Serial measurements and use of combinations of markers have been reported to improve sensitivity and negative predictive value of these tests. Current markers are not infallible, however, and do not permit neonatologists to withhold antibiotics in sick infants with suspected infection. Thus, many have emerged as useful indicators for early discontinuation of unnecessary antimicrobial therapy. Some infection markers are also useful for identifying infants with severe infection and adverse prognosis. Advances in flow cytometry have allowed simultaneous measurement of key markers using only minimal blood volume. Judicious selection of a panel of markers with complementary properties could greatly increase the ability of neonatologists to diagnose infection and discern valuable prognostic information.

Abbreviations: CRP, C-reactive protein; IL, interleukin; LBP, lipopolysaccharide-binding protein; NK, natural killer; PCT, procalcitonin; SAA, serum amyloid A; suPAR, soluble form of urokinase-type plasminogen activator; VLBW, very low birth weight