[Evaluation of glomerular filtration in patients after renal transplantation and treatment with cyclosporin A].

According to some findings (Ross et al. 1987) the creatinine plasma concentration (Pcr) is an inaccurate indicator of glomerular filtration (GFR) in patients with a transplanted kidney, treated with cyclosporin A (CyA), who are in a stabilized state of renal function. In the submitted work the authors investigated whether the inaccuracy of the assessed GFR based on Pcr or creatinine clearance (Ccr) is greater than in patients with various chronic renal diseases who at the time of examination did not take any drugs. The investigation was made in 30 patients with a transplanted kidney treated with CyA as well as azathioprine and prednisone. The authors examined also 51 patients with various chronic renal diseases, mostly chronic glomerulonephritis or tubulo-interstitial nephritis. The GFR value was assessed on the basis of polyfructosan clearance (CPF). In subjects with a transplanted kidney a significant linear relationship was found between Ccr and CPF (r = 0.829, p < 0.001). A similar relationship was found in patients with chronic renal disease (r = 0.935, p < 0.001). The regression lines characterize this relationship in both groups and do not differ significantly. Between values of Pcr and CPF a significant relationship of a hyperbolic character was found in both groups (r = 0.693, p < 0.001 and r = 0.741, p < 0.001 resp.). The hyperbolic relations found in the examined groups did not differ significantly. The findings confirm that a normal or only slightly elevated Pcr value can be associated with a markedly reduced GFR, in some instances to as much as one third of the normal values.(ABSTRACT TRUNCATED AT 250 WORDS)