methods Twenty-four consecutive carnation greenhouse workers with allergy-related symptoms, referred to our outpatient clinic during a 6-month period, were included. We made the diagnostic extract from carnation leaves heavily infested with TU. Skin-prick test, specific IgE measurement and bronchial provocation test with TU extract were carried out in all subjects. Allergen characterization was achieved by SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis) and immunoblotting Results Sixteen patients (66%) presented positive skin-prick test and specific IgE and were diagnosed allergic to TU. Fifteen patients suffered from bronchial asthma, 14 rhinitis and five urticaria. Twelve exibited positive bronchial provocation test to the TU extract. On RAST-inhibition studies, there was no evidence of crossreactivity between TU extract and D. pteronyssinus. An allergen at 19 kDa was determined in the TU extract by SDS-PAGE immunoblotting studies. Conclusion TU could be an important occupational allergen in greenhouse workers showing allergic symptomatology. There is no crossreactivity between this mite and the house dust mite D. pteronyssinus.     

Occupational allergy due to spider mites: Tetranychus urticae (Koch) and Panonychus citri (Koch)

Background Allergy to both house dust and storage mites is well established, but information about other species of mites is seant. Objective One hundred and fifty patients directly exposed to an occupational environment were studied to assess whether spider mites (Tetranychidue) caused their allergic symptoms. We also studied a group of 50 patients from an urban environment, who were not occupationally exposed to spider mites, with a strong sensitization to Dermatophagoides pteronyssinus (RAST class 4). Methods Case history (including questions about work-related symptoms), skin tests, RAST and conjunctival provocation tests were performed in both groups using Tetranychus urticae and Panonychus citri extracts as allergens. Cross-reactivity between spider mites and D. Pteronyssinus was determined by RAST inhibition. Results Fifty-four of 150 rural workers were positive to Tetranychidae and in all cases there was an associated sensitization to D. pteronyssinus. All individuals belonging to the urban group were positive to spider mites. RAST inhibition demonstrated a significant cross-reactivity between Tetranychidae and D. pteronyssinus. Five of fifty-four rural workers sensitized to spider mites developed symptoms only when they handled plants or fruits infested with spider mites and they became asymptomatic when exposure ceased. Conclusion In the rural population studied. 36% of workers were found to be sensitized to spider mites and 10% had symptoms associated with occupational exposure. Since specific IgE antibodies to spider mites could not be detected in the absence of the specific IgE antibodies to D. pteronyssinus, and as all the affected workers were RAST positive to D. pteronyssinus, prior sensitization to house dust mites may be a risk factor for occupational allergy to spider miles.     

Prevalence of sensitization to Tetranychus urticae in greenhouse workers

BACKGROUND: Tetranychus urticae (TU) is a macroscopic mite which infests a large number of plants of economic interest worldwide. It has recently been described as a cause of occupational allergic disease in greenhouse workers. However, there are no epidemiological data concerning the prevalence of TU allergy in an unselected exposed population. OBJECTIVE: The aims were to study the prevalence of TU sensitization among greenhouse workers and its relationship to the working environment and to personal factors. METHODS: We studied 246 consecutive greenhouse workers, recruited directly from the field. A clinical and epidemiological questionnaire, a skin-prick test (SPT) to TU and common allergens and TU-specific IgE (RAST) determinations were performed. Seventy-five healthy volunteers and 152 atopic patients were used as a control group. RESULTS: The prevalence of a positive SPT to TU was of 25%. Forty-five workers (19%) were TU-allergic, occurring more often in atopic greenhouse workers (P < 0.0001). Seven per cent showed asymptomatic sensitization. The time of exposure to TU was significantly greater in the TU-allergic patients (P < 0.05). The probability of sensitization to TU was 3.7 times greater in exposed than in non-exposed subjects (P < 0.0001). CONCLUSIONS: In this study, the prevalence of TU sensitization was 25%. There were significant associations with TU allergy and atopy and the time of exposure to TU.     

