Airways of allergic rhinitics are 'primed' to repeated allergen inhalation challenge

Nasal Challenge, Skin Tests, and Serum Antibodies in the Diagnosis of Latex-Induced Occupational Rhinitis

The purpose of the study was to develop a suitable natural rubber latex (NRL) antigen powder and a control material for the nasal application of the test reagent and to evaluate the nasal provocation test (NPT) response pattern in latex allergic and nonlatex allergic subjects with a suspicion of latex-induced rhinitis. A questionnaire was completed among health care workers (n = 268) in one hospital. Seven health care workers who had upper respiratory symptoms associated with daily usage of latex gloves were examined by using skin prick test (SPT), NPT, and sinus plain X-ray. NRL allergen for the nasal challenge was collected from surgical gloves. The powder was obtained by washing the gloves, freeze-drying the solution, and the powder was then used in NPT. As a negative control, clean corn starch powder was applicated on nasal mucous. SDS-PAGE analysis of the NRL test powder was performed. After the nasal challenge, one of seven workers showed rhinorrhea, a significant increase in nasal obstruction, and in the amount of nasal secretion in NPT. This patient also showed a positive SPT to NRL allergens and an elevated NRL specific IgE level in her serum. In six patients NPT, SPT, and specific IgE for latex were negative. SDS-PAGE analysis of the glove powder showed a major NRL antigen, with molecular weight of 14 kDa. The NPT may be used in persons with a suspicion of latex-induced rhinitis and borderline skin and humoral test results for NRL and in subjects with heavy glove powder-associated nasal symptoms but negative skin and humoral tests for latex. Only well known test reagents should be used in NPT.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Minimal persistent inflammation in allergic rhinitis: implications for current treatment strategies

Patients with allergic rhinitis have traditionally been placed into 'seasonal' and 'perennial' categories, which do not account for the subclinical inflammatory state that exists in many patients. In subjects with seasonal and perennial allergic rhinitis, even subthreshold doses of allergen have been found to cause inflammatory cell infiltration in the nasal mucosa, including increases in expression of cellular adhesion molecules, nasal and conjunctival eosinophilia, and other markers of inflammation, which do not result in overt allergy symptoms. This state - which has been termed 'minimal persistent inflammation'- may contribute to hyperreactivity and increased susceptibility to development of clinical symptoms as well as common co-morbidities of allergic rhinitis, such as asthma. Treating overt allergy symptoms as well as this underlying inflammatory state requires agents that have well-established clinical efficacy, convenient administration, potent anti-inflammatory effects and proven long-term safety, so that long-term continuous administration is feasible. Of the three major classes of commonly used allergic rhinitis medications - intranasal corticosteroids, anti-histamines, and anti-leukotrienes - intranasal corticosteroids appear to represent the most reasonable therapeutic option in patients who would benefit from continuous inhibition of persistent inflammation.

Local nasal specific immunotherapy for allergic rhinitis

The possibility of producing local hyposensitization by administering allergens via mucosal routes was envisaged at the beginning of 1900, and local nasal immunotherapy has been extensively studied since the 1970s. Presently, there are 21 randomized controlled trials being conducted with the most common allergens, consistently showing the clinical efficacy of local nasal immunotherapy for rhinitis. Other advantages are that it has an optimal safety profile and can be self-administered at home by the patient. Moreover, there are several data from animal models and from humans that confirm the immunomodulatory effect of intranasally administered antigens. On the other hand, local nasal immunotherapy seems to be effective only on rhinitis symptoms and requires a particular technique of administration. For these reasons, its clinical use is progressively declining in favour of the sublingual route although nasal immunotherapy is validated in official documents and remains a viable alternative to injection.

Determinants of allergen-induced late bronchial responses in mild asthmatics

STUDY OBJECTIVE

To examine the baseline factors influencing the occurrence and magnitude of immediate- and late-phase responses in asthmatic patients after an allergen-induced bronchial provocation test (A-BPT).

DESIGN

Cross-sectional analysis in a homogenous group of 31 mild, Dermatophagoides pteronyssinus-allergic patients with asthma.

SETTING

Allergy Department, Hospital Virgen del Camino, Pamplona, Spain.

INTERVENTIONS AND MEASUREMENTS

Patients completed an asthma symptom questionnaire and underwent skin tests, sputum induction, and methacholine bronchial provocation test. The A-BPT was performed on a separate day. Sputum cell profile and eosinophil cationic protein (ECP), tryptase, albumin, and interleukin-5 levels were quantified in the entire sputum supernatant. Assays were done for eosinophils in blood, and/or ECP, and total and specific IgE levels in serum. Exposure to D pteronyssinus major allergens (Der p1 and Der 2) was measured by an assay based on monoclonal antibodies.

