Ankylosing Spondylitis and Psoriatic Arthritis Patients

1. Identify gene expression of TNFAIP3 in ankylosing spondylitis and psoriatic arthritis patients. 2. Detect relation between TNFAIP3 and disease activity. Inclusion criteria: 1. Patients diagnosed with ankylosing spondylitis according to Modified New York classification criteria 1984 (10). 2. Patients diagnosed with psoriatic arthritis (PsA patients (age ≥18 years) who fulfilled the CASPAR classification criteria for PsA 2010) (11). b. Exclusion criteria: Patients with erythrodermic or pustular psoriasis, pregnant and lactating females, patients with autoimmune diseases e.g. systemic lupus erythematosus, or major systemic diseases, and patients receiving any immunosuppressive drug will be excluded from the study.