Relationship between cytokines and human cytomegalovirus infection of breast milk

Colostrum and breast milk samples were collected from 65 anti-human cytomegalovirus (HCMV) IgG antibody-positive nursing mothers at 3 days and at 1 month after delivery. The colostrum supernatant from 10 mothers did not exert an inhibitory effect on HCMV-infected cells. The activity of tumor necrosis factor (TNF)-α was significantly higher in HCMV DNA-negative colostrum than in DNA-positive breast milk (P<0.05). Also, serum levels of cell-free soluble interleukin-2 receptor (sIL-2R) from mothers of DNA-positive milk at 1 month after delivery were significantly higher than those of mothers with DNA-negative milk (P<0.05). Interferon (IFN)-γ was detected at very low levels in most samples with no statistical correlation observed between the study groups, and IL-4 was not detected in any sample. It is likely that levels of cytokines such as sIL-2R in serum are related to the reactivation of HCMV which occurs locally in the mammary gland of the lactating mother after delivery