The median CRP levels in the sepsis group (n = 16), pneumonia group (n = 134), and non-infection group (n = 214) were 18.80 mg/L, 6.015 mg/L, and 3.920 mg/L, respectively; the CRP level in the sepsis group was higher than that in the non-infection group (P = 0.009). Here, CRP is linked to pneumonia.