Prognostic Value of Effective Renal Plasma Flow for First-year Renal Outcome in Kidney Allograft Recipients

Introduction: Many studies have suggested that post-transplantation renal allograft function is associated with long-term allograft outcomes. However, accurate examination through non-invasive methods remains rare. The aim of the present study is to assess the association between ^99mTc mercaptoacetyltriglycine (MAG3) effective renal plasma flow (ERPF) and first-year post-transplantation renal allograft function.

Methods: We conducted a retrospective cohort study at our center between January 2011 and December 2016. Kidney transplant recipients without an ERPF examination within 14 days post-transplantation, or those with less than 1 year of follow-up were excluded. Eligible cases were divided into 3 groups according to first-year eGFR <45, 45 < eGFR <60, eGFR >60. The Kruskal-Wallis test and χ² were used for comparisons between continuous and categorical variables.

Results: A total of 123 patients were analyzed. Each group received 41 patients. The baseline characteristics were comparable in the 3 groups, except for repeated transplantation and delayed graft function. The results of the ERPF median (interquartile range) for the 3 groups were 193 (140.0-244.5) in the eGFR < 45 group, 236 (182.5-301.0) in the 45 < eGFR < 60 group, and 294 (202.5-384.5) in the eGFR > 60 group (P < .001). The receiver operating characteristic analysis showed that a cutoff ERPF value of >276 exhibited the best sensitivity (65.85%) and specificity (75.61%) for predicting first-year eGFR > 60 mL/min/1.73 m², with an area under the receiver operating characteristic curve of .712, P < .0001.

Conclusion: Our findings suggest that an ERPF value of more than 276 is likely to be associated with a favorable first-year renal graft outcome after transplantation. The ^99mTc MAG3 ERPF may be a non-invasive alternative to sequential protocol biopsies.