Outcomes of Simultaneous Liver and Kidney Transplantation in Relation to a High Level of Preformed Donor-Specific Antibodies

Background. The protective effect of the liver allograft when simultaneously transplanted with a kidney in the setting of allosensitization is unclear. Methods. We analyzed the significance of sensitization, defined based on positive cytotoxicity crossmatches, positive flow cytometry crossmatches, and/or the presence of high levels of donor-specific antibodies, on the outcomes of simultaneous liver and kidney (SLK) transplantation. We reviewed 56 SLK performed at our center through December 31, 2011 and identified 13 patients who met high sensitization criteria. Results. Median patient survival was not significantly different: 86 months (95% confidence interval [CI], 47-135) for nonsensitized patients versus 151 months (95% CI, 4 to infinity) for sensitized patients (P=0.5). The 5-year survival was 67% (95% CI, 0.5-0.8) in the nonsensitized group and 64% (95% CI, 0.3-0.9) in the sensitized group. There were six renal allograft failures in the nonsensitized group but none in the sensitized group. The adjusted hazard ratios associated with the risk of death or the combined risk of death or renal allograft failure were 0.7 (95% CI, 0.1-3.8) and 0.4 (95% CI, 0.1-2.2) for sensitized versus nonsensitized patients. There were significantly more renal allograft rejections in the sensitized group (5 vs. 1; P=0.002) in the first year after transplantation, only one showing C4d positivity. Creatinine levels at 1 year after transplantation were similar: 1.5 mg/dL in the nonsensitized group versus 1.36 mg/dL in the sensitized group (P=0.6). Conclusion. Sensitization does not appear to have a significant negative impact on the survival of SLK patients.