In patients with type 1 diabetes simultaneous pancreas and kidney transplantation preserves long-term kidney graft ultrastructure and function better than transplantation of kidney alone

Aims/hypothesis

In patients with type 1 diabetes and end-stage renal disease (ESRD) we aimed to determine whether long-term normoglycaemia, as achieved by successful simultaneous pancreas and kidney (SPK) transplantation, would preserve kidney graft structure and function better than live donor kidney (LDK) transplantation alone.

Methods

Estimated GFR (eGFR) was calculated in SPK (n?=?25) and LDK (n?=?17) recipients in a stable phase 3 months after transplantation and annually during follow-up. Kidney graft biopsies were obtained at follow-up for measurement of glomerular volume (light microscopy), glomerular basement membrane (GBM) and podocyte foot process widths and mesangial volume fraction (electron microscopy).

Results

SPK and LDK recipients were similar in age and diabetes duration at engraftment. Donor age was higher in the LDK group. Median follow-up time was 10.1 years. Mean HbA_1c levels during follow-up were 5.5?±?0.4% (37?±?5 mmol/mol) and 8.3?±?1.5% (68?±?16 mmol/mol) in the SPK and LDK group, respectively (p?p?=?0.008) and increased mesangial volume fraction (median 0.23 [range 0.13–0.59] vs 0.16 [0.10–0.41]; p?=?0.007) at follow-up. Absolute eGFR change from baseline was ?11?±?21 and ?23?±?15 ml min^?1 1.73 m^?2 (p?=?0.060), whereas eGFR slope was ?1.1 (95% CI ?1.7, ?0.5) and ?2.6 (95% CI ?3.1, ?2.1)?ml min^?1 1.73 m^?2 per year in the SPK and LDK group, respectively (p?=?0.001).

Conclusions/interpretation

In patients with type 1 diabetes and long-term normoglycaemia after successful SPK transplantation, kidney graft ultrastructure and function were better preserved compared with LDK transplantation alone.