Antiphospholipid Syndrome Nephropathy with Acute Thrombotic Microangiopathy after Renal Transplantation

We experienced a 36-year-old man with lupus nephritis and antiphospholipid syndrome (APS) who received a donor kidney from his father. Twenty-two months after transplantation, at a time of poor adherence to immunosuppressants and warfarin, the patient developed sudden graft loss due to hemolytic uremic syndrome with rapid deterioration of renal function, thrombocytopenia, and hemolytic anemia. A kidney biopsy showed thrombotic microangiopathy (TMA) related to platelet thrombus formation; however, there was no recurrence of lupus and no findings suggestive of post-transplant rejection, so acute TMA associated with APS was thought to be the cause of the graft loss. This case highlights the importance of instructing patients with lupus nephritis to adhere to treatment with warfarin, a therapeutic drug for APS.

Two Faces of the Same Coin: A Case Report of Antiphospholipid Syndrome Nephropathy

Antiphospholipid syndrome (APS) is an autoimmune disease which can be primary or secondary to other autoimmune conditions and is defined by the occurrence of arterial or venous thrombosis, or pregnancy morbidity associated with persistently positive antiphospholipid antibodies (aPLA). The kidney may be affected by thrombosis at any level of its vasculature. When small vessels are involved, this results in thrombotic microangiopathy (TMA), which can manifest as either acute vaso-occlusive or chronic vascular lesions in glomeruli, arterioles and interlobular arteries. We report the case of 26-year-old man, with a previous medical history suggestive of APS, who was found to have a small elevation in serum creatinine. A kidney biopsy was performed and revealed features of chronic TMA. Anticoagulation was begun and kidney function remained stable. However, one year later, upon suspension of anticoagulation, the patient developed acute kidney injury and a second kidney biopsy showed acute TMA. This case describes different manifestations of antiphospholipid syndrome nephropathy (APSN) and highlights the importance of anticoagulation for thrombosis prevention.