Background: Pulmonary nocardiosis (PN) is an opportunistic infection that usually affects immunocompromised patients. Currently, evidence regarding PN is scarce. In one third of cases, it may occur in immunocompetent patients. Local alterations of lung defenses, like in chronic obstructive pulmonary disease (COPD) or bronchiectasis (B), predispose to PN.
Aim: To describe a case series of PN.
Methods: From our about 200 medical charts in 2022, we selected all subjects with a laboratory confirmation of PN.
Results: Table 1
| Patient | 1 | 2 | 3 | 4 |
| Age | 59 | 64 | 57 | 64 |
| Gender | F | F | F | F |
| Smoke | No | Former 25 P/Y | Former 5 P/Y | Former 5 P/Y |
| Lung Disease | B | COPD | B, asthma | B |
| Immunosuppression | Yes | No | No | No |
| Comorbidity | Non-tuberculous mycobacteriosis in 2015 | No | Past bladder cancer | Past pleuritis |
| Signs/Symptoms | Cough, sputum, dyspnea | Hemoptysis, frequent bronchitis | Cough, dyspnea, recurrent fever | Cough, sputum, dyspnea, frequent bronchitis |
| CRP (mg/dL) | < 0.50 | 0.55 | 1.21 | 2.21 |
| Leuk (Exp3/µL) | 3.4 | 7.8 | 8.7 | 12.5 |
| Neu % | 36.2 | 67.4 | 65.6 | 63.7 |
| Eos % | 6.2 | 1.2 | 3.1 | 0.9 |
| CXR | Basal BO | BO | BO | Basal BO |
| CT | Peri-bronchiectasis exudation and TiB | Consolidations with cavitas, TiB | TiB with cavitas | TiB, consolidations, nodules |
| Hospitalization | No | Yes | No | Yes |
| Pathogen | N. spp. | N. abscessus | N. spp. | N. cyriacigeorgica |
| Treatment | TMP-SMX 4 mo. | L 12 mo. | TMP-SMX 6 mo. | L 12 mo. |
F female; BO bilateral opacities; TiB tree-in-bud; N. Nocardia; TMP-SMX Trimethoprim-sulfamethoxazole; L Linezolid
Conclusion: B should be investigated as a possible risk factor for PN and, in patients with recurrent or persistent exacerbations of B PN should always be considered in the differential diagnosis. An implemented and shared PN register may help to better understand this emerging infection.