Immunity, inflammation and infection in post-partum breast and formula feeders.

PROBLEM Little is known about immunological recovery in post-partum women and if lactational status affects immunocompetence. Many physiological changes occur, such as uterine involution and recovery of non-pregnant immune status. These changes may also affect susceptibility to disease. METHOD The study compared immune and inflammatory activation markers (serum cytokines, Epstein Barr viral antibody titer, neopterin, c-reactive protein (CRP), lymphocyte subset percentages, ex vivo cytokine production, lymphocyte proliferation, salivary Immunoglubulin A (sIgA) in exclusively breastfeeding (EB) and exclusively formula feeding (EF) women at 4-6 weeks post-partum, and control (C) women. RESULTS EBs had higher ratios of interferon-gamma (IFN-gamma)/interleukin-10 (IL-10) than EFs, and post-partums were higher than Cs. Both IFN-gamma and IL-10 were significantly higher in post-partums compared to controls. Post-partums also had higher proinflammatory cytokines, CRP and neopterin, salivary IgA and fewer infection symptoms. There were also differences in lymphocyte subsets. CONCLUSIONS The post-partum period is oriented towards heightened and activated innate and specific immune defenses, with breastfeeding providing a boost in these phenomena.