Fungal atopy in adult cystic fibrosis

This study set out to estimate the prevalence of atopy to a variety of comm on ubiquitous fungi, including A. fumigatus, in cystic fibrosis (CF), and t o evaluate the investigations by which the diagnosis was made. Particular a ttention was paid to the usefulness of skin testing and immunoassays in det ecting which patients had simple fungal atopy, and which patients were at h igh risk of developing allergic bronchopulmonary mycoses. This cross-sectional study included 21 adult CF patients and 20 matched con trols. Serum samples were taken for the measurement of total serum IgE and specific serum IgE to nine common fungi. Immediate hypersensitivity skin pr ick testing to each of the fungi was also performed. Simple fungal atopy wa s described in subjects fulfilling the following criteria: total serum IgE > 100 KU l(-1) with specific radioimmunoassay greater than or equal to grad e 1 to at least one fungus and a positive skin prick test (SPT) greater tha n or equal to 3 mm to the same fungus. 'High risk' for developing allergic bronchopulmonary mycosis (ABPM) was described in subjects fulfilling the fo llowing criteria: total serum IgE > 200 KU l(-1) with specific radioimmunoa ssay greater than or equal to grade 2 to at least one fungus and a positive skin prick test (SPT) greater than or equal to 6 mm to the same fungus. The adult CF group had a significantly higher total SPT score (P = 0.005) a nd mean total serum IgE (P < 0.05) than controls. Forty-three percent of CF patients fulfilled the criteria for fungal atopy to at least a single fung us. Over half this group had an atopic tendency to more than one fungus. Ni neteen percent of the CF group were at least 'high risk' of developing ABPM . Skin prick testing is a better marker of fungal atopy and a better predic tor of those adult CF patients at higher risk of developing ABPM than speci fic radioimmunoassay serum testing. There is a high prevalence of fungal atopy in the adult CF population. Tota l serum IgE and skin prick testing are good predictors of fungal atopy and help predict those at risk of developing ABPM in CF.