Ankylosing spondylitis (AS) is a chronic, inflammatory autoimmune disease characterized by axial bone inflammation. The main clinical manifestations include back pain and progressive spinal rigidity, as well as inflammation of the hips, shoulders, and peripheral joints. Also, extra-articular manifestations, such as psoriasis, uveitis, and inflammatory bowel disease (IBD).

Indicators of inflammation such as erythrocyte sedimentation rate (ESR) and Creactive protein (CRP), which are typically elevated in AS patients, particularly when peripheral joints are involved, these tests ultimately do not reflect the disease process and have limited sensitivity and specificity. Disease activity in AS has been measured by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), which includes only patient-reported measures. The assessment of Spondyloarthritis International society (ASAS) developed a new AS disease activity score (ASDAS) that combines patient-reported assessments with erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP). Although platelets play important functions in hemostasis and thrombosis, their functions in controlling immunity and inflammation have drawn more attention recently. Platelets are known to have a key role in controlling inflammatory processes in a variety of pathological states. Overactivated platelets can induce inflammation, which in turn can increase the risk of the development of atherosclerosis, thrombosis, and cardiovascular disorders. Inflammatory diseases, including inflammatory bowel disease (IBD), have platelets play a crucial role in their development. The first-line recommended treatment for active AS is NSAIDs.

Tumor necrosis factor (TNF) inhibitors have completely changed the therapy options for patients who have not improved despite receiving standard NSAID treatment. TNF inhibitors can, however, cause tolerability problems in certain patients or inadequate responses in others, and their effectiveness may gradually diminish. Interleukin (IL)-17 inhibitors are among the new therapeutic alternatives that are currently accessible for these individuals.

Inclusion Criteria:

• Patients fulfill the Assessment in Spondyloarthritis International Society (ASAS) classification criteria for Axial Spondyloarthritis.
• Patients with disease duration more than 6 months.
• Patients who failed conventional treatment and on bDMARDs (IL17 or Anti-TNF-α).
• Age above 16 years old.
• Patient cooperative and can answer questions.
• Patients who are able and willing to give written informed consent.

Exclusion Criteria:

• Other rheumatologic or collagen diseases.
• Age below 16 years and above 60 years.
• Uncooperative patients.
• Patient not able and willing to give written informed consent.
• Patient with other causes of platelet dysfunction, count irregularity.

1. Patients fulfill the Assessment in Spondyloarthritis International Society (ASAS) classification criteria for Axial Spondyloarthritis. [13]
2. Patients with disease duration more than 6 months.
3. Patients who failed conventional treatment and on bDMARDs (IL17 or Anti-TNF-α).
4. Age above 16 years old.
5. Patient cooperative and can answer questions.
6. Patients who are able and willing to give written informed consent