Neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and monocyte-to-lymphocyte ratio as prognostic indicators in Pneumocystis jirovecii pneumonia

Background Pneumocystis jirovecii pneumonia (PJP) remains a life-threatening opportunistic infection with high mortality, particularly among non-HIV immunocompromised patients. Identifying accessible and reliable prognostic biomarkers is of major clinical importance. Objectives To investigate the prognostic value of dynamic changes in the neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), and platelet-to-lymphocyte ratio (PLR) among patients with PJP. Methods A retrospective study of 165 PJP patients was conducted at two tertiary hospitals. Post-diagnostic trajectories of NLR, MLR, and PLR were analyzed using group-based trajectory modeling (GBTM). Associations between these trajectories and 28-day survival were assessed by Cox proportional hazards regression and Kaplan–Meier survival analysis. Results Three distinct NLR trajectories were identified: continuously decreasing (15%), stable (68%), and continuously increasing (17%). Patients with continuously decreasing NLR had significantly lower 28-day survival ( P < 0.05). The log-transformed NLR (logNLR) trajectory was an independent prognostic factor, whereas logMLR and logPLR were not significantly associated with outcomes. Conclusion The temporal trajectory of logNLR is strongly associated with 28-day survival in PJP. A persistently declining logNLR predicts poor prognosis, suggesting its utility in early risk stratification.