Outcome and Treatment of Nocardiosis After Solid Organ Transplantation: New Insights From a European Study

Abstract

Background: Solid organ transplant (SOT) recipients are at risk of nocardiosis, a rare opportunistic bacterial infection, but prognosis and outcome of these patients are poorly defined. Our objectives were to identify factors associated with 1-year mortality after nocardiosis and describe the outcome of patients receiving short-course antibiotics (≤120 days).

Methods: We analyzed data from a multicenter European case-control study that included 117 SOT recipients with nocardiosis diagnosed between 2000 and 2014. Factors associated with 1-year all-cause mortality were identified using multivariable conditional logistic regression.

Results: One-year mortality was 10-fold higher in patients with nocardiosis (16.2%, 19/117) than in control transplant recipients (1.3%, 3/233, P < .001). A history of tumor (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.1-1.8), invasive fungal infection (OR, 1.3; 95% CI, 1.1-1.5), and donor age (OR, 1.0046; 95% CI, 1.0007-1.0083) were independently associated with 1-year mortality. Acute rejection in the year before nocardiosis was associated with improved survival (OR, 0.85; 95% CI, 0.73-0.98). Seventeen patients received short-course antibiotics (median duration 56 [24-120] days) with a 1-year success rate (cured and surviving) of 88% and a 5.9% risk of relapse (median follow-up 49 [6-136] months).

Conclusions: One-year mortality was 10-fold higher in SOT patients with nocardiosis than in those without. Four factors, largely reflecting general medical condition rather than severity and/or management of nocardiosis, were independently associated with 1-year mortality. Patients who received short-course antibiotic treatment had good outcomes, suggesting that this may be a strategy for further study.

Keywords: Nocardia; mortality; opportunistic infections.; organ transplantation; prognosis.

Figure 1.

One-year survival curves after diagnosis of post-solid organ transplantation nocardiosis. Survival was assessed using Kaplan-Meier curves and compared among groups using log-rank tests. A, Survival curves of patients with nocardiosis (n = 117) and matched control transplant recipients (n = 234). B–D, Survival curves among patients with nocardiosis according to the presence of invasive fungal infection (including Pneumocystis pneumonia) in the 6 months before nocardiosis (B), history of tumor defined as a nonmetastatic tumor (if active or initially treated in the 5 years before diagnosis of nocardiosis) or metastatic solid tumor (C), and episode of acute rejection in the year before nocardiosis (D). Abbreviations: AR, acute rejection; IFI, invasive fungal infection.