CD30-targeted therapy induces apoptosis of inflammatory cytokine-stimulated synovial fibroblasts and ameliorates collagen antibody-induced arthritis in mice

Objective: It has been reported that levels of soluble CD30 in serum and joint fluid are significantly elevated in patients with rheumatoid arthritis (RA). This study aimed to investigate whether CD30 could be a therapeutic target for RA. Methods: The expression and localization of CD30 were examined by immunohistochemical and double immunofluorescence staining on synovial tissue samples obtained from patients with RA or osteoarthritis (OA) during surgery. Changes in CD30 expression of fibroblast-like synoviocytes (FLS) from RA patients with or without TNFα and IL-1β stimulation were examined by the polymerase chain reaction (PCR) and flow cytometry. Collagen antibody-induced arthritis (CAIA) was created in DBA/1 mice, and the therapeutic effect of brentuximab vedotin (BV) was examined by clinical score, histological findings and measurement of serum levels of SAA, IL-6, and TNFα. Results: CD30 expression was significantly higher in samples from patients with RA than from those with OA. Double immunofluorescence showed a low rate of co-localization of CD30 with CD20 or CD90, but a high rate of co-localization of CD30 and CD138. CD30 mRNA expression was upregulated 11.7-fold in FLS following stimulation by inflammatory cytokines. The clinical scores of CAIA mice were significantly lower following both BV treatments, however, the histological scores of CAIA mice were significantly lower only following treatment with high dose BV (70 mg/kg). Conclusions: CD30 was expressed on immunocompetent cells in synovial tissue from RA patients and in cytokine-stimulated FLS in vitro. High dose BV (70 mg/kg) showed significant therapeutic effects in ameliorating inflammation and joint destruction in CAIA mice, but low dose BV (30 mg/kg) was insufficient.