A 45-year-old man with chronic hepatitis C virus infection develops palpable purpura on lower extremities, arthralgias, and weakness. Serum cryoglobulins are positive. The underlying pathogenic mechanism in HCV-associated cryoglobulinemia involves:

• A HCV direct cytopathic effect on endothelial cells
• B HCV integration into B-cell genome causing lymphoma
• C HCV-specific CD8+ T-cell destruction of hepatocytes
• D HCV-induced polyclonal B-cell activation producing immune complexes ✓

Explanation

HCV infects D lymphocytes and causes polyclonal D-cell activation with production of IgM rheumatoid factor (anti-IgG) forming mixed cryoglobulins. These immune complexes deposit in small vessels causing leukocytoclastic vasculitis. This is a Type III hypersensitivity mechanism. Options A, C, and B describe other HCV complications but not cryoglobulinemia pathogenesis.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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