Mirtazapine and Maraviroc were started, but unfortunately, she rapidly deteriorated and died 5 weeks after PML diagnosis.<h4>Conclusion</h4>Although peripheral lymphocyte counts were never low and CD4 T-cell count was close to normal, the persistent black fungus infection was a hallmark of severely compromised cellular immunity. Here, CD4 is linked to progressive multifocal leukoencephalopathy.