Soluble intercellular adhesion molecule and C-reactive protein as early markers of infection in newborns.

In order to find a reliable early marker of infection in newborns a study with simultaneous determination of soluble Intercellular Adhesion Molecule-1 (sICAM-1) and C-Reactive Protein (CRP) was planned. Prospectively 90 babies < 5 days of age suspect of infection were included. Retrospectively this population was classified into an "infected" group (n = 45) and a "non-infected" group (n = 45). For each of these two groups we calculated the sensitivity, specificity and predictive values of sICAM-1 and CRP as early markers of infection. We determined the best cut-off level for sICAM-1 to be 300 micrograms/l and for CRP 5 mg/l. As a biochemical test for infection in the newborns the sensitivity and negative predictive value for CRP were 0.69 and 0.73 respectively. When sICAM-1 was added and CRP and s-ICAM-1 were used in combination the sensitivity improved significantly to 0.93, p < 0.01 and the negative predictive value improved to 0.92, p < 0.05. In normal 5-8 days old babies' sICAM-1 was significantly higher than at birth (cord blood), p < 0.0001. In conclusion, sICAM-1 and CRP in combination are better than CRP as a primary test for identification of infection in babies < 5 days of age.