Abstract

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has emerged as a major nosocomial pathogen associated with increased mortality, morbidity and limited treatment options. Identification of readily available laboratory biomarkers may facilitate early clinical assessment and disease monitoring. This retrospective study included 507 hospitalized patients with confirmed CRPA infection admitted to a tertiary hospital in Shanxi province, China, between January 2019 and December 2023. Demographic characteristics, specimen sources, white blood cell (WBC) count, neutrophil count, lymphocyte count, monocyte count, and C-reactive protein (CRP) levels were collected and analyzed. Differences between male and female patients were evaluated, and receiver operating characteristic (ROC) curve analysis was performed to assess the discriminatory performance of selected inflammatory markers. Among the 507 CRPA-infected patients, respiratory specimens represented the predominant source of isolates. Elderly patients (>66 years) accounted for the largest proportion of cases. Female patients exhibited significantly lower WBC counts and CRP levels than male patients (P<0.05), whereas neutrophil, lymphocyte, and monocyte counts showed no significant sex-related differences. ROC analysis demonstrated modest discriminatory performance for WBC count (AUC = 0.629) and neutrophil count (AUC = 0.644), while their combined assessment did not improve diagnostic performance. Routine inflammatory markers, particularly WBC count and CRP, may provide useful information regarding the inflammatory status of patients with CRPA infection. However, their diagnostic utility remains limited and requires further validation in larger multicenter studies incorporating appropriate control populations.

Keywords:Carbapenem-resistant; Pseudomonas aeruginosa; White blood cell count; Neutrophil count; C-reactive protein.