Adequacy of decision-making based on each kidney function estimation method for Japanese living kidney donor candidates: a retrospective observational study

Background Living kidney transplantation comprises the majority of kidney transplantations in Japan. Living kidney donors should be assured of their own health. Therefore, Japanese guidelines define the criterion of kidney function for living donors. Glomerular filtration rates (GFR) ≥ 70 mL/min/1.73 m2 are required for marginal donors. The guidelines require that GFRs of donors be measured by the inulin (In) clearance method (CIn) or the radioisotope method, but these methods can be substituted with the creatinine (Cr) clearance method (CCr). Methods for estimating kidney function are susceptible to error, and decision-making regarding donor eligibility could be affected by the estimation method used. We investigated the adequacy of decision-making based on kidney function estimation methods used in Japanese living kidney donor candidates by comparing CCr or estimated GFR (eGFR), calculated by several equations, and CIn as measured GFR (mGFR).