Early predictors of neonatal intraventricular hemorrhage

Activin A Is a Master Regulator of Phenotypic Switch in Adipose Stromal Cells Initiated by Activated Immune Cell-Secreted Interleukin-1β

Prolonged tissue ischemia and inflammation lead to organ deterioration and are often accompanied by microvasculature rarefaction, fibrosis, and elevated systemic Activin A (ActA), the level of which frequently correlates with disease severity. Mesenchymal stromal cells are prevalent in the perivascular niche and are likely involved in tissue homeostasis and pathology. This study investigated the effects of inflammatory cells on modulation of phenotype of adipose mesenchymal stromal cells (ASC) and the role of ActA in this process. Peripheral blood mononuclear cells were activated with lipopolysaccharide (activated peripheral blood mononuclear cells [aPBMC]) and presented to ASC. Expression of smooth muscle/myofibroblast markers, ActA, transforming growth factors beta 1-3 (TGFβ1-3), and connective tissue growth factor (CTGF) was assessed in ASC. Silencing approaches were used to dissect the signaling cascade of aPBMC-induced acquisition of myofibroblast phenotype by ASC. ASC cocultured with aPBMC or exposed to the secretome of aPBMC upregulated smooth muscle cell markers alpha smooth muscle actin (αSMA), SM22α, and Calponin I; increased contractility; and initiated expression of ActA. Interleukin (IL)-1β was sufficient to replicate this response, whereas blocking IL-1β eliminated aPBMC effects. ASC-derived ActA stimulated CTGF and αSMA expression in ASC; the latter independent of CTGF. Induction of αSMA in ASC by IL-1β or ActA-enriched media relied on extracellular enzymatic activity. ActA upregulated mRNA levels of several extracellular matrix proteins in ASC, albeit to a lesser degree than TGFβ1, and marginally increased cell contractility. In conclusion, the study suggests that aPBMC induce myofibroblast phenotype with weak fibrotic activity in perivascular progenitors, such as ASC, through the IL-1β-ActA signaling axis, which also promotes CTGF secretion, and these effects require ActA extracellular enzymatic processing.

Serum Activin A as Brain Injury Biomarker in the First Three Days of Life. A Prospective Case-Control Longitudinal Study in Human Premature Neonates

Disruption of normal intrauterine brain development is a significant consequence of premature birth and may lead to serious complications, such as neonatal brain injury (NBI). This prospective case-control longitudinal study aimed at determining the levels and prognostic value of serum activin A during the first three days of life in human premature neonates which later developed NBI. It was conducted in a single tertiary hospital and eligible participants were live-born premature (<34 weeks) neonates. Each case (n = 29) developed NBI in the form of an intraventricular haemorrhage, or periventricular leukomalacia, and was matched according to birth weight and gestational age to one neonate with normal head ultrasound scans. Serum activin A levels in both groups showed a stable concentration during the first three days of life as no difference was observed within the two groups from the first to the third day. Neonates diagnosed with NBI had significantly higher activin A levels during the first two days of life compared to control neonates and its levels correlated to the severity of NBI during the second and third day of life. Although serum activin A on the second day was the best predictor for neonates at risk to develop NBI, the overall predictive value was marginally fair (area under the ROC-curve 69.2%). Activin A, in combination with other biomarkers, may provide the first clinically useful panel for the early detection of premature neonates at high risk of NBI.

What clinical practice strategies have been shown to decrease incidence rates of intraventricular haemorrhage in preterm infants?

AIM

To answer the clinical question 'In infants about to be delivered and admitted to neonatal units, what clinical practice strategies, compared to standard care, have been shown to decrease incidence rates of intraventricular haemorrhage (IVH)?'

METHODS

MEDLINE via Ovid (1943 to 5 January 2018), Embase via Ovid (1974 to 5 January 2018) and the Cochrane Library (5 January 2018) were searched for relevant articles.

RESULTS

A total of 478 articles, after the removal of duplicates, were found and screened by title and abstract. Forty full-text articles were subsequently reviewed, and 19 were included as relevant to the structured clinical question. An additional article was included based on expert advice.

CONCLUSION

There are various levels of research evidence for clinical practice strategies to decrease the incidence rates of IVH. Higher-quality evidence suggests that antenatal corticosteroids decrease the rates of IVH, and multiple evidence-based intervention bundles implemented in the neonatal unit are associated with decreased rates of IVH.