Identification of a polygalacturonase (Cup s 2) as the major CCD-bearing allergen in Cupressus sempervirens pollen.

As IgE glyco-epitopes, also referred to as cross-reactive carbohydrate determinants (CCDs), can share significant structural homologies between different plants, they are prone to extensive cross-reactivity among allergen pollen extracts. Here, cypress pollen allergens, especially a polygalacturonase (PG), were further characterized using double one-dimensional electrophoresis (D1-DE). The presence of specific IgE directed against CCDs was investigated by bromelain IgE inhibition and concanavalin A binding assays using sera of cypress pollen-sensitized patients. Our results showed that IgE reactivity to CCDs in Cupressus sempervirens pollen extracts is mainly related to bromelain-type epitopes of a newly identified cypress PG. This glycoprotein has been further characterized through an immunoproteomic approach and officially indexed as Cup s 2 by the WHO/IUIS allergen nomenclature. Cup s 2 could thus be associated with the increased prevalence of IgE reactivity to cypress pollen extracts because of CCD interference.

Asthma among workers in healthcare settings: role of disinfection with quaternary ammonium compounds.

INTRODUCTION: An increased incidence of asthma has been reported among healthcare workers. The role of quaternary ammonium compounds (QACs), commonly used in cleaning/disinfection products, has not been clearly defined. The aim of this study was to analyse associations between asthma and occupational exposure to disinfectants, especially QACs. METHODS: The study was performed on a stratified random sample of the various healthcare departments of 7 healthcare settings. The study included: questionnaire, physical examination and specific IgE assays. Occupational exposure assessment was performed by means of a work questionnaire, workplace studies and a review of products ingredients. Data were analysed by logistic regression. RESULTS: Response rate was 77%; 543 workers (89% female) participated; 37.1% were registered nurses (RNs), 16.4% auxiliary nurses (ANs), 17.3% cleaners; 32.8% were atopic. 335 participants were exposed to QACs. Nursing professionals reported a significantly higher risk of reported physician-diagnosed asthma and, for RNs, of nasal symptoms at work than administrative staff working in healthcare sector. This risk was particularly marked during disinfection tasks and when exposure to QACs. Exposure to QACs increased significantly the risk of reported physician-diagnosed asthma and nasal symptoms at work (adjusted OR = 7.5 and 3.2, respectively). No significant association was found with other exposures such as latex glove use, chlorinated products/bleach or glutaraldehyde. CONCLUSION: RNs and ANs presented a higher risk of reported asthma than administrative staff. The highest risk was associated with tasks involving dilution of disinfection products by manual mixing, suggesting possible exposure to repeated peaks of concentrated products known to be strong respiratory irritants. Workplace interventions should be conducted to more clearly determine QAC exposure and improve disinfection procedures.

Ragweed pollen in France: origin, diffusion, exposure.

PURPOSE OF THE STUDY: To detect the origin of ragweed pollen and to measure the impact of this pollen exposure on allergic patients, so their sensitivity can be noted (using specific IgE production: sIgEw1) in order to inform the population about an "allergy" against those ragweed pollen grains. MATERIAL AND METHODS: To measure population exposure to ragweed pollen, the R.N.S.A (National Aerobiological Monitoring Network, a French association) has a pollen trap network located in urban areas. These traps allow continuous recording of airborne pollen, the light microscope analysis (with a bi-hourly time step) allows one to know the daily concentrations of ragweed grains and the circadian rhythm of grains impaction. It is thus possible to follow the evolution of pollination during each day ofeach season and to compare seasons and years at each station. Biomnis is a biological laboratory which performs more than 85% of ragweed specific IgE assay in France. It seems to be clear that when allergists ask ragweed IgE for a patient, it is because they think that this patient seems to be allergic to this specific pollen. The statistical analysis of results about specific IgE (for ragweed) from the Allergology laboratories Biomnis (located in Lyon and Paris) can determine the number ofpatients sensitized to ragweed in French departments. RESULTS: The distribution ofsensitized patients to ragweed is compared to ragweed pollen distribution studied by the R.N.S.A from the year 2005 to 2008 in France, whatever the ragweed plant' origin: local (closed topollen trap) or imported (by wind). CONCLUSION: The biological database (Health impact) allows a correlation between the geographical distribution ofragweed pollen and the number ofpatients with specific IgE against ragweed (sIgEw1), i.e., whose sensitization is due to local plants. That also permits one to estimate the expected number of allergy cases in the next years, because the sensitivity precedes the allergy.

