This study aimed to compare the serum concentration levels of IL-33 in psoriatic patients undergoing treatment with two commonly prescribed immunosuppressive drugs, methotrexate and cyclosporine. Blood samples will be collected, Serum IL-33 concentrations will be measured using enzyme-linked immunosorbent assay (ELISA) techniques. Clinical assessments, including Psoriasis Area and Severity Index (PASI) scores, will be also recorded to evaluate disease severity and treatment efficacy.

Psoriasis is a chronic immune-mediated disease with significant clinical and immunological heterogeneity. Although methotrexate and cyclosporine are widely used in moderate to severe psoriasis, their comparative effects on IL-33 - a key pro-inflammatory cytokine - have not been adequately evaluated. In this randomized controlled trial involving 118 Egyptian psoriatic patients, we directly compared the therapeutic efficacy of methotrexate versus cyclosporine and analyzed their impact on serum IL-33 levels in relation to Psoriasis Area and Severity Index (PASI).

Our findings demonstrated that while both drugs significantly reduced PASI scores and IL-33 serum levels, cyclosporine showed superior efficacy and achieved a greater reduction in both clinical severity and IL-33. A strong positive correlation was observed between IL-33 levels and PASI scores, supporting IL-33 as a reliable biomarker of disease activity and therapeutic response.

This is one of the few clinical studies in Egypt and the region evaluating IL-33 modulation in psoriasis therapy. Our results may guide clinicians in selecting optimal systemic treatment and highlight IL-33 as a potential therapeutic target.

Inclusion Criteria:

• Patient included who had age more than 18 years old from both sexes, and manifested with moderate to severe psoriasis (according to the body surface area BSA): moderate; BSA 5-10 and severe; BSA > 10)

Exclusion Criteria:

• Patient excluded from the study, who was pregnant or lactating women, and patient who had associated comorbidity namely inflammatory, autoimmune diseases , systemic diseases (mainly hypertension, renal, and hepatic diseases). In addition presence of any dermatologic diseases other than psoriasis, and history of receiving other systemic drugs, phototherapy for psoriasis within the last 6 months, or hypersensitivity to methotrexate and/or cyclosporine. Lastly, patients with body dismorphic disorders were also excluded.

Randomized controlled trial study following ethical guidelines (Approval No.: AFMC-PSO-2023/011) at Dermatology outpatient clinic in Kobry El Kobba Hospital. A 118 Egyptian Patients with psoriasis were recruited in the study where 59 treated with methotrexate group, and 59 for treatment with, cyclosporine group.