Need to re-look cut-off of Aspergillus-specific IgE levels in children with ABPA.

The cut-offs for total and specific IgE used for diagnosing ABPA in children have been adopted from adult literature and have not been validated in the paediatric population. To establish the ideal cut-offs of total IgE and Aspergillus-specific IgE for the diagnosis of ABPA in children. This study was a prospective observational case-control study, conducted in a tertiary care hospital in North India, enrolling 140 children with partly controlled and uncontrolled asthma. Seventy children had ABPA based on the Rosenberg-Patterson Criteria (Cases) whereas 70 children were without ABPA (Controls). All children were subjected to clinical examination and investigations such as absolute eosinophil count, total IgE, Aspergillus-specific IgE, Aspergillus skin prick test and radiological tests. ROC curve analysis was done to determine the ideal cut-offs of total and specific IgE to diagnose ABPA. The ROC curve analysis determined 1204IU/L as the cut-off value of total IgE with a sensitivity of 79.7% (95%CI 68.31% to 88.44%) and specificity of 53.1% (95%CI 40.23 to 65.7). The ROC analysis of specific IgE levels of children with ABPA determined the cut-off value of 0.49 KAU/L with a sensitivity of 94.03% (95%CI 85.41 to 98.35) and specificity of 88.89% (95%CI 75.94% to 96.29%). We propose that the cut-offs of total and specific IgE need to be relooked in the paediatric population. Cut-offs of total IgE as 1204 IU/L and for Aspergillus-specific IgE as 0.49KAU/L seem appropriate. Large multicentric studies should be conducted to determine the ideal values for diagnosing paediatric ABPA.