Anti-inflammatory effects of systemic anti-tumour necrosis factor [alpha] treatment in human/murine SCID arthritis

OBJECTIVES To evaluate in vivo the contribution of tumour necrosis factor α (TNFα) to the chimeric transfer model of human rheumatoid arthritis synovial membrane into SCID mice (hu/mu SCID arthritis), systemic anti-TNFα treatment was performed and the clinical, serological, and histopathological effects of this treatment assessed. METHODS Animals were treated with the rat-antimouse TNFα monoclonal antibody V1q, starting on day 1 after hu/mu engraftment, twice weekly for 12 weeks. Joint swelling, serum concentrations of human and murine interleukin 6 (IL6), and serum amyloid P (SAP) were measured. Histopathological and immunohistochemical analyses of the joints were also performed at the end of treatment. RESULTS Neutralisation of murine TNFα induced the following effects: (a) reduction of extent and duration of the acute arthritis phase, with significant reduction of joint swelling at two weeks; (b) decrease of murine SAP concentrations after the first antibody administration; and (c) increase of murine IL6 in the serum. At the end of treatment, there was a significant reduction of the inflammatory infiltration in the engrafted joints. Because of the mild degree of joint erosion, no treatment effects could be demonstrated on the destructive process. CONCLUSION In the lymphocyte independent hu/mu SCID arthritis, anti-TNFα treatment reduces local and systemic signs of inflammation.