Evaluation of C reactive protein and others immunologic markers in the diagnosis of neonatal sepsis

Neonatal sepsis occurs from 1 to 21 newborns out of 1 000 live births with mortality rates as high as 30% up to 69%. The most important risk factors are prematurity, low birth weight, invasive medical procedure and prolonged hospitalization in neonatal intensive care units. An aimed and restrictive antibiotic therapy has an outstanding importance to reduce both morbidity-mortality rates and multiple drug-resistance. Generally, preterm newborns present nonspecific clinical signs of infection. The use of high sensitivity infection markers and a negative predictive value (near 100%) are important to distinguish infected and noninfected patients before the culture results and to verify adequacy and duration of antibiotic therapy. This article reviews the immunologic function and practical use of C reactive protein (CRP) and other markers in the diagnosis of neonatal sepsis. While CRP is a specific late infection marker, cytokines, cell surface markers and procalcitonin (PCT) are early infection markers. The use of multiple markers as CRP, PCT, IL-6, IL-8, CD64, CD11b is useful both to early (24-48 h) diagnose of neonatal sepsis, and to monitorate the antibiotic treatment while waiting for the results of cultural examinations.