Tags: Disease.
Progressive multifocal leukoencephalopathy (PML) also known as progressive multifocal leukoencephalitis is a rare and usually fatal viral disease characterized by progressive damage (-pathy) or inflammation of the white matter (leuko-) of the brain (-encephalo-) at multiple locations (multifocal).It occurs almost exclusively in people with severe immune deficiency such as transplant patients on immunosuppressive medications those receiving certain kinds of chemotherapy receiving natalizumab (Tysabri) for multiple sclerosis on long-term efalizumab (Raptiva) for psoriasis brentuximab (Adcetris) for Hodgkin’s Lymphoma or those with AIDS.It is caused by the JC virus which is normally present and kept under control by the immune system.