P. Guardia

Understanding patient sensitization profiles in complex pollen areas: a molecular epidemiological study

Background:  Allergy diagnosis in patients exposed to multiple pollen species is complex and misdiagnosis is often a cause for unsuccessful specific immunotherapy.

Neutrophils as a Novel Source of Eosinophil Cationic Protein in IgE-Mediated Processes

The production of eosinophil cationic protein (ECP) in IgE-mediated diseases has been associated mainly with eosinophils, although no IgE-dependent ECP release has been observed in these cells. Because there is increasing evidence of neutrophil participation in allergic processes, we have examined whether human neutrophils from allergic patients were able to produce ECP by an IgE-dependent mechanism. After challenge with specific Ags to which the patients were sensitized, ECP release was detected in the culture medium. Furthermore, intracellular protein was detected by flow cytometry, immunofluorescence staining, and Western blotting. Expression at both mRNA and de novo protein synthesis were detected, respectively, by RT-PCR and radiolabeling with 35S. Ag effect was mimicked by cell treatment with anti-IgE Abs or Abs against FcεRI and galectin-3 (FcεRI>galectin-3), but not against FcεRII. These observations represent a novel view of neutrophils as possible source of ECP in IgE-dependent diseases.

Clustered schedules in allergen-specific immunotherapy.

BACKGROUND Injective immunotherapy is traditionally performed with a build-up phase lasting 3 to 4 months. The costs, decreasing compliance from both patients and clinicians and inconveniences due to this schedule may be overcome using different schedules. METHODS AND RESULTS A revision of the published papers with clustered schedules has been made. Attention has been focussed on tolerance and its relationships with relevant parameters such as kind of extract (aqueous or depot), allergens and their pharmaceutical presentation, schedule followed, use or not of a premedication, clinical manifestations of patients before treatment. For a better revision, papers dealing with clustered schedules have been divided into two groups. The first group includes 20 papers not designed to study the clustered schedule but using it to study other parameters affected by specific immunotherapy. The second group includes 9 papers specifically or mainly designed to study the clustered schedule. A huge difference in the rate of side effects could be assessed among different papers, even in studies run with similar allergens from the same producer and with a similar schedule. CONCLUSIONS Summarizing the results of the revision, the following conditions seem to lead to the optimal tolerance of the clustered schedule: use of a premedication; use of a depot preparation; use of no more than 4 administrations per cluster; administration of 1-2 clusters per week and of 4 to 6 clusters in total. These results seem promising but further efforts are required to better define the optimal clustered schedule.

Respiratory Burst in Neutrophils from Asthmatic Patients

Background: The role of oxygen radicals has been implicated in disease processes of asthma. We have previously shown that specific allergens were able to activate respiratory burst by neutrophils from allergic patients sensitized to allergens of the same type as those which produce clinical allergy. Objectives: In this study, we attempted to evaluate the production of respiratory burst by an anti-IgE Ab in neutrophils from asthmatic allergic patients (with and without immunotherapy treatment) and in neutrophils from healthy subjects. Method: Neutrophils were stimulated by 10 µg/mL of anti-IgE Ab for 15 min at 37°C. The production of respiratory burst from neutrophils was assayed by luminol-amplified chemiluminescence method. Results: The respiratory burst was significantly higher in neutrophils from non-IT-asthmatic patients than in neutrophils from both healthy (p<0.001) and IT-asthmatic (p<0.001) groups. The IT-asthmatic group presented levels of respiratory burst approximately equal to those from non-allergic subjects (p=0.426). Conclusions: We conclude that neutrophils obtained from allergic asthmatic patients have an increased propensity to generate respiratory bursts, in comparison with neutrophils from healthy subjects. Immunotherapy actively modifies the respiratory burst by neutrophils from allergic asthmatic patients.

l‐Selectin expression on neutrophils from allergic patients

Background L‐selectin (CD62L) is an adhesion molecule involved in leucocyte attachment to endothelium at sites of inflammation, and it has been demonstrated that L‐selectin is rapidly shed after neutrophil activation. Recently, it has been reported that there is increasing evidence of neutrophil participation in asthma and the allergic process.

