Urinary protein analysis in pre- and postoperative cancer patients.

Urinary proteins from six patients with esophageal cancer and two with stomach cancer were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Analyses were performed on days-1 to 3, 5, 7, 10, 14, and 21 (or 22) after surgery. The protein patterns were scanned by densitometry and divided into nine fractions. The main proteins in the fractions (Fr.) were identified as follows: immunoglobulin G in Fr. A, Tamm-Horsfall glycoprotein (THP) in Fr. B, transferrin in Fr. C, albumin in Fr. D, alpha(1)-acid glycoprotein in Fr. E, alpha(1)-microglobulin in Fr. F, retinol binding protein in Fr. G, and beta(2)-microglobulin in Fr. I. The protein in Fr. H was not identified. The percentage of each fraction was calculated from the densitometry pattern of each lane. The percentage values were averaged among all the patients, and pre- and postoperative data were compared. The percentage of Frs. E, F, and G increased on days 1-7, and the changes in these three proteins were similar to changes in serum C-reactive protein (CRP). In particular, the percentage of Fr. G peaked within 1 day of operation, which was faster than for CRP. Conversely, other fractions decreased. These results suggest that urinary protein analysis is useful for monitoring the response to surgical stress. Copyright 2005 Wiley-Liss, Inc.