Background:Low molecular weight proteins (LMWP) are considered uremic toxins. There is controversy whether in peritoneal dialysis (PD) the elimination of these toxins is influenced mainly by dialysis or by residual renal function (RRF).Material/Methods:The aim of our study was to evaluate the relationship between serum levels of selected LMWPs, dialysis adequacy, and RRF in PD patients. 27 stable subjects were studied, mean age 50±11, dialyzed for a median period of 10 months. Serum activity of acid RNA-se and alkaline RNA-se was measured by spectrophotometry, and serum alpha1-microglobulin ((alpha) 1M) concentration by ELISA. Kt/V and weekly creatinine clearance (wClCr) were assessed as adequacy indices (both as the sum of renal and dialysis components) and RRF as the mean of residual urea and creatinine clearances.Results:Significant inverse correlations were found between RRF and (alpha) 1M level, as well as alkaline RNA-se activity (p

Keywords: Alpha-Globulins - biosynthesis, Creatine - blood, Ribonucleases - blood