Chronic pulmonary aspergillosis (CPA) is well known to develop in individuals whose lungs have already been damaged by tuberculosis (TB), but less is known about the links with a related condition caused by the same Mycobacterium bacteria. Non-tuberculous mycobacterial lung disease (NTM-LD) is a chronic but generally non-fatal infection that causes small nodules or cavities with symptoms including coughing, breathlessness, fatigue and sometimes haemoptysis. Patients who have CPA associated with NTM-LD are very difficult to treat, not least because antifungals often interact with antibiotics (e.g. itraconazole interacts with rifamycin), and the clinical signs of the conditions overlap. More information about how NTM-LD develop CPA would be of great help.
Jhun and colleagues in Seoul reviewed the medical records of 1,334 consecutive Korean patients with NTM-LD, spanning a period of 5 years. Of 566 who fulfilled the inclusion criteria, 41 (7%) went on to develop CPA at an average time of around 18 months. These patients were more likely to be older male smokers with a low BMI and a history of COPd and/or steroid treatment.
This is a striking illustration of how different lung conditions can lead to further conditions, and how this can complicate both diagnosis and treatment.