Prevalence of chronic pulmonary aspergillosis misdiagnosed as microbiologically negative pulmonary tuberculosis

<bold>Background:</bold> Chronic Pulmonary Aspergillosis(CPA), a fatal lung infection by Aspergillus, is often misdiagnosed as tuberculosis (TB) due to the overlapping symptoms and radiology. <bold>Aims and Objectives:</bold> To assess the prevalence and risk factors of CPA in patients clinically diagnosed with microbiologically-negative TB and to evaluate Aspergillus-specific IgG antibody titres as a prognostic marker for disease activity. <bold>Methods:</bold> Patients (N=114) diagnosed with pulmonary tuberculosis (TB) on clinical grounds/without microbiological evidence of the same were enrolled and Aspergillus-specific Immunoglobulin G (IgG) titres, mycologic and clinico-radiological findings compatible with CPA were evaluated. Prevalence of CPA and risk factors in patients thus diagnosed was noted. Effectiveness of azole-antifungal treatments was assessed by clinico-radiologic response and IgG titre reduction at 3 and 6 months after treatment initiation. <bold>Results:</bold> Average age of the patients was 43.3±14.1years, with 82 males. CPA was diagnosed in 18 patients (15.78%). At baseline, mean specific IgG titre was 57.4 MgA/L and CRP-12.62 mg/dL. Six patients were classified as subacute invasive aspergillosis and simple aspergilloma each. Of the risk factors, past tuberculosis and diabetes mellitus was noted in 94.4% and 27.8% patients respectively. Six months of azole antifungals induced remission in 94% cases. <bold>Conclusion:</bold> Nearly 16% patients treated for smear-negative pulmonary TB may harbour CPA and thus a high index of suspicion for the latter is required. Six months of azole antifungals effectively induce remission for which serial IgG titres are an effective, minimally-invasive prognostic marker.