Model of pathogenesis of psoriasis. Part 2. Local processes

TL;DR

This paper proposes a new model of psoriasis pathogenesis emphasizing skin immune response to systemic psoriatic processes, highlighting local inflammation, immune cell interactions, and the role of Y-antigen in plaque formation and remission.

Contribution

It introduces a novel model of psoriasis involving skin immune reactions to systemic processes and details mechanisms of plaque initiation and remission not previously described.

Findings

Psoriatic inflammation is a reaction of skin immune system to Mo-R and DC-R activity.

Y-antigen presentation can trigger epidermal hyperproliferation, leading to plaques.

Remission occurs when systemic psoriatic process severity decreases, weakening vicious cycles.

Abstract

Analytical research of results of experimental and theoretical studies on pathogenesis of psoriatic disease is carried out. The new model of pathogenesis - skin reaction to systemic psoriatic process SPP is formulated. ... Psoriatic inflammation is regarded as a reaction of the skin immune system to activity of Mo-R and DC-R involved in derma from blood flow. They contain Y-antigen and, getting to derma, can be transformed in mature maDC-Y and present this antigen to Y-specific T-lymphocytes as well as activate them. Y-antigen is a part of the interpeptide bridge IB-Y. Therefore, the skin immune system can incorrectly interpret Y-antigen presentation as a sign of external PsB-infection and switch one of mechanisms of protection against bacterial infection - epidermal hyperproliferation. Psoriatic plaque can be initiated only during action of local inflammatory process LP2 in derma causing not only innate, but also adaptive response. In particular, it is possible at LP2(IN) - open trauma of derma or at LP2(HPV) - HPV-carriage of keratinocytes. The level of Y-priming (presence and concentration of Y-specific T-lymphocytes in prepsoriatic derma and in lymph nodes) also determines possibility of psoriatic plaque initiation. Existence and severity of psoriatic plaque is determined by intensity of Y-antigen income into derma (inside Mo-R and DC-R). ... Severity of plaque is aggravated by LP2-inflammation if it persists after this plaque initiation. New Mo-T, DC-T (incl. Mo-R, DC-R) and Y-specific T-lymphocytes are constantly attracted into plaques from blood flow, and so support vicious cycles. Only at decrease of SPP severity, these vicious cycles weaken and natural remission of plaques takes place, up to their complete disappearance. The detailed analysis comparing the new model of pathogenesis with five other previously published models is carried out. Part 1. arXiv:1110.0584