Provocation tests with allergens

China Consensus Document on Allergy Diagnostics

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

[Environmental exposure chambers (EEC): A novel tool for pathophysiological and pharmaceutical research]

Airborne allergic diseases (allergic asthma, rhinitis and conjunctivitis) have reached epidemic proportions and are a great burden for both society and individuals. Therefore we need to better understand the physiopathological mechanisms and to increase clinical research in these diseases. However, traditional outpatient studies are difficult and have number of limitations, in particular the variability of allergen exposure. Yet allergen provocation tests, especially bronchial challenges in asthma, are excellent tools to measure the efficiency of anti-allergic therapies. Environmental exposure chambers (EEC) allow the performance of controlled allergen provocation tests on a large scale with remarkable sensitivity, specificity and reproducibility. Moreover, they allow a precise collection of allergic symptoms, making them interesting tools for patho-physiological and clinical studies. During the last thirty years, they have assisted the study of anti-allergic therapies and provided data on their pharmacodynamic characteristics, particularly in allergic rhinitis. However, there are still no EEC tests centered on asthma. The EEC of Strasbourg (ALYATEC^®) was developed to fulfill two objectives: to allow standardized allergenic and non-allergenic exposures with better control of the parameters than in other EEC and to offer a place to study asthma and anti-asthmatic therapies safely.

Risk and safety requirements for diagnostic and therapeutic procedures in allergology: World Allergy Organization Statement

One of the major concerns in the practice of allergy is related to the safety of procedures for the diagnosis and treatment of allergic disease. Management (diagnosis and treatment) of hypersensitivity disorders involves often intentional exposure to potentially allergenic substances (during skin testing), deliberate induction in the office of allergic symptoms to offending compounds (provocation tests) or intentional application of potentially dangerous substances (allergy vaccine) to sensitized patients. These situations may be associated with a significant risk of unwanted, excessive or even dangerous reactions, which in many instances cannot be completely avoided. However, adverse reactions can be minimized or even avoided if a physician is fully aware of potential risk and is prepared to appropriately handle the situation. Information on the risk of diagnostic and therapeutic procedures in allergic diseases has been accumulated in the medical literature for decades; however, except for allergen specific immunotherapy, it has never been presented in a systematic fashion. Up to now no single document addressed the risk of the most commonly used medical procedures in the allergy office nor attempted to present general requirements necessary to assure the safety of these procedures. Following review of available literature a group of allergy experts within the World Allergy Organization (WAO), representing various continents and areas of allergy expertise, presents this report on risk associated with diagnostic and therapeutic procedures in allergology and proposes a consensus on safety requirements for performing procedures in allergy offices. Optimal safety measures including appropriate location, type and required time of supervision, availability of safety equipment, access to specialized emergency services, etc. for various procedures have been recommended. This document should be useful for allergists with already established practices and experience as well as to other specialists taking care of patients with allergies.

Conjunctival provocation tests: a predictive factor for patients' seasonal allergic rhinoconjunctivitis symptoms

BACKGROUND

No parameters currently exist that can reliably predict the impact of preseasonal immunotherapy on the symptoms occurring during the season.

OBJECTIVE

The purpose of our studies was to prove a correlation between preseasonal conjunctival allergen challenge and coseasonal primary clinical endpoints using the total combined score, ie, a combination of symptoms and medication score, as the primary outcome parameter.

METHODS

Twelve weeks before both the birch and the grass pollen seasons, 2 separate prospective, double-blind, randomized, controlled studies were conducted followed by posttrial observations for each study during the active season. In the studies, patients who reacted to conjunctival allergen challenge were treated with sublingual immunotherapy tablets that contain either birch and/or alder or grass pollen allergoids.

RESULTS

In all, 158 patients were included in the grass and 160 in the tree pollen study; of these, 100 and 109 patients, respectively, took part in the posttrial observations. When comparing patients with and without a positive reaction in the final conjunctival allergen challenge, the results revealed a significant difference in the total combined score (grass: P < .001; birch: P = .025). The same applied to the rescue medication score (P = .005; P = .025). A significant difference regarding the rhinoconjunctivitis symptom score was shown in the grass pollen study (P = .002), and the difference of well days was significant in the tree pollen study (P = .049).

CONCLUSION

When comparing patients based on their reaction to allergen challenge after immunotherapy, each study leads to similarly significant results. Therefore, conjunctival allergen challenge can be used effectively as a parameter to predict allergic rhinoconjunctivitis symptoms during the season in patients treated with preseasonal sublingual immunotherapy tablets. Whether this can be transferred to untreated patients needs to be determined.

Expression of surface markers on the blood cells during the delayed asthmatic response to allergen challenge

Patients with bronchial asthma develop various types of asthmatic response to bronchial challenge with allergen, such as immediate/early asthmatic response (IAR), late asthmatic response (LAR) or delayed asthmatic response (DYAR), because of different immunologic mechanisms. The DYAR, occurring between 24 and 56 hours after the bronchial allergen challenge (p < 0.01), differs from IAR and LAR in clinical as well as immunologic features. This study investigates the expression of CD molecules (markers) on the surface of particular cell populations in the peripheral blood and their changes during the DYAR. In 17 patients developing the DYAR (p < 0.01), the bronchial challenge with allergen was repeated 2-6 weeks later. The repeated DYAR (p < 0.001) was combined with recording of CD molecule expression on various types of blood cells by means of flow cytometry up to 72 hours after the challenge. The results were expressed in percent of the mean relative fluorescence intensity. The DYAR was accompanied by (a) increased expression of CD11b, CD11b/18, CD16,CD32, CD35, CD62E, CD62L, CD64, and CD66b on neutrophils; CD203C on basophils; CD25 and CD62L on eosinophils; CD14, CD16, CD64, and CD86 on monocytes; CD3, CD4, CD8, CD11a, CD18, and CD69 on lymphocytes; CD16, CD56, CD57, and CD94 on natural killer (NK) cells; and CD31, CD41, CD61, CD62P, and CD63 on thrombocytes and (b) decreased expression of CD18 and CD62L on eosinophils, CD15 on neutrophils, and CD40 on lymphocytes. These results suggest involvement of cell-mediated hypersensitivity mechanism, on participation of Th1- lymphocytes, neutrophils, monocytes, NK cells, and thrombocytes in the DYAR.

Cytokines in tears during the secondary keratoconjunctival responses induced by allergic reaction in the nasal mucosa

BACKGROUND

Allergic keratoconjunctivitis (KC) can occur in a primary form due to an allergic reaction taking place in the conjunctivae or in a secondary form induced by nasal allergy.

OBJECTIVES

To search for the cytokine changes in tears accompanying the secondary keratoconjunctival response types (SKCR), caused by the nasal allergy.

METHODS

In 43 KC patients developing 15 immediate (SIKCR), 16 late (SLKCR) and 12 delayed (SDYKCR) responses to nasal provocation tests with allergens (NPT), the NPTs were repeated with subsequent recording of cytokine concentrations in tears up to 72 h.

RESULTS

The SIKCRs (p<0.001), occurring 10-120 min after the NPT, were accompanied by significant changes (p<0.05) of interleukin (IL)-4, IL-6, IL-10, IL-12p70 and granulocyte-macrophage colony-stimulating factor (GM-CSF). The SLKCRs (p<0.01), appearing 5-12 h after the NPT, were associated with significant changes (p<0.05) of IL-3, IL-4, IL-5, IL-8, IL-10, tumor necrosis factor (TNF)-α, GM-CSF and granulocyte colony-stimulating factor. The SDYKCRs (p<0.01), occurring 24-48 h after the NPT, were accompanied by significant changes (p<0.05) of IL-2, IL-8, IL-10, interferon-γ, transforming growth factor-β and TNF-α.

CONCLUSIONS

The particular SKCR types, induced by an allergic reaction in the nasal mucosa, were accompanied by different cytokine profiles in the tears, suggesting involvement of different hypersensitivity mechanisms. These results also stress the diagnostic usefulness of NPTs combined with monitoring of ocular features in KC patients who did not respond satisfactorily to the topical ophthalmological treatment.

Cellular changes in tears associated with keratoconjunctival responses induced by nasal allergy

BACKGROUND

Allergic keratoconjunctivitis occurs in a primary form, caused by an allergic reaction localized in the conjunctiva, and in a secondary form, induced by an allergic reaction originating in the nasal mucosa. Various hypersensitivity mechanisms involved in the keratoconjunctivitis forms result in different keratoconjunctival response types.

