Usefulness of C-reactive protein in the diagnosis of neonatal sepsis

Early diagnosis of sepsis in the neonate is often difficult because symptoms and signs are usually non-specific. A study was conducted to evaluate C-reactive protein (CRP) as a screening tool for neonatal sepsis among very low birth weight (VLBW) infants.

The study population consisted of 70 VLBW infants suspected of sepsis. Sepsis was diagnosed from positive cultures of blood, cerebro-spinal fluid or bone/joint aspirate in the presence of signs. Positive cultures were the "gold standard" against which the performance of CRP > or = 1.0 mg/dL, abnormal white cell counts (WCC), absolute neutrophil (ANC) and platelet counts were compared.

Of 152 septic screens, 30 (20%) had positive cultures. From analysis of the receiver operating characteristic (ROC) curve, CRP > or = 0.7 mg/dL rather than CRP > or = 1.0 mg/dL appeared a better cut-off for screening. The sensitivity, specificity, positive and negative predictive values of CRP > or = 0.7 mg/dL were 56%, 72%, 71% and 57% respectively. Only abnormal platelet counts had similar efficiency as CRP. Abnormal WCC had the lowest sensitivity and positive predictive value while abnormal ANC had the lowest specificity and negative predictive value among them.

CRP assay using laser nephelometry is a valuable adjunct in screening for neonatal sepsis, complementing clinical decision-making.