Although the exact mechanism of the pathogenesis of scleroderma is still unknown, bleomycin plays some role in the induction of scleroderma. The growth effects of supernatants of bleomycin-stimulated peripheral blood mononuclear cells (CM) of scleroderma patients and normal controls on fibroblasts was examined by 3H-TdR uptake. CM showed significant growth activity compared with DMEM supplemented with 0. 1% FCS, and CM derived from patients with scleroderma showed stronger growth activity than that from normal controls. Addition of antisense oligonucleotide of bFGF inhibited the growth stimulatory activity of CM and 7% FCS much intensely than sense oligonucleotide on mouse 3T3 fibroblasts and normal skin-derived fibroblasts. Antisense oligonucleotide of PDGF also showed growth inhibition.