SHORT REPORTS Assessment of Peritoneal Fibrosis by Conventional Light Microscopy and Hydroxyproline

Peritoneal fibrosis may develop during long-term peritoneal dialysis (PD), probably as a result of chronic exposure to dialysis fluids (1,2). Fibrosis has not only been described in PD patients but has also been in-duced in chronic peritoneal exposure models in the rat (3,4). Scoring of fibrosis in these studies has been assessed using semiquantitative methods, on either parietal peritoneum or omentum. Also, measurements of the thickness of the submesothelial compact zone of the parietal peritoneum have been performed (5). These methods are not objective and are very time consuming. The hydroxyproline content in tissue specimens has been considered a characteristic bio-chemical marker for the amount of fibrosis (6). The aim of this study was to compare the semiquantitative scoring of fibrosis to the peritoneal hydroxyproline content in peritoneal tissues of rats chronically ex-posed to dialysis solutions