Maternal infection-induced white matter injury is reduced by treatment with interleukin-10

Objective The purpose of this study was to test the hypothesis that interleukin-10 can prevent white matter injury in neonatal rats that are born to infected dams. Study design Timed pregnant rats (day 17) were assigned to the following treatment groups: (1) saline control (n = 5 rats), (2) Escherichia coli–infected (n = 10 rats), and (3) E coli + interleukin-10 (n = 5 rats). E coli was administered at a titer of 1 × 107 colony-forming units by intrauterine inoculation just above the cervix at the bifurcation of the uterine horns. Rat interleukin-10 was administered intravenously at a dose of 1 μg/kg of body weight. After delivery, the pups were maintained with dams until day 8, at which time they were placed under general anesthesia and perfused with saline solution followed by 10% paraformaldehyde. The brains were removed, placed in 30% sucrose solution, and then frozen at −20°C until the preparation of the frozen sections. Standard hematoxylin/eosin staining was performed, and the brains were evaluated for matter necrosis, apoptotic cells, and ventricular swelling. Results In pups that were born to infected dams, 11 of 38 pups (29%) displayed symmetric lesions around the lateral ventricles. These lesions were characterized by marked looseness/edema of the neuropil, foamy-appearing histiocytes, and granular neuropil breakdown. None of the pups (n = 17) that were born to interleukin-10–treated infected dams displayed this pattern of severe white matter injury. Conclusion These results suggest that maternal interleukin-10 therapy could provide neuroprotection for infants who are born to mothers with intrauterine infection.