The Effect of Intrauterine Growth Restriction on Circulating Surfactant Protein D Concentrations in the Perinatal Period

Abstract

The aim of this study was to investigate possible alterations in circulating concentrations of surfactant protein D (SP-D)-an important component of the innate immune system that is upregulated in pulmonary diseases-in appropriate for gestational age (AGA) and intrauterine growth-restricted (IUGR) pregnancies, because the latter are characterized by structural lung immaturity, impaired immunocompetence, and increased risk of respiratory infections and chronic obstructive lung disease in later life. Serum SP-D concentrations were determined in 40 mothers and their 20 IUGR and 20 AGA full-term fetuses-neonates on postnatal day 1 (N1) and 4 (N4). Fetal SP-D concentrations were higher in the IUGR group (b = 18.16, 95% CI: 6.86-29.47, P = .002) and negatively correlated with infants' customized centiles and gestational age (r = -.326, P = .04, and r = -.446, P = .004, respectively). In both groups, fetal SP-D concentrations were lower than N1 and N4 ones (P <or= .015 in all cases). In the IUGR group, N1 SP-D concentrations were higher in vaginal deliveries (P = .032). Higher SP-D concentrations in IUGR fetuses may reflect structural lung immaturity, leading to increased alveolar-vascular permeability and protein leakage into the circulation. Alternatively, SP-D production may be increased due to intrauterine glucocorticoid exposure, leading to accelerated lung maturation. Surfactant protein D concentrations postnatally increase and are higher in neonates born vaginally, probably as a consequence of lung liquid reabsorption, concomitant with initiation of breathing and delivery stress. A progressive decrease in placental function may result in downregulated SP-D production, accounting for the negative correlation between fetal SP-D concentrations and gestational age.

Differential levels of surfactant protein A, surfactant protein D, and progesterone to estradiol ratio in maternal serum before and after the onset of severe early‐onset preeclampsia

“…Interestingly, six of these IUGR pregnancies also suffered from preeclampsia. 29 Role of elevated levels of MBL in the immunopathogenesis of PE has been documented previously in Caucasian population. [33][34][35] In view of these evidences, we speculate that elevated levels of collectins after the onset of severe whereas LOPE is the milder form characterized by maternal maladaptation to meet the metabolic demands of the growing fetus at term.…”

“…We speculate that the decreased P4/E2 ratio owing to increased levels of E2 and no change in P4 levels might lead to downregulated levels of SP-A and SP-D observed prior to onset of severe EOPE. Interestingly, six of these IUGR pregnancies also suffered from preeclampsia 29. Premature elevation in E2 levels in the first 60 days of pregnancy in the baboon model reduced EVT invasion, uterine blood flow dynamics, and increased uterine-artery pressure 51.…”

“…[15][16][17][18] Various evidences suggest the relevance of collectins in the pregnancy. 29 Decreased maternal serum MBL levels are associated with recurrent spontaneous abortions. [19][20][21] Levels of collectins are increased in the human amniotic fluid at term and are probably involved in the antibody-independent recognition and clearance of pathogens in the amniotic fluid.…”

“…Higher levels of SP-D were observed in the maternal serum and umbilical cord blood of intrauterine growth restricted (IUGR) cases. 29 Decreased maternal serum MBL levels are associated with recurrent spontaneous abortions. 30,31 In our previous study, we reported altered expression of SP-A and SP-D in the first-trimester placental tissues of women suffering from spontaneous abortion.…”

Impairment of cellular immunity is associated with overexpression of heat shock protein 70 in neonatal pigs with intrauterine growth retardation

“…IUGR places the newborn infant at considerable risk for increased mortality and morbidity; the latter includes poor physical growth, permanent maldevelopment, and increased susceptibility to infection (Pallotto and Kilbride 2006). IUGR also affects development and function of the immune system in the newborn infant (Cromi et al 2009;Briana et al 2010). Changes in thymus size and histopathology have been observed both in IUGR infants and in animal models of IUGR (Lang et al 2000;Cromi et al 2009).…”