Relationship between extracellular matrix both in choroid plexus and the wall of lateral ventricles and intraventricular hemorrhage in preterm neonates.

Pathogenesis of intraventricular hemorrhage (IVH) may relate to immature vessels. However extracellular matrix--such as Type IV collagen, laminin, and fibronectin has a direct bearing on the development of the endothelium and the immature microvessel. Twenty specimens taken from lateral ventricular walls and choroid plexus in 10 preterm neonates who died of intraventricular hemorrhage and another 10 preterm neonates who died of non-intraventricular hemorrhage, were marked with antibodies against Type IV collagen, laminin, and fibronectin. Average areas of positive staining around the microvessels in the IVH group showed less staining than that in the non-IVH group (P < 0.05), and the microvessel count of discontinuous positive staining in IVH group was more than that in non-IVH group, P < 0.05. We conclude that lacking Type IV collagen, laminin, and fibronectin may result not only in an incomplete basement membrane in choroid plexus and subependymal immature microvessels but also may be a factor contributing to IVH in preterm neonates.