Refining synovial inflammation assessment: A modified General Synovitis Score for active rheumatoid arthritis

The General Synovitis Score (GSS) is a well-established method for scoring synovial inflammation. Despite its widespread use, the GSS does not fully capture the inflammatory manifestations characteristic of the synovium in rheumatoid arthritis (RA). To address this limitation, the modified GSS (mGSS) was developed. The present study compared the correlation of the mGSS and the GSS with clinical disease activity. The aim was to provide a more precise histopathological scoring system based on hematoxylin and eosin (H&E) staining for assessing synovial inflammation in patients with active RA. In this cross-sectional study, synovial tissues were obtained from 60 patients with RA using a novel synovial biopsy device. Sections from synovial tissues were stained with H&E, and were assessed using the GSS and the mGSS. Neovascularization was observed in 56 patients (93.3%) and was significantly correlated with disease activity score in 28 joints-C-reactive protein (DAS28-CRP) (ρ=0.49; P<0.001), erythrocyte sedimentation rate (ESR) (ρ=0.44; P<0.001) and CRP (ρ=0.51; P<0.001). In addition, patients with severe neovascularization had significantly higher DAS28-CRP, ESR and CRP levels than those with mild-to-moderate neovascularization (P<0.05). Synoviocyte detachment, which occurred in nine patients (15.0%), was associated with higher DAS28-CRP, ESR and CRP levels than in the patients with synoviocyte proliferation (P<0.05). Furthermore, the mGSS was more strongly correlated with DAS28-CRP (ρ=0.62; P<0.001) than the GSS (ρ=0.37; P=0.003). These findings indicated that neovascularization and synoviocyte detachment, which are critical yet often overlooked aspects in the traditional GSS, are important in RA. Incorporating these elements into the mGSS may enhance the assessment of disease activity, providing a more precise and accurate evaluation of the synovial histopathology in patients with RA.