Abstract
Objective: A functional immune system is essential for recovery from pneumonia; hence, measuring and monitoring immune-status indicators is clinically important. This study aimed to determine whether QuantiFERON monitoring (QMF) could predict healthcare-associated infection (HCAI) according to the immune-status of patients with pneumonia. Methods: Prospective, observational, single-center study, patients ≥19 years hospitalized for pneumonia between October 2020 and November 2021. QFM was performed at hospital admission (D1) and seven days after (D2). Data from 90 patients in the D1 QFM group were analyzed, which was further divided into the non-healthcare-associated infection (non-HCAI, n = 41, 45.6%) and HCAI (n = 49, 54.4%) groups. Results: The D1 and D2 QFM levels were both significantly higher in the non-HCAI group than in the HCAI group (D1 hCAI vs non-HCAI: 4.40 vs 5.75 IU/mL, D2 hCAI vs non-HCAI: 4.38 vs 6.10 IU/mL). Analysis of the change in D1 and D2 QFM levels by each group showed that D2 QFM levels increased over D1 QFM levels in the non-HCAI group (5.75 vs 6.10 IU/mL), while D2 QFM levels decreased over D1 QFM levels in the HCAI group (4.40 vs 4.38 IU/mL). D1 QFM was consistently negatively correlated with TNF-α and CRP. The integrated analysis of D1 QFM and CCI and D1 QFM and CURB-65 had fair to predict the occurrence of HCAI. Conclusion: QFM can be used to predict the immune-status of patients in the context of healthcare-associated infections. These findings provide important insights into the current understanding of pneumonia treatment and recovery.