PURPOSE

To investigate the cytologic changes in tears during the secondary immediate (SIKCR), late (SLKCR), and delayed (SDYKCR) keratoconjunctival responses.

METHODS

In 61 patients, comprising 20 SIKCRs, 23 SLKCRs, and 18 SDYKCRs, nasal provocation tests (NPTs) with allergens and 61 phosphate-buffered control challenges were repeated and supplemented with cell counting in the tears.

RESULTS

The SIKCR (P<0.01), appearing 10-120 min after the NPT, was associated with increased eosinophil and mast cell counts in tears. The SLKCR (P<0.01), appearing 5-12 h after the NPT, was accompanied by increased counts of eosinophils, neutrophils, basophils, and conjunctival epithelial and goblet cells. The SDYKCR (P<0.05), appearing 24-48 h after NPT, was associated with increased counts of lymphocytes, neutrophils, monocytes, basophils, conjunctival epithelial, corneal epithelial and goblet cells.

CONCLUSIONS

The SIKCR, SLKCR, and SDYKCR, induced by nasal allergy, were associated with different cellular profiles in the tears. The cells, except mast, epithelial and goblet cells, displaying no intracellular changes, migrated probably from the conjunctival capillaries, in response to the factors released during the primary allergic reaction in the nasal mucosa and subsequently penetrating into the conjunctiva. These results demonstrate a causal role of nasal allergy and diagnostic value of NPT combined with recording of ocular features and cellular profiles in tears in some keratoconjunctivitis patients.

Cytokine profiles in tears accompanying the secondary conjunctival responses induced by nasal allergy

PURPOSE/AIM

Allergic conjunctivitis (AC) occurs either in a primary form, due to the allergic reaction localized in the conjunctivae or in a secondary form, induced by an allergic reaction initiated primarily in the nasal mucosa. The purpose of this study was to investigate the cytokine profiles in tears associated with the secondary conjunctival response (SCR) types.

MATERIALS AND METHODS

In 47 AC patients developing 16 immediate (SICR; p < 0.01), 20 late (SLCR; p < 0.001) and 11 delayed (SDYCR; p < 0.05) responses to nasal provocation tests (NPTs) with allergens, the NPTs were repeated and combined with recording of cytokine concentrations in the tears.

RESULTS

The SCRs were associated with significant concentration changes of particular cytokines in tears (p < 0.05) as follows: (1): SICRs: interleukin (IL)-3, IL-4, IL-10 and granulocyte macrophage colony-stimulating factor (GM-CSF); (2) SLCRs: IL-3, IL-4, IL-5, IL-8, IL-10, IL-12p40, GM-CSF and granulocyte colony-stimulating factor (G-CSF); and (3) SDYCRs: IL-2, IL-8, IL-10, interferon gamma, G-CSF and tumor necrosis factor alpha. No significant cytokine changes were recorded in tears during the phosphate-buffered saline controls or negative SCRs.

CONCLUSIONS

Different cytokine profiles in the tears accompanying the immediate, late and delayed types of SCR, induced by nasal allergy, would indicate involvement of different hypersensitivity mechanisms in the particular SCR types. The low cytokine concentrations in tears recorded during the SCRs may suggest their origin from the nasal mucosa. These results emphasize the diagnostic value of NPTs with allergens combined with monitoring of various ocular features in patients suffering from the secondary form of AC. These results may also have an impact on the therapeutical approach to this clinical entity.

Cytological Changes in Nasal Secretions Accompanying Delayed Nasal Response to Allergen Challenge

Background

Patients with allergic rhinitis when challenged with allergen develop various types of nasal response, such as an immediate nasal response (INR), late nasal response (LNR), dual late nasal response (DLNR), or delayed nasal response (DYNR), probably because of different hypersensitivity mechanisms. This study was designed to investigate the cytological changes in the nasal secretions (NSs) during the DYNR, beginning 24–32 hours, reaching maximum at 32–36 hours, and resolving within 56 hours after the nasal provocation tests (NPTs) with allergens.

Methods

In 45 allergic rhinitis patients developing 45 positive DYNRs (p < 0.01), the NPTs and the phosphate-buffered saline (PBS) controls were repeated and supplemented with cytological examination of the NSs and determination of interferon (IFN) γ and IL-4 in nasal lavage fluid (NLF).

Results

The repeated DYNR (p < 0.001) was accompanied by significant changes (p < 0.05) in the counts of neutrophils, monocytes, lymphocytes, epithelial and goblet cells, and, to a limited extent, of plasma cells and platelets in the NSs and increased concentrations of IFN-γ but not of IL-4, in NLF between 24 and 48 hours after the NPT. No significant cytological changes were found in NSs during the PBS controls (p > 0.1).

Conclusion

The DYNR is associated with cytological profiles in the NS different from those observed during the INR or LNR. The significant count changes of neutrophils, monocytes, lymphocytes, epithelial and goblet cells in NSs, and increased IFN-γ but not of IL-4 concentrations in the NLF, suggest a possible involvement of the cell-mediated hypersensitivity in the DYNR. These results also emphasize the diagnostic value of NPTs combined with cytological examination of the NSs in patients with nasal allergy.

Asthmatic response to milk ingestion challenge in adults: a comparison of the open and double-blind challenges

BACKGROUND

Cow's milk allergy can participate in pathophysiological mechanisms underlying bronchial asthma in some adult patients. This role should ultimately be confirmed by means of a milk ingestion challenge. In this study, the diagnostic value of the open food ingestion challenge (OFICH) and the double-blind placebo-controlled food challenge (DBPCFC) techniques with milk were compared in adult patients suffering from bronchial asthma with suspected milk allergy.

METHODS

In 87 asthmatics with a suspected history and positive skin tests for milk, the 87 OFICHs and DBPCFCs were performed in combination with spirometry and followed up to 72 h after the challenge.

RESULTS

Of 87 patients, 74 (85%) developed a positive asthmatic response (AR) (20 immediate, 33 late, 6 dual late and 15 delayed; p < 0.01) and 13 (15%) developed a negative AR (p > 0.1) to OFICH. Seventy-five (86%) developed a positive AR (17 immediate, 35 late, 8 dual late and 15 delayed; p < 0.01) and 12 (14%) developed a negative AR (p > 0.05) to DBPCFC. The correlation between the OFICH and DBPCFC was statistically significant (p < 0.01). All placebo control challenges were negative (p > 0.2).

CONCLUSIONS

In some adults with bronchial asthma, involvement of an allergy to cow's milk results in the appearance of various AR types (immediate, late, dual late or delayed). The milk allergy can be confirmed by open or double-blind techniques, combined with spirometry. No significant differences were found between the OFICH and DBPCFC results. OFICH with natural milk combined with spirometry seems, therefore, to be an adequate technique for the detection of milk allergy in asthmatics. The DBPCFC can be performed as an additional check, if necessary.

Chemokine profiles in blood associated with delayed asthmatic response to allergen challenge

BACKGROUND

Patients with bronchial asthma having been challenged with allergen develop various types of asthmatic response, such as immediate (IAR), late (LAR) or delayed (DYAR) response, due to different immunologic mechanisms. The DYAR, beginning 26-32 h, reaching maximum between 32 and 48 h and resolving within 56 h after the challenge, differs from IAR and LAR in clinical and immunologic features.

OBJECTIVES

To investigate the changes in the serum concentrations of chemokines associated with the isolated form of DYAR.

METHODS

In 22 patients the repeated DYAR (p < 0.001) was supplemented with recording of blood cell counts and serum concentrations of chemokines before, and up to 72 h after the bronchial challenge by means of enzyme-linked immunoassay, (ELISA).

RESULTS

The DYAR was associated with (a) significantly increased serum concentrations (p < 0.05) of CCL 2, CCL 3, CCL 4, CCL 7, CCL 20, CXCL 1, CXCL 8, CXCL 9, CXCL 10 and CXCL 11, and (b) significantly decreased serum concentrations, (p < 0.05) of CCL 5, CCL 11, CCL 17, CCL 22, CCL 24 and CCL 26, as compared with their pre-challenge as well as the PBS control values. No significant chemokine changes were recorded during the PBS controls (p > 0.1).

