A case report of progressive multifocal leucoencephalopathy (PML) associated with adalimumab

Progressive multifocal leucoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by polyomavirus JC. It results from lytic infection of glial cells and is often fatal.1 ,2 A common risk factor for PML is immunosuppression due to HIV infection or malignancy (or its treatment). PML has also been reported in those using immunomodulation therapies.3 A previous study estimated incidence of PML at 0.2/100 000 among patients with autoimmune diseases who did not have HIV or malignancy. Based on the single case of PML exposed to a biological agent, another study reported the incidence rate (IR) of PML was 2.3 (95% CI 0.1 to 71) per 100 000 person-years in patients who were exposed to biological agents and 0.8 (95% CI 0.2 to 2.5) per 100 000 person-years in those not exposed to biological agents.4 Cases of PML associated …