Peanut allergy diagnosis in the context of grass pollen sensitization for 125 patients: roles of peanut and cross-reactive carbohydrate determinants specific IgE.

BACKGROUND: In vitro testing for food allergy may yield clinically irrelevant results due to cross-reactive carbohydrate determinants (CCD) specific immunoglobulin E (sIgE) induced by pollen exposure. The performances of 2 in vitro methods were evaluated for peanut sIgE measurement in patients allergic to grass pollen with or without subsequent allergy to peanuts. The correlation between clinically irrelevant peanut sIgE and the presence of CCD sIgE was investigated. METHODS: In vitro measurement of peanut sIgE was performed using the Pharmacia ImmunoCap system Radio Immuno Assay (RIA) and the Immulite 2000 3gAllergy system. Discrepancies between in vitro results and peanut allergy diagnosis were evaluated by measurement of CCD sIgE using bromelain and ascorbic acid oxydase (AAO). RESULTS: The sensitivity was 100% with both systems for the diagnosis of allergy to peanut (58 patients), nevertheless the specificity obtained with Immulite (73%) was better than that obtained using ImmunoCap (46%) in patients who were not allergic to peanuts, but who had a grass pollen allergy (n = 41). In 22 out of 41 patients who presented clinically irrelevant peanut sIgE results using ImmunoCAP, CCD sIgE was detected in 72% of the cases by bromelain and in 86% by AAO. In 11 patients out of 41 who presented irrelevant peanut sIgE results using Immulite, CCD sIgE was detected in 81% of the cases by bromelain and in 100% by AAO. CONCLUSION: The Immulite 2000 system had better specificity than the ImmunoCap system for accurate diagnosis of peanut allergy in patients allergic to grass pollen. CCD sIgE was identified in most of the false-positive peanut sIgE results.

Systematic follow-up increases incidence of anaphylaxis during adverse reactions in anesthetized patients.

BACKGROUND: The incidence of hypersensitivity reactions during anesthesia is underestimated because clinical symptoms may vary and diagnosis is not obvious. Our aim was to investigate the consequences of a systematic follow-up of patients on the estimated incidence of allergic reactions during anesthesia. METHODS: We conducted a prospective study over a 2-year period (70,000 anesthesias). When patients were suspected with hypersensitivity reactions or with unexplained adverse reactions during anesthesia, blood was sampled to measure histamine and tryptase, and then skin tests were performed 4-6 weeks later. RESULTS: During the studied period, 39 patients were enrolled in the database. Eight were excluded because of lack of skin tests. Twenty-two patients had clinical features compatible with immediate hypersensitivity reaction, and nine had reactions rated as 'unexplained' by the attending physician. Following systematic investigation, we found 22 hypersensitivity reactions (15 patients with obvious and seven with unexplained reactions) during anesthesia. This increases the estimated incidence of hypersensitivity reactions from 1 : 4667 to 1 : 3180 anesthesias. Tryptase concentrations were increased in only 50% of these patients. In our series, positive and negative predictive values of tryptase at T(0) for the diagnosis of anaphylaxis were 100% and 60%, respectively. Latex was the major causative agent, followed by neuromuscular blocking agents and antibiotics. CONCLUSIONS: Systematic follow-up of patients with unexplained reactions during anesthesia increases the estimated incidence of IgE-mediated hypersensitivity reactions during anesthesia by 50%.

Blotting methods applied to investigations of the mitogenic activity of phytohaemagglutinin (PHA).

PHA polypeptides were separated by SDS-polyacrylamide gel electrophoresis and transferred to nitrocellulose filters which were then cut into identical discs and used to perform blastogenic stimulation on cultured human peripheral blood lymphocytes. This method offers the following advantages: the high resolution of SDS-polyacrylamide gel electrophoresis, the sensitive immunochemical identification of the polypeptides involved in the mitogenic responses of lymphocytes, the determination in the same experiment of the molecular weight, antigenicity and biological activities of the proteins.

Flow cytometry versus histamine release analysis of in vitro basophil degranulation in allergy to Hymenoptera venom.

