Umbilical cord blood cell characteristics in very preterm neonates for autologous cell therapy of preterm-associated complications.

BACKGROUND: There are emerging clinical evidence for umbilical cord blood mononuclear cells (UCBMNCs) intervention to improve preterm complications. The first critical step in cell therapy is to obtain high-quality cells. This retrospective study aimed to investigate the quantity and quality of UCBMNCs from very preterm infants (VPIs) for the purpose of autologous cell therapy in prevention and treatment of preterm complications. METHODS: Very preterm infants (VPIs) born in Guangdong Women and Children Hospital from January 1, 2017, to December 8, 2022, from whom cord blood was successfully collected and separated for public or private banking, were enrolled. The UCBMNCs characters from route cord blood tests performed in cord blood bank, impact of perinatal factors on UCBMNCs, the relationship between UCBMNCs characteristics and preterm outcomes, and the correlation of UCBMNCs characteristics and peripheral blood cells in VPIs were analyzed. RESULTS: Totally, 89 VPIs underwent UCB collection and processing successfully. The median cell number post processing was 2.6 × 108. To infuse a dose of 5 × 107 cells/kg, only 3.4% of infants required a volume of more than 20 mL/kg, which exceeded the maximum safe volume limit for VPIs. However, when infusing 10 × 107 cells/kg, 25.8% of infants required a volume of more than 20 ml/kg volume. Antenatal glucocorticoids use and preeclampsia was associated with lower original UCBMNCs concentration. Both CD34+ hematopoietic stem cells (HSC) frequency and colony forming unit - granulocyte and macrophage (CFU-GM) number correlated negatively with gestational age (GA). UCBMNCs characters had no significant effect on preterm outcomes, whereas a significant positive correlation was observed between UCBMNCs concentration and total white blood cell, neutrophil, lymphocyte and PLT counts in peripheral blood. CONCLUSION: UCBMNCs collected from VPIs was feasible for autologous cell therapy in improving preterm complications. Setting the infusion dose of 5 × 107 cells/kg guaranteed a safe infusion volume in more than 95% of the targeted infants. UCBMNCs characters did not affect preterm complications; however, the effect of UCBMNCs concentration on peripheral blood classification count should be considered when evaluating the immunomodulation of UCBMNCs transfusion.

Prevention for moderate or severe BPD with intravenous infusion of autologous cord blood mononuclear cells in very preterm infants-a prospective non-randomized placebo-controlled trial and two-year follow up outcomes.

