Pulmonary surfactant protein B in the peripheral circulation and functional impairment in patients with chronic heart failure

High postoperative serum levels of surfactant type B as novel prognostic markers for congenital heart surgery

OBJECTIVE

Congenital heart diseases are observed in 5 to 8 of every 1000 live births. The presence of a valuable biomarker during the surgical periods may aid the clinician in a more accurate prognosis during treatment.

METHODS

For this reason, surfactant protein B plasma levels may help to evaluate patients with cardiac problems diminishing the alveolocapillary membrane stability. In this study, plasma levels of this biomarker were measured in the preoperative and postoperative periods. This study was conducted to detect the differences between pulmonary hypertensive and normotensive patients. The differences before and after cardiopulmonary bypass were examined.

RESULTS

The differences in cardiopulmonary bypass time, cross-clamp time , inotropic support dose, and duration of intensive care of patients with and without pulmonary hypertensive were found to be statistically significant (P<0.05). The results revealed that this pathophysiological state was related to other variables that were studied. We believe that the differences in preoperative and postoperative SPB levels could be attributed to alveolocapillary membrane damage and alveolar surfactant dysfunction. We found that this pathophysiological condition was significantly associated with postoperative parameters.

CONCLUSION

The findings of the current study showed that surfactant protein B was present in the blood of patients with a congenital heart disease during the preoperative period. Long by-pass times may exert damage to the alveolocapillary membrane in patients with pulmonary hypertension and preoperative heart failure, and it is recommended to keep the option of surfactant therapy in mind during the postoperative course at the intensive care unit before preparing the patients for extubation.

Fetal and neonatal samples of a precursor surfactant protein B inversely related to gestational age

Background

Alveolar–capillary membrane leaks can increase the amount of surfactant protein B (SP-B) in the bloodstream. The purpose of this study was to measure the concentration of C-proSP-B, a SP-B precursor that includes C-terminal domains, in various body fluids of newborn infants and determine its dependence on gestational age.

Methods

C-pro-SPB was measured in amniotic fluid and umbilical cord blood at birth, and in peripheral blood and urine on postnatal day 3 in 137 newborn infants with a median birth weight of 2015 g (range, 550–4475 g) and gestational age of 34 weeks (range, 23–42 weeks).

Results

C-proSP-B levels differed more than 100-fold among samples. The levels (median; interquartile range) were highest in peripheral blood (655.6 ng/mL; 419.0-1467.0 ng/mL) and lowest in urine (3.08 ng/mL; 2.96-3.35 ng/mL). C-proSP-B levels in amniotic fluid (314.9 ng/mL; 192.7–603.6 ng/mL) were approximately half of those in peripheral blood. In cord blood C-proSP-B was slightly lower (589.1 ng/mL; 181.2-1129.0 ng/mL) compared with peripheral blood. C-proSP-B levels significantly increased in all the fluids sampled except urine with decreasing gestational age (p < 0.001).

Conclusions

This novel assay allows for the quantitative measurement of C-proSP-B in blood and amniotic fluid. The dependence of C-proSP-B on gestational age may hamper its use for the detection of alveolar leaks in preterm newborns.