Analysis of Clinical Characteristics of 25 Patients With Pulmonary Nocardiosis Diagnosed by Next-Generation Sequencing.

Abstract

Objective: To analyze the clinical characteristics of patients with pulmonary nocardiosis, enhance clinicians' understanding of the disease, and explore the clinical value of Next-Generation Sequencing (NGS) in diagnosing pulmonary nocardiosis.

Methods: A retrospective analysis of clinical data from patients diagnosed with pulmonary nocardiosis by bronchoscopic alveolar lavage fluid NGS in our hospital from April 2022 to April 2024 was conducted. The clinical characteristics were analyzed, and their treatment and outcomes were tracked.

Results: (1) Among the 25 patients with pulmonary nocardiosis, 10 were male, and 15 were female, aged 38-91 years, with an average age of 64.60 ± 12.40 and a BMI of 21.6 ± 3.06 kg/m². Six patients had a long-term smoking history, and two had smoked in the past. Six were farmers. Twenty-one patients had a history of underlying diseases, mainly chronic respiratory diseases such as bronchiectasis and COPD. Twenty patients had comorbidities, mainly respiratory failure, hypoxemia, liver and kidney dysfunction, and electrolyte disturbances. (2) The main clinical manifestations were fever, cough, sputum production, shortness of breath, fatigue, and poor appetite. Laboratory tests mainly showed elevated neutrophil percentage, hypersensitive C-reactive protein, erythrocyte sedimentation rate, procalcitonin, and decreased serum albumin. (3) Imaging of the chest revealed bilateral lung involvement in 16 patients, right lung involvement in 8, and left lung involvement in 1. The main imaging features included cavities, consolidation, exudation, and nodules. Bronchoscopy is an important way to obtain BALF. Bronchoscopic findings are nonspecific. They can be bronchial inflammatory changes, viscous secretions in the lumen, occlusion of the lumen, stenosis of the segment, etc. (4) Fourteen cases were identified as Nocardia cyriacigeorgica , six as Nocardia abscessus , three as Nocardia otitidiscaviarum , and two as Nocardia asteroides . Twenty-three patients received treatment; six were treated with sulfamethoxazole and trimethoprim (SMX/TMP) alone, 17 with a combination of sulfonamide and linezolid or other drugs, one was discharged automatically, and the remaining 22 showed improvement.

Conclusion: Pulmonary nocardiosis often occurs in patients with chronic respiratory diseases and has nonspecific clinical features, making misdiagnosis easy. NGS can rapidly and accurately diagnose this disease in patient specimens. Early, adequate, and long-term combined therapy based on sulfonamide generally leads to a good prognosis.