CONCLUSIONS

These results, together with changes in the blood cell counts, provide evidence for an involvement of activated Th(1), cells and NK cells (CCL-2, -3, -4, -20, CXCL-9,-10,-11), neutrophils (CCL-20, CXCL-1,-8) and monocytes (CCL-2,-3,-4, -7, CXCL-10), upon co-operation of other cell types, such as epithelial, endothelial and dendritic cells, in the immunologic mechanism(s) underlying the DYAR.

House dust mite-specific immunotherapy alters the basal expression of T regulatory and FcεRI pathway genes

BACKGROUND

Regulatory T (Treg) cells and IgE-mediated signaling pathways could play important roles in the induction of allergen tolerance during house dust mite-specific subcutaneous immunotherapy (HDM-SCIT). Our aim was to compare the basal expression levels of Treg, T helper 1 (Th1) and Th2 transcription factors and components involved in IgE-mediated signaling in healthy subjects with those in HDM-allergic patients both untreated and successfully treated with HDM-SCIT.

METHODS

Thirty-nine HDM-allergic patients who completed a 3- to 5-year course of mite extract SCIT, 20 mite-allergic controls and 25 healthy controls participated in this study. The efficacy of SCIT was monitored using skin-prick tests (SPTs), total immunoglobulin E (tIgE), specific IgE (sIgE), sIgG(4), nasal challenge and visual analog scale (VAS) scores at several time points. The mRNA levels of forkhead box protein 3 (FOXP3), T-BET, GATA-3, FcεRI, spleen tyrosine kinase (Syk), phosphatidylinositol 3 kinase (PI3K) and SH2 domain-containing inositol phosphatase (SHIP) were quantified by real-time RT-PCR using nonstimulated whole blood samples.

RESULTS

Decreased wheal sizes and VAS scores, negative challenges and increased sIgG(4) levels indicated that SCIT was effective in the treated patients. Basal expression levels of FOXP3 and GATA-3 decreased and T-BET levels increased in both treated patients and in healthy controls compared to untreated patients. The IgE-mediated pathway kinases Syk and PI3K exhibited reduced expression, whereas SHIP phosphatase levels were elevated in both treated patients and healthy controls relative to untreated patients. The expression levels of FcεRI were not significantly altered.

CONCLUSIONS

Immunotherapy using HDM extracts results in a modification of the basal expression levels of several IgE-related signaling factors and induces a highly significant upregulation of Th1-response and downregulation of Th2-response transcription factors. Interestingly, this therapy also appears to reduce the basal expression of FOXP3.

Changes in exhaled nitric oxide levels after bronchial allergen challenge

BACKGROUND

Fractional exhaled nitric oxide (FeNO) is a marker of inflammation of the airways accompanying changes in the clinical condition of asthma. Allergen exposure has been associated with a delayed elevation of FeNO. The aim of this study was to assess airway inflammation with FeNO measurements during bronchial allergen challenge (BAC), and to determine the diagnostic performance of FeNO changes.

METHODS

Thirty-four patients with asthma and sensitization to inhalant allergens were studied. BAC with common or high-molecular-weight occupational aeroallergens was performed. FeNO was measured before and 24 h after BAC. Receiver operating characteristics curve was built to assess the sensitivity and specificity of increase in FeNO levels associated with BAC outcome.

RESULTS

In 21 patients (61.76%) a positive asthmatic reaction (responders) was observed. A significant increase in postchallenge FeNO was observed in this group of patients compared to the group of nonresponders. A median increase (FeNO postchallenge-FeNO prechallenge) of 14.0 ppb was observed in the group of responders, whereas a -1.0 ppb change was attained in the nonresponder group (P < 0.001). The cutoff point providing maximal sensitivity and specificity for %ΔFeNO after BAC was 12%. This change in FeNO levels has a sensitivity of 0.81 and a specificity of 0.92 for predicting a positive outcome in the BAC.

CONCLUSION

FeNO measurements can be used as a surrogate of airway inflammation accompanying the asthmatic reaction induced by BAC. FeNO measurements may be a useful and reliable tool in the monitoring and interpreting specific bronchial challenge test with allergens.

Delayed asthmatic response to bronchial challenge with allergen-mediators, eicosanoids, eosinophil and neutrophil constituents in the blood and urine

BACKGROUND

In patients with allergic bronchial asthma, different immunologic mechanisms may participate and lead to different types of asthmatic response to allergen challenge, such as immediate/early (IAR/EAR), late (LAR) or delayed asthmatic response (DYAR).

OBJECTIVES

In 55 of 397 asthmatics, DYAR has been recorded (p < 0.001) and confirmed by repeated bronchial challenge with the same allergen (p < 0.001). DYAR began between 26 and 32 h, reached a maximum between 32 and 48 h and resolved within 56 h after the challenge. DYAR was associated with various clinical symptoms and diagnostic parameters having diverged from those recorded during the IARs/EARs and LARs.

METHODS

In 25 of 55 patients, repeated DYAR has been supplemented with the recording of leukotriene B(4) (LTB(4)), LTC(4), LTE(4), prostaglandin D(2) (PGD(2)), PGE(2), PGF(2)(α), thromboxane B(2), lipoxin A(4), eosinophil cationic protein, eosinophil-derived neurotoxin/eosinophil protein X, eosinophilic peroxidase, myeloperoxidase, histamine and tryptase in peripheral blood, and of LTC(4), thromboxane B(2), eosinophil-derived neurotoxin and 9α,11β-PGF(2) in urine, before and up to 72 h after the bronchial allergen challenge, by means of enzyme-linked immunoassay (ELISA/EIA) or ImmunoCAP.

RESULTS

DYAR was accompanied by a significant increase in the plasma concentrations of LTB(4) (p < 0.05) and myeloperoxidase (p < 0.05) at 24, 36 and 48 h after the challenge, whereas the plasma/serum or urine concentrations of the other factors did not demonstrate any significant changes (p > 0.05).

CONCLUSIONS

These results would indicate an active and prominent involvement of neutrophils, in addition to the previously demonstrated role of the Th1 lymphocytes, in the clinical DYAR.

Delayed asthmatic response: a new phenotype of bronchial response to allergen challenge and soluble adhesion molecules in the serum

BACKGROUND

Patients with bronchial asthma develop various types of asthmatic response to bronchial challenge with allergen, such as immediate asthmatic response, late asthmatic response, or delayed asthmatic response (DYAR), due to different immunologic mechanisms.

OBJECTIVES

To investigate the appearance and possible changes in the concentrations of soluble cell adhesion molecules during the DYAR, to explore the involvement of particular cell types in the mechanism(s) leading to DYAR, and to contribute to a fuller understanding of this clinical phenomenon.

METHODS

The DYAR recorded in 28 patients (P < .001), appearing within 26 to 32 hours, reaching maximum within 32 to 48 hours, and resolving within 56 hours after the allergen challenge, was repeated 2 to 6 weeks later. The repeated DYAR (P < .001) was supplemented with blood cell counts and measurement of serum concentrations of soluble adhesion molecules by an enzyme-linked immunoassay.

RESULTS

The prechallenge concentrations of soluble intercellular adhesion molecule 1 (sICAM-1), soluble vascular cell adhesion molecule 1 (sVCAM-1), soluble platelet endothelial cell adhesion molecule (sPECAM-1), soluble E-selectin, soluble L-selectin, soluble P-selectin, and soluble E-cadherin did not differ significantly from healthy controls. The DYAR was associated with the following changes in the serum: an increase of sICAM-1 at 6 and 12 hours and a decrease at 24 hours; an increase of sVCAM-1 at 24 and 36 hours; an increase of sPECAM-1 at 36 and 48 hours and a decrease at 56 and 72 hours; an increase of soluble E-selectin at 56 hours; an increase of soluble L-selectin at 56 and 72 hours; a decrease of soluble E-cadherin at 48 and 56 hours; and increased counts of blood leukocytes at 36, 48, and 56 hours, neutrophils at 24, 36, 48, and 56 hours, lymphocytes at 24, 36, and 48 hours, and monocytes at 6, 12, and 24 hours. The Th1/Th2 ratio in blood increased at 24, 36, 48, and 56 hours. The intracellular concentration of interferon γ, but not of interleukin 4, increased at 24, 36, 48, and 56 hours.

CONCLUSIONS

These results provide evidence of the involvement of neutrophils, Th1 lymphocytes, monocytes, platelets, and endothelial cells, upon participation of various adhesion molecules, in mechanisms(s) underlying the clinical DYAR.

