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, receiving certain kinds of chemotherapy, receiving natalizumab (Tysabri) for multiple sclerosis, on long-term efalizumab (Raptiva) for psoriasis, or have AIDS.
It is caused by a virus, the JC virus, which is normally present and kept under control by the immune system. Immunosuppressive drugs prevent the immune system from controlling the virus.
Read more about Progressive Multifocal Leukoencephalopathy: Cause, Contributing Causes, Pathogenesis, Symptoms, Diagnosis, Treatment
Famous quotes containing the word progressive:
“The self ... might be regarded as a sort of citadel of the mind, fortified without and containing selected treasures within, while love is an undivided share in the rest of the universe. In a healthy mind each contributes to the growth of the other: what we love intensely or for a long time we are likely to bring within the citadel, and to assert as part of ourself. On the other hand, it is only on the basis of a substantial self that a person is capable of progressive sympathy or love.”
—Charles Horton Cooley (1864–1929)