Background: Bronchopulmonary dysplasia (BPD) is the primary severe complication of preterm birth. Severe BPD was associated with higher risks of mortality, more postnatal growth failure, long term respiratory and neurological developmental retardation. Inflammation plays a central role in alveolar simplification and dysregulated vascularization of BPD. There is no effective treatment to improve BPD severity in clinical practice. Our previous clinical study showed autologous cord blood mononuclear cells (ACBMNCs) infusion could reduce the respiratory support duration safely and potential improved BPD severity. Abundant preclinical studies have reported the immunomodulation effect as an important mechanism underlying the beneficial results of stem cell therapies in preventing and treating BPD. However, clinical studies assessing the immunomodulatory effect after stem cells therapy were rare. This study was to investigate the effect of ACBMNCs infusion soon after birth on prevention for severe BPD and long term outcomes in very preterm neonates. The immune cells and inflammatory biomarkers were detected to investigate the underlying immunomodulatory mechanisms. Methods: This single-center, prospective, investigator-initiated, non-randomized trial with blinded outcome assessment aimed to assess the effect of a single intravenous infusion of ACBMNCs in preventing severe BPD (moderate or severe BPD at 36 weeks of gestational age or discharge home) in surviving very preterm neonates less than 32 gestational weeks. Patients admitted to the Neonatal Intensive Care Unit (NICU) of Guangdong Women and Children Hospital from July 01, 2018 to January 1, 2020 were assigned to receiving a targeted dosage of 5 × 107 cells/kg ACBMNC or normal saline intravenously within 24 h after enrollment. Incidence of moderate or severe BPD in survivors were investigated as the primary short term outcome. Growth, respiratory and neurological development were assessed as long term outcomes at corrected age of 18-24 month-old. Immune cells and inflammatory biomarkers were detected for potential mechanism investigation. The trial was registered at ClinicalTrials.gov (NCT02999373). Findings: Six-two infants were enrolled, of which 29 were enrolled to intervention group, 33 to control group. Moderate or severe BPD in survivors significantly decreased in intervention group (adjusted p = 0.021). The number of patients needed to treat to gain one moderate or severe BPD-free survival was 5 (95% confidence interval: 3-20). Survivors in the intervention group had a significantly higher chance to be extubated than infants in the control group (adjusted p = 0.018). There was no statistical significant difference in total BPD incidence (adjusted p = 0.106) or mortality (p = 1.000). Incidence of developmental delay reduced in intervention group in long term follow-up (adjusted p = 0.047). Specific immune cells including proportion of T cells (p = 0.04) and CD4+ T cells in lymphocytes (p = 0.03), and CD4+ CD25+ forkhead box protein 3 (FoxP3)+ regulatory T cells in CD4+ T cells increased significantly after ACBMNCs intervention (p ï¼œ 0.001). Anti-inflammatory factor IL-10 was higher (p = 0.03), while pro-inflammatory factor such as TNF-a (p = 0.03) and C reactive protein (p ï¼œ 0.001) level was lower in intervention group than in control group after intervention. Interpretation: ACBMNCs could prevent moderate or severe BPD in surviving very premature neonates and might improve neurodevelopmental outcomes in long term. An immunomodulatory effect of MNCs contributed to the improvement of BPD severity. Funding: This work was supported by National Key R&D Program of China (2021YFC2701700), National Natural Science Foundation of China (82101817, 82171714, 8187060625), Guangzhou science and technology program (202102080104).

Wnt5a-Flt1 activation contributes to preterm altered cerebral angiogenesis after prenatal inflammation.

OBJECTIVE: Intraventricular hemorrhage (IVH) causes morbidity and mortality in preterm infants and prenatal exposure to inflammation contributes to brain injury. Moreover, prenatal exposure to severe inflammation increases the risk of IVH in preterm neonates. The current study investigated whether intrauterine exposure to inflammation affects cerebral angiogenesis and its underlying mechanisms. METHODS: Wnt5a, flt1, and vascular endothelial growth factor (VEGF)-A levels in cord blood serum (stored in a bio-bank) of the enrolled patients were measured via enzyme-linked immunosorbent assay. A preterm prenatal inflammation exposure model was established in rats by intraperitoneal injection intraperitoneally during pregnancy. Angiogenesis of cerebral tissue was analyzed using immunohistochemistry. Wnt5a, flt1, and VEGF-A expression levels were measured via immunohistochemistry, immunofluorescence, or western blotting. The correlation between Wnt5a and flt1 expression and the cerebral vessel area was also analyzed. RESULTS: The Wnt5a and flt1 levels in the cord blood serum were significantly higher in the amnionitis group than in the non-amnionitis group. The VEGF-A level in the cord blood serum was significantly lower in the amnionitis group. In the rat model, preterm rats in the prenatal inflammation group exhibited increased microglial cell infiltration and decreased vessel area and diameter in the cerebral tissue compared to the control group. Wnt5a was located in microglial cells, and Wnt5a and flt1 expression in brain tissue significantly increased after prenatal lipopolysaccharide (LPS) exposure. VEGF-A expression declined after prenatal LPS exposure. The cerebral vessel area was negatively correlated with Wnt5a and flt1 expression. CONCLUSION: Disordered cerebral angiogenesis is associated with increased Wnt5a-Flt1 activation in microglial cells after exposure to intrauterine inflammation.