Sensitization to Alternaria and Cladosporium in asthmatic patients and its in vitro diagnostic confirmation.

In order to determine the prevalence of airborne mould sensitization and the reliability of the in vitro diagnostic techniques in daily practice (antigen-specific IgE and histamine release test), we performed a 3-year study in 2,200 patients diagnosed with rhinosinusitis and/or bronchial asthma. We found mould sensitization in 101 patients, 20% of whom presented monosensitization against airborne moulds, and the rest associated other sensitizations as follows: 53.7% against Dermatophagoides pteronyssinus, 45% against grass pollen and 30% against Olea europea. The most frequently involved moulds in our patients were Alternaria and Cladosporium. Seventy-six percent of the patients presented sensitization against Alternaria, 56% of whom were monosensitized, 26% presented cosensitization to Cladosporium and the remainder were sensitive to more than two moulds. Regarding Cladosporium, the percentage of patients was similar (66%), although only 23% were monosensitized and 46% presented an associated sensitization against Alternaria. We also observed a correlation between skin tests and both in vitro diagnostic techniques, with a relative sensitivity of the specific IgE determination compared to the skin test of 98% against Alternaria and 90.4% against Cladosporium, whereas the relative sensitivity of the histamine release test was 97.4% for Alternaria and 85% for Cladosporium. In conclusion, we think that in order to confirm the etiopathogenesis of the airborne moulds and before an immunotherapy treatment is indicated, the positive skin reactions should be confirmed by means of reliable laboratory diagnostic techniques, such as antigen-specific IgE determination and histamine release test.