Introduction: One of the major points of living kidney donor qualification is renal function examination. According to KDIGO, GFR should be estimated using CKD-EPI creatinine-cystatin C formula (CKD-EPIcrea/cys). It is supposed that novel markers such as BTP and uromodulin may be useful in estimating renal function.
Aim: The aim of the study was to compare eGFR measured using CKD-EPI creatinine-cystatin C with serum uromodulin, BTP and BTP-based eGFR in living kidney donor candidates. Material and methods 51 living kidney donor candidates were enrolled into the study. Clinical and laboratory data were collected including serum uromodulin, BTP, cystatin C and creatinine concentrations. eGFR was calculated using CKD-EPIcrea/cys, White and Poge formula. Results Serum BTP had a positive correlation with serum cystatin C (R=-0.54; p<0.001) and a negative correlation with eGFR CKD-EPIcrea/cys (R=-0.57; p<0.001). Serum BTP had much stronger correlation with eGFR CKD-EPIcrea/cys in the subgroup of patients with normal BMI (versus BMI >25 kg/m2) (R=-0.68; p<001 vs. -0.38; p=0,06 respectively). Both BTP-based eGFR equations had a positive correlation with eGFR CKD-EPIcrea/cys (R=0.62; p<0.001; R=0.54; p<0.001 for White and Poge formulas respectively). Uromodulin did not reveal statistically significant correlation with cystatin C, creatinine, BTP and eGFR CKD-EPIcrea/cys.
Conclusion: BTP is a useful tool in estimating renal function in living kidney donor candidates. Both serum BTP and BTP-based formulas had a strong correlation with eGFR CKD-EPIcrea/cys. Uromodulin does not seem to be useful in qualification of living kidney donor.