Lymphocyte-C-reactive protein ratio as a predictor of severity in acute lower respiratory infections due to respiratory syncytial virus in hospitalized infants

Abstract

Respiratory Syncytial Virus (RSV) is a common cause of acute lower respiratory tract infection (LRTI) in pediatrics. The lymphocyte-to-C-reactive protein ratio (LCR) has been studied as a predictor of inflammation, sepsis, and severity in viral respiratory infections.

Objectives: To estimate the LCR in hospitalized infants with RSV-associated acute LRTI and assess its ability to identify disease severity.

Patients and Method: A cross-sectional study including infants hospitalized with a diagnosis of RSV-associated acute LRTI over 12 months. Absolute lymphocyte count (cells/mm³), C-reactive protein (CRP) level (mg/L), and the Argentine Respiratory Distress Assessment Scale (EDRAR) score at admission were recorded. The LCR was calculated and categorized into two groups: LCR < 100 and ≥ 100, and its relationship with EDRAR was analyzed.

Results: A total of 209 patients were included, with a mean age of 8.03 ± 6.9 months. According to the EDRAR, only 6.7% (n = 14) were classified as severe. The median LCR was 305.7 (IQR 109.3–1201.5), with no significant difference between severe and non-severe patients (p = 0.9). In 23.4% of patients, LCR was < 100, with a sensitivity of 70.3% (95% CI: 63.2–76.4) and specificity of 28.57% (95% CI: 9.58–58) for predicting severity.

Conclusion: In infants hospitalized with RSV-associated acute LRTI, the LCR was not useful in predicting disease severity.