Clinical characteristics and treatment strategy of nocardiosis in lung transplant recipients: A single-center experience

Abstract

Objective: Nocardia are infrequent pathogens that disproportionately afflict organ transplant recipients. The present study aimed to summarize the clinical manifestations, diagnostic approaches, and treatment strategies of nocardiosis in lung transplant recipients.

Methods: This retrospective study reviewed the clinical data of adult lung transplant recipients who were complicated with nocardiosis between January 2018 and December 2021 at the largest lung transplant center in South China.

Results: The incidence of nocardiosis was 4.2% (13/316), including 9 cases of pulmonary nocardiosis and 4 disseminated nocardiosis (blood, pulmonary and intracranial). The accuracy in diagnosing nocardiosis was 77.8% by culture and 100% by metagenomic next-generation sequencing (mNGS). Nocardia farcinica was the most common causative pathogen. Trimethoprim-sulfamethoxazole-based combination therapy was administered initially, followed by a single antibiotic as the maintained therapy, lasting for 4-8 months.

Conclusions: mNGS is more accurate than culture in diagnosing nocardiosis. Most patients responded well to the antibiotic therapy with combined antibiotics at the initial stage followed by a single antibiotic treatment.

Keywords: Infection; Lung transplantation; Metagenomic next-generation sequencing.

Fig. 1

Flowchart of the study.

Fig. 2

Chest HRCT and brain MRI images of lung transplant recipients with nocardiosis. A) A 66-year-old man was diagnosed with nocardiosis 5 months after left-lung transplantation. Thoracic CT shows multiple nodules and patches in both lungs, and a thin-walled cavity in the right lung. Reticular patterns and honeycombing were also seen in the left lung. B) A 58-year-old man was diagnosed with nocardiosis 9 months after right-lung transplantation. Thoracic CT shows large areas of consolidation and scattered opacities in the upper lobe of the left lung, and emphysema in the lower lobe of the left lung. C) A 56-year-old man was diagnosed with nocardiosis 7 months after left-lung transplantation. Thoracic CT shows patch shadows in the upper lobe of the left lung, a thin-walled cavity in the right lung, and emphysema in the lower lobe of the left lung. D) A 32-year-old woman was diagnosed with nocardiosis 16 months after double-lung transplantation. Cranial MRI shows intracranial abscesses in the left cerebral hemisphere.