Renal thrombotic microangiopathy associated with interferon-α treatment of chronic myeloid leukemia

Recent reports have documented the development of renal thrombotic microangiopathy in patients with chronic myeloid leukemia (CML) who have undergone treatment with interferon-alpha. The pathogenesis of the renal lesion in such cases remains unclear. We report the case of a patient with chronic myeloid leukemia who developed renal failure and nephrotic syndrome while being treated with hydroxyurea and interferon-or. The renal biopsy showed features of chronic thrombotic microangiopathy. The patient had serologic and functional evidence of antiphospholipid antibody. Interferon-or is known to cause induction of multiple autoantibodies. We propose that in the context of CML, interferon-or treatment can induce pathogenic anti-phospholipid antibodies that result in renal thrombotic microangiopathy. This has important implications for patients with CML receiving immune-stimulating therapy because it suggests that prospective monitoring of such patients for anti-phospholipid antibody might identify those at risk of developing thrombotic microangiopathy. Furthermore, patients with established antiphospholipid antibody syndrome in this context might benefit from intervention such as early anticoagulation. (C) 2000 by the National Kidney Foundation, Inc.