All 4 cases were complicated with severe pneumonia, the percentage of neutrophils was high (44.00–81.54%), C-reactive protein was higher than normal in 3 cases (21.1–235.5 mg/L, with normal value of < 5 mg/L), and procalcitonin was high in 2 cases (1.05–8.22 ng/ml, with normal value of < 0.25 ng/ml). Here, CRP is linked to susceptibility to pneumonia measurement.