关键词: 耶氏肺孢子菌肺炎, 急性呼吸窘迫综合征, 肾移植, 绝对淋巴细胞计数, 基于组的轨迹模型

Abstract: Objective: Group⁃based trajectory modeling (GBTM) was applied to identify the dynamic trajectory of absolute lymphocyte count (ALC) within 7 days after admission to intensive care unit (ICU) in patients with Pneumocystis jirovecii pneumonia (PJP)⁃related acute respiratory distress syndrome (ARDS) in kidney transplant recipients (KTR), and to explore the relationship between different trajectories and 30⁃day all⁃cause mortality. Methods: In this study, a retrospective cohort design was used to include 101 PJP⁃related ARDS renal transplant recipients. GBTM was used to fit the trajectory of ALC data within 7 consecutive days after ICU admission. The 30⁃day survival curve was drawn by Kaplan⁃Meier method, and the Cox proportional hazard regression model was used to evaluate the association between different trajectory groups and 30⁃day mortality risk. Subgroup analysis was performed according to variables such as age, gender, and immunosuppression score to verify the robustness of the results. Results: A total of 101 patients were included, with a median age of 44 years (34-51 years), and 76.2% (77/101) were male. GBTM identified three ALC dynamic trajectories: continuous rising group (Traj⁃1, n=20), stable medium group (Traj⁃2, n=45) and continuous low level group (Traj⁃3, n=36). Patients in the Traj⁃3 group were more severe, with higher inflammatory markers, lower CD4 and CD8 cell counts, and a higher proportion of patients receiving continuous renal replacement therapy (CRRT). Kaplan⁃Meier analysis showed that the 30⁃day survival rate of the three groups was significantly different (Log⁃rank P=0.004). Multivariate Cox regression showed that in the fully adjusted model (Model 4), the 30⁃day mortality risk of Traj⁃3 was 3.46 times that of Traj⁃2 (HR=3.46, 95%CI 1.38-8.66, P=0.008). Subgroup analysis confirmed that the association remained robust in most clinical situations. Conclusion: In patients with PJP⁃related ARDS in renal transplant recipients, ALC dynamic trajectory are significantly associated with 30⁃day mortality risk, and persistent low ALC level was a poor prognostic indicator independent of traditional risk factors.