A patient with HIV and CD4 count of 80 cells/µL presents with progressive multifocal leukoencephalopathy (PML). The causative virus and its cellular receptor are:

• A JC virus (John Cunningham virus) — enters via 5-HT2A receptors on oligodendrocytes ✓
• B Cytomegalovirus (CMV) — enters via PDGFR-alpha on oligodendrocytes
• C Epstein-Barr virus (EBV) — enters via CD21 on CNS B cells
• D Varicella-zoster virus (VZV) — reactivates from posterior root ganglia, infects oligodendrocytes

Explanation

PML is caused by JC virus (a polyomavirus) reactivating from latency in immunosuppressed states. JC virus infects oligodendrocytes and astrocytes, causing demyelination. It binds to the serotonin receptor 5-HT2A on glial cell surfaces (along with LSTc glycan). Diagnosis is by JC virus PCR in CSF (sensitivity ~75–90%). Treatment is immune reconstitution by starting or optimising ART. No specific antiviral is proven effective. CMV causes other CNS complications (encephalitis, retinitis). EBV causes primary CNS lymphoma 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.