Renal thrombotic microangiopathy caused by interferon beta-1a treatment for multiple sclerosis

Julien Mahe,¹ Aurélie Meurette,² Anne Moreau,³ Caroline Vercel,² Pascale Jolliet<sup>1,4

1</sup>Clinical Pharmacology Department, Institute of Biology, University Hospital, Nantes, France; ²Clinical Nephrology and Immunology Department, University Hospital, Nantes, France; ³Laboratory of Pathology, University Hospital, Nantes, France; ⁴EA 4275 Biostatistics, Pharmacoepidemiology and Subjective Measures in Health Sciences, University of Nantes, Nantes, France

Abstract: Interferon beta-1a is available as an immunomodulating agent for relapsing forms of multiple sclerosis. Common side effects include flu-like symptoms, asthenia, anorexia, and administration site reaction. Kidney disorders are rarely reported. In this study we describe the case of a woman who has been undergoing treatment with interferon beta-1a for multiple sclerosis for 5 years. She developed a hemolytic-uremic syndrome with intravascular hemolysis in a context of severe hypertension. A kidney biopsy showed a thrombotic microangiopathy. This observation highlights an uncommon side effect of long-term interferon beta-1a therapy. Pathophysiological mechanisms leading to this complication might be explained by the antiangiogenic activity of interferon.

Keywords: thrombotic microangiopathy, interferon beta, hemolytic-uremic syndrome, antiangiogenic activity