Mucin-like carcinoma-associated antigen in paired serum and breast milk samples of lactating mothers and sera of their neonates in the early postpartum period.

OBJECTIVE: To evaluate postpartum MCH changes in the early postpartum period, and to examine whether neonatal MCA is related to that in maternal serum (MS) or milk. STUDY DESIGN: MCA was measured by EIA on the second and fifth postpartum day in serum and BM from 30 lactating women and their single term neonates. Sera from 20 healthy women (controls), were also analyzed. RESULTS: All neonatal antigen concentrations were below the cut-off level for MCA (11 ng/ml). MS MCA was significantly increased compared with that in controls (P<0.00001), while antigen values in BM were highly elevated (P<0.00001), with a significant increase (P<0.0003) from the second to the fifth postpartum day. A strong correlation was found between the second and fifth day postpartum samples in MS, neonatal serum and BM MCA concentrations (r(s)=0.94, P<0.00001; r(s)=0.75, P<0.00001 and r(s)=0.69, P<0.0001, respectively). A significant correlation was also found in MCA values on the fifth postpartum day between neonatal serum and BM (r(s)=0.54, P<0.02). CONCLUSIONS: From these findings one may speculate on some ripening process in milk production and a possible transition of MCA from the neonatal gastro-intestinal tract into circulation.

sCD31/sPECAM-1 levels in breast milk and sera of mother-infant pairs in the early postpartum period.

Immunomediators seem to have a central role in the immune system of both human milk and newborn infants. CD31/PECAM-1 is an adhesion molecule, member of Ig gene superfamily, mediating cell-cell adhesion in both homophilic and heterophilic ways. Levels of the soluble form of PECAM-1 (sPECAM-1) were evaluated on the 2nd and 5th day postpartum in breast milk and serum paired samples from 20 lactating women as well as in time-matched serum from their single, term, healthy neonates. Concentrations of sPECAM-1 in breast milk (median, range) on both the 2nd (2.05 ng/ml, 0.0-7.2) and 5th day postpartum (0.89 ng/ml, 0.0-3.6) were about 10 and 20 times lower than those (mean +/- SD) in controls (healthy adults) (19.83 +/- 5.17, p<7 x 10(-8)), showing a significant fall from the 2nd to the 5th day postpartum (p<0.0005). Maternal serum sPECAM-1 values (mean +/- SD) were significantly lower on the 2nd day postpartum (14.21 +/- 5.15 ng/ml) than those in controls (p<0.002), but reached control values on the 5th day postpartum after a significant rise (p<0.0075). Neonatal serum sPECAM-1 values with no significant difference between the 2nd (14.4 +/- 4.11 ng/ml) and 5th day of life (14.54 +/- 4.99 ng/ml) were significantly lower than those in controls (p<0.002). Values of sPECAM-1 in milk and sera of lactating mothers and their neonates on the 2nd day postpartum depended on the mode of delivery, being significantly lower after caesarean section (p<0.034, p<0.0075 and p<0.035, respectively). In conclusion, our findings in the early postpartum period demonstrate that: (a) sPECAM-1 is present in human milk in low and decreasing concentrations; (b) the shedding of sPECAM-1 is an established component of the neonatal immune system from birth, though in lower concentrations than in adults, possibly reflecting its immaturity; and (c) the mode of delivery has a significant effect on sPECAM-1 values in milk and sera of lactating mothers and their neonates; the lower values after caesarean section may reveal a deranged endothelial homeostasis.