We considered the possibility that thrombophilia may propagate graft thrombosis and therefore we evaluated the protein C system, which is a natural anticoagulant. Potential alterations in this system include protein C or protein S deficiency, inhibition through a lupus anticoagulant (LA), or a resistance to activated protein C due to the factor V Leiden (FVL) mutation.Methods.
One hundred thirty-two consecutive renal transplant patients, not known to have abnormal thrombostasis, in whom 1-year graft survival could be assessed, underwent laboratory testing for protein C or S activity, LA, and FVL. Transplant survival and demographic data were extracted from the hospital record.Results.
We identified 18 patients with thrombophilia (FVL, 10; LA, 6; protein S, 2) who had received a total of 28 renal transplants. Of these 28 transplant recipients, 11 transplants were lost within the first year, compared with 21 of 155 transplants to 114 patients without thrombophilia(P=0.0003). Median graft survival for patients with thrombophilia was 30 months (range: 0 to 166), compared with 86 months (range: 0 to 212) for patients without thrombophilia(P<0.01). The presence of thrombophilia represented a 3.5-fold (95% confidence interval, 2.3-5.3-fold) risk for 1-year graft loss.Conclusion.
In this retrospective study, patients with thrombophilia had a significantly higher risk of early transplant failure. These data point toward a potential contribution of thrombophilia to transplant loss, a hypothesis that needs further study.