Context
Synovitis in rheumatoid arthritis (RA) involves local activation of lymphocytes, infiltration of inflamatory cells, synovial hyperplasia and angiogenesis. The current animal and in vivo models for RA have their limitations, since they do not reproduce all of the clinical and histopathological features of RA. The aim of the present study was to examine whether synovial tissue taken from RA joints retains its phenotypic and functional features after engraftment in a severe combined immunideficient (SCID) mouse, in order to develop an experimental model that reflects human RA without losing the complexity of RA synovitis.