Outcome of Kidney Transplantation in Patients with Antiphospholipid Antibodies: A Case Series

Thrombotic and obstetric complications occur in association with antiphospholipid antibodies (aPL), as do intrarenal vascular changes in primary and secondary APS. There are a limited number of studies reporting the outcome of patients with aPL receiving kidney allografts.

A retrospective chart review of patients who underwent kidney transplantation in our institution between 2005 and 2010 (inclusive) was performed. Patients who had at least 1 positive aPL at the time of transplantation were identified, their demographic, immediate and long-term outcome details obtained including any aPL related complications (thrombotic episodes including intrarenal vascular complications). Comparison was made with a control group consisting of transplant recipients not known to have aPL, matched for age, sex, transplant type and year of transplant.

884 patients underwent kidney transplantation between 2005 and 2010. 87 patients were screened for aPL(9.8%), 41 patients with aPL were identified(4.6%), 34 patients had a lupus anticoagulant, 1 had anti-cardiolipin antibodies and 6 both lupus anticoagulant and anti-cardiolipin antibodies. Long-term follow up was available for 31 patients. 25/31 patients were found to have persistent aPL (25/31 had repeated aPL screening). Patients included 17 males, 24 females, mean age 42 (range 19–61) years). 14 patients were known to have persistent aPL prior to transplantation and 5 of these were receiving long-term anticoagulation because of a history of thrombosis prior to renal transplant. 3 of the 27 patients not known to have persistent aPL prior to transplantation had a history of thrombosis prior to renal transplant; none of these were receiving long-term anticoagulation.

13 patients had aPL in association with other autoimmune disease (SLE). 30 patients had screening for other thrombophilic disorders performed. Other risk factors included hypercholesterolaemia, hypertension and cigarette smoking.

The table below summarises short and long-term aPL related complications.

25 patients had a cadaveric transplant, 2 had live unrelated donor transplants and 14 had live-related donor kidney transplants. Immediate thrombotic complications in patients with aPL included 4 patients who had graft failure due to renal vessel thrombosis resulting in graft excision because of ischaemia of the transplanted organ and 2 had a lower limb DVT (receiving perioperative thromboprophylaxis with aspirin, n=6) compared to 1 patient in the control group who experienced a lower limb DVT(significantly higher in patients with aPL compared to controls p=0.03).

Of the patients for whom long term follow up was available, long-term thrombotic complications were significantly higher in patients with aPL compared to controls (5/31 patients with aPL compared to 0/31 controls, p=0.02). Complications included fatal PE in 1 patient (on warfarin with subtherapeutic INR), bowel ischaemia secondary to mesenteric artery occlusion in another (on aspirin), and 1 patient had graft failure 9 months following transplant due to thrombotic microangiopathy (commenced on warfarin 6 months post transplant due to persistent aPL). Renal artery stenosis occurred in 2 patients (both receiving aspirin).

Conclusions: There is a high risk of thrombotic complications in patients with aPL who are undergoing renal allograft. These patients should be considered for perioperative and longterm thromboprophylaxis.

No relevant conflicts of interest to declare.