Mononuclear cell subpopulations in preterm and full-term neonates: independent effects of gestational age, neonatal infection, maternal pre-eclampsia, maternal betamethason therapy, and mode of delivery

Blood samples from 29 preterm (24-32 weeks of gestation) and 21 full-term ( 37-42 weeks of gestation) neonates were analysed for surface markers of lym phocyte subtypes and macrophages, and the effects of gestational age, neona tal infection, maternal pre-eclampsia, maternal betamethason therapy and mo de of delivery were assessed with multiple regression analysis. Gestational age alone had few independent effects (increase in CD3(+), CD8(+)CD45RA(+) , and CD11 alpha(+) cells, and decrease in CD14(+), HLA-DR- cells) during t he third trimester on the proportions of the immune cell subtypes studied. Neonatal infection and mother's pre-eclampsia had the broadest and very opp osite kinds of effects on the profile of immune cells in the blood. Infecti on of the neonate increased the proportions of several `immature' cells (CD 11 alpha(-)CD20(+), CD40(+)CD19(-), and CD14(+)HLA-DR-), whereas mother's p re-eclampsia decreased the proportions of naive cell types (CD4(+)CD8(+),CD 5(+)CD19(+)). In addition, neonatal infection increased the proportion of T cells (CD3(+), CD3(+)CD25(+), and CD4(+)/CD8(+) ratio, and CD45RA(+) cells ), while maternal pre-eclampsia had a decreasing effect on the proportion o f CD4(+) cells, CD4(+)/CD8(+) ratio, and proportions of CD11 alpha(+), CD14 (+) and CD14(+)HLA-DR+ cells. Maternal betamethason therapy increased the p roportion of T cells (CD3(+)) and macrophages (CD14(+), CD14(+)/HLA-DR+), b ut decreased the proportion of natural killer (NK) cells. Caesarean section was associated with a decrease in the proportion of CD14(+) cells. We conc lude that the `normal range' of proportions of different mononuclear cells is wide during the last trimester; further, the effect of gestational age o n these proportions is more limited than the effects of other neonatal and even maternal factors.