Investigation of Risk Factors and Development of Clinical Prediction Model for Nocardiosis in Lung Transplant Recipients

Purpose: Nocardiosis is an opportunistic infection in lung transplant recipients but is often misdiagnosed or overlooked. This study aimed to identify risk factors and develop an effective predictive model for nocardiosis in this population. Patients and Methods: This single-center retrospective study analyzed 679 lung transplant recipients from January 1, 2015, to July 9, 2024. Twenty patients with nocardiosis were compared with 40 matched controls. Feature selection was performed using LASSO regression, and logistic regression identified risk factors. Model performance was assessed via ROC curves, calibration curves, and decision curve analysis. Results: Decreased CD4 + T cells, elevated CD8 + T cells, and reduced IgA levels were significantly associated with nocardiosis (P < 0.05). The model incorporating these factors demonstrated strong predictive ability with an area under the ROC curve of 0.955. Conclusion: CD4 + T cells, CD8 + T cells, and IgA are independent risk factors for nocardiosis post-lung transplantation. The developed model effectively distinguishes nocardiosis cases, aiding early clinical identification.