Reactivation of JC virus and development of PML in patients with multiple sclerosis

Neurology. 2007 Mar 27;68(13):985-90. doi: 10.1212/01.wnl.0000257832.38943.2b.

Abstract

The attention of researchers and clinicians specializing in both multiple sclerosis (MS) and JC virus (JCV), the etiologic agent of progressive multifocal leukoencephalopathy (PML), was rekindled by the development of PML in two patients with MS enrolled in a clinical trial of combination therapy with natalizumab (Tysabri) and interferon beta-1A (Avonex) in recent years. PML had not been previously reported with either MS or treatment with interferon beta alone. This occurrence of PML with alpha4beta1-integrin inhibition in MS raised a number of issues in terms both of the scientific understanding of these diseases and for the future of immunomodulatory treatment for MS. In this review, we examine the current status of knowledge of the virus, its molecular biology, life cycle, and pathogenetic mechanisms, and how this relates to the basic science and clinical perspectives of MS. A better understanding of the specific steps from JCV infection to the development of PML is key to this issue. Other critical issues for further investigation include the role of alpha4beta1-integrin inhibition by natalizumab in the re-expression of JCV from latent sites and in the inhibition of entry into the brain and peripheral sites.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Adjuvants, Immunologic / adverse effects
  • Antibodies, Monoclonal / adverse effects
  • Antibodies, Monoclonal, Humanized
  • Drug Therapy, Combination
  • Humans
  • Integrin alpha4beta1 / antagonists & inhibitors
  • Integrin alpha4beta1 / immunology
  • Interferon beta-1a
  • Interferon-beta / adverse effects
  • JC Virus / immunology*
  • Leukoencephalopathy, Progressive Multifocal / immunology*
  • Leukoencephalopathy, Progressive Multifocal / physiopathology
  • Leukoencephalopathy, Progressive Multifocal / virology*
  • Multiple Sclerosis / complications*
  • Multiple Sclerosis / immunology
  • Multiple Sclerosis / virology
  • Natalizumab
  • Virus Activation / drug effects
  • Virus Activation / immunology*

Substances

  • Adjuvants, Immunologic
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Integrin alpha4beta1
  • Natalizumab
  • Interferon-beta
  • Interferon beta-1a