OBJECTIVE: To determine whether children breast fed by mothers with silicone implants (BFSI) have increased urinary excretion of nitric oxide (NO) metabolites and neopterin, whether these are associated with esophageal dysmotility, and whether in vitro incubation of macrophages with silicone increases NO synthesis.

METHODS: In a case-control study based on laboratory investigation, 38 BFSI children (17 male, 21 female, mean age 7.1 +/- 3.6 years, range 0.5-16.5) were compared with 30 controls (14 male, 16 female, mean age 8.4 +/- 3.5 years, range 2.5-17). Urinary NO was quantitated using the Griess reaction. Urinary neopterin was determined by radioimmunoassay. Murine macrophages were cultured with or without silicone and NO production assayed.

RESULTS: Urinary NO and neopterin were significantly increased in BFSI children compared with controls. There was a significant

Inverse relationship between urinary neopterin excretion and the severity of esophageal dysfunction. In vitro nitrite production was nearly 60% higher in macrophages grown on silicone compared to other growth conditions.

CONCLUSION: BFSI children have evidence of macrophage activation and this is associated with esophageal dysmotility. In vitro data support the proposal that silicone exposure causes macrophage activation.