Serum IgE and IgG reactivity to Aspergillus recombinant antigens in patients with cystic fibrosis

Purpose:

The diagnosis of aspergillosis in cystic fibrosis (CF) patients remains a challenge due to overlapping features of both diseases. This is further complicated by inconsistent antibody reactivity to the currently used crude antigen, which has led a more focused evaluation of the efficacy of IgE response to a number of pure Aspergillus fumigatus recombinant proteins in patients with CF and asthma. In this study, we dissected the IgE and IgG responses to multiple A. fumigatus recombinant antigens in CF patients with different Aspergillus diseases.

Methodology:

Serum IgE and IgG antibodies were measured in 12 CF patients with allergic bronchopulmonary aspergillosis (ABPA), 12 with Aspergillus sensitization (AS) and 12 with Aspergillus bronchitis (AB) against recombinant antigens Asp f1, f2, f3, f4 and f6.

Results:

The ABPA group showed significantly greater IgE reactivity to Asp f1, f2, f3 and f4 compared to patients with AS. Patients with AB expressed higher IgG positivity to Asp f1 and Asp f2 compared with those with ABPA. There were very low IgE antibody levels against all recombinant antigens in patients with AS. Aspf1 IgG reactivity in ABPA patients correlated with positive culture.

Conclusion:

The use of multiple recombinant antigens may improve the diagnostic accuracy in CF complicated with ABPA or AB. Asp f1 reactivity may relate to the presence of actively growing Aspergillus spp., which might be a useful marker for guiding antifungal therapy in ABPA.