Effect of prematurity on protein glycosylation in the newborn.

BACKGROUND

Glycohemoglobins (GHb) are the products of irreversible non-enzymatic reactions between glucose and the hemoglobin molecule. Glycosylation of proteins in general can modify protein structure and alter catalytic properties, thereby causing cellular dysfunction. The aim of the present study was to test the hypothesis that protein glycosylation levels in premature infants are elevated compared with full-term infants (neonates). Blood GHb levels in pre-term and full-term infants were studied, and the in vitro glycosylation of erythrocytes obtained from both pre-term and full-term infants was assessed.

METHODS

Cord-blood from 31 pre-term and 11 full-term infants was collected and GHb levels were determined using affinity columns. Erythrocytes from the cord blood of 17 additional infants (eight pre-term, ≤ 36 weeks gestation, and nine full-term, ≥ 37 weeks gestation) were obtained and incubated for 24 h in a high-glucose medium. Baseline and post-incubation GHb levels were calculated to determine the in vitro susceptibility of pre-term versus full-term infants to glycosylation.

RESULTS

Blood GHb levels were significantly higher (P < 0.01) in full-term compared with pre-term infants. The percent increase in GHb formation in vitro was similar between the erythrocytes of full-term and those of pre-term infants.

CONCLUSION

Contrary to the original hypothesis, the erythrocytes of pre-term infants do not show increased glycosylation of proteins when compared with those of full-term infants.