Abstract
Objective
To examine serum concentrations of insulin-like growth factor (IGF-1) and IGF binding protein (IGFBP-3), a major carrier protein for IGF-1, in patients with systemic sclerosis (SSc); and to relate the results to clinical features in SSc.
Methods
Serum IGF-1 and IGFBP-3 levels in 92 Japanese patients with SSc were measured by ELISA. Expression of IGF-1 and IGFBP-3 messenger RNA (mRNA) in the skin was quantified by real-time reverse transcription-polymerase chain reaction.
Results
Serum IGF-1 and IGFBP-3 levels were significantly elevated in patients with SSc compared with patients with systemic lupus erythematosus or healthy controls. IGF-1 levels were higher in patients with diffuse cutaneous SSc (dcSSc) than in patients with limited cutaneous SSc (lcSSc). Patients with increased IGF-1 levels had more severe skin involvement and pulmonary fibrosis. IGF- 1 mRNA was upregulated in the affected skin of patients with SSc. There were no significant differences in serum IGFBP-3 levels between dcSSc and lcSSc. IGFBP-3 levels were not associated with skin thickness and pulmonary fibrosis. Patients with increased IGF-1 or IGFBP-3 had lower frequency of telangiectasia than patients with normal levels.
Conclusion
These results suggest that both IGF-1 and IGFBP-3 are involved in the development of SSc. The role of IGF-1 appears to be different from that of IGFBP-3.
Key Indexing Terms:Footnotes
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Y. Hamaguchi, MD, PhD; M. Fujimoto, MD; T. Matsushita, MD, PhD; M. Hasegawa, MD, PhD; K. Takehara, MD, PhD, Department of Dermatology, Kanazawa University Graduate School of Medical Science; S. Sato, MD, PhD, Department of Dermatology, Nagasaki University Graduate School of Biomedical Sciences.
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Supported by a grant to Dr. Fujimoto for research on intractable diseases from the Ministry of Health, Labour and Welfare of Japan.
- Accepted for publication August 14, 2008.