Clinical Features of Pulmonary Nocardiosis in Patients with Different Underlying Diseases: A Case Series Study

Abstract

Objective To investigate the clinical features of pulmonary nocardiosis (PN) in patients with different underlying diseases. Methods Clinical, imaging, treatment and prognosis data from patients diagnosed with PN from July 2011 to June 2021 at the First Affiliated Hospital, Zhejiang University School of Medicine were collected and analyzed. According to different underlying diseases, patients were grouped into immunocompromised host (ICH) group and immunocompetent host (ICO) group, and clinical characteristics were compared between the two groups. Results There were 64 patients with PN, including 42 males, aged from 21 to 86 (57.1 ± 15.7) years. The most common clinical manifestations were cough, expectoration, fever. There were 41 cases in the ICH group and 23 cases in the ICO group. There were 11 cases with underlying pulmonary diseases in the ICH group, including 2 cases of bronchiectasis, 4 cases of chronic obstructive pulmonary disease (COPD), etc. There were 11 cases of underlying pulmonary basic diseases in ICO group, including 7 cases of bronchiectasis and COPD, 1 case of bronchiectasis, 1 case of COPD, etc. The proportion of patients with bronchiectasis and COPD in the ICO group was significantly higher (P < 0.05). Extrapulmonary nocardiosis infection occurred in 6 patients of the ICH group. During the period of hospitalization, 87.0% patients in ICO group received SMZ/TMP therapy, 73.2% of patients in ICH group received two drug combination therapy. In the ICH group, mortality at 28 days was 14.6% and 8.7% in the ICO group. Conclusion PN mainly occurred in ICH patients, but also occurred in the ICO cases to a lesser extent, especially in patients with bronchiectasis and/or COPD. Complicated with extrapulmonary infections mainly occurred in ICH population and combination of two antibiotics was often used in ICH group. The case fatality rates were 14.6% in ICH and 8.7% in ICO cases, respectively.

The Computed Tomography Findings and Follow-up Course of Pulmonary Nocardiosis

“…In addition, underlying chronic pulmonary diseases such as chronic obstructive pulmonary disease and bronchiectasis were observed in approximately 47% of our patients, all of whom were immunocompetent. This suggests that chronic structural pulmonary diseases may be a predisposing factor for pulmonary nocardiosis, as previously reported 14–16 . The underlying pathophysiology of this may be related to the disrupted immune defense system of the lungs secondary to structural abnormalities, resulting in a predisposition to lower respiratory tract and airway infections.…”

“…This suggests that chronic structural pulmonary diseases may be a predisposing factor for pulmonary nocardiosis, as previously reported. [14][15][16] The underlying pathophysiology of this may be related to the disrupted immune defense system of the lungs secondary to structural abnormalities, resulting in a predisposition to lower respiratory tract and airway infections. Bacterial colonization of the bronchus can then cause ciliary dysmotility and epithelial damage, which ultimately increases the risk of nocardiosis.…”

Nocardiosis pulmonar como causa de exacerbación de EPOC

“…Hasta ahora no está claro si la EPOC es un factor de riesgo independiente para la NP, pues se han reportado casos en pacientes con EPOC que consumen o habían consumido recientemente corticosteroides sistémicos o inhalados, o que además presentaban comorbilidad que por sí sola era un factor de riesgo para NP. En contraparte, también se ha reportado NP en pacientes con EPOC que no habían tomado corticosteroides de forma reciente 2,3 .…”

“…La forma más común de presentación es como un nódulo o una masa, con o sin cavitación. No obstante, puede manifestarse como consolidación, patrón en empedrado, engrosamiento de la pared bronquial o derrame pleural 3,4 . En vista de la inespecificidad clínica y radiológica, el diagnóstico se establece mediante el aislamiento del patógeno en cultivos de muestras respiratorias.…”

“…La sintomatología es insidiosa e inespecífica, al igual que los hallazgos de laboratorio y radiológicos, lo que complican aún más su identificación 2 . La notificación temprana al laboratorio de su sospecha es esencial para favorecer su identificación, optimizando así la orientación terapéutica 3 .…”