Background: Over the last decades, genomics and proteomics have contributed to the current knowledge of individualized allergenic components and their potential use in the diagnosis of IgE-mediated allergies. Recent investigations have demonstrated that Alt a 1 should be considered as a relevant allergen of the Pleosporaceae group and that enolase is the main allergen involved in the cross-reactivity to fungi. However, the real utility of these allergens as tools for the diagnosis of allergy to Alternaria is still unclear.
Objective: To demonstrate the current value of the available fungal allergen panel and the need to build an accurate mould allergen array for the diagnosis of allergy to Pleosporaceae.
Methods: Specific IgEs to individual mould allergens and allergenic mould extracts were evaluated using the ImmunoCAP™ system in 30 patients allergic to Alternaria and in 100 blood donors. Cross-reactivity studies were performed by Fluoro Enzyme ImmunoAssay (FEIA) and FEIA inhibition using individual allergens and allergenic extracts. Two-dimensional electrophoresis associated with a MALDI-TOF analysis was carried out to identify new allergen molecules.
Results: All allergic patients had positive specific IgE responses to several moulds from different taxonomical families. Classic and molecular diagnosis demonstrated that 23% of patients had multi-sensitization. The current commercially available fungal allergen array was not sufficient to establish an accurate diagnosis. Unexpected correlations between Alternaria or Alt a 1 and Curvularia or Cladosporium stimulated the investigation of a more accurate allergen panel. A manganese-dependent superoxide dismutase (MnSOD) homologous to Asp f 6 was identified as a new IgE-binding molecule from Alternaria alternata.
Conclusions and clinical relevance: Alt a 1 is the marker for allergy to Pleosporaceae, not including Curvularia. MnSOD can explain 6.6% of allergy to Alternaria without Alt a 1 sensitization and should be included together with Alt a 1 and fungal enolase in the molecular array for the diagnosis of allergy to Pleosporaceae.
© 2011 Blackwell Publishing Ltd.