Psoriasis is a common chronic, immune-mediated, skin disease with a significantly negative impact on patients' quality of life. It is one of papulosquamous diseases defined by erythematous plaques with silvery scales.

The interplay among cytokines released by dendritic, Th1, Th2, and Th17 cells leads to the clinical manifestations seen in psoriasis. Although discovering novel biomarkers for psoriasis is challenging step., it may play an essential role in diagnosis, severity assessment and prediction of treatment outcome and prognosis of the disease

The protein expression of gelsolin- which is an actin scavenger controlling cytoskeletal remodeling, cell morphology, differentiation, movement, and apoptosis- has been found to be significantly decreased in several pathological conditions including neurodegenerative diseases, inflammatory disorders, and cancers.

Gelsolin (GSN) is a member of the GSN protein family, the main function of it is to cut and seal actin filaments to regulate the cytoskeleton and participate in a variety of biological functions.

Low serum gelsolin levels are linked to the severity of psoriasis, suggesting that gelsolin may help in assessing the severity of the disease and how it responds to treatment.

Methotrexate (MTX) is the first-choice drug when phototherapy or retinoid treatment are not effective in psoriatic patients.

It is a cytotoxic drug with powerful anti-proliferative and anti-inflammatory effects that has gained prominence in treating inflammatory diseases one of them is psoriasis.

Narrowband (NB) UVB phototherapy is a common line of treatment in psoriasis. It was proven to be more effective than broadband UVB and safer and/or more practicable than psoralen_UVA in treatment of psoriasis

Inclusion Criteria:

• Patients with moderate to severe plaque psoriasis.
• No restriction of age, race nor occupation.

Exclusion Criteria:

• History of psoriasis treatment with systemic and biological agents prior to the study for at least 3 months.
• Pregnancy and lactation.
• Infections.
• Patients with chronic diseases: hepatic disorders, hematologic diseases, chronic renal failure or cancer.