Adrenocorticotropin/cortisol ratio - a marker of psoriasis severity

The hypothalamic-pituitary-adrenal (HPA) axis plays a crucial role in systemic homeostasis and hormonal regulation of metabolic and immune functions. A similar HPA axis analog exists in the skin, where it regulates inflammation, cell proliferation and differentiation. Data regarding central HPA axis dysregulation in psoriasis are interesting but so far inconclusive.

In the study we attempted to determine whether central HPA axis serum components correlate with psoriasis severity.

Forty-two patients (10 women and 32 men) hospitalized at the Department of Dermatology participated in the study. None of our patients received any systemic treatment. Venous blood samples were collected at 6.00 AM. The relationship between quantitative variables and psoriasis severity based on the Psoriasis Area and Severity Index (PASI) was assessed with proc logistic in SAS 9.4.

The effect of adrenocorticotropin/cortisol ratio on the PASI group was OR 3.621 (95% confidence limits 1.217-10.775) for a 0.1 change in ratio (p = 0.02), meaning ACTH/cortisol ratio positively correlates with psoriasis severity. The effect of ACTH and cortisol on the PASI group was not statistically significant, with p-values of 0.30 and 0.23 respectively. Other inflammatory markers such as high-sensitivity C-reactive protein, neutrophils level, LDL, and total cholesterol did not show a significant correlation with PASI score.

Our results support the role of HPA axis dysfunction in the complex pathogenesis of psoriasis, showing a positive correlation between morning ACTH/cortisol ratio and disease severity. ACTH/cortisol ratio can be regarded as a new biochemical marker of psoriasis severity worth further studies.