Background Antenatal independent factors predict the risk of respiratory distress syndrome (RDS) or bronchopulmonary dysplasia (BPD). As yet unknown biomarkers may further define the risk of these inflammatory diseases. In the present study we investigated whether the serum proteins in cord blood predict the acute or chronic respiratory outcome.

Patients and Methods The prospective regional cohort included 163 surviving very preterm infants born in Oulu University Hospital during 1998–2202. The study was approved by the ethics committee. Informed consent was signed. Antenatal clinical data were collected. The placentas were evaluated for histologic chorioamnionitis (HCA). From cord blood, 107 proteins were analyzed using sensitive and specific fluorescent sandwich immunoassay with rolling circle signal amplification (RCA). Together with prospectively collected antenatal risk factors the biomarkers were evaluated, using classification and regression trees (CART) analysis. This data mining method detects complex relationships between independent and dependent variables.

Results RDS was defined in 64% and BPD in 25% of study infants. Histologic chorioamnionitis protected from RDS (OR 0.24, 95% CI 0.11 to 0.53; p<0.001). Besides the length of gestation, other clinical factors poorly predicted the outcomes. Matrix metalloproteinase-9 (MMP-9) predicted the risk of RDS (OR 8.3, 95% CI 3.0 to 23.1, p<0.001) after considering the length of gestation and CA as risk factors. Soluble glycoprotein 130 (sgp130), a constitutionally expressed component of IL-6 receptor, was not affected by HCA. Sgp130 independently predicted BPD (OR 6.07, 95% CI 2.20 to 16.7; p<0.001).

Conclusion In very premature fetuses the concentrations of MMP-9 and sgp130 in cord blood independently predict the risk of RDS and BPD, respectively.