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

## TL;DR

This study shows that a continuously decreasing neutrophil-to-lymphocyte ratio (NLR) is linked to worse survival in patients with Pneumocystis jirovecii pneumonia.

## Contribution

The study introduces the dynamic trajectory of log-transformed NLR as a novel independent prognostic indicator for PJP outcomes.

## Key findings

- Three NLR trajectories were identified: continuously decreasing, stable, and continuously increasing.
- Patients with a continuously decreasing NLR had significantly lower 28-day survival.
- LogNLR trajectory was an independent prognostic factor, while logMLR and logPLR were not.

## Abstract

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.

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.

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.

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.

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.