A patient with advanced HIV (CD4 count 40 cells/µL) presents with progressive multifocal leukoencephalopathy (PML). The causative virus and its cell tropism are:

• A CMV (HHV-5) — infects oligodendrocytes and astrocytes
• B JC virus (JCV, a polyomavirus) — infects oligodendrocytes causing demyelination ✓
• C HHV-6 — infects CD4 T-cells and neural progenitors
• D Epstein-Barr virus — infects B-cells and CNS neurons

Explanation

Progressive multifocal leukoencephalopathy (PML) is caused by JC virus (John Cunningham virus), a double-stranded DNA polyomavirus that selectively infects oligodendrocytes (myelin-producing cells) causing demyelination, and also astrocytes. Reactivation occurs in severely immunosuppressed states (AIDS, natalizumab therapy). Diagnosis is by CSF JCV PCR. There is no specific antiviral; immune reconstitution with ART is the only effective intervention. CMV causes retinitis and colitis in AIDS.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.