Collagen synthesis in generalized morphea.

Synthesis of collagen and non-collagenous proteins was measured in fibroblast cultures derived from different layers of the dermis from a patient with an early stage of localized scleroderma. Increased synthesis of collagen was found in fibroblasts grown from the subcutaneous fat of this patient, whereas cells obtained from the papillary dermis revealed normal metabolism. These data agree with the results obtained in previous experiments with cells derived from patients with progressive systemic sclerosis in primary culture, thus indicating that the two diseases have a common pathomechanism. Several subcultures of the activated fibroblast populations were also studied. Normal collagen synthesis in these cultures was observed after the fifth passage, probably indicating selection of cell populations or loss of the previous phenotype.