Risk prediction of pneumocystis jirovecii pneumonia in kidney transplant recipients using a clinical nomogram

Pneumocystis jirovecii pneumonia (PJP) remains a life-threatening opportunistic infection in renal transplant recipients despite universal prophylaxis, with its risk factors in this setting poorly defined. This study aimed to investigate these factors and develop a nomogram to predict PJP risk, identifying patients requiring extended prophylaxis.

Demographic characteristics and perioperative outcomes of consecutive patients who underwent kidney transplantation from DCD or DCBD donors at a high-volume kidney transplant center in China between January 2016 and January 2019 were retrospectively analyzed. A nomogram was developed using data from a retrospective training cohort based on a Cox regression model. The model was tested in a validation cohort.

Among 702 patients, 52 developed postoperative PJP (7.4%). PJP occurred in 38 of 491 patients (7.73%) in the training cohort and in 14 of 211 patients (6.64%) in the validation cohort. The nomogram included the following variables: postoperative CD4+T cell count, CD8/lymphocyte ratio (CD8/L), blood glucose, NEU percentage and CRP ≥ 8μg/mL. The C-statistics and AUC values of the nomogram for PJP prediction were 0.88, 0.93, and 0.89 in the training, validation, and entire cohorts, respectively. The incidence of PJP was significantly higher in the high-risk group than in the low-risk group across all three cohorts (p < 0.001).

Renal transplant recipients with lower CD4+T cell counts and higher CD8/L, blood glucose, NEU percentage, and CRP levels are at increased risk of PJP. The nomogram may serve as a useful and practical tool for predicting the individualized risk of PJP after kidney transplantation, facilitating the identification of high-risk patients requiring extended prophylaxis.