Component-resolved diagnosis using microarray for diagnosing hypersensitivity to raw fruits in birch pollen sensitized children

PURPOSE: Recently, component-resolved diagnosis (CRD) using microarray technology has been introduced to the field of clinical allergy. This study was aimed to investigate the clinical usefulness of microarray-based IgE detection for diagnosing clinical raw fruit allergy in birch pollen-sensitized children. METHODS: Thirty-one children with allergic disease who had been sensitized to pollen were studied. A pollen-sensitized patient was defined as having an allergen-specific history with concomitant positive skin-prick tests (SPTs) to natural allergen extracts or positive allergen-specific IgE. All subjects underwent SPTs for pollen and fruit. In all subjects, specific IgE to pollen and fruit were measured by ImmunoCAP. Specific IgE antibodies to allergen components were determined by a customized allergen microarray (ISAC). RESULTS: Thirteen of the 31 patients (41.9%) had a history of fruit hypersensitivity with positive SPTs. Measuring IgE to allergen components by ISAC, all the 13 patients with fruit hypersensitivity were positive to at least one of Mal d 1, Pru p 1, Pru p 3, Act d 8, and Act d 2 compared to 12 of the 13 patients (92.3%) who had at least 1 positive IgE to fruits (apple, peach, and kiwi) using ImmunoCAP. The sensitivity of ISAC microarray was 100.0% for the diagnosis of fruit hypersensitivity, but its specificity was 27.7% (5/18). The sensitivity of ImmunoCAP was 92.3%, and its specificity was 83.3%. CONCLUSION: The sensitivity of allergen components tested using microarray for the diagnosis of clinical fruit hypersensitivity in children with pollen allergy was high; however, its specificity was low.

Prevalence of latex allergy in spina bifida patients in Singapore

BACKGROUND: Latex allergy and its clinical presentation are rising in prevalence across the globe, especially amongst patients with spina bifida (SB). While studies have been well-established in Europe and America, data from Asia are limited. OBJECTIVE: The aim of this study is to investigate the scenario in Singapore. METHODS: 35 subjects with SB, aged 5 to 32 years answered a questionnaire and underwent skin prick test (SPT) using a latex solution, 3 common house dust mites and 3 commonly cross-reacting food allergens (banana, kiwi and avocado). We also noted the relation between latex sensitization with atopy and doctor-diagnosed allergy. The prevalence of cross-reactivity with fruits was also studied. RESULTS: Sensitization to latex (i.e. a positive SPT) was found in 16 (46%, 95% confidence interval 29%-63%) of the subjects. Only 5 (31%) of the subjects who were sensitized to latex had clinical manifestations. Atopy (i.e. positive SPT to house dust mites) was present in 23 (66%) of the subjects and 13 (57%) of them was also sensitized to latex. There was a positive trend between latex sensitization and atopy (81.2% vs. 52.6%, p = 0.076), as well as latex sensitization with those having both atopy and doctor-diagnosed allergy (i.e. asthma, allergic rhinitis, eczema, drug allergy) (93.8% vs. 63.2%, p = 0.032). Only 6 (38%) subjects had allergy to the food allergens tested. CONCLUSION: Almost half of the SB patients in Singapore are sensitized to latex. This number is comparable to that in Europe and America. Positive trend between latex sensitization and those with both atopy and doctor-diagnosed allergy (p = 0.032) is suggestive of a possible cause-effect relationship.

Frozen fruit skin prick test for the diagnosis of fruit allergy.

Background: Diagnosis of fruit sensitisation by skin prick test (SPT) is fast and easy to perform. Nevertheless, some fruit is not available throughout the year. Freezing aliquots of these fresh fruits to be defrosted would be a good solution to perform SPT at any time. Objective: To compare the reproducibility of SPT with Rosaceae and Cucurbitaceae frozen fruit with fresh and commercial fruit extracts. Methods: SPT with the following fruit were performed: apricot, cherry, strawberry, nectarine, Japanese medlar, peach, (peel and pulp), yellow and red plum, melon and watermelon. We compared fresh fruit, commercial extract and fruit which had been frozen at -18°C. Results were read by planimetry (Inmunotek prick-filmTM) after 15 minutes. Results: The study group comprised 48 patients (9 males, 39 females) with a mean age of 31, 6 ± 2,0 years. Concordance of positive and negative results was extremely high and significant in all cases. Correlation between frozen fruit and commercial extract, frozen fruit and fresh and commercial extract and fresh fruit was statistically significant in all cases except for strawberry. Conclusions: The use of frozen fruit is a valid method, as the performance of the SPT is similar to that of fresh fruit. This enables diagnostic procedures with seasonal fruit at any time of the year.

Síndrome de alergia oral / Oral allergy syndrome

A síndrome de alergia oral (SAO) é uma condição caracterizada por sintomas alérgicos mediados por IgE, que se restringem à mucosa oral. Em situações em que as manifestações são decorrentes da ingestão de frutas e vegetais em indivíduos sensibilizados aos pólens, o termo mais específico é síndrome pólen-frutas (SPF). Uma vez que as porções proteicas dos alérgenos envolvidos são degradadas pelo calor e enzimas digestivas, os sintomas são imediatos, restringem-se geralmente à cavidade oral e a forma cozida ou processada dos mesmos alimentos costuma ser bem tolerada.