Analysis of the relationship between indicators of oxidative stress and the amino acid profile of blood plasma in psoriasis

Introduction. Psoriasis is an autoimmune disease that affects the skin, has a number of systemic manifestations and is associated with the development of a number of somatic pathologies. Significant systemic metabolic features of psoriasis are changes in the pool of free amino acids and oxidative stress.

The purpose of the study: analysis of markers of lipid peroxidation and oxidative modification of plasma proteins and peripheral mononuclear cells, the amino acid spectrum of blood plasma, in relation to each other and clinical signs of severity and duration of psoriasis, body mass index and blood pressure indicators.

Material and methods. The study group included 45 patients with psoriasis vulgaris. The control group included 46 donors. Determination of the levels of products of lipid peroxidation and oxidative modification of proteins was carried out by spectrophotometric methods. Blood plasma amino acid levels were determined by capillary electrophoresis.

Results. In patients with psoriasis, an increase in the concentrations of primary and secondary products of lipid peroxidation and the level of metal-catalyzed oxidative modification of proteins in blood plasma, a decrease in the concentrations of end products of lipid peroxidation in peripheral mononuclear cells were revealed. In the amino acid profile of the blood plasma of patients with psoriasis, an increase in the relative concentration of sulfur-containing amino acids, concentrations of phenylalanine, leucine, cysteine, and a decrease in the relative concentration of oxyaminoacids were revealed. Relationships between the levels of amino acids and markers of oxidative stress with the duration of the course of the disease or exacerbation, as well as the severity of psoriatic lesions of the skin, were not revealed. Cysteine levels in patients with psoriasis are positively correlated with body mass index and diastolic blood pressure; the relative content of oxyaminoacids in blood plasma negatively correlates with body mass index.

Conclusions. Changes in the amino acid profile of blood plasma in psoriasis occur in parallel with oxidative stress and skin inflammation, but are associated with excess body weight for cysteine and oxyaminoacids, which allows us to consider the levels of cysteine and oxyaminoacids as promising prognostic and diagnostic markers of comorbid pathology associated with psoriasis.