Tolerance and short-term effect of a cluster schedule with pollen-extracts quantified in mass-units.

We performed a prospective, multicenter study to assess the tolerance and possible short-term effects of allergen vaccines administered according to a cluster schedule in the months immediately preceding the onset of the pollen season. The study was carried out in eight centers and included 191 patients (children and adults) with allergic respiratory disease due to sensitization to olive tree and/or grass pollen. Of these, 34 patients acted as controls and the remaining patients received immunotherapy administered in the initiation phase according to a cluster schedule of eight doses injected on four visits. After 3 months of treatment, significant differences were found between the two groups in medication consumption (antihistamines in drops and oral formulations: p = 0.045 and p = 0.001, respectively; short-acting beta2-agonist treatments: p = 0.004) and respiratory symptoms (wheezing and coughing: p = 0.035 and 0.014, respectively). The cytokine profile (interleukin [IL]-4, 5, 10 and 2, interferon [IFN-gamma], and tumor necrosis factor [TNF-alpha]) was determined before the start of treatment and at the end of follow-up (4-5 months). Levels of IL-4, 5 and 10 (Th2 profile) decreased while those of IL-2, IFN-gamma, and TNF-alpha (Th1 profile) decreased. These differences were more marked in the active group than in the control group but were not statistically significant. No severe adverse effects were recorded. This study shows that the schedule tested had an acceptable tolerance profile and produced significant changes in symptom and medication scores after a few months of treatment. A double-blind, placebo-controlled study is needed to confirm these results.

Clinical evolution of patients with respiratory allergic disease due to sensitisation to Alternaria alternata being treated with subcutaneous immunotherapy

INTRODUCTION Sensitisation to Alternaria is a cause of respiratory disease in Spain, particularly in childhood, but it is also a significant marker of the severity of this disease. Therefore, the use of an aetiological treatment (allergen specific immunotherapy) is essential, and both subjective and objective clinical parameters should be used to follow up this treatment. OBJECTIVE This open-label, uncontrolled, observational, prospective study was designed in order to study the evolution of these patients on allergen specific immunotherapy therapy in daily clinical practice and to assess the use of different monitoring tools. MATERIAL AND METHODS A total of 99 patients were included. They were monosensitised to this perennial allergen and treated with subcutaneous allergen specific immunotherapy. After one year of follow-up, these patients were assessed for the presence of symptoms, use of medication, clinical incidents, quality of life and asthma control. RESULTS After one year of treatment a significant fall was observed in the use of concomitant medication (β2-agonists: p=0.0278, inhaled corticosteroids: p=0.0007, anti-leukotrienes: p=0.0495), nasal symptoms (p=0.0081), quality of life (PAQLQ, p<0.0001) and asthma control (ACQ, p<0.0001). Twenty-one patients had to attend emergency department due to exacerbation of their allergic disease, and only one of them had to be admitted to hospital. CONCLUSION respiratory allergic disease due to Alternaria alternata is a disease which is hard to control, and in our daily practice, the use of specific subcutaneous immunotherapy can be of significant benefit in our paediatric patients.

Peripheral blood T lymphocytes in seasonal bronchial asthma.

Variations in T lymphocytes in asthmatic patients are related to disease severity. However, the effects of natural exposure to pollens on peripheral blood T lymphocytes have not been clarified. In this paper, the effects on peripheral blood CD4 and CD8 lymphocytes from pollen‐sensitive subjects and from nonatopic donors were studied during and outside the pollen season. In patients who suffer from seasonal asthma, we found an increase in the CD4/CD8 bright ratio and a decrease in the mean number of CD4 receptors per cell during the pollen season. No variation was observed in healthy subjects. These results suggest that CD4 lymphocytes may be causally linked to the pathogenesis of seasonal bronchial asthma.

Occupational rhinitis caused by beech wood dust

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Allergen-dependent CD14 modulation and apoptosis in monocytes from allergic patients.

Background: CD14 is a most important monocyte surface molecule. Recently, it has been reported that there is an important relationship between CD14 and immunoglobulin E, and that regulation of CD14 expression is an effector mechanism mediating apoptosis of monocytes.