…cyclophosphamide or mitoxantrone within the previous year, or treatment with interferon beta, glatiramer acetate, cyclosporine, azathioprine, methotrexate, or intravenous immune globulin within the previous 6 months. Patients who had received treatment with interferon beta, glatiramer acetate, or both…

…leukoencephalopathy (PML) is a rare, oligodendroglial infection caused by the polyomavirus JC virus. It usually occurs in people infected with the human immunodeficiency virus (HIV), but it has also been reported in immunocompromised patients receiving prolonged treatment with methotrexate, cyclophosphamide…

…the risk of PML. A data registry mandated by the TOUCH program may help to address unanswered questions. The single most important unanswered near-term questions are whether PML will occur with natalizumab monotherapy and, if so, at what frequency. It is also unclear whether the risk of PML will increase…

…multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system that is encountered most frequently in the setting of immunodeficiency. 1 The disease is caused by the human polyomavirus JC virus, a common and widespread infection in humans. PML was reported in three patients…

…example of gene amplification, which usually occurs during tumor progression, is the amplification of the dihydrofolate reductase gene ( DHFR) in methotrexate-resistant acute lymphoblastic leukemia. 47 Amplification of DHFR is accompanied by cytogenetic alterations that mirror amplification of oncogenes…