Plasma fibronectin levels during acute rejection and acute tubular necrosis in renal transplant patients.

Fibronectin (Fn), an acute phase glycoprotein synthesized by the liver, has an important immunomodulatory role. We have investigated the changes in plasma Fn in patients after renal transplantation in order to determine whether these changes predict graft injury or rejection episodes. Besides normal healthy controls, healthy pregnant controls, and a trauma control group, we used two groups of chronic renal failure patients as controls: group I, patients with end-stage renal failure (ESRF) on peritoneal dialysis; group II, patients with ESRF on hemodialysis. These were compared with two groups of renal transplant patients: group III, patients 3 months after successful renal transplantation; group IV, patients studied sequentially 10 days immediately posttransplantation. The renal transplant patients were treated with low-dose cyclosporine, azathioprine, and steroids. Citrated plasma samples were collected for Fn assay by a sandwich-type ELISA and for SDS-PAGE analysis and Western blotting. The mean plasma Fn levels were as follows: healthy controls 311.6 SEM, 13.5 micrograms/ml; healthy pregnant controls 357 SEM, 5.9 micrograms/ml; trauma controls 262.3 SEM 31.7, micrograms/ml; group I 169 SEM, 25.1 micrograms/ml; group II 199 SEM, 27.2 micrograms/ml; group III 272 SEM, 21.7 micrograms/ml; group IV 212 SEM, 27.4 micrograms/ml (day 3 postop). There was a significant difference in the plasma Fn levels on day 3 posttransplant between the patients with delayed and immediate renal function (P less than 0.03) (group IV). A significant decrease in plasma Fn levels occurred immediately after steroid therapy was stopped (P less than 0.03) in patients treated for acute rejection. Plasma Fn levels were significantly decreased in the presence of delayed graft function but did not predict rejection