Kupffer cell numbers during human development.

Immunohistological assessment of Kupffer cells was made using the antibody MAC387 and an antibody to lysozyme. Autopsy liver samples from 13 fetuses aged from 17 weeks gestation to term, and from 10 neonates and children aged 1 day to 18 months, were studied. For comparison, 10 normal adult autopsy liver specimens were included. The number of positively staining cells per unit area was counted for periportal sinusoids (zone 1) and centrilobular sinusoids (zone 3). No difference was found between zone 1 and zone 3 macrophage numbers with either antibody at any stage of development. Hepatic sinusoidal macrophage numbers were low during early gestation but increased during intra-uterine life to reach approximately normal adult values in the neonatal period. The numbers of cells staining with MAC387 or lysozyme were similar in each case except for hepatic sinusoidal macrophages in fetuses of less than 30 weeks gestation. Here anti-lysozyme stained significantly fewer cells, suggesting that lysozyme production may be low in immature fetuses. No difference was found between infants of similar maturity who had died immediately or had lived for more than 48 h and hence been exposed to gut antigens.