Asthma related to Alternaria sensitization: an analysis of skin-test and serum-specific IgE efficiency based on the bronchial provocation test

BACKGROUND

It is difficult to find a causal relationship between exposure to Alternaria spores and the development of asthma symptoms in sensitized individuals due to the complexity of clinical situations in which positive diagnostic tests are often found.

OBJECTIVE

To analyse the diagnostic efficiency of skin testing (ST) and serum-specific IgE to Alternaria, based on the results of a bronchial specific challenge with Alternaria extracts.

METHODS

Seventy-four asthmatic patients sensitized to Alternaria underwent a specific bronchial challenge with this mould. Skin-testing weal sizes, serum-specific IgE values (CAP-system) and bronchial challenge results were analysed by receiver operating characteristics curves (ROC curves) and logistic regression. The sensitivity, specificity, positive and negative predictive values were calculated for different cut-off points.

RESULTS

Bronchial challenges to Alternaria elicited a positive result in 45 patients (61%). Skin prick testing almost perfectly predicted the outcome of bronchoprovocation tests (area under the ROC curve of 0.957), whereas intradermal skin testing had moderate efficacy. A negative result for skin prick test (SPT) showed a 4% probability of a positive bronchial challenge in the logistic regression analysis. However, weals around 5.5 mm in diameter had 90% probability of a positive challenge. Quantification of serum-specific IgE correctly classified 86% of the cases. In the logistic regression analysis, a CAP value 16 kU(A)/L predicted a positive bronchial challenge result with 99% accuracy, whereas for a CAP value <0.35 kU(A)/L, this probability was 33%.

CONCLUSIONS AND CLINICAL RELEVANCE

Most asthmatic patients with positive SPT results to Alternaria would have a positive bronchial challenge. As atmospheric mould levels may vary significantly with the weather conditions, sensitized patients should be instructed on the risk situations, environmental control measures and the importance of correct medication compliance. Immunotherapy with Alternaria could also be taken into account as a valid therapeutic option.

Allergic conjunctivitis and nasal allergy

Allergic conjunctivitis (AC) can be divided into the primary form (caused by an allergic reaction occurring primarily in the conjunctivae) and the secondary form (induced by allergic reaction originating primarily in the nasal mucosa, where the released mediators can reach conjunctiva through the lacrimal system, the blood, the lymphatic network, or the neurogenic network). Patients with primary AC develop an immediate, late, or delayed conjunctival response (CR) during conjunctival provocation tests. Patients with secondary AC develop an immediate, late, or delayed type of secondary CR, induced by the nasal allergic reaction, due to the nasal allergen challenge. Various hypersensitivity mechanisms may be involved in the particular CR types. The secondarily induced AC and CRs can only be confirmed by nasal provocations tests, performed by rhinomanometry combined with recording of conjunctival signs. The existence of the primary and secondarily induced AC has an impact on treatment of this disorder.

Delayed-type asthmatic response to bronchial challenge with allergen, I: clinical features

BACKGROUND

Patients with allergic asthma being challenged with allergen may develop different types of asthmatic response, such as immediate asthmatic response (IAR), late asthmatic response (LAR), or dual late asthmatic response (DLAR), because of different immunologic mechanisms.

OBJECTIVES

To investigate the clinical features of delayed asthmatic response (DYAR), its reproducibility, and its association with other in vivo and in vitro diagnostic parameters and to contribute to the understanding of the possible mechanism(s) underlying this unusual clinical phenomenon.

METHODS

In 51 asthma patients developing 51 DYARs, the bronchial challenges with the same allergens were repeated and supplemented with additional diagnostic parameters. Control groups consisted of asthma patients developing IAR (n = 56), LAR (n = 43), and DLAR (n = 31) and healthy individuals (n = 48).

RESULTS

The DYAR began at 26 to 32 hours, reached a maximum at 32 to 48 hours, and resolved within 56 hours after the challenge. DYAR was statistically highly significant (P < .001) compared with phosphate-buffered saline controls.The differences between the initial and repeated DYAR were not significant (P = .14). The DYAR was associated with dyspnea, wheezing, tiredness, increased peripheral blood leukocyte count, lymphocytosis, neutrophilia but not eosinophilia, significant changes in the T(H)1/T(H)2 ratio in peripheral blood in favor of T(H)1 cells, and significant increase in the intracellular concentration of interferon gamma but not interleukin 4 or 5.

CONCLUSIONS

In addition to the previously established IAR, LAR, and DLAR, existence of another, the so-called DYAR to allergen challenge, has been demonstrated. In this type, the T(H)1 cells, together with neutrophils, may well play the predominant causal role.

Audiometric changes in chronic secretory otitis media due to nasal allergy

PURPOSE

To investigate the possible role of nasal allergy on hearing levels in chronic otitis media with effusion (OME).

METHOD

In 87 adults who had chronic OME, 185 nasal challenges with allergen were performed using rhinomanometry combined with tympanometry and pure-tone audiometry (PTA).

RESULTS

Of the 87 patients, 71 developed 131 positive nasal responses (NRs; p < 0.01), 119 of which were associated with significant changes in middle ear pressure (p < 0.01) and 96 with significant changes in PTA (p < 0.01). The hearing threshold increased significantly (>30 dB) at tone frequencies of 2,000 Hz during 63 NRs (p < 0.05) and at tone frequencies of 4,000 Hz during 93 NRs (p < 0.01).

CONCLUSION

Nasal allergy can affect Eustachian tube function, leading to the changes in the middle ear pressure and resulting in hearing impairment. Nasal challenges with allergen performed using rhinomanometry combined with tympanometry and PTA may be a useful diagnostic supplement in chronic OME patients.

Allergic asthma in patients with common variable immunodeficiency

BACKGROUND

Many patients with common variable immunodeficiency (CVID) have a clinical history suggestive of allergic respiratory disease. However, in such individuals, the prevalence of asthma and the role of atopy have not been well established. The objective of this study was to evaluate pulmonary function and identify asthma in patients with CVID. We also investigated the role of IgE as a trigger of asthma in these patients.

METHODS

Sixty-two patients diagnosed with CVID underwent spirometry, as well as skin prick testing and in vitro determination of serum-specific IgE levels for aeroallergens, together with bronchial provocation with histamine and allergen.

RESULTS

The most common alteration identified through spirometry was obstructive lung disease, which was observed in 29 (47.5%) of the 62 patients evaluated. Eighteen (29.0%) of the 62 patients had a clinical history suggestive of allergic asthma. By the end of the study, asthma had been diagnosed in nine (14.5%) patients and atopy had been identified in six (9.7%). In addition, allergic asthma had been diagnosed in four patients (6.5% of the sample as a whole; 22.2% of the 18 patients with a clinical history suggestive of the diagnosis).

CONCLUSION

In this study, CVID patients testing negative for specific IgE antibodies and suspected of having allergic asthma presented a positive response to bronchial provocation tests with allergens. To our knowledge, this is the first such study. When CVID patients with a history suggestive of allergic asthma test negative on traditional tests, additional tests designed to identify allergic asthma might be conducted.

A case of occupational rhinitis caused by rice powder in the grain industry

Rice is the major staple food in a large part of the world, especially in Asia. Hypersensitivity reactions to rice are rare. Moreover, cases of occupational allergies induced by inhalation of rice powder are uncommon. We report a 31-year-old male with work-related rhinitis and conjunctivitis symptoms caused by occupational exposure to rice powder in the grain industry. He showed positive responses to rice extracts on a skin prick test, and a high level of serum specific IgE to rice was detected by ELISA. Occupational rhinitis was confirmed by a nasal provocation test with rice extracts. An IgE ELISA inhibition test showed cross-creativity between rice and various grass pollen extracts. These findings suggest that the inhalation of rice powder can induce IgE-mediated occupational rhino-conjunctivitis, which may be derived from cross-reactivity to major grass pollens.

Seasonal and perennial allergic conjunctivitis: the possible role of nasal allergy

BACKGROUND

There is a link between conjunctiva and nose. Nasal allergy is suspected to be involved in some cases of conjunctivitis. This work aims to investigate the possible role of nasal allergy in seasonal (SAC) and perennial (PAC) allergic conjunctivitis and the value of nasal challenges with allergens (nasal provocation tests [NPTs]) for the diagnostic procedures of the conjunctivitis.

