Preterm infants are highly susceptible to life-threatening infections that are clinically difficult to detect, such as late-onset septicemia and necrotizing enterocolitis (NEC). Here, we used a proteomic approach to identify biomarkers for diagnosis of these devastating conditions. In a case-control study comprising 77 sepsis/NEC and 77 nonsepsis cases (10 in each group being monitored longitudinally), plasma samples collected at clinical presentation were assessed in the biomarker discovery and independent validation phases. We validated the discovered biomarkers in a prospective cohort study with 104 consecutively suspected sepsis/NEC episodes. Proapolipoprotein CII (Pro-apoC2) and a des-arginine variant of serum amyloid A (SAA) were identified as the most promising biomarkers. The ApoSAA score computed from plasma apoC2 and SAA concentrations was effective in identifying sepsis/NEC cases in the case-control and cohort studies. Stratification of infants into different risk categories by the ApoSAA score enabled neonatologists to withhold treatment in 45% and enact early stoppage of antibiotics in 16% of nonsepsis infants. The negative predictive value of this antibiotic policy was 100%. The ApoSAA score could potentially allow early and accurate diagnosis of sepsis/NEC. Upon confirmation by further multicenter trials, the score would facilitate rational prescription of antibiotics and target infants who require urgent treatment.
Pak Cheung Ng, Irene Ling Ang, Rossa Wai Kwun Chiu, Karen Li, Hugh Simon Lam, Raymond Pui On Wong, Kit Man Chui, Hon Ming Cheung, Eddy Wing Yin Ng, Tai Fai Fok, Joseph Jao Yiu Sung, Yuk Ming Dennis Lo, Terence Chuen Wai Poon
Submitter: Kostan Reisinger | k.reisinger@maastrichtuniversity.nl
Authors: Joep P.M. Derikx, and Boris W. Kramer
Departments of Surgery and Paediatrics, Maastricht University Medical Center +, Maastricht, The Netherlands
Published October 27, 2010
With great interest we read the article by Ng et al. (1). Their thorough and profound approach, led to the discovery of two promising biomarkers for the detection of both sepsis and necrotizing enterocolitis in preterm infants, serum amyloid A (SAA) and proapolipoprotein CII (pro-apoC2). As the authors state on page 2997, medical management of NEC and sepsis is identical in the initial stage. However, the decision to perform surgery in case of suspected NEC remains critical (2), while the needless use of antibiotics in non-sepsis cases seems less dangerous. When resection of affected bowel is not achieved timely, the subsequent disease progression can be devastating with high mortality (3). It is therefore highly desirable to distinguish between sepsis and NEC at an early time-point. Recent literature indicates markers of gut injury to be suitable candidates for this purpose (4, 5). Moreover, Thuijls et al. reported promising results on gut-specific non-invasive markers, namely urinary intestinal Fatty Acid Binding Protein (iFABP) and fecal calprotectin, to differentiate between NEC and sepsis (6). Combining these markers with the reported inflammatory markers of Ng et al. might overcome the essential diagnostic dilemma of early discrimination of NEC and sepsis in preterm neonates.