CD4 and progressive multifocal leukoencephalopathy: CD4 T cell counts in the latter patients were similar to those in the AIDS patients with active PML, suggesting a similar degree of immunodeficiency (195 cells/mm3 [28–979] in active PML, 201 cells/mm3 [24–898] in neuro-AIDS; median [range], p=0.746, Mann-Whitney test).