Progressive multifocal leukoencephalopathy in two natalizumab-treated stepsisters: An intriguing coincidence.
BACKGROUND
Natalizumab, a treatment used in multiple sclerosis (MS), is associated with cases of progressive multifocal leukoencephalopathy (PML).


OBJECTIVE
We describe two cases of PML in related but not genetically apparented natalizumab-treated MS patients who are stepsisters. Reported cases/outcomes: While Patient 1 developed PML, Patient 2 was on natalizumab and had contacts with Patient 1. Patient 2 was diagnosed with PML 5 months after Patient 1.


CONCLUSIONS
The clinical and temporal data highly suggest that there was JC virus (JCV) transmission from one patient to the other with development of PML as primo-infection in Patient 2.
Laboratory of Neuroimmunology, Service of Neurology, Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland.
Frédéric
F
Bacchetta
Laboratory of Neuroimmunology, Service of Neurology, Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland.
Amandine
A
Mathias
Laboratory of Neuroimmunology, Service of Neurology, Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland.
Myriam
M
Schluep
Laboratory of Neuroimmunology, Service of Neurology, Department of Clinical Neurosciences, CHUV, Lausanne, Switzerland.
Renaud
R
Du Pasquier
D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use; D000914:Antibodies, Viral / Q000276:immunology*; D001921:Brain / Q000473:pathology; D005260:Female; D006801:Humans; D007577:JC Virus / Q000276:immunology / Q000472:pathogenicity*; D007968:Leukoencephalopathy, Progressive Multifocal / Q000175:diagnosis / Q000209:etiology* / Q000473:pathology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000188:drug therapy; D000069442:Natalizumab / Q000009:adverse effects* / Q000627:therapeutic use
D061067:Antibodies, Monoclonal, Humanized; D000914:Antibodies, Viral; D000069442:Natalizumab
JC virus; Natalizumab; multiple sclerosis; progressive multifocal leukoencephalopathy; transmission