Serum perforin-1 concentration predicts severity and prognosis in community-acquired pneumonia patients

As a critical protein in cytotoxic granules, perforin-1 is involved in the immune response, triggering cell-killing effects and programmed cell death. However, existing research has not yet elucidated the role of perforin-1 in community-acquired pneumonia (CAP). We aimed to determine whether serum perforin-1 concentration was correlated with CAP. This study enrolled 348 CAP patients. Blood samples were drawn at admission and clinical data were recorded. Serum perforin-1 concentration was measured via enzyme-linked immunosorbent assay (ELISA). Serum perforin-1 concentration increased progressively with the severity of CAP. Spearman correlative analysis showed that serum perforin-1 concentration was associated with clinical physiological indicators. Univariate and multivariate linear regression analyses found that serum perforin-1 concentration was positively associated with the scores of CURB-65, CRB-65, PSI, CURXO, and APACHE II in CAP patients. Logistic regression analyses suggested that serum higher perforin-1 concentration elevated the risks of mechanical ventilation, vasoactive agent usage, and death in hospital. Additionally, the predictive capacity for the worse prognosis in serum perforin-1 concentration was equivalent to CAP severity scores. The combination of serum perforin-1 with severity scores elevated the predictive powers. Serum perforin-1 concentration at admission is positively correlated with disease severity and worse prognosis. Therefore, serum perforin-1 may serve as an effective prognostic biomarker for estimating disease severity and predicting poor prognosis in CAP patients.