METHODS

In 61 adults suffering from SAC or PAC with a positive history and skin tests, but responding insufficiently to the local treatment, 122 NPTs and 61 control nasal challenges with phosphate-buffered saline (PBS) were performed using rhinomanometry combined with recording of ocular response. In 16 control subjects suffering only from allergic rhinitis without a history of conjunctivitis, 16 positive NPTs were repeated and supplemented with registration of ocular features.

RESULTS

Of the 61 patients, 55 developed 103 positive nasal responses of various types (P < 0.01), 82 of which were accompanied by significant conjunctival response (P < 0.01) without any corneal involvement. No significant ocular responses were recorded during 61 control PBS challenges (P > 0.05) as well as during 16 challenges in control subjects (P > 0.1).

CONCLUSIONS

These results illustrate a possible involvement of nasal allergy in some patients with allergic conjunctivitis (SAC and PAC) and the value of the nasal challenges with allergen combined with registration of the ocular features in the diagnostic approach to these disorders.

Role of nasal allergy in chronic secretory otitis media

Nasal allergy seems to be one of the important causes of chronic secretory otitis media (SOM) in children and adults. Chronic SOM is unequivocally related to disturbed function of the eustachian tube, which facilitates communication of the middle ear with the nasopharynx, nasal cavity, and indirectly with paranasal sinuses. The most serious consequences of chronic SOM are decreased elasticity of the tympanic membrane and hearing impairment. Allergic reactions in the nasal mucosa leading to release of various mediators result in development of three types of nasal response characterized predominantly by nasal obstruction. Eustachian tube functions can be affected directly by the mediators released in the nasal mucosa or indirectly by the nasal obstruction. Nasal challenges with allergens performed by rhinomanometry, combined with tympanometry and eventually audiometry, may be a useful diagnostic supplement for this disorder.

EAACI position paper on occupational rhinitis

The present document is the result of a consensus reached by a panel of experts from European and non-European countries on Occupational Rhinitis (OR), a disease of emerging relevance which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio-economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored on that of occupational asthma, as well as a diagnostic algorithm based on steps allowing for different levels of diagnostic evidence are proposed. The needs for future research are pointed out. Key messages are issued for each item.

Bronchial challenge test in asthmatics sensitized to mites: role of particle size in bronchial response

Although major house dust mite allergen (Der p 1) is carried mainly on large particles (>10 microm), standard bronchial challenge tests (BCT) use nebulizers that deliver smaller particles (sizes from 1 to 5 microm) and may therefore not reflect actual domestic exposure. The objective of this study was to evaluate the influence of particle size of Dermatophagoides pteronyssinus extract on bronchial response. Specific BCT were performed with different mass median aerodynamic diameters (MMAD): 1.1, 5.6, and 9.7 microm. Each of the 19 mite-sensitized patients underwent mite BCT three times, once with each nebulizer. IL-5 levels were assessed in induced sputum and blood samples. The PD(20) for Der p 1 differed substantially with particle size, with less Der p 1 (11.2 ng) needed to produce a PD(20) with the largest particles (9.7 microm), compared to 18.1 ng for the 5.6 microm particles and 142.5 ng for the 1.1 microm particles (p < 0.0001). Large particles also induced an early phase response significantly more often than small particles (100% vs. 63%). Although the late phase reaction (LPR) frequency was similar with all three particle sizes, lower mean oral corticosteroid doses were needed to treat LPR with the largest particles (23 mg), compared to the smaller particles, with 34 mg for the 5.6 microm particles and 51 mg for the 1.1 microm. The 1.1 microm particles produced a significantly greater increase in IL-5 concentrations in sputum and blood compared to the larger particles. Large particles clearly play a role in the immediate bronchial response in asthmatics sensitized to mites and, therefore, should be included in pharmacological studies in humans.

The role of nasal allergy in chronic secretory otitis media

BACKGROUND

Chronic secretory otitis media (SOM) has multifactorial causes, and nasal allergy is suspected as one of these causative factors.

OBJECTIVES

To investigate the possible role of nasal allergy in SOM in adults and to determine the diagnostic value of nasal challenges with allergens (nasal provocation tests) combined with tympanometry for the diagnosis of this disorder.

METHODS

In 69 young adults with chronic or recurrent SOM, 173 nasal challenges with allergens were performed by anterior rhinomanometry combined with tympanometry (pure-tone air conduction tympanometry). In 42 control subjects with only allergic rhinitis and no history of middle ear disease, 42 nasal challenges with allergens were repeated and combined with tympanometry. The study design was a placebo-controlled comparison.

RESULTS

Of the 69 patients, 54 developed 129 positive nasal responses of various types (P < .01), 117 of which were accompanied by significant changes in middle ear pressure (P < .01). No significant tympanometric changes (P > .10) were recorded during the 42 positive nasal responses in control subjects.

CONCLUSIONS

These results may confirm the occurrence of chronic SOM in some adult patients and the possible involvement of nasal allergy in chronic SOM. The nasal challenges with allergen performed by rhinomanometry, combined with tympanometry, seem to be a valuable supplementary tool for the diagnosis of this disorder.

Analysis of skin testing and serum-specific immunoglobulin E to predict airway reactivity to cat allergens

BACKGROUND

When the clinical history is not conclusive, it may be difficult to make an accurate interpretation of the value of skin tests and serum-specific IgE to cat allergens in asthma cases.

OBJECTIVE

To analyse the diagnostic efficiency of skin testing (ST) and serum-specific IgE to cat allergens, based on the results of bronchial-specific challenge with cat epithelium.

METHODS

Sixty-four asthma patients (49 with cat exposure and 15 without) who did not clearly relate their asthma symptoms to cat exposure and had a positive skin prick testing and/or a positive cat dander-specific IgE determination (CAP-system) underwent intradermal skin tests and specific bronchial challenge with cat epithelium. The results were analysed by receiver operating characteristics curves (ROC curves) and logistic regression. Sensitivity, specificity, positive predictive values and negative predictive values were calculated for different cut-off points.

RESULTS

Twenty-seven patients (42.2%) had a positive bronchial-specific challenge. The area under the ROC curve for serum-specific IgE quantification is 0.85, which makes a good diagnostic tool out of this test. Intradermal ST predicts the outcome of the bronchoprovocation test better than skin prick testing (area under the ROC curve of 0.74 vs. area under the ROC curve of 0.54, respectively). The logistic regression analysis shows that the estimated probability of a positive bronchial challenge is > or =93% if CAP values are > or =17 kU(A)/L, whereas if CAP values are less than 0.35 kU(A)/L the estimated probability of a positive bronchial challenge is 16%. When the intradermal skin test is negative, the estimated probability of a positive bronchoprovocation test is 9%, being the test that better identifies patients with a negative bronchoprovocation test.

CONCLUSIONS

Levels of serum-specific IgE to cat allergens and intradermal ST can be used to diagnose and treat more accurately asthmatic patients sensitized to cat epithelium when there is uncertainty about cat epithelium causality.

Hypersensitivity to black locust (Robinia pseudoacacia) pollen: "allergy mirages"

BACKGROUND

The allergenicity of the ornamental tree Robinia pseudoacacia, or black locust, is unknown.

OBJECTIVE

To evaluate the prevalence of sensitization to R. pseudoacacia pollen, its possible allergenic cross-reactivity with other common pollens, and the potential implication of pollen panallergens (profilin, polcalcin, and 1,3-beta-glucanase) as a cause of sensitization to R. pseudoacacia pollen.

METHODS

Skin prick testing with R. pseudoacacia pollen was performed in 149 patients with pollinosis. Nasal challenge with R. pseudoacacia pollen was performed in 10 patients. The prevalence of sensitization to the recombinant forms of profilin (rChe a 2), polcalcin (rChe a 3), and the N-terminal of the 1,3-beta-glucanase (rNtD of Ole e 9) was investigated. Immunoblotting, enzyme-linked immunosorbent assay, and competitive inhibition assays were performed with R. pseudoacacia pollen and recombinant pollen allergens.

RESULTS

Sixty-four patients (43%) had positive skin prick test reactions to R. pseudoacacia pollen. Nasal challenge results were positive in 5 sensitized patients and negative in 4 controls and 1 sensitized patient. The allergenic profile of R. pseudoacacia pollen comprises at least the panallergen profilin, a calcium-binding protein, and a 1,3-beta-glucanase. The prevalence of sensitization to rChe a 2, rChe a 3, and rNtD of Ole e 9 was 60%, 33%, and 87%, respectively, among patients sensitized to R. pseudoacacia pollen. Binding of IgE to R. pseudoacacia extract was completely inhibited by Robinia, Chenopodium, Olea, Cupressus, and Lolium extracts.

