[Changing profiles of proteinuria in renal transplantation. Predictive factors for its appearance]

Proteinuria is a risks factor that accelerates the progression of renal insufficiency by several mechanisms. In the renal transplant proteinuria is a predictor of progressive renal insufficiency and it is associated with poor patient and graft survival. We have performed a longitudinal observational case-control study to defect and quantify proteinuria in a group of 100 cadaveric renal transplant recipients and to evaluate the influence of several factors on its appearance. We have considered the variables age and sex of the donor and recipient, number of HLA-DR, A and B mismatches, cold ischemia time, basal renal disease, initial immunosuppression, immediate versus delayed graft function and acute rejection. Three patients who did with a functioning graft were excluded from the analysis of the data. All variables were analysed in a regression model of multivariate analysis. Proteinuria in the moths 1, 3, 6, 9 and 12 was: 0.38 +/- 0.27 g/day, 0.38 +/- 0.32 g/day, 0.44 +/- 0.99 g/day, 0.42 +/- 0.58 g/day and 0.37 +/- 0.54 g/day, respectively. We analysed the profile of the proteinuria in each patient individually. Fifty three patients (54.6%) did not develop proteinuria, 12 patients (12.4%) had transient initial proteinuria, 23 patients (23.7%) had persistent proteinuria and 9 patients (9.3%) had progressive proteinuria. The renal function differed between groups. Higher creatinine levels were found in the patients with persistent proteinuria and those with progressive proteinuria. We analysed the patients according to several variables. The age of the donor was higher in the group of patients with persistent proteinuria and the incidence of acute rejection was higher in the group of patients who developed progressive proteinuria, with differences statistically significant. There was no difference in the univariate analysis in the other variables considered. The multivariate analysis confirms that the age of the donor and the basal glomerular disease predict persistent proteinuria and acute rejection predicts progressive proteinuria. According to our study, proteinuria is frequent in the renal transplant recipient with different evolutionary profiles. Two types are associated with bad renal function and have different predictive factors. We encourage the use of drugs which reduce proteinuria.