Claudin-3 - a new intestinal integrity marker in patients with psoriasis: association with disease severity

Gut dysbiosis and increased intestinal permeability play a significant role in the pathogenesis of psoriasis and its comorbidities. Claudin-3 is a key component of tight junctions, which may serve as marker of gut barrier integrity.

The aim of the study was to investigate circulating plasma claudin-3 in patients with psoriasis and to evaluate clinical and metabolic factors, which determine its concentration.

This cross-sectional study included 60 patients with psoriasis (39 men and 21 women, mean age: 45.6 ± 12.1 years) and 30 healthy controls (18 men and 12 women, mean age: 46.3 ± 15.5 years) age, sex and body mass index-matched. Plasma claudin-3 concentration was measured using an enzyme-linked immunosorbent assay.

Plasma claudin-3 concentration was significantly higher in patients with psoriasis in comparison with healthy control [median (interquartile range), 50.7 ng/mL (47.3-54.2) vs. 43.3 ng/mL (42.3-44.2), P < 0.001]. Patients who achieved ΔPASI90 response after 16 weeks of treatment showed tendency to decrease in circulating claudin-3 plasma concentration. Positive correlations between claudin-3 concentration and the PASI score (r = 0.828; P < 0.001) as well as claudin-3 and neutrophil-to-lymphocyte ratio (r = 0.847; P < 0.001) were found. A multivariable linear regression analysis confirmed association of claudin-3 with the PASI score (P < 0.001), neutrophil-to-lymphocyte ratio (P < 0.01) and active smoking (P < 0.05).

Claudin-3, a biomarker for gut permeability, is increased in psoriasis and correlates with disease severity and smoking. Further investigations are needed to determine whether reinforcing intestinal barrier may be a new therapeutic target in psoriasis.