Setting: Aspergillus complicates the course of healed pulmonary tuberculosis (PTB), causing aspergilloma and chronic pulmonary aspergillosis. Whether Aspergillus also causes allergic sensitisation in PTB-related fibrocavitary disease and bronchiectasis remains unknown.
Objective: To investigate the prevalence of Aspergillus sensitisation in healed fibrocavitary PTB.
Design: In a case-control design, consecutive symptomatic new referrals with PTB-related fibrocavitary disease underwent spirometry, Aspergillus skin test and computed tomography of the chest, determination of serum IgE levels (total and Aspergillus fumigatus-specific), serum precipitins against A. fumigatus and eosinophil count. Aspergillus sensitisation was defined as either a positive Aspergillus skin test or A. fumigatus IgE >0.35 kUA/l.
Results: A total of 100 subjects (50 PTB-related fibrocavitary disease, 50 controls) with a mean age of 40.8 years (standard deviation [SD] 12.2) were enrolled. Aspergillus sensitisation was present in 16 (32%) cases and two (4%) controls. Fourteen cases (one control) had IgE values >1000 IU/ml, while two cases manifested eosinophilia. Aspergillus precipitins were positive in 13 cases (two controls); of these, 8 did not have Aspergillus sensitisation. The presence of airflow obstruction on spirometry was significantly associated with Aspergillus sensitisation on univariate analysis (OR 4.96, 95%CI 1.36-18.03).
Conclusions: There is a high prevalence of Aspergillus sensitisation in PTB-related fibrocavitary disease. The clinical relevance and therapeutic implications of this finding require further investigation.