RESULTS

A-BPT findings were positive in all patients, and late-phase responses were detected in 29%. Late responders were exposed to higher levels of Der p1 (p = 0.028), had greater levels of ECP (p = 0.007) and albumin (p = 0.019) in sputum, and showed a trend toward higher lymphocyte numbers (p = 0.053) in sputum than isolated early responders. The allergen-induced provocative dose that induced a fall in FEV(1) values > or =20% from the postdiluent values correlated with bronchial hyperresponsiveness (r = 0.36). The late-phase response magnitude correlated with Der p1 exposure (r = 0.49) and showed a trend toward correlation with sputum ECP levels (r = 0.38).

CONCLUSION

Factors involved in the development of allergen-induced immediate- and late-phase responses are different. Allergen natural exposure might prime the infiltration of the airway by activated inflammatory cells enhancing the appearance and the severity of late-phase responses.

Nordic consensus report on asthma management. Nordic Asthma Consensus Group

The work with the Nordic consensus report on asthma management started some years ago. The Nordic countries have common socioeconomic conditions. We acknowledge the international as well as other European guidelines providing valuable recommendations. Nevertheless, we felt the need to combine the common Nordic experiences in order to have a local statement of asthma and asthma care, based upon Nordic clinical science and tradition. The work has been rewarding and we acknowledge many valuable contributions from paediatricians, allergologists and lung physicians in all Nordic countries. The response has so far been positive and we feel that the present material reflects the main opinion of Nordic physicians taking care of asthma patients of all ages. However, the asthma and allergy research field is rapidly developing. Thus, this document should merely be regarded as a time-limited contribution to the continuing scientific discussion of this fascinating field.

A scientific reappraisal of the 'principle of similarity'

In the history of therapeutics, the 'principle of similarity'--the treatment of 'same by same' or of 'like by like'--may be traced back to a number of medical traditions, including the systems of Hippocrates, Paracelsus and Hahnemann. Although in recent years we have witnessed a renaissance of interest in traditional medicines and 'holistic' medical practices, the reliability of the principle of similarity has still to be demonstrated on experimental grounds, and very few studies have been conducted to understand the underlying mechanism(s). Acceptance of this phenomenon requires supporting evidence of possible mechanisms and high-quality studies exploring its effectiveness in clinical medicine. The aim of this work is to provide a rational approach to the analysis of the various aspects of this historical yet also modern medical principle, in order to construct a plausible framework of ideas capable of facilitating further basic and clinical research into this field.

Allergen-induced airway reactions in atopic asthmatics correlate with allergen-specific IL-5 response by BAL cells

Allergen-specific cytokine responses in the airways are thought to play a critical role in the pathogenesis of atopic asthma. This study examined whether there is a quantitative difference in bronchoalveolar lavage (BAL) cell allergen-induced IL-5 production between atopic subjects with and without asthma which may relate to a difference in airway response induced by allergen exposure. Twelve atopic asthmatics (AA), nine atopic non-asthmatics (AN) and 10 normal controls (N) underwent inhalation challenge with house dust mite allergen (HDM) extract. AA differed from AN in having late airway reactions (LAR) after HDM inhalation (P < 0.01), which correlated with an increased percentage of BAL eosinophils and increased BAL cell IL-5 production after in vivo or in vitro HDM challenge for the AA group (P < 0.01). IL-5 production by PBMC from both atopic groups was elevated with HDM stimulation in vitro, but AA again had a higher level under baseline conditions than AN (P < 0.02). Furthermore, there was a greater effect of BAL fluid from AA on ECP release by eosinophils compared to that for AN (P < 0.01). These findings suggest that increased IL-5 production in atopic asthmatic airways contributes to the increased physiological response to allergen inhalation, by modulating local eosinophil recruitment and activation.

A preceding airway reaction to one allergen may lead to priming of the airway responses to another allergen

This study aimed to determine whether a preceding airway response to one allergen leads to priming of the airway responses to another allergen. Twelve asthmatic children who had positive prick tests to two allergens, Dermatophagoides pteronyssinus (D.p.) and German cockroach (CR), participated in a randomized, placebo-controlled crossover study. We performed two consecutive inhalation challenges, D.p. challenge being followed 48 h later by CR challenge. The effect of initial (D.p.) challenge on the early and late airway responses to the subsequent (CR) challenge (CR2) was examined by comparing the responses with those to CR challenge preceded by sham challenge (CR1). The geometric mean PD20 of CR allergen in the CR2 was 2.8 BU (breath unit) (range of 1 SD; 0.77-10.4), which was 12.0-fold less than that (33.7 BU, 10.8-105.2) in the CR1. The administration of a 6.1-fold less dose (8.9 BU, 2.7-28.8) in the CR2 than in the CR1 (54.5 BU, 44.1-69.3) provoked a similar degree of late-phase reactions (18.7 +/- 7.3% vs 15.8 +/- 9.6%). Our data indicated that the early- and late-phase reactions to CR challenge were augmented by the preceding reaction to D.p. This suggests that a preceding airway response to one allergen may lead to priming, with enhancement of the early and late airway responses to the subsequent challenge with another allergen.