Diagnostic and immunophenotypic contribution of ultrasound-guided synovial biopsy in inflammatory arthritis: Real-world experience from a tertiary rheumatology center Enflamatuvar artritte ultrasonografi eşliğinde sinovyal biyopsinin tanısal ve immünofenotipik katkısı: Üçüncü basamak bir romatoloji merkezinden gerçek yaşam deneyimi

Creative Commons License

Yılmaz G. Ç., Apaydın H., Üner H., Kapaklı G. E. T., Başkaya M. İ., ÖZİŞLER C., ...Daha Fazla

Journal of Turkish Society For Rheumatology, cilt.18, sa.2, ss.204-214, 2026 (Scopus, TRDizin)

Özet

Objective: Synovial tissue-based assessment has re-emerged as a useful approach for characterizing disease heterogeneity in inflammatory arthritis; however, real-world data on the diagnostic and immunophenotypic contribution of ultrasound-guided synovial biopsy (USGSB) in routine rheumatology practice remain limited. We aimed to evaluate the diagnostic contribution, procedural feasibility, and immunophenotypic characteristics of USGSB in patients undergoing tissue sampling for suspected inflammatory arthritis at a tertiary rheumatology center. Methods: This single-center retrospective observational study included 53 consecutive adults who underwent USGSB for persistent synovitis and diagnostic uncertainty. Histopathological evaluation was performed using hematoxylin-eosin staining and Krenn synovitis scoring. Immunohistochemical analyses included CD3, CD20, CD68, CD138, and CD31. Synovial pathotypes were classified as lympho-myeloid, diffuse-myeloid, or pauci-immune/fibroid when tissue and staining qualities were sufficient. Biopsy contribution was defined as biopsy-supported diagnostic reclassification or the identification of a clinically actionable alternative etiology beyond standard clinical, laboratory, and imaging assessments. Results: Final diagnostic attribution was available for 51 of 53 patients. Inflammatory arthritis was the most frequent diagnostic category (39/51, 76.5%), with rheumatoid arthritis representing the largest subgroup (25/51, 49.0%). Alternative diagnoses or management-relevant diagnostic reclassifications were identified in 12 of 51 patients (23.5%), including infectious arthritis, degenerative joint disease, systemic inflammatory diseases, crystal-induced arthritis, and synovial lipoma. Among histologically assessable specimens (n=50), high-grade synovitis was observed in 34 cases (68.0%). CD68-positive macrophage infiltration was the most frequent immunohistochemical finding (48/53, 90.6%), followed by CD3-positive T lymphocytes (42/53, 79.2%), CD20-positive B cells (26/53, 49.1%), CD138-positive plasma cells (21/53, 39.6%), and CD31 positivity (37/53, 69.8%). Definitive pathotype classification was possible in 44/53 cases (83.0%). No major procedure-related complication was documented. Conclusion: In this real-world cohort, USGSB provided useful diagnostic refinement and tissue-level immunophenotypic characterization in selected patients with suspected inflammatory arthritis. Biopsy-based treatment stratification remains exploratory and requires validation.