Abstract:

Objective To investigate the combined determination of serum amyloid A （SAA） and C-reactive protein （CRP） for the diagnosis of infectious diseases in children. Methodse SAA and CRP levels were determined in 65 patients with viral infection,72 patients with bacterial infection and 60 healthy children （healthy control group）,and white blood cell （WBC） count and differentiation were determined,and the neutrophil/lymphocyte ratio （NLR） was calculated. Receiver operating characteristic （ROC）curve was used to analyze the efficacy of SAA,CRP,SAA/CRP ratio,WBC count and NLR in the diagnosis of bacterial and viral infections. Results The levels of SAA,CRP,WBC count and NLR in bacterial infection group were higher than those in healthy control group （P<0.05）,and SAA/CRP ratio was lower（P<0.05）. The levels of SAA and SAA/CRP ratio were higher in viral infection group than those in healthy control group （P<0.05）,and there was no statistical significance for CRP,WBC count and NLR compared with healthy control group（P>0.05）. ROC curve showed that CRP had the best performance for the diagnosis of bacterial infection,and the area under ROC curve （AUC）,sensitivity and specificity were 0.977,99.0% and 83.2%,respectively. SAA/CRP ratio had the best performance for the diagnosis of viral infection,and AUC,sensitivity and specificity were 0.916,87.7% and 89.4%. Conclusions SAA and CRP can be used as diagnostic parameters for bacterial infection. In viral infection,SAA increases more obviously than CRP,and SAA/CRP ratio is sensitive. The combined determination of SAA and CRP can determine the types of infections quickly and accurately,and can provide a reference for the early diagnosis and follow-up treatment.

Key words: Serum amyloid A, C-reactive protein, Infectious diseases in children