Fig. 4.

Two representative skin biopsy samples of HIV-infected participants. (A) Participant from HIV-SN peripheral neuropathy group demonstrating complete absence of small unmyelinated sensory nerve fibres reaching epidermis. Subepidermal dermal plexus fibres are present (blue arrow) as identified by pan neuronal marker PGP 9.5. (B) Participant from HIV–No SN group with normal counts of small unmyelinated nerve fibres (black arrows) reaching epidermis beyond dermal epidermal junction (red dotted line), and positive dermal plexus staining (blue arrows). Original magnification, 40×. Scale bar = 50 μm. HIV-SN, HIV sensory neuropathy; HIV–No SN, no HIV sensory neuropathy.