CONCLUSIONS

The high prevalence of R. pseudoacacia pollen sensitization in patients with pollinosis is likely to be due to cross-sensitization to panallergens (profilin, polcalcin, and 1,3-beta-glucanase) from other common pollens. This phenomenon may lead to a diagnosis of "allergy mirages."

Pathogenesis and management of aspirin-intolerant asthma

In 2-23% of adults with asthma, and rarely in children with asthma, aspirin (acetylsalicylic acid) and non-steroidal anti-inflammatory drugs (NSAIDs) cause asthma exacerbations. Within 3 hours of ingestion of aspirin/NSAIDs, individuals with aspirin-intolerant asthma (AIA) develop bronchoconstriction, often accompanied by rhinorrhea, conjunctival irritation, and scarlet flush. In severe cases, a single therapeutic dose of aspirin/NSAIDs can provoke violent bronchospasm, loss of consciousness, and respiratory arrest. In order to diagnose AIA, oral, inhaled, nasal or intravenous aspirin challenge tests are performed in facilities where experienced physicians are present and emergency treatment is available. The exact differences in the pathogenesis of AIA and other types of asthma are not fully understood. The interference of aspirin/NSAIDs with arachidonic acid metabolism in the lungs plays an important role in the mechanism of AIA; inhibition of cyclo-oxygenase is accompanied by overproduction of cysteinyl leukotrienes (cys-LTs). It has been proposed that overproduction of cys-LTs, together with removal by aspirin/NSAIDs of the 'brake' imposed by the bronchodilator prostaglandin E2, may cause an asthma attack in patients with AIA. Development of a suitable animal model to investigate the pathogenesis of AIA would help to clarify this question. Although it is still controversial whether leukotriene modifiers are more effective in patients with AIA compared with other types of asthma, because LT plays an important role in the pathogenesis of AIA, leukotriene modifiers are the preferred medication for the long-term control of AIA. Add-on efficacy of leukotriene modifiers has been confirmed in patients with AIA already treated with inhaled corticosteroids. However, this does not mean that aspirin/NSAIDs can be safely taken by aspirin-sensitive patients treated with leukotriene modifiers. To prevent attacks of AIA, sensitive patients should avoid the use of aspirin/NSAIDs or use selective cyclo-oxygenase 2 inhibitors when required. When patients with AIA need aspirin for specific situations they should receive aspirin desensitization therapy or treatment with selective cyclo-oxygenase 2 inhibitors.

Double-blind and placebo-controlled study to assess efficacy and safety of a modified allergen extract of Dermatophagoides pteronyssinus in allergic asthma

BACKGROUND

A randomized double-blind, placebo-controlled study was conducted in patients allergic asthma sensitized to Dermatophagoides pteronyssinus.

OBJECTIVE

To evaluate the efficacy and safety after 1-year of immunotherapy with a modified D. pteronyssinus extract compared with placebo.

MATERIAL AND METHODS

Fifty-five patients were randomly allocated to receive the active treatment (n = 29), or placebo (n = 26). The main outcome was the specific bronchial provocation test (BPT). Other parameters analysed were dose-response skin prick test (SPT), symptom and medication scores and asthma quality of life (AQLQ).

RESULTS

At the end of the study, the active group showed a significant increase in the PD(20)FEV(1) compared with placebo (P = 0.0029). Nineteen patients of the active vs 10 of the placebo group needed more than twice the initial amount of allergen extract to have a positive BPT (P = 0.0293); seven patients in the placebo vs one in the active group needed less than half (P = 0.0137). In SPT, a significant improvement (P = 0.0049) was found in the active group. This group also had a median reduction of 91.5% in symptom scores, whereas the placebo group increased by 86%. Medication scores decreased in both groups (56% in the active and 11.4% in the placebo). In AQLQ, the differences between both groups were significant (P = 0.0234) at the end of the study.

CONCLUSION

After 1 year of treatment, the modified extract of D. pteronyssinus demonstrated to be safe and efficacious to treat patients with asthma and allergic rhinoconjunctivitis sensitized to this mite.

Provocation testing with recombinant allergens

In the past few decades, DNA technology has enabled the production of defined recombinant allergen molecules for diagnostic and therapeutic purposes. Recombinant allergens containing most of the relevant IgE epitopes present in natural allergen sources are now available and allergen proteins can be produced that are identical, without biological or batch-to-batch variation. A great advantage of recombinant allergens is that they can be used for component-resolved diagnostics, which makes it possible to establish the patient's individual IgE reactivity profile before therapy is selected. However, before recombinant allergens can be applied in clinical practice their biological activity has to be carefully investigated in vivo. We here describe the most commonly used provocation methods (skin tests (prick and intradermal), nasal, bronchial, and conjunctival provocations) and how they can be performed. We also discuss the results so far obtained with in vivo testing using recombinant allergens and envisage their future use for immunotherapy.

Inhalation challenge with bovine dander allergens: who needs it?

STUDY OBJECTIVES

To identify which tests would be useful in selecting patients for a specific inhalation challenge with bovine dander allergens (bSIC).

DESIGN

A prospective study.

SETTING

A university hospital.

PATIENTS

Thirty-seven dairy farmers with a clinical suspicion of occupational asthma due to bovine allergens.

INTERVENTIONS

Each patient (n = 27) underwent histamine challenge, mannitol challenge, exhaled nitric oxide (NO) measurement, bovine-specific serum IgE measurement, and skin-prick test (SPT) with bovine allergens prior to undergoing a bSIC.

RESULTS

Eleven patients responded to the inhalation challenge with bovine allergens. The sensitivity and specificity of the tests, based on this response, were 82% and 65%, respectively, for the histamine challenge; 20% and 94%, respectively, for the mannitol challenge; 27% and 77%, respectively, for the NO measurement; 82% and 100%, respectively, for the bovine-specific serum IgE measurement; and 100% and 50%, respectively, for the SPT. Multiple regression analysis revealed that only IgE-mediated sensitivity to bovine allergens, but neither bronchial hyperreactivity nor exhaled NO concentration, contributed significantly to the response.

CONCLUSION

Only the SPT with bovine allergens and bovine-specific serum IgE measurements were useful in selecting patients for the bSIC. This challenge should not be performed in SPT-negative subjects. A diagnosis of occupational asthma due to bovine dander allergens could be made without an inhalation challenge test in asthmatic patients with high bovine-specific serum IgE levels. This practice would eliminate the need for the majority of bSICs.

Bronchial challenge tests in patients with asthma sensitized to cats: the importance of large particles in the immediate response

Our aim was to compare bronchial responses to major cat allergen (Fel d 1) in individuals with intermittent asthma sensitized to cats (19 subjects) according to the droplet particle size. We used three nebulizers, which delivered particles with mass median aerodynamic diameters of 1.4, 4.8, and 10.3 microm. A dosimeter nebulizer was used. The cat allergen was diluted to obtain the same amount of Fel d 1 per puff with each nebulizer. Each patient underwent three methacholine bronchial challenge tests (BCT), each followed 24 hours later by a cat allergen BCT, each performed with a different nebulizer (randomly selected each time, with patient and tester always blinded). Subjects did not differ for methacholine responsiveness, FEV1, mean forced expiratory flow during the middle half of the FVC (FEF25-75), PEF, or dyspnea (Borg scale) before any of the three cat BCTs. Cat allergen PD20 was 271 ng of Fel d 1 with the 1.4 microm nebulizer, 46 ng with the 4.8 microm nebulizer, and 13.5 ng with the 10.3 microm nebulizer (p = 0.00001). Inhalation of small particles (1.4 microm) resulted in significantly lower FEF25-75 24 hours after provocation than large particles did. In conclusion, immediate bronchial response appears to be localized in large airways, and the use of large particles is more appropriate for cat allergen BCTs.

Nasal cellularity in 183 unselected schoolchildren aged 9 to 11 years

OBJECTIVE

Although rhinitis is extremely frequent in children, methods for assessing the severity of nasal inflammation produce results with wide variability and hence weak clinical significance. We designed this epidemiologic investigation to define the clinical usefulness of assessing nasal cellularity in children.

