Abstract
Background
Growing evidence suggests the important role of IL-36 in the pathogenesis of psoriasis. Cathepsin G is a neutrophil-derived protease that can activate IL-36γ.
Objective
To assess the expression of IL-36γ and cathepsin G in psoriasis and to quantify the impact of treatment with narrow-band ultraviolet B phototherapy (NB-UVB) on their levels.
Methods
This case-control study involved 26 patients with moderate-severe psoriasis and 25 healthy volunteers. Psoriasis patients eligible for phototherapy received 24 NB-UVB sessions. Punch skin biopsies were obtained from all participants at recruitment and after phototherapy from patients. Real-time PCR was utilized for quantitative assessment of IL-36γ and cathepsin G expression in tissue samples.
Results
The expression of IL-36γ and cathepsin G was significantly higher in psoriasis before NB-UVB therapy compared to controls (p < .001). Both proteins decreased significantly with clinical improvement following NB-UVB therapy compared to baseline (p < .001). However, their expression after treatment was still higher than controls (p < .001).
Conclusion
IL-36γ and cathepsin G expression is upregulated in psoriatic lesions, supporting their role as mediators of inflammation in psoriasis. Downregulation of IL-36γ and cathepsin G is a possible mechanism for psoriasis improvement after NB-UVB therapy. IL-36 and cathepsin G can be considered as therapeutic targets for psoriasis.
Author contributions
All authors contributed significantly to the conception and the study design. Material preparation, data collection, and analysis were performed by Dina G Saadi, Mona El-Kalioby, Eman R Said, Marwa Ahmed Amer, Faisal Nouredin Mohammed, Laila A Rashed, Eman D El Desouky, and Aya M AlOrbani. The manuscript draft was first written by Mona El-Kalioby, Mohamed HM EL-Komy, Eman R Said, FaisalNouredin Mohammed, Aya M AlOrbani. All authors commented on the manuscript revisions and approved the final version of the manuscript.
Disclosure statement
No potential conflict of interest was reported by the author(s).