Peripheral Kynurenine Pathway Metabolites in Patients with Psoriasis

Area of Science:

• Biochemistry
• Immunology
• Dermatology

Background:

• Psoriasis is a chronic systemic inflammatory disease affecting 2-3% of the population.
• The kynurenine pathway (KP) metabolizes tryptophan (TRP) and is implicated in inflammatory processes.
• Understanding KP alterations in psoriasis may reveal insights into disease mechanisms and comorbidities.

Purpose of the Study:

• To quantify kynurenine pathway metabolites in the serum and urine of psoriasis patients.
• To investigate the relationship between KP metabolite levels and psoriasis pathogenesis.
• To explore potential links between KP alterations and psoriasis comorbidities, including depression.

Main Methods:

• Serum and urine samples were collected from 60 plaque psoriasis patients and 30 healthy controls.
• Levels of TRP, indoleamine 2,3-dioxygenase (IDO), 2,3-tryptophan dioxygenase (TDO), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QUIN) were measured.
• Statistical analysis correlated metabolite levels with clinical data, laboratory parameters, and depression occurrence.

Main Results:

• Significantly higher concentrations of TRP, KYNA, and QUIN were observed in both serum and urine of psoriasis patients compared to controls (p < 0.05 and p < 0.001).
• A notable stimulation of the kynurenine pathway was evident in psoriatic individuals.
• Correlations between KP metabolites and clinical/laboratory parameters, including depression, were evaluated.

Conclusions:

• The study indicates a significant activation of the kynurenine pathway in psoriasis patients.
• This KP dysregulation may contribute to the pathogenesis of psoriasis and its associated chronic inflammation or comorbidities.
• Further research is warranted to determine if elevated KP metabolites are indicative of inflammation or a compensatory response in psoriasis.