Dimethyl dioctadecyl ammonium bromide (DDA)-induced arthritis in rats: a model of experimental arthritis

A single intradermal injection of 2 mg of dimethyl dioctadecyl ammonium bro mide (DDA) in phosphate buffered saline (PBS) could induce polyarthritis in both LEW and DA rats with low incidence and severity whereas 2 mg of DDA i n incomplete Freund's adjuvant (IFA) could induce very severe polyarthritis with 100% incidence in LEW rats. Histology of DDA-induced arthritis (DIA) revealed cellular infiltration, synovial hypertrophy, development of granul ation tissue, destruction of cartilage and bone deformation in the articula r joints. Lymph node cells (LNCs) but not immunoglobulin fractions from the DIA rats successfully transferred the severe disease into the naive recipi ents. A challenge injection of DDA in IFA in the rats, which had recovered from the DIA, could reactivate the disease. It is thus concluded that DDA h as arthritis-inducing ability in the rats which is potentiated by IFA and t he DIA is a cell-mediated immune disease which might be a model of experime ntal arthritis. (C) 2000 Academic Press.