Introduction: The renal function of patients referred to our unit for intestinal (IT) or multivisceral (MVT) transplant is assessed by MDRD eGFR, nGFR and renal ultrasound. In the UK patients with pre-transplant GFR <45ml/min/1.73m² are considered for simultaneous intestinal-kidney transplant (SIKT). The aim of this study was to identify differences in the methods of assessment of GFR. 

Methods: A retrospective review of all IT and MVT patients between 1st January 2006 and 31st December 2016 was performed. Data were retreived from the electronic patient record including MDRD eGFR, CKD-EPI eGFR and nGFR at assessment. 

Results: 73 patients were transplanted of which 6 were re-transplants (63% MVT, 13% modified MVT, 31% IT). Median age was 46 years (IQR 33-54), 52% were male and 48% female. All 3 results were retrieved for 44 patients. Median nGFR was 70ml/min/1.73m² (IQR 54-84), median MDRD eGFR was 94µmol/L (IQR 71-112) and median CKD-EPI eGFR 104µmol/L (IQR 78-114). nGFR was 75% of MDRD eGFR and 67% of CKD-EPI eGFR.  4 patients with GFR <45 had a SIKT and 3 patients did not; nGFR 29ml/min/1.73m², 37ml/min/1.73m², 38ml/min/1.73m² and MDRD eGFR 52µmol/L, 57µmol/L and 72µmol/L respectively. The latter had one native kidney and died 7m post-transplant from sepsis and multi-organ failure.  The other 2 patients are alive and have required intravenous fluid support, switched immunosuppression and undergone continuity surgery.  MDRD eGFR was 42µmol/L at 36m (25% drop from time 0) and 31µmol/L at 24m (39% drop).  Neither have required home haemodialysis. 

Conclusions: At higher levels of GFR, MDRD and CKD-EPI eGFR were disproportionately high and of little use clinically. The differences in nGFR versus eGFR support measuring nGFR in addition to eGFR when the eGFR is ≤60µmol/L to aid consideration of SIKT. This data suggests the UK could consider lowering the eGFR cut off for SIKT but the numbers are very small and should be interpreted with caution.