METHODS

We studied 183 of 203 eligible unselected schoolchildren who were aged 9 to 11 years and whose parents gave informed consent and completed a questionnaire on the history of atopic and respiratory symptoms. In all children, nasal swabs were obtained from both nostrils and eluted in saline and slides were prepared from cytospin preparations for staining and white cell counts. Children also underwent determination of nasal volume, skin prick tests with 7 common local allergens, flow volume curves, and nitric oxide measurement in expired air. Blood samples were drawn for the measurement of total immunoglobulin E, eosinophil percentage, and detection of Chlamydia pneumoniae antibodies. C pneumoniae DNA was also sought in eluates from nasal swabs. The percentage, standard deviations, and percentiles of the various nasal white cell populations were determined.

RESULTS

No correlation of the percentage of these cells was found with the history of allergies or respiratory disease or with functional or laboratory finding. Repeat nasal swabs obtained 1 month after the initial examination in 31 children (20 with neutrophils higher and 11 lower than 14%) in 77.4% of the cases confirmed the previous (high or normal) result. Twelve of the 16 eligible children with persistently high nasal neutrophil counts completed a 15-day cycle of intranasal flunisolide therapy (200 micro g twice a day). Therapy significantly reduced nasal neutrophil percentage and increased nasal volume.

CONCLUSIONS

Increased nasal neutrophils, although related neither to the clinical history nor to laboratory variables, are a common important finding in children. A 15-day cycle of intranasal flunisolide is sufficient to restore normal nasal neutrophilia.

Human nasal allergen provocation for determination of true allergic rhinitis: methods for clinicians

The nasal provocation test (NPT) could be more extensively used in the diagnosis of allergic rhinitis by practicing physicians. However, the procedure has not been standardized, and has mainly been utilized for scientific purposes in the US. This review illustrates a wide variety of techniques and approaches to dosing and concentration of allergen extracts, and delivery systems. It also outlines the lack of a unified outcomes-evaluation system, including clinical symptom scores and nasal patency measurements, in different countries. NPT is a safe, simple, and useful method when conducted with the consideration of indications and contraindications. Standardized NPT has the potential to become a more frequently used additional clinical test in the diagnosis of allergic rhinitis.

Increased CD69 expression on peripheral blood eosinophils after specific inhalation challenge

BACKGROUND

CD69 is a molecule expressed on human eosinophils after cytokine-activation. Different studies have described the eosinophil activation, evaluated by CD69 expression, at the site of an allergic inflammation. In this study we evaluated the expression of CD69 on peripheral blood eosinophils after a specific inhalation challenge (SIC), in order to better define the state of activation of peripheral blood eosinophils after exposure to sensitizers.

METHODS

CD69 expression was evaluated by flow cytometry in nine asthmatic patients before and after a positive SIC with high or low molecular weight agents (pollens, house dust mites, Penicillia, isocyanates) and in 11 asthmatic patients who underwent an inhalation challenge with placebo. CD69 expression was evaluated at baseline, 120 min, and 240 min after the SIC or the placebo.

RESULTS

Baseline (before challenge) CD69 expression was comparable between the group of SIC positive patients and the placebo group. CD69 expression on peripheral eosinophils significantly increased 240 min after the challenge in positive SIC patients compared to placebo. In patients with a positive SIC the percentage of peripheral blood eosinophils significantly decreased at 120 and 240 min after the inhalation challenge with respect to the baseline.

CONCLUSION

CD69 expression on peripheral blood eosinophils is significantly increased in asthmatic patients after exposure to the sensitizing agent. These data show that the effects of a bronchial stimulation are also detectable on peripheral blood eosinophils.

Occupational asthma and rhinitis due to glutaraldehyde: changes in nasal lavage fluid after specific inhalatory challenge test

BACKGROUNDd: Glutaraldehyde (GA) is a known respiratory sensitizers, and some studies have reported occupational asthma in exposed workers. Specific changes in nasal lavage fluid (NLF) induced by high-molecular-weight allergen provocation in sensitized subjects were described previously. The purpose of this study was to evaluate the changes in cytogram, protein content, eosinophil cationic protein (ECP), and mast-cell tryptase concentrations in NLF after GA inhalation challenge in patients with a positive history of GA-induced asthma and late or dual asthmatic response due to exposure to low-level GA.

METHODS

A single-blind, placebo-controlled study was performed on 11 health workers with occupational asthma and rhinitis due to GA. The control groups comprised 10 atopic subjects with perennial asthma and rhinitis and 10 healthy ones. A "nasal pool" technique was used to evaluate the examined parameters in nasal washings before and 30 min, 4 h, and 24 h after the inhalatory provocation with GA and placebo.

RESULTS

There was a significant increase in eosinophil number and percentage, and albumin, ECP, and tryptase concentrations in NLF from patients with occupational asthma and rhinitis when compared to controls.

CONCLUSIONS

The results indicate the immunologic mechanism of GA-induced asthma and the applicability of the "nasal pool" technique as the diagnostic procedure in GA-induced airway allergy.

Skin test results but not serology reflect immediate type respiratory sensitivity: a study performed with recombinant allergen molecules

The diagnosis of type I allergy, an IgE-antibody-mediated hypersensitivity disease affecting more than 25% of the population, is based on the measurement of allergen-specific serum IgE levels and provocation testing. Whether the determination of allergen- specific serum IgE levels can replace in vivo provocation testing for allergy diagnosis is a controversial issue. We used purified recombinant timothy grass and birch pollen allergens to compare by skin prick and nasal provocation testing as well as by serology in vivo sensitivity with antibody-binding capacity in 24 pollen allergic patients and eight control individuals. Results from biologic tests were correlated with each other and with allergen-specific IgE and IgG1-4 levels. IgE-reactive allergens induced immediate skin and nasal reactions, but the intensity of the allergic tissue reactions was not correlated with either the levels of allergen-specific IgE or the levels of allergen-specific IgG antibodies. Less frequently detected allergens with low IgE-binding capacity were able to induce strong allergic reactions comparable to those caused by major allergens with high IgE-binding capacity. In contrast, skin test and nasal provocation results were significantly correlated (r = 0.63, p < 0.01). Our study thus demonstrates on a molecular level that skin testing provides a better reflection of immediate type respiratory sensitivity than serologic measurements. These results have implications for allergy diagnosis and, in particular, for the selection of relevant allergen components for specific immunotherapy.

Inflammatory and mechanical factors of allergen-induced bronchoconstriction in mild asthma and rhinitis

We studied whether different bronchial responses to allergen in asthma and rhinitis are associated with different bronchial inflammation and remodeling or airway mechanics. Nine subjects with mild asthma and eight with rhinitis alone underwent methacholine and allergen inhalation challenges. The latter was preceded and followed by bronchoalveolar lavage and bronchial biopsy. The response to methacholine was positive in all asthmatic but in only two rhinitic subjects. The response to allergen was positive in all asthmatic and most, i.e., five, rhinitic subjects. No significant differences between groups were found in airway inflammatory cells or basement membrane thickness either at baseline or after allergen. The ability of deep inhalation to dilate methacholine-constricted airways was greater in rhinitis than in asthma, but it was progressively reduced in rhinitis during allergen challenge. We conclude that 1) rhinitic subjects may develop similar airway inflammation and remodeling as the asthmatic subjects do and 2) the difference in bronchial response to allergen between asthma and rhinitis is associated with different airway mechanics.

Nasal provocation testing: a review

OBJECTIVE

This review focuses on the uses of nasal provocation testing (NPT) for scientific investigations of the mechanisms of allergic and nonallergic rhinitis. It also describes the use of NPT as a diagnostic tool in clinical practice. The indications, contraindications, advantages, and limitations of different techniques for evaluation of nasal responses are reviewed. The paper familiarizes investigators with particulars of different nasal delivery systems, provocation agents, nasal patency measurements, secretion collection, and nasal lavage techniques.

DATA SOURCES

Relevant publications obtained from a literature review.

STUDY SELECTION

Relevant publications on the topics of NPT, allergic, and nonallergic rhinitis were critically evaluated.

RESULTS AND CONCLUSIONS

To date, NPT has been used primarily as a research tool for the investigation of allergic and nonallergic rhinitis with a wide variety of techniques depending on the specific scientific purposes. NPT will continue to provide useful information about the pathogenesis of airway diseases. Standardized nasal provocation testing has the potential to become a more frequently used clinical test in the diagnosis of allergic and occupational rhinitis and for determination of the appropriate and focused therapy.

