Nephromegaly and elevated plasma hepatocyte growth factor-transforming growth factor-beta1 ratio in infants with...

Nephromegaly, assessed by calculating kidney volume using renal ultrasound, was studied in infants with biliary atresia, neonatal hepatitis, or fulminant hepatitis. We evaluated kidney volume in 29 patients with biliary atresia, 17 patients with neonatal hepatitis, and 10 patients with fulminant hepatitis, as well as 32 healthy infants. Levels of plasma hepatocyte growth factor (HGF) were measured in all infants. Levels of plasma transforming growth factor-beta1 (TGF-beta1) were also measured in diseased infants and 20 healthy infants. Significant nephromegaly was found in infants with biliary atresia compared with healthy infants (P < 0.001 by analysis of covariance). Marked nephromegaly was also noted in all infants with fulminant hepatitis and 35% of infants with neonatal hepatitis. No nephromegaly was found in infants at 2 months of age with biliary atresia or neonatal hepatitis despite mildly elevated plasma HGF levels. Regardless of the duration of HGF exposure and healthy renal growth by a certain age, a positive correlation existed between plasma HGF level and kidney volume (r = 0.529; P < 0.001), but an inverse correlation was found between plasma TGF-beta1 level and nephromegaly (r = -0.505; P < 0.001) in all diseased infants. There was a stronger positive correlation between plasma HGF-TGF-beta1 ratio and kidney volume (r = 0.666; P < 0.001) and degree of nephromegaly (r = 0.717; P < 0.001). These results confirm the presence of large kidneys not only in patients with biliary atresia but also in patients with fulminant hepatitis, which suggests the possible pathogenic role of HGF and manifests as elevated HGF-TGF-beta1 ratios in patients with such conditions. Nephromegaly in patients with severe or chronic liver dysfunction may provide a new in vivo model to study the mechanisms of renal growth.