RESUMO
Experimental data imply that serum C-reactive protein (CRP) is a marker of general systemic inflammation, and inflammation may have a role in the development of pneumonia. The aim of the present study was to investigate the associations of serum CRP levels in infant patients with pneumonia by meta-analysis. The Science Citation Index, Cochrane Library, PubMed, Embase, CINAHL, Current Contents and two Chinese (CMB and CNKI) databases were searched. Studies were pooled and standard mean difference (SMD) and the corresponding 95% confidence interval (CI) were calculated. Subgroup analyses and publication bias detection were also conducted. The statistical analysis was conducted using Stata software version 12.0. Serum CRP levels were analyzed in 10 clinical case-control studies (652 infants with pneumonia and 845 healthy controls); significant differences in serum CRP levels were observed between infants with pneumonia and the healthy controls (SMD=4.41, 95% CI: 3.34-5.47, P<0.001). Ethnicity-stratified subgroup analysis detected that high levels of serum CRP may be the main risk factor for infant pneumonia in Asian, African and Caucasian populations (all P<0.05). Serum CRP levels were statistically higher in infants with pneumonia than in healthy infants, and thus serum levels of CRP may have independent diagnostic value for pneumonia in children.