Pleural empyema with endobronchial mass due to Rhodococcus equi infection after renal transplantation: A case report and review of literature

Abstract

Background: Kidney transplantation is the best option for patients with end-stage renal disease. However, the need for lifelong immunosuppression results in renal transplant recipients being susceptible to various infections. Rhodococcus equi (R. equi) is a rare opportunistic pathogen in humans, and there are limited reports of infection with R. equi in post-renal transplant recipients and no uniform standard of treatment. This article reports on the diagnosis and treatment of a renal transplant recipient infected with R. equi 21 mo postoperatively and summarizes the characteristics of infection with R. equi after renal transplantation, along with a detailed review of the literature.

Case summary: Here, we present the case of a 25-year-old man who was infected with R. equi 21 mo after renal transplantation. Although the clinical features at the time of presentation were not specific, chest computed tomography (CT) showed a large volume of pus in the right thoracic cavity and right middle lung atelectasis, and fiberoptic bronchoscopy showed an endobronchial mass in the right middle and lower lobe orifices. Bacterial culture and metagenomic next-generation sequencing sequencing of the pus were suggestive of R. equi infection. The immunosuppressive drugs were immediately suspended and intravenous vancomycin and azithromycin were administered, along with adequate drainage of the abscess. The endobronchial mass was then resected. After the patient's clinical symptoms and chest CT presentation resolved, he was switched to intravenous ciprofloxacin and azithromycin, followed by oral ciprofloxacin and azithromycin. The patient was re-hospitalized 2 wk after discharge for recurrence of R. equi infection. He recovered after another round of adequate abscess drainage and intravenous ciprofloxacin and azithromycin.

Conclusion: Infection with R. equi in renal transplant recipients is rare and complex, and the clinical presentation lacks specificity. Elaborate antibiotic therapy is required, and adequate abscess drainage and surgical excision are necessary. Given the recurrent nature of R. equi, patients need to be followed-up closely.

Keywords: Case report; Immunosuppression; Kidney transplantation; Pleural empyema; Pulmonary atelectasis; Rhodococcus equi.

Figure 1

Chest computed tomography scan. A: Right-sided fluid pneumothorax with multiple fluid within it; right lung with multiple exudates, right lower lobe abscesses; B: After drainage of right-sided fluid pneumothorax, the right-sided encapsulated effusion was significantly reduced compared with the previous one, and the pneumoperitoneum had been largely absorbed; the right intrapulmonary exudation and right lower lobe abscess were reduced compared with the previous one; the right middle lobe of the lung was atelectatic; C: Right pleural encapsulated effusion as before; right lower lobe abscess and multiple exudates in both lungs as before; right middle lobe atelectasis was slightly worse than before; D: Right pleural encapsulated effusion absorbed more than before; right lower lobe abscess and multiple right lung exudates reduced more than before; right middle lobe atelectasis as before; E: Right pleural encapsulated effusion was significantly greater than before; right lower lobe abscess and multiple right lung exudates were lesser than before; right middle lobe atelectasis was the same as before; F: Right pleural encapsulated effusion decreased compared to before; right lower lobe abscess and multiple right lung exudates as before; right middle lobe atelectasis as before.

Figure 2

Biopsy of endobronchial mass. A: Nascent mass at the mouth of the right middle and lower lobes with symptomatic hypertrophic luminal narrowing of the right pulmonary mucosa; B: Fibrinoscopic biopsy: The mucosa shows chronic inflammation. Fibrillar hyperplasia within the lamina propria was seen with a large number of histiocyte-like cells; C: Fiberscope brushing: A large number of erythrocytes and ciliated columnar cells and a few neutrophils and phagocytes are seen; no malignant cells are seen; D: Immunohistochemistry: Chronic inflammation of the mucosa. Fibrous granulation tissue proliferation.