Advanced protein glycation in psoriasis

The aetiopathogenesis of psoriasis is very complex and has not been well known. Recently, it has been proposed that mechanisms dependent on free radicals may be involved in the development of this dermatosis. Also, psoriasis coincides with lipid disturbances, diabetes and diseases of cardiovascular system. However, the common mechanism connecting these diseases is still unknown.

The aim of this study was to measure concentration of peptides containing glycated residues (AGE-peptides) and IgG, IgA and IgM antibodies against carboxymethyllysine (anti-CML) and carboxyethyllysine (anti-CEL) in the sera of patients at different phases of psoriasis activity in comparison with the sera of healthy individuals.

The study material consisted of sera from psoriasis patients (n = 80) in active phase and in the remission phase and healthy individuals (n = 80) (controls). Concentrations of AGE-peptides were measured spectrofluorimetrically. Anti-CML and anti-CEL antibody concentrations were determined using ELISA.

In psoriasis patients in active phase disease concentrations of AGE-peptides and anti-CML and anti-CEL antibodies in all tested classes were significantly higher than those in healthy individuals. At remission, concentrations of AGE-peptides and tested antibodies decreased significantly, but concentrations of anti-CEL IgG and anti-CML IgG and IgM antibodies were remaining significantly higher in comparison with the control group.

The obtained results indicate for existence of increased oxidative stress in psoriasis and resulting increased protein glycation and stimulation of the immune system to response to these end-products. Increased protein glyco-oxidation consist a linker between psoriasis and increased prevalence of atherosclerosis, cardiovascular incidents and vascular complications of diabetes.