GLYCAN MICROHETEROGENEITY OF ALPHA-1-ANTITRYPSIN IN SERUM AND MECONIUM FROM NORMAL AND CYSTIC-FIBROSIS PATIENTS BY CROSSED IMMUNOAFFINOELECTROPHORESIS WITH DIFFERENT LECTINS (CON A, LCA, WGA)

In order to test whether abnormalities of glycosylation occur in cystic fibrosis (CF), the glycan microheterogeneity of alpha1-antitrypsin (alpha1-AT) was studied in serum and meconium from normal individuals and patients with cystic fibrosis, by crossed immunoaffinoelectrophoresis (CIAE) using free Concanavalin A (Con A), Lens culinaris lectin (LCA) and wheat germ agglutinin (WGA). Three main results emerged from this study: (1) modification of glycosylation in serum alpha1-AT from patients with cystic fibrosis were only significant with free Con A and WGA; this probably results from a reduced synthesis of the bi-antennary side-chains or by their increased catabolism. (2) Differences in isoforms found in alpha1-AT from normal individuals and patients with CF using free Con A, LCA, were more pronounced in the meconium than in the serum; this may provide a useful test in diagnosis of cystic fibrosis. (3) There was parallelism between the behaviour of alpha1-AT in serum and meconium from patients with CF using LCA, Con A; this may be explained by different types or levels of disfunction affecting a glycosylation mechanism.