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

Recent reports have documented the development of renal thrombotic microang iopathy in patients with chronic myeloid leukemia (CML) who have undergone treatment with interferon-alpha. The pathogenesis of the renal lesion in su ch cases remains unclear. We report the case of a patient with chronic myel oid leukemia who developed renal failure and nephrotic syndrome while being treated with hydroxyurea and interferon-or. The renal biopsy showed featur es of chronic thrombotic microangiopathy. The patient had serologic and fun ctional evidence of antiphospholipid antibody. Interferon-or is known to ca use induction of multiple autoantibodies. We propose that in the context of CML, interferon-or treatment can induce pathogenic anti-phospholipid antib odies that result in renal thrombotic microangiopathy. This has important i mplications for patients with CML receiving immune-stimulating therapy beca use it suggests that prospective monitoring of such patients for anti-phosp holipid antibody might identify those at risk of developing thrombotic micr oangiopathy. Furthermore, patients with established antiphospholipid antibo dy syndrome in this context might benefit from intervention such as early a nticoagulation. (C) 2000 by the National Kidney Foundation, Inc.