THE PLATELET-LYMPHOCYTE RATIO COMPARED WITH PNEUMONIA SEVERITY INDEX IN THE PREDICTION OF COMMUNITY-ACQUIRED PNEUMONIA

Objective: Community-acquired pneumonia (CAP) is a frequent cause of hospitalization and a leading cause of mortality worldwide. The pneumonia severity index (PSI) is a clinical prediction score for determining short-term mortality and morbidity in patients with community-acquired pneumonia. The usefulness of rapid biochemical tests in predicting the severity of pneumonia have been investigated. Platelet-lymphocyte ratio (PLR) have been proposed as indicators of systemic inflammation and infection. The aim of this study was to investigate the predictive value of PLR levels and its association with PSI in patients with CAP in the emergency department. Material and Method: This prospective case-control study included 78 patients admitted with CAP and 78 control patients. The PLR mean levels were compared between the study and control group. PSI were calculated and C-reactive protein (CRP) were measured. Correlation analyses were performed to investigate the association of PLR levels with CRP, PSI and hospitalization. Results: PLR levels were significantly higher in the study group compared to the control group (p <0.001).The PLR level of 140,5 had sensitivity of 70.5% and specificity of 82.1% and was positively correlated with PSI, CRP and hospitalization (r = 0.333; p= 0.003, r = 0.478; p <0.001, r=0.386; p<0.001). PLR levels were significantly higher in the inpatients subgroup compared to the outpatients subgroup (p= 0,001). Conclusion: PLR levels significantly increased and positively correlated with PSI, CRP and hospitalization in adult patients presenting with CAP. PLR may be considered as a predictive biomarker of CAP