Asthma and rhinitis induced by exposure to raw green beans and chards

BACKGROUND

Although the vast majority of IgE-mediated allergic reactions to foods occurs through ingestion, a few cases of unexpected allergic reactions to foods may occur through the exposure to airborne food allergen particles.

METHODS

Case reports. Skin prick tests and serum-specific IgE (CAP-FEIA) were used to identify specific IgE antibodies. Bronchial provocation tests were performed to determine the clinical relevance of inhaled exposure to raw and cooked green beans and raw chards. After demonstrating specific reactivity to them, SDS-PAGE and immunoblotting of raw and cooked green beans were carried out to identify relevant antigens.

RESULTS

Three women developed bronchial asthma and rhinitis after exposure to raw green beans, and one of them also when exposed to raw chards. All women tolerated ingestion of green beans. Patients reported multiple episodes while handling these vegetables for cooking activities. Allergy to green beans and chards was demonstrated by skin testing and serum-specific IgE. Bronchial challenge test with these allergens showed positive responses to raw, but not cooked, green beans and chards. Oral food challenges with green beans (raw and cooked) and chards were negative in all patients. In order to further characterize the allergenic components of these extracts, SDS-PAGE and electroblotting studies were also performed. Immunoblots of raw and cooked green beans extract showed two IgE-binding bands with apparent molecular weights of 41.1 and 70.6 kD. Interestingly, a 47-kD IgE-binding protein was detected only in raw green bean extracts.

CONCLUSIONS

We report three patients who developed asthma and rhinitis caused by exposure to raw, but not to cooked, green beans and chards in a non-occupational environment. Only minor differences of IgE reactivity between nitrocellulose-blotted raw and boiled green bean extract were found.

Nasal provocation test in the diagnosis of natural rubber latex allergy

BACKGROUND

Natural rubber latex (NRL) allergy in workers using rubber gloves has been an occupational health problem for the last 10 years. In the case of the occupational agents, clinical history may be far from conclusive; hence, appropriate provocation should be carried out. The objective was to evaluate the usefulness of the nasal challenge test in the diagnosis of allergic rhinitis in subjects occupationally exposed to NRL.

METHODS

A single-blind, placebo-controlled study was conducted in 16 nurses with respiratory symptoms (bronchial asthma and/or rhinitis) related to NRL exposure as well as positive skin prick test (SPT) response to NRL. The controls were nine nurses with asthma and/or perennial rhinitis unrelated to NRL exposure; six atopic patients not occupationally exposed to NRL, with asthma and/or perennial rhinitis; and six healthy subjects. All the controls had negative results of SPT with NRL. Patients with a history of anaphylaxis or positive results of RAST to NRL were not considered in the study. The "nasal pool" technique was used to evaluate the cellular response and changes in protein level and ECP concentration in nasal washings after topical provocation with allergen or placebo.

RESULTS

A significant increase was noted in eosinophil and basophil number, albumin/total protein ratio, and ECP level only in NRL SPT-positive patients subjected to nasal challenge with NRL. Neither bronchial nor systemic reactions were found after the nasal provocation with NRL.

CONCLUSIONS

The nasal challenge test appears to be useful for diagnosing occupational rhinitis in NRL-sensitized patients.

Pollinosis to Ricinus communis (castor bean): an aerobiological, clinical and immunochemical study

BACKGROUND

Ricinus communis (castor bean) is a species included into the Euphorbiaceae family, common to all the warm regions of the world. Although the allergenicity of its seed is well known, references are scarce regarding the role played by its pollen as a pneumo-allergen.

OBJECTIVES

To carry out an aerobiological study of this pollen in the Málaga area (southern Spain); describe the physicochemical characteristics of its most relevant allergens; and to demonstrate the existence of patients with respiratory allergy due to this pollen.

METHODS

A Burkard spore trap was used for the aerobiological study from 1992 to 1996. Skin prick tests with castor bean pollen extract were performed to 1946 patients with rhinitis and/or asthma. Specific IgE levels were measured in castor bean-positive SPT patient sera. Immunochemical characterization of the most relevant allergens was performed using electrophoretic techniques. In vitro cross-reactivity studies using positive patient sera were carried out. Nasal challenge tests were done in 32 subjects randomly selected from the sensitized patient group.

RESULTS

Castor bean is a perennial pollen with total annual pollen levels never exceeding 1%. One hundred and eighteen (7.7%) patients showed positive prick test (74 rhinitis, 36 rhinitis and asthma, eight asthma). Nine were monosensitized. Specific IgE levels were > or =0.35 PRU/mL in 39 (33%) of patient sera. Nasal challenge test: 10 subjects presented non-specific nasal hyperactivity, 15 were positive and seven negative. The molecular masses and isoelectric points of the main IgE-binding proteins, ranged from approximately 67-15.5/14.5 kDa and approximately 4.5-5.5, respectively. Profilin of the extract was purified by poli-L-proline-Sepharose chromatography and it appeared as one of the most frequent allergens.

CONCLUSION

Castor bean pollen is an allergen which causes respiratory (mainly nasal) symptoms.

Comparison of the effects of terfenadine with fexofenadine on nasal provocation tests with allergen

BACKGROUND

Fexofenadine, the hydrochloride salt of terfenadine active metabolite, is a nonsedative, noncardiotoxic antihistamine derivative for the treatment of allergic rhinitis.

OBJECTIVE

We sought to compare the effects of terfenadine and fexofenadine on nasal provocation tests with allergen.

METHODS

A preliminary provocation test (screening phase) was performed in 25 patients with a history of seasonal allergic rhinitis to grass pollen to determine the combined nasal reaction threshold, which was defined as 2 of the 3 following criteria: (1) at least a 40% decrease in peak nasal inspiratory flow and/or a 30% decrease in minimal cross-sectional area as measured by acoustic rhinometry, nasal secretions of 0.5 g, and 5 to 10 sneezes per minute. Patients were then included into a double-blind, randomized, 2-way crossover study to receive terfenadine or fexofenadine 120 mg 2 hours before provocation. Rhinorrhea, sneezing, peak nasal flow, and minimal nasal cross-sectional area, as well as symptom scores for nasal congestion and itchiness, were recorded at each allergen concentration up to the reaction threshold. The whole study was performed out of allergy season.

RESULTS

Fexofenadine was as potent as terfenadine in limiting pruritus and nasal congestion. Rhinorrhea and sneezing were better controlled by fexofenadine than by terfenadine. Overall, the allergen concentration necessary to reach the combined reaction threshold was increased after treatment with both drugs. Comparison between screening and each treatment phase indicated that the shift in allergen concentration to reach the reaction threshold was significantly greater after fexofenadine than after terfenadine (P =. 033).

CONCLUSION

After oral administration, fexofenadine provided better protection than terfenadine against the immediate allergic reaction.

Occupational asthma caused by exposure to asparagus: detection of allergens by immunoblotting

BACKGROUND

Vegetables of the Liliaceae family, such as garlic or onion, have been reported to cause occupational asthma. However, there are few data on adverse reactions to asparagus. We evaluated the role of asparagus as a cause of asthma in a patient with respiratory symptoms occurring at work (horticulture) and studied relevant allergens.

METHODS

A 28-year-old man complained of rhinoconjunctivitis and asthma when harvesting asparagus at work. Eating cooked asparagus did not provoke symptoms. A positive skin test reaction was observed with raw asparagus, Alternaria alternata, and grass-pollen extracts. The methacholine test demonstrated mild bronchial hyperresponsiveness. The patient had an immediate asthmatic response after challenge with raw asparagus extract. Bronchial provocation tests with boiled asparagus, A. alternata, and control extracts were negative. Two unexposed subjects with seasonal allergic asthma did not react to the raw asparagus extract.

RESULTS

The double-blind, placebo-controlled food challenge with raw asparagus was negative. Serum asparagus-specific IgE was 13.9 kU(A)/l. By SDS-PAGE immunoblot, at least six IgE-binding components, ranging from 22 to 73 kDa, were detected only in raw asparagus.

CONCLUSIONS

We report a case of occupational asthma caused by asparagus inhalation, confirmed by specific bronchoprovocation. Immunoblot analysis showed that asparagus allergens are very labile and quite sensitive to heat denaturation.