ABSTRACT
C-reactive protein [CRP] analysis is a simple, established and widely available test to identify an evidence of plasma acute phase response to infection and tissue injury. Standard CRP assays such as: latex agglutination and quantitative assays lack sensitivity at the early onset of neonatal sepsis. They can detect CRP concentrations. The development of the new high sensitivity immunoassay technique for CRP [HSCRP] has enabled its detection at lower concentrations. In HSCRP immunoassay, anti CRP antibodies react with antigen in the serum to form antigen antibody complex measured turbidimetrically. Evaluation of the diagnostic value of highly sensitivity CRP immunoassay in comparison to standard CRP latex agglutination and quantitative assays in early onset neonatal sepsis. A prospective controlled study including 51 neonates with culture proven bacterial sepsis. Ten healthy neonates served as control group. All neonates were subjected to full clinical examination, and laboratory investigations including: CBC with differential leukocytic count, blood culture and sensitivity. CRP analysis was performed using 3 techniques for each patient: CRP latex agglutination, CRP quantitative assay where values ? 6mg/L were considered abnormal, and HSCRP immunoassay where values ? 2mg/L were considered abnormal. CRP latex agglutination was positive in 8/51 [15.68%] and had sensitivity of 15.68%, specificity 100%, positive predictive value 100%, negative predictive value 18.86% and diagnostic accuracy 29.5%. CRP quantitative assay was positive in 12/51 [23.52%]. At cut of level 6mg/L: sensitivity was 23.5%, specificity 100%, positive predictive value 100%, negative predictive value 20.4% and diagnostic accuracy 36.06%. HSCRP immunoassay was positive in 34/51 [66.66%]. At cut off level 2mg/L: sensitivity was 66.6%, specificity 100%, positive predicative value 100%, negative predictive value 37.03% and diagnostic accuracy 72.13%. CRP analysis using high sensitivity immunoassay is likely to improve the diagnostic accuracy of CRP in detection of early onset neonatal sepsis. It allows detection of CRP at low concentrations. Only 40micro l of serum is needed, and results are available within 15 minutes