Enhanced diagnosis of pollen allergy using specific immunoglobulin E determination to detect major allergens and panallergens.

BACKGROUND: Pollen is one of the main causes of allergic sensitization. It is not easy to make an etiological diagnosis of pollen-allergic patients because of the wide variety of sensitizing pollens, association with food allergy, and increasing incidence of polysensitization, which may result from the presence of allergens that are common to different species, as is the case of panallergens. OBJECTIVE: To compare the results of skin prick tests (SPT) using whole pollen extract with specific immunoglobulin (Ig) E determination for several allergens (purified panallergens included) in the diagnosis of polysensitized pollen-allergic patients. METHODS: The study sample comprised 179 pollen-sensitized patients who underwent SPT with pollen extract and allergen-specific IgE determination against different allergens. RESULTS: The level of concordance between the traditional diagnostic test (SPT) and IgE determination was low, especially in patients sensitized to the panallergens profilin and polcalcin. In the case of SPT, the results demonstrated that patients who are sensitized to either of these panallergens present a significantly higher number of positive results than patients who are not. However, IgE determination revealed that while patients sensitized to polcalcins are sensitized to allergens from a higher number of pollens than the rest of the sample, this is not the case in patients sensitized to profilins. On the other hand, sensitization to profilin or lipid transfer proteins was clearly associated with food allergy. CONCLUSIONS: Sensitization to panallergens could be a confounding factor in the diagnosis of polysensitized pollen-allergic patients as well as a marker for food allergy. However, more studies are required to further investigate the role of these molecules.

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. OBJECTIVE: We studied the sensitization profile of individual allergens (major, minor and pan-allergens) in pollen-sensitized patients in a region with high exposure to olive pollen by investigating the influence of minor allergens on allergic disease and the association between pan- and minor allergen sensitizations. METHODS: A panel of 13 purified allergens, which included the most relevant allergens in the area, as well as minor olive allergens and pan-allergens, were screened using a high-capacity technology (ADVIA-Centaur) in 891 patients. RESULTS: Olive allergy as measured by specific IgE to Ole e 1 was the leading pollinosis in the area. The minor olive allergens Ole e 7 and Ole e 9 were markers of more severe allergic illness. Profilin sensitization was associated mainly with grass allergy, the second most prevalent pollinosis. Salsola kali pollen allergy was the third most common cause of pollinosis in the area. The prevalence of sensitization to the peach allergen Pru p 3, a nonspecific lipid-transfer protein, was notable. CONCLUSION: Epidemiological analysis by component-resolved diagnosis is a new method, which elucidates the interaction between allergen exposure gradient and patient sensitization. High exposure leads to differential sensitization profiles some of which are associated with more severe allergic conditions. Profilin sensitization, related mainly to grass pollinosis, was a marker of more severe grass pollen sensitization.

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.

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 β2-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-γ], and tumor necrosis factor [TNF-α]) 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-γ, and TNF-α (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 (AU)

Se ha llevado a cabo un estudio prospectivo y multicéntrico con el objetivo de valorar la tolerancia y posible efecto a corto plazo de las vacunas alergénicas administradas bajo pauta cluster en los meses inmediatamente anteriores al inicio de la estación polínica. El estudio se realizó en 8 centros, incluyéndose un total de 191 pacientes (niños y adultos) con enfermedad alérgica respiratoria por sensibilización a polen de olivo y/o gramíneas. De ellos, 34 actuaron como controles y a los pacientes restantes se les administró inmunoterapia bajo una pauta cluster, en la fase de iniciación, de 8 dosis administradas en 4 visitas. Tras 3 meses de tratamiento, se registraron diferencias significativas entre ambos grupos en el consumo de medicación (antihistamínicos en colirio y orales -p = 0,045 y p = 0,001 respectivamente- y ß2 de corta duración -p = 0,004-) así como en síntomas pulmonares (sibilancias y tos -p = 0,035 y 0,014 respectivamente-). Por otro lado, se determinó el perfil de citocinas (IL-4, 5, 10 y 2, IFN-gamma y TNF-a) de forma previa al inicio del tratamiento y al finalizar el seguimiento (4-5 meses). Se observaron descensos en los niveles de IL-4, 5 y 10 (perfil TH2) y aumento en los valores de IL-2, IFN-gamma y TNF-a (perfil TH1), más marcados en el grupo activo que en el control, sin alcanzar significación estadística. No se registraron efectos adversos severos. Por tanto, podemos observar que la pauta ensayada mostró un adecuado perfil de tolerancia, y tras pocos meses de tratamiento se registraron cambios significativos en la puntuación de síntomas y medicación, siendo necesaria la realización de un estudio con un diseño doble ciego frente a placebo para confirmar los resultados obtenidos (AU)

Tolerance of a cluster schedule on the treatment of seasonal allergic respiratory disease with pollen extracts quantified in mass units.

In order to evaluate the tolerance of a cluster schedule on specific immunotherapy (SIT), 306 patients were included in a multicenter study. The patients were suffering from rhinoconjunctivitis with/without asthma, caused by sensitization to olive and/or grass pollen. SIT was administered subcutaneously according to a cluster schedule in which the maintenance dose is reached after four visits (3 weeks). The extracts were biologically standardized with major allergens quantified in mass units. Local reactions appeared in 7.2% of the patients and 1.3% of the doses. Systemic reactions (SR) were recorded in 1.2% of the doses administered to 9.5% of the patients. No anaphylactic shock was registered, and all the SR responded fully and rapidly to treatment. There was no difference in SR according to diagnosis or allergen extract used. The majority of SR occurred with the administration of vial of higher concentration (Vial 2: 7 SR (22%), Vial 3: 32 SR (78%), p < 0.05). Of the 32 SR recorded with Vial 3, 13 (41%) were immediate, with no existing association between dose administered and appearance of SR. However, of the 18 delayed SR (56%), 14 occurred after the administration of the first two doses of Vial 3 and four occurred after administration of the second two doses (78% vs 22%, p < 0.05). On the other hand, this regime realized an important saving in cost and time compared to the conventional schedule (1581 fewer doses and 2754 fewer visits were necessary to reach the optimal dose). Considering all these factors, the clinical profile of the proposed regime may be qualified as good. However, future studies are necessary in order to better adjust the schedule to avoid the delayed SR that occurred after the administration of the first two doses of Vial 3.

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.