Table 1.

Summary of tryptase and cytokine immunolocalization data

Antigen	Cartilage-pannus junctions (n = 35)	Rheumatoid synovial tissue (n = 26)
MC tryptase	Approximately 50% of specimens showed local	All specimens contained MCs, but with variable distributions and
	accumulations of MCs, most with extracellular enzyme	states of activation both between and within individual specimens
	indicative of activation/degranulation
TNF-α	Approximately 80% of specimens stained; occasional	Most specimens showed only intracellular staining; usually
	extracellular staining of cartilage matrix and intracellular	macrophages of the synovial lining layer
	staining of chondrocytes
IL-1β	Approximately 80% of specimens positive; extracellular	Commonly observed for a proportion of macrophages, especially
	distribution often reflecting that for TNF-α	those in the lining layer
IL-1α	Staining limited to about 30% of specimens and	Mainly restricted to a minor proportion of macrophages of the
	usually associated with macrophages	synovial lining layer
IL-15*	Microfocal staining observed for about 30% of	Restricted to approximately 40% of specimens; usually
	specimens, usually associated with macrophages,	macrophages of the synovial lining and a few fibroblastic cells;
	and especially chondrocytes; no association with TNF	seldom associated with TNF+, IL-1+ or tryptase+ cells
	or IL-1

*Interleukin (IL)-15 was examined in 9 and 12 different specimens for cartilage-pannus junction and rheumatoid synovial tisue respectively. The tryptase, tumour necrosis factor (TNF) and IL-1 data are partly adapted from Tetlow and Woolley [2]. MC, mast cell.