Epidemiology of neonatal stroke: A population-based study.

OBJECTIVE: The goal of this study was to obtain population-based data on the incidence, clinical presentation, management, imaging features, and long-term outcomes of patients with all types of neonatal stroke (NS). METHODS: Full-term neonates with NS born between January 2007 and December 2013 were identified through the Nova Scotia Provincial Perinatal Follow-up Program Database. Perinatal data and neonatal course were reviewed. Neurodevelopmental outcomes were assessed at 18 and 36 months of age using standardized testing. RESULTS: Twenty-nine neonates with NS were identified during the study period, giving an incidence of 47 per 100,000 live births in Nova Scotia. Arterial ischemic stroke was the most common stroke type (76%), followed by neonatal hemorrhagic stroke (17%), then cerebral sinovenous thrombosis (7%). The majority of neonates presented with seizures (86%) on the first day of life (76%). At 36 months of age, 23 (79%) of the children had a normal outcome, while 3 (10%) were diagnosed with cerebral palsy (2 with neonatal arterial stroke and one with neonatal hemorrhagic stroke) and 3 (10%) had recurrent seizures (1 patient from each stroke subtype group). CONCLUSION: The incidence of NS in Nova Scotia is higher than what has been reported internationally in the literature. However, the neurodevelopmental outcomes at 3 years of age are better. Further studies are required to better understand the reasons for these findings.

VPAC1 receptor expression in peripheral blood mononuclear cells in a human endotoxemia model.

BACKGROUND: Vasoactive intestinal peptide (VIP) exerts immune-modulatory actions mainly via VPAC1 receptor stimulation. VPAC1 may be a treatment target of inflammatory diseases, but little is known about the receptor expression profile in immune-competent cells in vivo. MATERIAL AND METHODS: 20 male healthy subjects received a single intravenous bolus of 2 ng/kg body weight Escherichia coli endotoxin (LPS). Receptor status was evaluated in peripherial blood cells before and 3, 6 and 24 h after LPS by FACS analysis and q-PCR. VIP plasma concentrations were measured by ELISA. RESULTS: Granulocytes accounted for 51% of leukocytes at baseline and 58 ± 37% were positive for VPAC1. The granulocyte population increased 2.6 fold after LPS, and a transient down-regulation of VPAC1 to 28 ± 23% was noted at 3 h (p < 0.001), which returned to baseline at 24 hours. Baseline VPAC1 expression was low in lymphocytes (6.3 ± 3.2%) and monocytes (11 ± 9.6%). In these cells, LPS up-regulated VPAC1 at 6 h (13.2 ± 4.9%, p < 0.001) and 24 h (31.6 ± 20.5%, p = 0.001), respectively. Consistent changes were noted for the VIP-receptors VPAC2 and PAC1. VPAC1, VPAC2 and PAC1 mRNA levels were unchanged in peripheral blood mononuclear cells (PBMC). VIP plasma concentration increased from 0.5 ± 0.3 ng/ml to 0.7 ± 0.4 ng/ml at 6 h after LPS (p < 0.05) and returned to baseline within 24 h. CONCLUSION: The time profile of VPAC receptor expression differs in granulocytes, monocytes and lymphocytes after LPS challenge in humans. Changes in circulating VIP concentrations may reflect innate immune responses.

Inflammatory effects of ex vivo human Th17 cells are suppressed by regulatory T cells.

Th17 cells are proinflammatory cells associated with many immune-mediated diseases. Major factors limiting the study of human Th17 cells are the lack of an accepted method for their in vitro differentiation or for isolation of a homogenous population of Th17 cells that do not cosecrete IFN-gamma. To overcome these hurdles, we established a novel method to isolate in vivo differentiated Th17 cells from peripheral blood by sorting CD161(+)CCR4(+)CCR6(+)CXCR3(-)CD4(+) T cells. The resulting cells produce high levels of IL-17 but not IFN-gamma, express high levels of retinoic acid-related orphan receptor variant 2, and maintain this phenotype upon expansion. Ex vivo Th17 cells exhibit a low cytotoxic potential and are hyporesponsive to polyclonal anti-CD3/anti-CD28 stimulation. Importantly, ex vivo Th17 cells were susceptible to suppression by both naive and memory regulatory T cells (Tregs), which inhibited production of IL-17, IL-22, and CXCL8. Moreover, Tregs suppressed the antifibrotic effects of Th17 cells in a wound-healing model. These findings provide new tools for the study of normal and pathological functions of bona fide Th17 cells in humans. They also provide new insight into the cross-talk between Th17 cells and immune and nonimmune cells, and they establish the paradigm that adoptive Treg-based therapies may effectively limit Th17-mediated inflammation.