John cunningham virus status and progressive multifocal leukoencephalopathy as material risks when treating relapsing remitting multiple sclerosis

Introduction Progressive Multifocal Leukoencephaly (PML) is an opportunistic central nervous system infection with John Cunningham Virus (JCV) that is potentially fatal or severely debilitating. Most neurologists think the risk of PML with JCV positive patients, treated with either fingolimod or dimethyl fumarate is so low that they avoid testing or discussing it with patients. Patients and Methods Patients offered testing for JCV readily accepted the option, despite being advised that most neurologists would not order the test and would take little note of the result. Results The 4 patients who were positive for testing for JCV all opted to change treatment to a perceived less efficacious medication, which has no reported cases of PML associated with it. Discussion The Australian case of Rogers vs Whitaker set the benchmark for material risk consideration in which such risk should be respected when doctors discuss treatment with patients. In Rogers the risk was 1/14,800 while for fingolimod the risk is 1/10,000 if JCV positive and less so for dimethyl fumarate. This report confirms that even these low risks directly influence patient choices and leave clinicians potentially liable in negligence if they do not inform patients of the risk of developing PML