Platelet-rich plasma in ankylosing spondylitis: bench-to-bedside potential and unanswered questions

Objective: To review the pathophysiological rationale and available clinical evidence for platelet-rich plasma (PRP) therapy in ankylosing spondylitis (AS), and to propose a framework for future investigations.Methods: A narrative review of the literature was conducted using PubMed, Google Scholar, Embase, Scopus, and Web of Science, covering publications from inception to December 30, 2025.The search combined terms related to PRP, AS, spondyloarthritis, sacroiliac joint (SIJ), and enthesopathy.Two reviewers independently screened articles for eligibility.Predefined inclusion criteria targeted peer-reviewed publications evaluating PRP in AS or in conditions sharing pathophysiological or anatomical features with AS, comprising both primary clinical studies and evidence syntheses.Methodological quality of the primary studies was assessed using validated tools appropriate to each design.Results: Eleven publications evaluating PRP in conditions relevant to AS were identified, comprising five primary clinical studies and six evidence syntheses (four systematic reviews, two of which included meta-analysis, and two narrative reviews); by condition, four addressed SIJ dysfunction, three enthesopathy and tendinopathy, three rheumatoid arthritis, and one rheumatic diseases in general.No randomized controlled trials (RCTs) specifically evaluating PRP in AS patients were identified.In these non-AS populations, PRP showed benefits over corticosteroids for SIJ dysfunction and plantar fasciitis, though all evidence was indirect.Conclusion: Direct evidence is currently absent.While indirect clinical evidence from related conditions and the combination of regenerative and immunomodulatory properties of PRP provide a hypothesis-generating rationale, no clinical recommendation can be made at this time.Well-designed, AS-specific RCTs are urgently needed before any clinical adoption.