Relationship between total and allergen-specific IgE serum levels and presence of symptoms in farm workers sensitized to Tetranychus urticae

BACKGROUND: Clinical complaints in atopic subjects with asthma and rhinitis occur more frequently in the presence of high total and allergen-specific IgE serum levels. Here we report on the relationship between total and allergen-specific IgE serum levels and presence of symptoms in an unselected farmer population sensitized to Tetranychus urticae (TU). METHODS: Farmers were recruited as previously described. Total IgE and allergen-specific IgE were measured by immunoassay in TU-positive skin prick test (SPT) farmers (n = 58) and two control groups including Dermatophagoides pteronyssinus (Dp)-positive SPT subjects (n = 40) and non-atopic, TU-negative SPT healthy farmers (n = 25). RESULTS: Both TU+ and Dp+ subjects had significantly higher total IgE values (P < 0.001) than healthy non-atopic subjects. TU-specific IgE levels were significantly more elevated in symptomatic than non-symptomatic TU+ subjects (P = 0.028). Dp-specific IgE levels were higher in symptomatic than non-symptomatic Dp+ subjects (P = 0.003). Finally, total IgE levels were significantly higher in the symptomatic than non-symptomatic subgroups in both TU+ and Dp+ subjects (P < 0.0001 and P = 0.007, respectively). Logistic regression analysis showed that only total IgE concentrations were significant predictors of current symptoms in TU+ subjects. CONCLUSIONS: High total IgE and allergen-specific IgE levels are associated with symptoms in TU+ subjects. Definition of their predictive value requires further studies.     

IgE-sensitization to predatory mites and respiratory symptoms in Swedish greenhouse workers

BACKGROUND: Predatory mites are used as biological pesticides worldwide for control of spider mites and other pests in greenhouses. The aim of this study was to evaluate the impact of occupational exposure to Phytoseiulus persimilis and Hypoaspis miles on IgE sensitization among a large group of Swedish greenhouse workers and to examine the relationship between exposure and allergic asthma and rhinoconjunctivitis. METHODS: A total of 96 greenhouse workers from the southern part of Sweden, who were using the predatory mites for control of pests, were investigated with a questionnaire and a medical examination including lung function test. Blood samples were taken to test for allergen-specific IgE antibodies to Phytoseiulus persimilis and Hypoaspis miles as well as to Tetranychus urticae, Dermatophagoides pteronyssinus/farinae and Tyrophagus putrescentiae. RESULTS: Seventeen of the 96 workers were positive in ImmunoCAP to predatory mites: 17 to P. persimilis (17.7%) and 14 to H. miles (14.6%). Subjects sensitized to predatory mites were significantly more often atopic (13/17), defined as a positive Phadiatop, than those who lacked IgE against these mite species (17/79) (P <0.01). IgE antibodies to the red spider mite T. urticae were present among 23 subjects. Thirty-five of the investigated subjects displayed a positive ImmunoCAP to at least one of the investigated mite species. Furthermore, sensitization to any of the mites tested was significantly associated with asthma (OR=9.3) and rhinoconjunctivitis (OR=4.3). CONCLUSIONS: IgE sensitization to predatory mites, P. persimilis and H. miles, is common among greenhouse workers. The findings stress the importance of improved allergen avoidance in greenhouse environments.     

IgE binding components in Tetranychus urticae and Panonychus ulmi-derived crude extracts and their cross-reactivity with domestic mites

BACKGROUND: Recent investigation has revealed that spider mites such as Tetranychus urticae and Panonychus ulmi are important allergens in the development of occupational asthma among apple farmers. OBJECTIVE: To evaluate IgE binding components in T. urticae and P. ulmi-derived crude extracts and their cross-reactivity with Panonychus citri, Tyrophagus putrescentiae and Dermatophagoides pteronyssinus in apple cultivating farmers. METHODS: Thirty-one apple farmers with positive skin responses to T. urticae or P. ulmi were randomly recruited, and specific IgE levels in their sera were measured using ELISA. Cross-reactivity was evaluated by ELISA inhibition. IgE binding components were evaluated by IgE immunoblotting. RESULTS: A total of 11 IgE binding components in T. urticae and 10 in P. ulmi were found. Among them, the 17 kDa, 27 kDa, 33 kDa, 37 kDa, 41 kDa, 56 kDa, and 75 kDa allergens in T. urticae, and the 33 kDa, 41 kDa, and 51 kDa allergens in P. ulmi were identified as dominant allergens. T. urticae-specific IgE binding was completely inhibited by 100 microg/mL of T. urticae (99.7%), but only partially inhibited by P. citri (83.0%), P. ulmi (71.6%), T. putrescentiae (69.7%), and D. pternonyssinus (60.1%). P. ulmi-specific IgE binding was completely inhibited by additions of P. citri (92.3%) and P. ulmi (91.2%), but only partially inhibited by the addition of T. urticae (61.5%), T. putrescentiae (57.7%), and D. pteronyssinus (54.4%). CONCLUSION: There were seven dominant allergens found in T. urticae and three in P. ulmi. T. urticae- and P. ulmi-specific IgE bindings were partially inhibited by crude extracts derived from D. pteronyssinus and T. putrescentiae.     

