Abstract
Surfactant derived protein B (SPB) and plasma receptor for advanced glycation end products (RAGE) have been proposed as markers of lung injury. The former is produced specifically by pneumocytes while RAGE production is present in several body tissues. Cardiopulmonary by-pass (CPB) generates a transient lung injury. We measured SPB and RAGE in plasma before surgery, after CPB, as well as 24h and 48h later.
We analysed plasma samples of 20 subjects scheduled for elective CABG. We performed a quantitative analysis of plasma levels of RAGE and SPB mature form (8 kDa) by enzyme-linked immunosorbent assays and a semiquantitative analysis of SPB immature form (∼40 kDa) by Western blotting.
Surgery procedures were uneventful. After CPB RAGE increased from 633 (median) pg·mL−1 (539, 75th–25th interquartile difference) to 1362 (557)$, while mature SPB increased from 5587 ng·mL−1 (3089) to 20307 (19873)$, $ =p<0.01. RAGE and mature SPB returned to normal values within 48h. This behaviour was confirmed when RAGE and SPB were normalized for protein content. Parallel changes were observed for immature SPB.
Plasma RAGE and SPBs are sensible and rapid markers of lung distress.
- ERS