Progressive multifocal leukoencephalopathy (PML) is caused by reactivation of JC virus in immunocompromised patients. The cell type specifically infected and destroyed, causing demyelination, is:

• A Oligodendrocytes (myelin-producing cells of the CNS) ✓
• B Neurons of the cortical gray matter
• C Astrocytes causing reactive gliosis without myelin loss
• D Endothelial cells causing vasculitis and ischemic demyelination

Explanation

JC virus (a polyomavirus) has a specific tropism for oligodendrocytes in the CNS. Lytic infection destroys oligodendrocytes, causing patchy multifocal demyelination of the white matter. Histologically, enlarged oligodendrocyte nuclei with viral inclusions are seen at lesion edges, along with bizarre reactive astrocytes ('Creutzfeldt astrocytes'). Neurons are not infected.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.