[Possible disorder of tissue immunity function in mothers who have given birth to a child with Down's disease]

The rates of DNA synthesis were studied in PHA-stimulated lymphocytes from the peripheral blood of mothers giving birth to a child with Down's disease. For control purposes a group of donors of the same age and sex were studied as wells. A decrease of 3H-thymidine incorporation was detected in the lymphocytes of the mothers of such children. The found differences were due to a drop of lymphocyte PH-reactivity in the older maternal age group (over 30 years). Interrelation between the changed function of the maternal immune system and the birth of children with chromosome unbalance are discussed.