Histopathological and immunohistochemical changes in psoriatic skin during peptide T treatment

Abstract

Ten patients with plaque-type psoriasis were treated with 2 mg peptide T i.v. for 28 days. Six patients responded with a substantial clinical improvement. Sequential biopsies from skin lesions were taken before, during and after treatment. The histological score (defining the activity of the psoriasis), the epidermal thickness and the number of infiltrating dermal lymphocytes were all reduced in the six patients who responded to the treatment. An increase in the number of CD1+ dendritic cells was detected immunohistochemically in the epidermis of the responders. The nonresponders did not display any pronounced changes.

Plasma concentration of selected neuropeptides in patients suffering from psoriasis

“…Naukkarinen et al did not reveal any significant difference in the number of CGRP-positive nerve endings within the lesional psoriatic skin (14). However, the treatment of psoriatic patients with intravenous peptide T, a VIP antagonist, led to significant improvement in skin lesions in about 60% of patients (23,24). However, the treatment of psoriatic patients with intravenous peptide T, a VIP antagonist, led to significant improvement in skin lesions in about 60% of patients (23,24).…”

“…Similarly, other authors also did not find any differences in density of CGRP-positive nerve fibres (35) or VIP-positive nerve fibres (16) in the skin from patients with psoriasis. However, the treatment of psoriatic patients with intravenous peptide T, a VIP antagonist, led to significant improvement in skin lesions in about 60% of patients (23,24). During treatment of peptide T, the number of lymphocytes infiltrating the skin was significantly diminished and the number of CD1+ dendritic cell markedly increased (24).…”

“…Several neuropeptides including SP (14)(15)(16)(17)(18)(19), CGRP (14,22) and VIP (20,21) were found to be overexpressed in lesional psoriatic skin. Moreover, treatment with capsaicin -a SP antagonist, and with peptide T -a VIP antagonist, leads to a significant improvement of psoriasis in many patients (23)(24)(25)(26)(27). Despite many studies on neuropeptides expression in psoriatic skin, little is known about the level of circulating neuropeptides in the patients suffering from psoriasis.…”

Immunomodulatory effects of peptide T on human keratinocyte cells

“…show that psoriatic patients treated with PT have dendritic cells that are immunoreactive with dermal somatostatin, and they also hypothesize that PT may stimulate the local synthesis and/or release of somatostatin, or the proliferation and/or migration of certain dendritic cell populations in psoriatic lesions during healing. The clear clinical and histological improvement in the majority of patients studied by Talme et al 25 . indicate that PT may possibly become a new option for the treatment of psoriasis.…”

“…PT appears to be beneficial in the treatment of psoriasis 4,24 , 25 . Various hypotheses have been proposed concerning the mechanism of PT action.…”