Volutrauma and pulmonary inflammation are thought to be the most important predisposing factors of chronic lung disease (CLD), a major complication of prematurity. A new option in patient-triggered ventilation (PTV), the volume guarantee (VG), a volume-targeted ventilation, seems to be a promising approach in reducing the risk of CLD, by limiting lung inflammatory injury and volutrauma. Our aim was to evaluate lung inflammatory response in preterm infants with respiratory distress syndrome (RDS), mechanically ventilated with and without VG, as measured by proinflammatory cytokines (IL-6, IL-8, and TNF-alpha) in tracheobronchial aspirate (TA) fluid. Fifty-three preterm infants (GA = 25-32 weeks) with RDS were randomized at birth to be ventilated using pressure support ventilation (PSV) with VG (Vt = 5 ml/kg) (n = 30) and without VG (n = 23) (Draeger Babylog 8000 Plus, 5.n). IL-6, IL-8, and TNF-alpha were determined by ELISA in TA samples on days 1, 3, and 7 of life. We observed a significant difference (ANOVA) in IL-8 and IL-6 levels on day 3 between the two groups (P < 0.05), and an increasing significative trend in IL-8 values in PSV group (P < 0.05). Mechanical ventilation lasted longer in the PSV group (12.3 +/- 3 vs. 8.8 +/- 3 days) (P = no significance). In conclusion, these preliminary data suggest a role for volume-targeted ventilatory strategy in reducing acute inflammatory response in preterm infants with RDS. Further studies are required in order to define whether this ventilatory strategy prevents lung injury.

Mesenchymal stem cells (MSC) have been derived from different cultured human tissues, including bone marrow, adipose tissue, amniotic fluid and umbilical cord blood. Only recently it was suggested that MSC descended from perivascular cells, the latter being defined as CD146+ neuro-glial proteoglycan (NG)2+ platelet-derived growth factor-Rβ+ ALP+ CD34– CD45– von Willebrand factor (vWF)– CD144–. Herein we studied the properties of perivascular cells from a novel source, the foetal human umbilical cord (HUC) collected from pre-term newborns. By immunohistochemistry and flow cytometry we show that pre-term/foetal HUCs contain more perivascular cells than their full-term counterparts (2.5%versus 0.15%). Moreover, foetal HUC perivascular cells (HUCPC) express the embryonic cell markers specific embryonic antigen-4, Runx1 and Oct-4 and can be cultured over the long term. To further confirm the MSC identity of these cultured perivascular cells, we also showed their expression at different passages of antigens that typify MSC. The multilineage differentiative capacity of HUCPC into osteogenic, adipogenic and myogenic cell lineages was demonstrated in culture. In the perspective of a therapeutic application in chronic lung disease of pre-term newborns, we demonstrated the in vitro ability of HUCPC to migrate towards an alveolar type II cell line damaged with bleomycin, an anti-cancer agent with known pulmonary toxicity. The secretory profile exhibited by foetal HUCPC in the migration assay suggested a paracrine effect that could be exploited in various clinical conditions including lung disorders.

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