Confirmation of peripheral neuropathy in patients withvenous ulceration through immunohistochemistry

Abstract

Patients with venous ulceration demonstrate clinical signs of peripheral neuropathy. Using immunohistochemistry we investigated cutaneous innervations immediately adjacent to chronic and healing venous ulcers. Punch biopsies (4 mm) were taken from sites adjacent to venous ulcers: (1) from nonhealing ulcers (n = 15), (2) from healing ulcers and (n = 14), and (3) from control patients with varicose veins (n = 12). Immunohistochemistry using anti-protein gene product 9.5 (PGP) antibody was used to assess total nerve fibers. Antibodies against the neuropeptides calcitonin generelated protein (CGRP) and substance P (SP) were used to assess distribution of CGRP and SP-containing fibers. Innervations of the epidermis and papillary dermis were quantified with image analysis by two blinded investigators. Using PGP 9.5, total nerve fibers are decreased in the dermis adjacent to healing ulcers but not in nonhealing group. The total nerve fibres of the epidermis are decreased in non-healing group but not in healing group. PGP-positive fibers are shorter in the dermis in both groups, but more in the nonhealers. CGRP-positive fibers are decreased in the dermis in both groups and in the epidermis in healing group. The epidermal fibers are shorter in both groups. There were few SP-positive fibers in all groups. Reduced dermal and epidermal innervations may contribute to the initial development of a venous ulcer. The decrease in epidermal fibers in chronic ulcers suggests that epidermal innervations may be important in healing. This study confirms the clinical studies with immunohistochemical evidence of peripheral neuropathy in venous ulceration. IntroductionIt is somewhat surprising that patients with venous ulceration do not experience more pain and discomfort.