Allergy to Dermatophagoides pteronyssinus was determined in 61 rhinitis patients using prick test (PT), enzyme-immunoassay (EIA) and enzyme-linked immunosorbent assay (ELISA). A total of 43 patients tested positive with PT. Forty six patients were positive when tested with EIA and ELISA. With PT as standard test, EIA was found to have 83.7% sensitivity and 44.4% specificity; ELISA had 81.4% sensitivity and 38.9% specificity. There was a linear relationship between absorbance values obtained by EIA and ELISA. The performance time was 8 hours, 24 hours and 30 minutes for ELISA, EIA and PT respectively. The cost per test for ELISA, EIA and PT was US$ 0.20, US$ 5.20 and US$ 0.14 respectively. It was concluded that ELISA was more cost-effective than EIA should be used to supplement PT for a more complete diagnosis of allergy.
Allergy diagnosis needs to be improved in polysensitized patients due to the existence of possible confounding factors in this type of patients. Component resolved diagnosis (CRD) is a new concept in the investigation of polysensitized patients. The aim of this study was to evaluate if the utilization of ImmunoCAP ISAC improve the diagnosis of the polysensitized allergic rhinitis patients. Skin prick test (SPT) to 58 crude allergen extracts and CRD (ImmunoCAP ISAC) were carried out for 5 polysensitized allergic rhinitis patients. Two patients had a shellfish allergy and avoidance of shellfish was the only way to prevent an allergic reaction. In contrast, although the remaining three patients had low risk for shellfish allergy, but they were the best candidates for immunotherapy using mite extracts. CRD and particularly ImmunoCAP ISAC have proven to be a valuable diagnostic tool in polysensitized patients. ImmunoCAP ISAC helps refine the individual patient's sensitization profile and predict the potential risk of allergic reactions and improve the selection of patients for immunotherapy.
Allergic rhinitis is the single most common chronic allergic disease affecting an estimated four million people in Malaysia. House dust mites, grass pollens and fungal spores play has been identified to play a major role in the pathogenesis of allergic rhinitis. However, sensitization to pollen and spores in Malaysia is not well documented. On the basis of the results of an aerobiological survey of the common mold spores and pollens in the Klang Valley, twelve local extracts of molds and two local extracts of grass pollens were prepared by the Institute for Medical Research for this study. The study evaluated the prevalence of skin prick test (SPT) reactivity to the extracts of those airborne molds and pollens in allergic rhinitis patients in the Klang Valley. A total of 85 allergic rhinitis patients were recruited. All molds and grass pollens extracts tested, elicited positive response to SPT. Among the molds extracts, Fusarium was observed to have the highest prevalence of SPT reactivity (23.5%), followed by Aspergillus flavum (21.2%), Dreselera orysae (18.8%), Alternaria sp (17.6%), Curvularis eragrostidis (17.6%), Penicillium oxa (16.5%), Pestolotriopsis gtuepini (16.5%), Rhizopphus arrhi (16.5%), Aspergilluls nigus (15.3%). Penicillium choy (12.9%), Aspergillus fumigatus (11.8%), and Cladosporium sp (4.7%). In the grass pollen, the SPT reactivity to Ischaemum and Enilia is 14.1% and 5.9% respectively. However, the prevalence of SPT reactivity was not influenced by the age, sex, ethnicity, symptomatology and concurrent allergic condition. We have documented the prevalence of skin prick test reactivity to common molds and grass pollens in the Klang valley, which is comparable to the neighboring countries. Its prevalence in our allergic rhinitis patients suggests that it has a role in pathogenesis of allergic diseases. A larger representative sample involving multi-centric centers in Malaysia should be encouraged in the near future.
Study site: ENT
Department, Pusat Perubatan University Kebangsaan Malaysia
Peanut allergy is a hypersensitivity reaction with symptoms varying from mild to severe anaphylaxis, tends to be lifelong and very few are able to outgrow this allergy. The prevalence of peanut allergy is highest among the Western countries and over the past decade, a 3.5 fold increase in prevalence of peanut allergy was reported among children in the United States. Increasing prevalence has also been observed among the Asian countries. As with other food allergies, peanut allergy reduces quality of life for the affected individuals and the social and economy burden of healthcare for peanut allergy is substantial. To date, there is no effective treatment for peanut allergy and disease management is by avoidance or relieve of symptoms via administration of epinephrine. Peanut allergy is a type-1 hypersensitivity reaction due to specific IgE production by activated T-helper type 2 (TH2) cells. Studies on various immunotherapy routes such as oral immunotherapy (OIT), sublingual immunotherapy and epicutaneous immunotherapy trials using peanut have shown the ability to induce desensitisation, shifting the allergen-specific cytokine production away from a TH2 respond. In the recent years, lactic acid bacteria probiotics have been reported to down-regulate allergy due to its inherent immunomodulatory properties. Wild-type probiotic in combination with peanut proteins or recombinant probiotics harbouring peanut allergens have been explored for OIT due to its ability to down-regulate allergen-specific-IgE production and the TH2 responses, while increasing the beneficiary population of TH1 regulatory T cells (Treg). This review discusses the current strategies in immunotherapy for peanut allergy.