Renal handling of albumin and beta-2 microglobulin in neonates

Urinary albumin and β₂-microglobulin (B₂M) were measured during the neonatal period. Urinary albumin decreased postnatally in term neonates, while it remained almost constant in preterm neonates. Urinary B₂M showed a peak level on day 7 both in term and preterm neonates. There was some trend towards higher levels of albumin and B₂M with decreasing gestation. showing that glomerular permeability increases and proximal tubular protein reabsorption decreases with increasing degrees of prematurity. In sick preterms who were depressed at birth and had respiratory failure, both parameters were elevated during the first 2 weeks, indicating the presence Or glomerular and tubular damage in this period. The changes in B₂M with gestation or clinical condition were more pronounced than those in albumin.