Flow cytometry of fibroblasts cultured from skin of patients with localized scleroderma.

Fibroblast cultures were initiated from affected and unaffected skin sites of 6 patients with localized scleroderma. Two of the affected cell lines exhibited more than threefold increases in procollagen production and mRNA levels. All the cell lines were analyzed by flow cytometry to detect a possible heterogeneity of scleroderma fibroblast cultures which could explain the production of excessive amounts of collagen. No evidence of a subpopulation responsible for elevated collagen production was detected using cytoplasmic dot hybridization of cells fractionated by flow cytometry. When compared with the nonaffected controls, all the cell lines from affected skin areas of scleroderma patients were found to exhibit a lower level of cellular autofluorescence, suggesting an alteration in metabolic activity. The results show that the heterogeneity of scleroderma fibroblasts that was found in vivo is lost when the cells are cultured.