A retrospective study exploring chronic pulmonary aspergillosis in post-tuberculosis lung disease patients.

BACKGROUND

Chronic pulmonary aspergillosis (CPA) complicates post-tuberculosis lung disease (PTLD), causing significant morbidity and mortality. Predictors for Aspergillus seropositivity and CPA in a PTLD population remain unclear. The objective of this study was to identify the clinical, radiological, physiological, and biochemical characteristics of patients presenting to an adult PTLD clinical service, who met full criteria for CPA, and to compare them to those who did not, as well as compare those with positive Aspergillus serology to those without.

METHODS

This retrospective cross-sectional study, performed in a tertiary adult PTLD clinical service in South Africa, investigated the clinical, radiological, physiological and biochemical characteristics of patients who had Aspergillus serology performed and compared those with positive and negative serology, as well as those meeting CPA diagnostic criteria with those who did not.

RESULTS

Over a 2-year period, 238 patients were seen in the PTLD clinic, of which 79 had registered Aspergillus immunoglobulin G (IgG) serology testing and computed tomography (CT) chest imaging performed. Twenty-six (32.9%) patients had positive Aspergillus serology and 20 (25.3%) met criteria for CPA. Current radiological definitions for CPA when applied in a blinded fashion, had a sensitivity of 80.8% and a specificity of 58.5% for Aspergillus seropositivity, with a positive predictive value of 48.8%. Having ≥4 episodes of previous pulmonary tuberculosis (PTB) was significantly associated with both Aspergillus seropositivity [odds ratio (OR) =10.9; 95% confidence interval (CI): 2.1-84.9] and CPA diagnosis (OR =15.5; 95% CI: 2.8-125.6). Haemoptysis was significantly more common in those with positive Aspergillus serology (OR =2.7; 95% CI: 1.4-5.2) and in those with CPA (OR =2.7; 95% CI: 1.4-5.4). Total immunoglobulin E (IgE) levels were significantly higher in those with Aspergillus seropositivity (P value =0.006) and in those with CPA (P value =0.03). Other symptoms, spirometric and laboratory findings were similar between groups.

CONCLUSIONS

Current radiological criteria are not sufficiently specific for the diagnosis of CPA in PTLD populations, necessitating wider use of Aspergillus serology. The significant overlap in clinical syndromes highlights a complicated yet poorly understood relationship between CPA and PTLD, with increased frequency of haemoptysis requiring further research.