N-Terminal Propetide of Type III Collagen in Tracheal Fluid and Serum in Preterm Infants at Risk for Bronchopulmonary Dysplasia

Abstract

ABSTRACT. Bronchopulmonary dysplasia (BPD) is a common pulmonary complication in preterm infants that leads to fibrosis of the bronchoalveolar walls and often to severe clinical consequences. Type I11 collagen is deposited early in progressive fibrosis. Because the N-terminal propeptide of type I11 collagen (PIIINP), a by-product of type I11 collagen synthesis, reflects the degree of pulmonary fibrosis in adults, we hypothesized that PIIINP in tracheal aspirates and/or serum may be a useful early marker of developing BPD in neonates. We serially measured PIIINP in tracheal fluid and serum samples during the first weeks of life in 41 consecutive respirator-treated preterm infants (mean birth weight 1067 g, mean gestational age 28.3 wk). Eight of the infants died and 22 infants fulfilled the criteria for BPD at age 28 d. The mean level of PIIINP decreased with advancing postnatal age in tracheal fluid but not in serum. The mean tracheal fluid PIIINP during d 1 and 2 of life, respectively, was 175 and 200 ng/mg protein in infants who were still in a respirator at age 28 d (n = 13), 122 and 97 ng/mg protein in those who were weaned earlier (n = 20), and 50 and 30 ng/mg protein in those who died before age 28 d (n = 8). These differences are not statistically significant, and the variability of the values was large. The PIIINP concentrations in tracheal aspirates of infants subsequently developing BPD did not differ from those without BPD. Neither did the levels correlate with the degree of BPD or radiologically defined fibrosis. In contrast to the findings in tracheal fluid, the serum PIIINP levels in infants subsequently developing BPD were significantly higher (p = 0.01) than those in infants without BPD, the respective mean (90% confidence intervals) concentrations being 788 (range 519-1057) and 256 (range 171-341) ng/mL. We conclude that serum PIIINP should be further evaluated as an early marker of BPD, whereas tracheal fluid levels are useless for this purpose. (Pediatr Res 31: 340-344,1992) Abbreviations PIIINP, N-terminal propeptide of type I11 collagen BPD, bronchopulmonary dysplasia RDS, respiratory distress syndrome BPD is a common complication of respirator treatment of pulmonary disease in the preterm infant. Its main risk factors

Fibroblast mitogenic activity of lung lavage fluid from infants with chronic lung disease of prematurity

“…Other components, especially of collagen, have also been shown to be increased in infants who progress to develop CLD. 7 8 24 In newborn infants, rapid growth and remodelling of the airways is occurring. The same growth factors that are important to the fibrotic process are also thought to play a role in normal lung growth and development, including normal alveolisation.…”

Potential Biochemical Growth Markers in Premature Infants

“…Furthermore, for the purposes of data interpretation, they pooled all samples obtained from days 1 to 22 when comparing babies with or without BPD. 31 This is in contrast to our study where we looked at babies with much worse BPD (defined as oxygen requirement with characteristic radiographic features at 36 weeks postconceptional age), controlled for variables like birth weight and ventilator days (factors known to have a significant impact on the etiopathogenesis of BPD), and had serial weekly measurements of PICP.…”

“…One study 31 found elevated serum levels of Akerminal propeptide of type III collagen (PIIINP) in infants with BPD, defined radiographically at 28 days. In that study, 31 PIIINP concentrations in cord blood declined with advancing gestational age. They also found no correlation of postnatal PIIINP levels either with gestational or postnatal age.…”

Serial bronchoalveolar lavage of preterm infants is not associated with chest radiological changes

“…Some groups collect bronchoalveolar lavage fluid [1,4,5,11] whilst others collect tracheal aspirate [6,14,22]. Some have used a fixed volume of saline [16,17,24] whilst others administer a weightrelated quantity [5,11].…”