Objective: To confirm significant improvement of the skin score in systemic sclerosis by treatment with interferon gamma in a larger group of patients and to investigate on a molecular level the influence of interferon gamma on collagen type I messenger RNA expression.
Design: Open, noncontrolled multicenter study.
Setting: Five outpatient clinics specializing in the care of systemic scleroderma.
Patients: Thirty-two patients suffering from the diffuse or limited form of systemic sclerosis and progressive disease were recruited; 20 patients finished the study.
Intervention: Each patient received interferon gamma, 50 micrograms subcutaneously 3 times a week for 1 year.
Main outcome measure: Skin score, collagen type I messenger RNA in skin biopsy specimens.
Results: The patients who completed the study showed an unchanged median skin score after 1 year of therapy. In addition, similar collagen type I messenger RNA levels were detected in skin biopsy specimens taken from involved skin before and after therapy in these patients.
Conclusions: Treatment of systemic scleroderma with interferon gamma is associated with stabilization of the skin score and lack of worsening of visceral involvement.