[Morphologic indication for the participation of neutrophil granulocytes in rheumatic cartilage destruction]

Cartilage destruction in rheumatoid arthritis may be mediated by enzymes of the synovial fluid and by cells of the proliferating pannus tissue. Neutrophilic granulocytes are usually said to affect the cartilage via the synovial fluid, and their local occurrence in the pannus-cartilage border is denied. However, a morphological study on pannus tissue and cartilage by use of histochemistry and immunfluorescence (leucocytes antielastase) exhibited an accumulation of neutrophilic granulocytes in the immediate vicinity of the cartilage in destruction. This result is in contrast to the observation of most investigators reporting studies of the pannus cartilage junction. Experimental datas of the effect of elastase moreover indicate that this enzyme is capable to penetrate into the cartilage and to degrade proteoglycans. Therefore the results show that the occurrence of neutrophilic granulocytes at the pannus-cartilage border is an important phenomenon for understanding the progressive cartilage destruction and that elastase may be at least one enzyme responsible for the degradation of the cartilage matrix.