The effect of anti-inflammatory compounds on the biochemical changes in the Arthus reaction

The effect of anti-inflammatory drugs on the biochemical changes in the Arthus reaction have been studied and correlated to changes in the pathology of the reaction. In the Arthus reaction all the non-steroidal anti-inflammatory drugs inhibited the migration of cells into the lesion and reduced the lysosomal enzyme concentration at the Arthus site. The steroids did not inhibit the cellular inflitration or the total lysosomal enzyme concentration in the skin but did reduce the concentration of cathepsin D in the oedema fluid. In addition, prednisolone and, to a lesser extent, hydrocortisone reduced the degree of oedema formation. The results suggest that non-steroidal anti-inflammatory drugs inhibit the Arthus reaction by reducing the cellular infiltration whereas anti-inflammatory steroids act by preventing these cells secreting their lysosomal enzymes and thus causing tissue damage.