IgE-mediated sensitization to predatory mites in Swedish greenhouse workers

BACKGROUND: Predatory mites are used as biological pesticides worldwide for control of spider mites and other pests in greenhouses. The aim of this study was to investigate if predatory and spider mites give rise to sensitization among greenhouse workers who use biological pesticides. METHODS: Blood samples were collected from 31 greenhouse workers from Stockholm area who were using the predatory mites Phytoseiulus persimilis and Hypoaspis miles for control of pesticides. Immunoglobulin E (IgE) binding to extracts of P. persimilis and H. miles and of the spider mite Tetranychus urticae was analysed with sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. RESULTS: A total of 16 workers displayed IgE antibodies to one or more of the three mite species, 32% (n = 10) to P. persimilis, 52% (n = 16) to H. miles and 26% (n = 8) to T. urticae. At least 17 IgE binding components in the molecular weight ranging from 28 to >94 kDa were identified in P. persimilis. In H. miles, at least 11 components were detected, among them at least one major component at about 70 kDa. Twenty-four IgE binding components were found in T. urticae. CONCLUSIONS: In this study we have for the first time shown that the predatory mites P. persimilis and H. miles can cause IgE-mediated sensitization among greenhouse workers. The clinical relevance of sensitization to predatory mites needs to be investigated in further studies.     

Spider mite allergy in apple-cultivating farmers: European red mite (Panonychus ulmi) and two-spotted spider mite (Tetranychus urticae) may be important allergens in the development of work-related asthma and rhinitis symptoms

BACKGROUND: Recent investigations have suggested that the citrus red mite (Panonychus citri) is the most important allergen affecting citrus-cultivating farmers with asthma, allergic rhinitis, or both. OBJECTIVE: We sought to evaluate type I hypersensitivity to spider mites, particularly the European red mite (Panonychus ulmi) and the two-spotted spider mite (Tetranychus urticae), and to determine the relationship between hypersensitivity to spider mites and respiratory dysfunction. METHODS: We performed a cross-sectional survey. Questionnaires were given, and skin prick tests for 11 inhalant allergens common in Korea and 2 species of spider mites (European red mite and two-spotted spider mite) were performed in 725 apple-cultivating farmers in Korea. RESULTS: Results of skin prick tests in the apple farmers indicated that European red mite (23.2%) was the most common sensitizing allergen, followed by Tyrophagus putrescentiae (21.2%), two-spotted spider mite (16.6%), Dermatophagoides farinae (16.3%), D pteronyssinus (14.4%), cockroach (13.1%), and Hop Japanese (Humulus Japonicus) pollen (12.0%). Positive skin responses (mean wheal size >/=3 mm) to one or more of 13 inhalant allergens were found in 48.2% of farmers tested, whereas 40 subjects (8.6%) had an isolated skin response to the spider mites. Among 119 farmers with work-related asthmatic symptoms, the positive skin response rates to European red mite and two-spotted spider mite were 40.4% and 27.0%, respectively. These figures were significantly higher than those found among farmers without work-related symptoms (19.1% and 14.1%, respectively; P <.01). The prevalence of work-related asthma symptoms was higher in farmers with positive skin responses to spider mites than in those with negative skin responses to spider mites and those with positive skin responses to any allergen tested (31.4% vs 15.0% vs 21.0%, respectively; P <.05). CONCLUSION: Spider mites, particularly European red mite and 2-spotted spider mite, are common sensitizing allergens in apple-cultivating farmers. These spider mites may be important causative allergens in the development of work-related respiratory symptoms in these workers.     

Hypersensitivity to Apple and Carrot Can Be Reliably Detected with Fresh Material

Hypersensitivity to birch pollen was linked with allergy to apple and carrot, apple seeds and carrot seeds and also with their fractions, Skin reactions among other atopics were rare, and non-atopic patient; showed no reactions to fresh fruits and vegetables.
Apple and carrot as well as apple seeds and carrot seeds were fractionated using column chromatography. Two major fractions were obtained, one with sugar and proteins, and one with proteins, the tatter giving skin reactions more often than the former. The correlation between clinical symptoms and skin lest results with the fractionated material was somewhat lower than that obtained with the non-fractionated fresh material. The allergens of fruits and vegetables might be proteins (enzymes).     