BACKGROUND: Flow cytometry (FCM) has been proposed for specific allergy in vitro testing. We investigated its biological significance for allergy to Hymenoptera venoms and compared it with the routinely performed basophil histamine release test (HRT). METHODS: Blood samples from 26 allergic and 8 nonallergic donors were incubated with venom at serial concentrations. Basophils were analyzed with anti-CD45-PE-Cyanin 5, Anti-IgE-FITC, and Anti-CD63-Phycoerythrine. HRT was measured by radioimmunoassay. RESULTS: FCM was as convenient as HRT for measuring basophil reactivity in at least 87% of allergic and 75% of nonallergic subjects. CD63 outer expression was specifically induced in 91% of releaser subjects (86% on HRT) and in 1 of 10 tests in nonallergic donors, or one of six tests (16% on HRT) in allergic patients tested with an irrelevant allergen. Both methods were concordant in 85.7% of the tests. The three discordant patients had low-grade reactions and borderline biological responses on FCM (n = 2) or HRT (n = 1). CONCLUSIONS: The dynamic, physiologic significance of CD63, the dose-response curve, and dependency on ethylene-diaminetetra acetic acid suggested that both tests reflect the same mechanism.

Anaphylactic shock induced by gadoterate meglumine (DOTAREM).

The use of contrast agent for magnetic resonance imaging improves the effectiveness of this diagnostic examination. Complexes of godolinium, which appear to be well tolerated, are used for this purpose. A few cases of anaphylactic shock have been attributed to these agents. We report a case of anaphylactic shock due to gadoterate meglumine (DOTAREM). While undergoing a magnetic resonance imaging examination, a 33-year-old nonatopic female patient became severely hypotensive, lost consciousness, and had generalized erythema immediately after the intravenous injection of this product. She recovered rapidly after she was given injection of epinephrine and her blood volume was restored with intravenous fluids. That DOTAREM had caused this immediate hypersensitivity reaction was proven by the positivity of prick-test and intradermal test at 10-3 (0.37 mg/ml) and in vitro leukocyte histamine release test. The results of these tests indicated that it was the gadoteric acid rather than the meglumine component of DOTAREM that was responsible: positivity of IDR at 10 mg/ml. Skin tests and leukocyte histamine release test to gadopentetate dimeglumine (MAGNEVIST) were negative. In addition of the exceptional character, this observation provides evidence for an immediate hypersensitivity without cross reactivity with gadopentetate dimeglumine.

[Specific IgG and immunotherapy]. / IgG spécifiques et immunothérapie.

The authors discuss about the functions and the evolution of total specific IgG antibodies and specific antibodies of the IgG1 and IgG4 isotype during desensitization treatment.

Histamine release assay and radioimmunoassay for the detection of IgE antibodies against neuromuscular blocking drugs.

It is well established that muscle-relaxant drugs may be responsible for anaphylactoid reactions during anaesthesia. In the present work we evaluated in 41 patients who had experienced anaphylactoid reactions during general anesthesia, the value of different radioimmunoassays (RIAs) and of an histamine release assay (HRA). The RIA was performed with different solid phases as PAPPC (para amino phenyl phosphoryl choline), morphine, TMA (trimethylamine) and TEA (triethylamine). The results were expressed as the percentage of 125I anti-human IgE adsorbed onto the solid phase. The sensitivity was estimated respectively at 95, 82, 93 and 64%. The results were significantly in accordance with those obtained with QAS-RIA (from Guéant) but a weak correlation was seen with Phadebas Rast succinylcholine (r = 0.85 and 0.53 respectively). The HRA gave with the NMBD incriminated a sensitivity of 88%. The correlation between HRA and IDR for the drug involved was 89% and 43% for the other NMBDs. The PAPPC RIA was apparently the most efficient test to screen sera for the presence of IgE antibodies whatever the NMBDs involved in anaphylaxis. An advantage is that this solid phase is commercially available and therefore this RIA can be used routinely with a high sensitivity, allowing the comparison of the results obtained by different laboratories.

[A simple test for the detection of respiratory allergy to current pneumallergens]. / Un test simple de dépistage de l'allergie respiratoire aux pneumallergènes courants.

Phadiatop is a new in vitro test used for screening patients with allergic respiratory diseases. This test, based on the RAST procedure, is performed with a paper disc to which a balanced mixture of relevant inhalant allergens has been coupled. One hundred and one adults ranging in age from 18 years to 73 years and 38 children (4 months to 15 years) were studied. We found a good correlation between this new test and total IgE (adults: 74.3 p. 100, children: 68.4 p. 100), specific IgE (adults: 91.1 p. 100, children: 100 p. 100) and skin test (adults: 79.2 p. 100, children: 97.1 p. 100). There was a high correlation between clinical atopy assessment and the result of Phadiatop, its efficiency was 83 p. 100 in adults and 97 p. 100 in children.

