Residual non-specific and disease-specific inflammatory markers in successfully treated young psoriasis patients: a cross-sectional study.

Psoriasis is a chronic, immune-mediated disease. The systemic inflammation triggered by psoriasis contributes significantly to increased cardiovascular risk. While various treatments completely clear the skin, the associated effects on systemic inflammation are not yet clear. We investigated residual systemic inflammation in successfully treated patients. Circulating disease-specific and non-specific inflammatory markers were measured and compared in 80 psoriasis patients (aged 30-45 years) successfully treated with topical therapy, methotrexate, adalimumab, secukinumab or guselkumab, and in 20 healthy controls. Non-specific inflammatory markers (high-sensitivity C-reactive protein (hs-CRP), complete blood count (CBC) parameters, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume-to-platelet ratio (MPR), and red blood cell distribution width-to-platelet ratio (RPR)) and disease-specific inflammatory markers (interferon-γ (IFN-γ), tumor necrosis factor (TNF), interleukin (IL)-1β, IL-12p70, IL-17, and IL-23) were measured and compared between groups. Disease-specific cytokines (IFN-γ, TNF, IL-1β, IL-12p70, and IL-17, but not IL-23), were significantly elevated in patients compared to controls, while non-specific inflammatory markers showed no differences compared to controls. The residual disease-specific cytokines were similarly elevated in all five treated groups. In addition, they correlated significantly with body mass index (BMI) and waist circumference. Our results suggest that psoriasis patients have elevated residual disease-specific cytokines despite successful treatment, while the non-specific inflammatory markers are similar to those in control subjects. Residual disease-specific inflammatory markers correlated with BMI and waist circumference. A possible beneficial effect of body weight control in psoriasis patients merits further investigation. The study was registered at http://clinicaltrials.gov (identifier: NCT05957120) on July 24, 2023.