The diagnosis of cystic fibrosis (CF) patients with allergic bronchopulmonary aspergillosis (ABPA) is clinically challenging, due to the absence of an objective biological test. Since blood basophils play a major role in allergic responses, we hypothesised that changes in their surface activation pattern discriminate between CF patients with and without ABPA.We conducted a prospective longitudinal study (Stanford cohort) comparing basophil activation test CD203c levels by flow cytometry before and after activation with Aspergillus fumigatus allergen extract or recombinant Asp f1 in 20 CF patients with ABPA (CF-ABPA) and in two comparison groups: CF patients with A. fumigatus colonisation (AC) but without ABPA (CF-AC; n=13) and CF patients without either AC or ABPA (CF; n=12). Patients were tested every 6 months and when ill with pulmonary exacerbation. We also conducted cross-sectional validation in a separate patient set (Dublin cohort).Basophil CD203c surface expression reliably discriminated CF-ABPA from CF-AC and CF over time. Ex vivo stimulation with A. fumigatus extract or recombinant Asp f1 produced similar results within the Stanford ( p<0.0001) and the Dublin cohorts. CF-ABPA patients were likelier to have elevated specific IgE to A. fumigatus and were less frequently co-infected with Staphylococcus aureus.Basophil CD203c upregulation is a suitable diagnostic and stable monitoring biomarker of ABPA in CF. @ERSpublications Blood basophil surface CD203c level is a method to diagnose ABPA in CF, and study phenotypes, therapy and management http://ow.ly/Sc8zr
To our knowledge, this is the first prospective study of Aspergillus species in CF using molecular methods. The paucity of non-A. fumigatus and of cryptic species of A. fumigatus suggests a special association of A. fumigatus sensu stricto with CF airways, indicating it likely displays unique characteristics making it suitable for chronic residence in that milieu. These findings could refine an epidemiologic and therapeutic approach geared to this pathogen.
RATIONALE: Cat dander is ubiquitous in our environment and is one of the most potent indoor allergens causing an IgE mediated Type 1 allergic response. While patients may be sensitized to several different allergens found in the dander, the major ones are Fel d1 and Fel d4 with more than 80% of these individuals exhibiting IgE antibodies to these two allergens. The purpose of this preliminary work was to measure the levels of Fel d1 and Fel d4 found in saliva, fur and urine of male and female domestic house cats and to determine whether there are differences in allergen levels dependent on breed, gender, sterilization status and age. METHODS: Cats volunteered by owners from a local animal hospital were used for this study. Owners signed an informed consent prior to any sample collection. Twenty cats were studied, five in each of four cohorts: neutered males, neutered females, females not in oestrus and males. The breed, age, weight and health status of each cat was recorded. Commercially available ELISA kits were used to measure the allergen levels and a standard curve created from the Fel d1 and Fel d4 standards. RESULTS: Triplicate samples were analyzed to allow for a sufficient sample size for analysis and comparison. CONCLUSIONS: The information generated by this study will be used to determine the characteristics of cats to be housed in a cat allergen challenge room in order to obtain consistent levels of airborne allergen.
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