Chest radiographic staging in allergic bronchopulmonary aspergillosis: relationship with immunological findings

The question of whether a chest radiographic severity staging system could be correlated with standard blood/serum diagnostic indices in allergic bronchopulmonary aspergillosis (ABPA) was addressed in 41 patients. Asthma and positive Aspergillus fumigatus (AF) serology were considered essential diagnostic inclusion criteria. Eosinophil count, serum immunoglobulin (Ig)E and immediate skin hypersensitivity were also tested to grade patients as "definite" or "likely" ABPA. Definite cases had all five of these factors present, whereas likely cases had three or more. Chest radiographs were examined by experienced radiologists blinded to the clinical data. The six-stage radiographic score (0-5) was based on the severity and duration of changes seen: stage 0: normal; stage 1: transient hyperinflation; stage 2: transient minor changes; stage 3: transient major changes; stage 4: permanent minor changes; and stage 5: permanent major changes. Significant positive correlations (p<0.05) were observed between peak AF titres (expressed as an index), peak eosinophil count and radiographic severity stage. When considered as subgroups, these correlations approached, but did not reach, significance for the group with "likely" ABPA (n=28), but in the group with definite ABPA (n=13), there was a high correlation between radiographic score and peak AF index (r=0.59), as well as peak eosinophil count (r=0.62). This study suggests that the peak Aspergillus fumigatus index and eosinophil counts correlate best with the severity of radiographic stages in allergic bronchopulmonary aspergillosis. This chest radiographic staging system may be useful in the clinical assessment and management of patients with allergic bronchopulmonary aspergillosis, particularly in those patients with more severe radiographic stages.