[In vitro exploratory methods in immuno-allergology]. / Méthodes d'exploration in vitro en immuno-allergologie.

The authors discuss different in vitro tests that provide evidence for: involvement of atopy in clinical symptoms (eosinophilia, total IgE titre, histaminemia); the identification of the responsible allergen (specific IgE, basophil degranulation, and release of histamine); following the course of hyposensitization treatment (specific IgG).

[Sequential analysis of specific IgE and IgG titres as a function of the cumulated doses of venoms injected in allergies to Hymenoptera and correlation with specific IgE, clinical manifestations and skin tests]. / Analyse séquentielle des titres d'IgE et d'IgG spécifiques en fonction des doses cumulées de venin injectées dans les allergies aux hyménoptères et corrélation entre IgE spécifique, manifestations cliniques et tests cutanés.

The numbers of IgE and specific IgE in ten desensitized to wasp-venom patients are retrospectively analysed, in order to study their variation according to the cumulated dose of administered venom during the desensitization (mean-time 18.4 months). Our results allow to find after a latency period, a growth of the specific IgE number, then their gradual decrease, while the specific IgE number gradually rises to reach a deal-level.

[Allergy to Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of young adult asthmatics]. / L'allergie à Tyrophagus putrescentiae et à lEpidoglyphus destructor dans une population d'adultes jeunes asthmatiques.

The goal of this work was the study of the prevalence of allergy to two mites, Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of 105 young asthmatic men from East of France. The association of skin tests and specific IgE shows that 43.10% are allergic to Tyrophagus and 44.95% to Lepidoglyphus destructor. The significance of skin tests is doubtful and depends on the laboratories which provide the allergens. Therefore, specific IgE has to be performed. As in other studies it has been observed that farmers are very often sensitized. But, nose difference has been noticed between people living in town or in country, between those having contacts with pets or not, feeding the cattle or not (except for the farmers). In the same way, no difference has been noticed between the asthmatics living in a wet country and/or wet house and those living in a dry area.

[Allergy to Thyrophagus putrescentiae and Lepidoglyphus destructor in a population of young asthmatic adults]. / L'allergie à Thyrophagus putrescentiae et à Lepidoglyphus destructordans une population d'adultes jeunes asthmatiques.

In the present work a study has been made of the prevalence of allergy to two storage mites, Tyrophagus putrescentiae and Lepidoglyphus destructor in a population of 105 young adults in the east of France. Combination of skin tests and specific IgE measurements shows that 43.10% of the subjects were sensitive to Tyrophagus and 44.95% to Lepidoglyphus. Interpretation of skin tests remains uncertain, particularly concerning the source of the allergen used and it is most often also necessary to measure the specific serum IgE. As in many studies, most sensitization was found amongst farmers. In contrast, no difference was seen between rural and city dwellers, subjects who were in contact with small animals and those in contact with food for livestock if they were not farmers, not between declared asthmatics who lived in a humid place and those who lived in an environment that was drier. Certainly these mites appeared in the present study to be much more ubiquitous than supposed previously and the fact that they seemed to be carriers of allergens and antigens that were different from those of Dermatophagoides raises the question as to whether the need for hyposensitization treatment for them has been under-estimated.

[The role of phadiatop in the screening of respiratory allergy]. / Place du phadiatop dans le dépistage de l'allergie respiratoire.

Phadiatop is a new in vitro screening test for respiratory allergy. This test, based on the RAST procedure, detects in serum, the presence of specific IgE to a mixture of common inhalent allergens. Among 70 patients (26 children and 44 adults) consulting for respiratory syndrome, Phadiatop was positive in 31 cases. There were a good correlation between this new test and skin tests (59% for adults and 92% for children), total IgE (70% for adults and 65% for children) and RAST (93% for adults and 96% for children). Phadiatop, with a specificity of 100%, a sensitivity of 82% (76% for adults and 92% for children) and an efficiency of 90% (86% for adults and 96% for children), is a more accurate test than total IgE and could be an excellent in vitro screening test for respiratory allergy.