Clinical Significance of Hyperattenuating Mucoid Impaction in Allergic Bronchopulmonary Aspergillosis : An Analysis of 155 Patients

BackgroundAllergic bronchopulmonary aspergillosis (ABPA) is a disease that presents with diverse clinicoradiologic manifestations. High-attenuation mucus (HAM) is a characteristic radiologic finding seen in patients with ABPA; however, the clinical significance of the entity remains unknown.Aims and objectivesTo describe the outcome of patients with ABPA who were demonstrated to have HAM, and compare with the outcome of patients without HAM.MethodsAll consecutive patients with asthma presenting to the Chest Clinic of this institute over a 4-year period were screened with an Aspergillus skin test. Patients with positive findings were further investigated, and the diagnosis of ABPA was confirmed based on predefined criteria. The patients were further classified into two groups based on the presence of HAM on HRCT scan.ResultsDuring the study period, 755 patients were screened for ABPA using the Aspergillus skin test; 291 patients (38.5%) had positive findings, and ABPA was diagnosed in 155 patients (mean age, 33.98 years; 76 women). Twenty-nine patients (18.7%) with ABPA were identified to have HAM on HRCT scans at presentation. The baseline characteristics were similar between the two groups, but patients with HAM had higher mean eosinophil counts, higher mean serum total IgE, and higher Aspergillus fumigatus-specific IgE levels. On multivariate analysis, both the severity of bronchiectasis and HAM predicted relapse of ABPA (odds ratio [OR], 1.23; 95% confidence interval [CI], 1.13 to 1.42; and OR, 3.61; 95% CI, 1.23 to 10.61, respectively). Failure to achieve complete remission was influenced by the severity of bronchiectasis but not by HAM (OR, 1.55; 95% CI, 1.29 to 1.85; and OR, 3.41; 95% CI, 0.89 to 13.1, respectively).ConclusionsHAM impaction in ABPA is associated with initial serologic severity and frequent relapses but does not seem to influence complete remission.