Occupational allergy caused by Dianthus caryophillus, Gypsophila paniculata, and Lilium longiflorum

Background Occupational allergy to ornamental flowers is seldom reported. Methods We report a case of a 35-year-old male flower supplier who developed IgE-mediated allergic rhinoconjunctivitis with nasal polyps, and contact urticaria and dermatitis after handling Gypsophila paniculata, Dianthus caryophiUtis. and Lilium longiflortim .
Results Studies revealed the presence of positive immediate skin prick tests. Rubbing tests were positive to G. paniculata and D. caryophillus . Serum specific IgE was detected against G. paniculata and L. longiflorum . In IgE immunoblot, two IgE-binding bands (15 and 17 kDa) were obtained against D. caryophillus, and two different bands (19 and 22 kDa) were visible against L. longiflorttm .
Conclusions TTiese findings suggest an IgE-mediated reaction as the mechanism responsible for the respiratory and cutaneous symptoms of the patient. No similar eases of allergy to D. caryophillus and L. longiflorum have been previously reported.     

Diversity of asparagus allergy: clinical and immunological features

BACKGROUND: Asparagus (Asparagus officinalis) is an extensively grown and consumed vegetable. To a lesser extent than other Liliaceae vegetables, allergic contact dermatitis (ACD) due to asparagus has been reported. However, only a few case reports of asparagus IgE-mediated allergy have been published. In a previous study, we demonstrated that two lipid transfer proteins (LTPs) (Aspa o 1.01 and Aspa o 1.02) were relevant allergens of asparagus. OBJECTIVE: We retrospectively analysed the 27 patients diagnosed with asparagus allergy during the last 5 years. All of them reported adverse symptoms after either asparagus ingestion or handling. We describe their clinical features and evaluate whether they were associated to immunological findings (immunoblot pattern and skin reactivity to LTPs). METHODS: Patients underwent skin prick and patch tests with standard panels of vegetables and aeroallergens. Besides crude asparagus extract, two purified LTPs were prick and patch tested. Total and specific IgE measurements and asparagus extract IgE immunoblotting were performed. Patients reporting asthma symptoms underwent specific inhalation challenge to asparagus. RESULTS: Of the 27 subjects, eight had ACD, 17 had IgE-mediated allergy and two had both ACD- and IgE-mediated allergy. Positive patch tests with the crude asparagus extract but not with LTPs were observed in subjects with ACD (n=10). Of 19 patients with IgE-mediated disease, 10 had contact urticaria after asparagus handling. Of them, five subjects and five others without skin allergy showed respiratory symptoms; of them, eight were diagnosed with occupational asthma confirmed by positive asparagus inhalation challenge, whereas the remaining two had isolated rhinitis. Four patients suffered from immediate allergic reactions related to asparagus ingestion (food allergy); three of them reported anaphylaxis whereas the other had oral allergic syndrome. Positive IgE immunoblotting (bands of 15 and 45-70 kDa) was observed in 10 subjects. Of 10 subjects with positive prick test to LTPs, six showed bands at 15 kDa. Either IgE-binding bands or positive prick tests to LTPs were observed in asthma (62%) and anaphylaxis (67%). CONCLUSION: Asparagus is a relevant source of occupational allergy inducing ACD and also IgE-mediated reactions. Severe disease (anaphylaxis or asthma) is common and LTPs seem to play a major role. The clinical relevance of LTP sensitization among patients with mild disease or symptom-free subjects should be addressed in prospective studies.     

Comparison of immunologic tests in the diagnosis of occupational asthma and rhinitis

In this study, three immunologic tests, skin prick test, RAST, and basophil histamine-release test (BHRT), were compared by provocation in the diagnosis of occupational asthma and rhinitis. Twenty-three positive bronchial or nasal challenges were performed on 16 patients (six farmers, six bakery workers, and four food industry workers) and asthma or rhinitis was diagnosed as caused by cereal flour or grain, cow epithelium, storage mites, garlic, or soy dust. A control group consisted of 12 patients, of whom four (two bakery workers, one food industry worker, and one farmer) were challenge-negative, and the rest suffered from pollen allergy and seasonal rhinitis and were not challenged. The sensitivity and specificity of the prick test, RAST, BHRT, and a panel of them were as follows: 74 and 89%, 57 and 86%, 78 and 93%, and 91 and 71%, respectively. The overall concordance among these three type I allergy tests or between immunologic tests and challenge was relatively good.     

