Maternal Circulating Dendritic Cell Subtypes at Delivery and During the 1-Year Postpartum Period.

Problem Dendritic cells ( DCs) play an important role in maintaining pregnancy by inducing tolerance toward the fetus. Such an immunologic change in the mother should be restored to normal after delivery, but few studies have reported postpartum maternal immune recovery, in terms of the types circulating DCs. Method of study The level of each DC subtype and HLA- DR-positive immunoreactivity of the blood from 29 pregnant women with uncomplicated labor was serially analyzed by flowcytometry at delivery and at 1.5, 6, and 12 months after delivery. DC subtypes were characterized as myeloid, lymphoid, and less differentiated (ld DC). Mean fluorescence intensity ( MFI) was evaluated for HLA- DR expression for each DC subtype. Results The total number and the percentage of DCs at delivery were lower than those at 12 months postpartum. The ld DC fractions were significantly higher at delivery and at 1.5 months than at 12 months postpartum. The MFI of HLA- DR expression on ld DCs at delivery was lower than that at 12 months postpartum. The myeloid-to-lymphoid DC ratio did not differ over the 1-year postpartum period. Conclusion The maternal alteration in DCs rapidly normalized within 1.5 months, except for the ld DC fraction, which persisted between 1.5 and 6 months after delivery. [ABSTRACT FROM AUTHOR]