In vitro autoreactivity against skin in rheumatoid arthritis: are peripheral blood mononuclear cells of patients with rheumatoid arthritis able to lyze autologous keratinocytes?
Abstract
An in vitro skin explant model was originally developed to predict the occurrence and severity of acute graft-versus-host disease in allogeneic hematopoietic stem cell transplants. In previous studies we reported that peripheral blood mononuclear cells of patients with rheumatoid arthritis were able to induce graft-versus-host-like histopathological changes when co-cultured in vitro with autologous skin explants.
The aim of the present study was to verify if observed skin damage was really of autoimmune origin. Using a (51)chromium release cytotoxic assay we found that peripheral blood mononuclear cells of patients lyzed autologous keratinocytes (n=5 patients with rheumatoid arthritis) but not autologous lymphoblasts (n=4 with rheumatoid arthritis, n=8 patients with juvenile idiopathic arthritis).
No specific lysis of keratinocytes or lymphoblasts was observed in healthy controls (n=15). We hypothesize that autologous peripheral blood mononuclear cells might recognize similar autoantigen(s) expressed on epidermal cells, which gives rise to an autoimmune response in the synovium.