An unusual course of progressive multifocal leukoencephalopathy in a patient with idiopathic CD4+ T lymphocytopenia

A case is reported of idiopathic CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy and cervical lymph node tuberculosis. A 57 year old Japanese man presented with cervical lymphadenopathy and progressive neurological deficits, and six months later he developed akinetic mutism. He had a persistent severely depressed number of circulating CD4+T lymphocytes in the absence of human immunodeficiency virus infection. T1 weighted MRI showed a diffuse decreased signal intensity limited to the white matter without mass effect. A brain biopsy specimen had a morphology similar to that of progressive multifocal leukoencephalopathy. Polyomavirus antigen was detected in the brain lesion, and viral DNA was identified in nucleated blood cells and urine. Unusually this serious medical condition has lasted for more than three years without remission. To our knowledge this is the first patient with CD4+T lymphocytopenia with progressive multifocal leukoencephalopathy, suggesting that similar opportunistic infections should be considered even in previously normal people.