Chronic pulmonary aspergillosis (CPA) is an important sequela of pulmonary tuberculosis (PTB), particularly in high-burden countries such as India. This study evaluated the diagnostic performance of the LDBio Aspergillus ICT lateral flow assay and western blot (WB) for CPA among post-TB patients in South India. In this prospective study (July 2023 to June 2025) conducted in Bengaluru, India, we enrolled adults with a history of PTB and persistent respiratory symptoms. CPA was diagnosed using the modified European Society for Clinical Microbiology and Infectious Diseases (ESCMID)-European Confederation of Medical Mycology (ECMM)-European Respiratory Society (ERS) criteria. All participants underwent comprehensive clinical evaluation; direct microscopy and culture of respiratory secretions; and testing with serum Aspergillus-specific IgG ELISA, ICT, WB, and galactomannan (GM). Of 132 post-TB patients, 107 (81%) were classified as CPA and 25 as non-CPA; 70 control sera were also included. ICT and WB were positive in 74% and 84% of CPA cases, respectively, outperforming ELISA (68%) and GM (30%). WB showed the highest sensitivity (84%, 95% CI: 75.8-90.5), whereas ICT demonstrated the highest specificity (94.7%, 95% CI: 88.1-98.3). Combining ICT and WB improved diagnostic accuracy (87.1%, 95% CI: 81.7-91.4) and yielded the highest discriminative power (Youden's index 0.805). WB displayed robust band-based differentiation, with strong reactivity in seropositive CPA. The agreement between ICT and WB was substantial (κ = 0.82). Latent class analysis estimated sensitivities of 92% (95% CI: 84-97) for ICT and 87% (95% CI: 77-94) for WB. These findings indicate that LDBio ICT and WB are robust diagnostic tools for CPA in post-TB patients and that their combined use offers optimal accuracy in resource-limited, high-burden settings.IMPORTANCEChronic pulmonary aspergillosis (CPA) is a serious but often overlooked complication in people who have previously been treated for tuberculosis. Many of these patients continue to struggle with cough, breathlessness, and lung damage; however, routine tests often fail to explain their symptoms. This study shows that CPA is extremely common in this high-risk group and demonstrates that two simple blood tests, the LDBio Aspergillus immunochromatographic test and western blot, can reliably identify the disease. Western blot detects CPA even in patients who typically test negative on standard methods, and using both tests together markedly improves accuracy. Because these tools are quick, inexpensive, and easy to perform, they offer a practical way to diagnose CPA earlier, especially in settings where advanced testing is unavailable. Early diagnosis allows timely antifungal treatment, which can greatly reduce illness and prevent unnecessary suffering among the growing number of TB survivors.
Samaddar et al. (Fri,) studied this question.