Combined liver-kidney transplantation (CLKT) has been widely thought to have an immunoprotective effect on the kidney. However, detailed studies are lacking. The goal of this study was to assess the incidence of immune-mediated injury in CLKT vs kidney transplant alone (KTA), including subclinical injury as evidenced on protocol biopsies.

Methods: Clinical, laboratory and kidney protocol biopsy (4 months, 1-, 2- and 5-years) data of 68 patients who underwent a CLKT between 2000-2011 were reviewed. The results were compared to those of 128 age, sex and race-matched recipients of a deceased donor KTA in the same period.

Results: Median HLA mismatch in CLKT and KTA were 5 and 2, respectively. There were no differences in donor age, sex and ECD status between the groups. Most common reasons for the renal failure were oxaluria (20.6%) and hepatorenal syndrome (14.7%) in CLKT; diabetes (18%) and polycystic kidney disease (14.1%) in KTA. 10 transplants in CLKT (14.7%) and 7 in KTA (5.5%) were done with positive cross-match. The median eGFR at the time of transplant, 1- and 5-years were 16, 53 and 53 in CLKT; and 9, 52 and 48 in KTA. Graft survival at last follow-up was 82.4% in CLKT and 70.3% in KTA (Table 1). A total of 232 biopsies in CLKT (median 3) and 487 biopsies in KTA (median 4) were reviewed. There were no kidney losses secondary to rejection in CLKT. In contrast, 4 kidneys in KTA were lost to rejection. Despite receiving lower immunosuppression, the cumulative incidence of acute cellular rejection was significantly lower in CLKT (8.8%) than in KTA (28.9%) (P=0.001). While humoral rejection was observed in similar rate in CLKT (7.4%) and KTA (9.4%), incidence of transplant glomerulopathy was higher in the KTA (8.6%) compared to CLKT (1.5%) (P=0.06). Interstitial fibrosis was observed similarly in both groups (27.9% in CLKT, 22.7% in KTA, P=0.48).

Conclusions: Despite lower doses of immunosuppression, both cellular and humoral kidney allograft rejection appear to be less common in the presence of a liver allograft. This suggests that the immunoprotective effect of liver transplantation is broad and may involve mechanisms beyond mere immunoabsorption of antibody.

« Back to 2013 American Transplant Congress