Elevated serum insulin-like growth factor (IGF-1) and IGF binding protein-3 levels in patients with systemic sclerosis: possible role in development of fibrosis.
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.


CONCLUSIONS
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.
Hamaguchi
Yasuhito
Y
Department of Dermatology, Kanazawa University Graduate School of Medical Science, Kanazawa, Japan.
Fujimoto
Manabu
M
Matsushita
Takashi
T
Hasegawa
Minoru
M
Takehara
Kazuhiko
K
Sato
Shinichi
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood* / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000235:genetics; D008180:Lupus Erythematosus, Systemic / Q000097:blood; D008297:Male; D008875:Middle Aged; D011658:Pulmonary Fibrosis / Q000097:blood / Q000150:complications*; D012333:RNA, Messenger / Q000378:metabolism; D045743:Scleroderma, Diffuse / Q000097:blood* / Q000150:complications*; D045745:Scleroderma, Limited / Q000097:blood* / Q000150:complications*; D015854:Up-Regulation; D055815:Young Adult
D018972:Insulin-Like Growth Factor Binding Protein 3; D012333:RNA, Messenger; D007334:Insulin-Like Growth Factor I