[The viewpoints of viral vertical transmission from fetal neonatal immunologic aspects]

A. The development of fetal Immune system 1. Complement: Alternative pathway is dominant in the development of fetal complement. 2. Neutrophil function: Phagocytosis in full term infants was increased to be adult-level, but bactericidal function was decreased. 3. NK activity: NK activity in full-term infants was significantly lower than in adults, however, IL-2-augmented NK activity did not indicate any significant difference with levels in adults. In pre-32 week infants both NK and IL-2-augmented NK activity were further decreased as opposed to in full-term infants. 4. LAK activity: LAK activity was fully developed already in 19 week infants, indicating that auto-monitoring of mutant cells is already under control from the early stages of fetal development. 5. Antibody production: Antibody production in infants was significantly decreased in comparison to adults. Reduced cytokine (IL-1, BCDF) production were considered to be the causal factors. 6. IL-2, IL-2R: In IL-2 production, no difference was recognized between normal neonates and adult subjects. In contrast, a significantly higher value of IL-2 production was observed for premature neonates born between 16 and 36 GW, compared with adults. IL-2 production and IL-2R system is fully developed at 22 weeks. 7. BCDF gamma, BCDF mu: Reduced compared to that of adults. 8. IL-6, IL-8, G-CSF: Much higher levels were found in cases of intrauterine infection, particularly in cases of premature delivery. The cytokine levels were 20-to-30-fold higher in chorioamnitis-positive premature delivery group. 9. M-CSF: M-CSF is increased, M-CSF may play a role in decidual function and placental function by the autocrine and paracrine system. 10. IL-1 alpha, IL-1 beta, IL-6: These production by macrophages was diminished in aborted fetuses, premature infants and IUGR infants. However, in the infants of mother with intrauterine infection, cytokine production was elevated to the level in full term infants and adults. 11. IFN gamma: Production of IFN gamma by memory T cells was diminished in premature infants. B. The vertical transmission of HTLV-I. The routes of vertical transmission of HTLV-I are intrauterine, intra-birth canal and via breast milk. Bottle-feeding is an effective way of avoiding mother-to-child infection. However breast milk is necessary for optimal infant nourishment, so we use -20 degrees C for 12 hours freeze-thawing of breast milk.(ABSTRACT TRUNCATED AT 400 WORDS)