Are COPD patients with Nocardia species identification different from those who have also co-morbid bronchiectasis?

Abstract

Introduction:Nocardia spp aren’t members of human flora. Pulmonary nocardiosis (PN) is typically an opportunistic infection, although chronic obstructive pulmonary disease (COPD) and bronchiectasis (BC) are recognized risk factors. We aimed to evaluate if COPD patients with identification of Nocardia spp are different from those who also have co-morbid bronchiectasis. Methods: COPD patients with Nocardia spp identification in respiratory samples were retrospectively analysed. Patients’ demographics, comorbidities, clinical and radiological parameters and mortality were gathered. Median follow-up period was 48 months. COPD patients with BC (COPD-BC) and COPD patients without BC (COPD-wtBC) were compared. Results: There were 38 cases of Nocardia spp identification in COPD patients, of those 68.4% were COPD-BC patients. Patients were predominantly male in both groups and had a similar mean age. COPD-BC patients more frequently had previous chronic infection by other microorganisms (p=0.004), tended to receive more previous antibiotic treatment (p=0.147) and to have a higher immunosuppression degree (p=0.142). De novo symptoms were less reported in COPD-BC patients, although chest CT changes were more frequent. In total, 11 patients had PN diagnosis and specific treatment was started, of them 7 were COPD-BC. Twelve patients died (COPD-wtBC: n=7; CPOD-BC: n=5). Conclusion: More than half of COPD patients with Nocardia spp identification had BC, with high rates of previous chronic infection, antibiotic treatment and radiological changes. Higher mortality rates were found in COPD-wtBC. Additional and larger studies are needed to validate these findings.