Table 1.

Effect of supernatant from type I collagen-stimulated PBMC (from patients with dcSSc) on MMP-1 production by dcSSc and normal fibroblasts

	Additions for 48 h	dcSSc fibroblast lines				Mean ± SE	Normal donor fibroblast lines				Mean ± SE	P value
Fibroblasts cultured with medium		004	008	1685	1822		1	3	2603	6858
	PBSa	4	18	69	38	32 ± 14	5	15	60	29	27 ± 12	NSb
	TNF-α (5 ng/ml)	100	100	100	100	100	100	100	100	100	100
Fibroblasts cultured with 30% v/v CI-stimulated dcSSc PBMC supernatant	PBSa	2	15	27	23	17 ± 5	125	69	92	22	77 ± 22	0.036b
	TNF-α (5 ng/ml)a	54	60	64	34	53 ± 7	578	413	210	106	327 ± 105	0.041c

MMP1 was measured by Western blot using pooled supernatants of CI-stimulated PBMC from ten dcSSc patients. The pooled PBMC supernatants were added at 30% v/v to cultures of normal and dsSSc fibroblasts for 14 days as described in the “Patients and methods” section. Normal and dcSSc fibroblasts cultured with pooled (n = 10) CI-stimulated dcSSc PBMC supernatants (bottom panel) were compared to the same cells cultured with the medium alone (top panel). The MMP-1 response to TNF-α in the medium alone was arbitrarily set at 100%

^aMMP-1 calculated as a percent of that seen with TNF-α stimulation in fibroblasts cultured with the medium alone

^bMMP-1 produced by SSc fibroblasts compared to normal dermal fibroblast cell lines following treatment with PBS

^cMMP-1 produced by SSc fibroblasts compared to normal dermal fibroblast cell lines following treatment with TNF-α