Fibroblast growth factors in scleroderma.

Area of Science:

• Biochemistry
• Dermatology
• Immunology

Background:

• Progressive systemic sclerosis (PSS) is a complex autoimmune disease.
• Fibroblast dysfunction is implicated in PSS pathogenesis.
• The role of serum factors in PSS fibroblast proliferation requires elucidation.

Purpose of the Study:

• To investigate the presence and characteristics of fibroblast growth promoting factors (FGPF) in the sera of PSS patients.
• To compare FGPF activity in PSS patients with healthy controls and rheumatoid arthritis patients.
• To determine the biochemical properties of FGPF.

Main Methods:

• Sera from PSS patients and controls were tested for fibroblast growth promoting activity.
• Fibroblast proliferation assays were performed using autologous and heterologous PSS and normal skin fibroblasts.
• Biochemical characterization included heat lability, dialysis, sensitivity to RNase A, dithiothreitol treatment, and gel filtration.

Main Results:

• Sera from PSS patients exhibited significantly increased FGPF activity compared to normal sera.
• FGPF stimulated both PSS and normal fibroblasts, with activity unaffected by dilution or normal serum.
• FGPF activity was not elevated in rheumatoid arthritis sera and showed no correlation with patient age or medication. It was heat-labile, nondialysable, required disulfide bonds, and was excluded by an XM-50 filter.

Conclusions:

• Elevated levels of FGPF in PSS sera contribute to fibroblast hyperproliferation.
• FGPF is a distinct serum factor, likely a protein, involved in PSS pathogenesis.
• Further characterization of FGPF may reveal therapeutic targets for PSS.