Multiple IgE-mediated sensitizations to enzymes after occupational exposure: evaluation by skin prick test, RAST, and immunoblot

We investigated 10 sensitized and 10 nonsensitized workers from a pharmaceutic factory who had been exposed to powdered trypsin, chymotrypsin, bromclain, papain, amylase, and lipase. Ten nonallergic subjects served as a control group. Titrated skin prick tests (SPT), RAST, and immunoblot studies were performed with all six enzymes. SPT reactivity revealed multiple sensitizations to proteolytic enzymes, i.e., papain (specifically sensitized/total number of sensitizations: 9/10), trypsin (8/10), chymotrypsin (8/10), and bromelain (7/10) and appeared to be more frequent and more pronounced than sensitizations to amylase (3/10) or lipase (3/10). The low molecular weight of proteolytic enzymes (20–30 kDa) and their biologic activity might facilitate mucosal penetration more easily and thus - compared to amylase and lipase - permit an immune response and induction of allergic hypersensitivity. Immunoblot studies demonstrated IgG-binding bands in both SPT-positive and -negative workers, indicating exposure to the enzymes, but not in 10 unexposed control subjects. IgE-binding bands of the enzymes were detected only in workers with a positive SPT reaction and/or a positive RAST result. IgG bands were more frequent and the IgG/IgE ratio was increased in workers without allergic complaints compared to symptomatic workers. This might indicate that high levels of specific IgG antibodies to enzymes arc associated with an immune response lacking allergic manifestations in spite of IgE-mediated sensitizations to the enzymes. Atopic subjects were at greater risk of developing IgE-mediated sensitization (7/10) and allergic symptoms to enzymes (5/7). However, even without risk of atopy, IgE-mediated hypersensitivity occurred in a few subjects (3/13) exposed to enzymes by inhalation for prolonged periods of time.     

Insect venom allergy: a prospective case study showing lack of correlation between immunologic reactivity and clinical sensitivity

This case report demonstrates the lack of correlation between clinical sensitivity to insect venoms and immunologic reactivity as indicated by the presence of venom-specific IgE. A 20-yr-old venom collector was monitored over a 3-yr period with measurements of venom-specific IgE (skin test and RAST) and venom-specific IgG. In the first year of venom collection, multiple stings were tolerated with no reaction. In the second season, she had an anaphylactic reaction after a yellow jacket sting. Subsequently, there was a rising titer of serum yellow jacket and bee venom-specific IgE and positive skin-test reactions. In the third season, yellow jacket, hornet, and bee venom skin tests remained positive and serum IgE antibody titers remained elevated. Stings from all three insects were tolerated with no reaction. Throughout the 3-yr course, serum venom-specific IgG remained low and unchanged. The factors other than IgE-modulating clinical anaphylaxis, perhaps responsible for this clinical and immunologic dichotomy, are unknown. These observations add a further complication to the choice of patients for venom immunotherapy.     

Prospective study of laboratory-animal allergy: factors predisposing to sensitization and development of allergic symptoms

In a prospective study of laboratory technicians, selected indicators of allergy and atopy were studied in an attempt to determine predictors of laboratory-animal allergy (LAA). Laboratory technicians underwent spirometry, methacholine provocation tests, and blood sampling, and responded to a questionnaire during training and after 2 years' work. Among 38 laboratory-animal-exposed subjects, total IgE before exposure gave the best correlation ( P < 0.01; Mann-Whitney U-test) to reported symptoms caused by laboratory animals ( n = 8) at follow-up. The prevalence of atopy and allergic symptoms had increased in exposed technicians at follow-up, but this was also found among unexposed matched referents ( n = 36 pairs). One subject in the exposed group reported asthma before exposure, compared with seven at follow-up ( P < 0.05; Fisher's exact test). However, the prevalence of asthma had increased from two to six (not significant) also among unexposed technicians. There were no significant differences between the groups in any measured variable at follow-up. Among 43 subjects who later worked with laboratory animals, 21%, had a positive skin prick test for common allergens, as compared with 37% among 112 without animal exposure P = 0.06; x² test), suggesting selection for laboratory animal work.