Increased circulating levels of soluble Fas ligand are correlated with disease activity in patients with fibrosing lung diseases.
OBJECTIVE
The Fas-Fas ligand (FasL) pathway is one of the important apoptosis-signalling molecule systems. We previously determined that this pathway may be involved in the pathogenesis of fibrosing lung diseases. In the present study, we evaluated the clinical significance of the levels of soluble forms of Fas (sFas) and FasL (sFasL) in serum from patients with fibrosing lung diseases.


METHODS
We measured sFas, sFasL, KL-6 (a measure of alveolar type II cell damage), surfactant protein D (SP-D), and surfactant protein A (SP-A) levels in serum from 35 patients with idiopathic pulmonary fibrosis (IPF), 17 patients with interstitial pneumonia associated with collagen vascular diseases (CVD-IP), and 13 normal healthy controls using enzyme-linked immunosorbent assays (ELISA).


RESULTS
The serum levels of sFasL were significantly increased in patients with active IPF and CVD-IP, compared with those with inactive disease and controls. There was no significant difference in sFasL levels between patients with inactive disease and controls. Serum sFasL levels were significantly correlated with lactate dehydrogenase and KL-6 levels in IPF. The decrease in sFasL levels following corticosteroid therapy was not correlated with the clinical course of IPF. There was no significant difference in serum sFas levels between IPF or CVD-IP patients and controls.


CONCLUSIONS
Although further studies need to be performed on a large number of patients with histologically proven IPF or CVD-IP, it would seem that serum sFasL levels may reflect the activity of IPF and CVD-IP.
Kuwano
Kazuyoshi
K
Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. kkuwano@kokyu.med.kyushu-u.ac.jp
Maeyama
Takashige
T
Inoshima
Ichiro
I
Ninomiya
Kiyoshi
K
Hagimoto
Naoki
N
Yoshimi
Michihiro
M
Fujita
Masaki
M
Nakamura
Norio
N
Shirakawa
Kamon
K
Hara
Nobuyuki
N
D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers / Q000097:blood; D003095:Collagen Diseases / Q000097:blood* / Q000175:diagnosis; D053222:Fas Ligand Protein; D005260:Female; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D008875:Middle Aged; D018396:Mucin-1; D009077:Mucins; D011510:Proteolipids / Q000097:blood; D011658:Pulmonary Fibrosis / Q000097:blood* / Q000175:diagnosis; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000097:blood; D014652:Vascular Diseases / Q000097:blood / Q000175:diagnosis; D019014:fas Receptor / Q000097:blood*
D000941:Antigens; D000951:Antigens, Neoplasm; D015415:Biomarkers; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D006023:Glycoproteins; C060192:MUC1 protein, human; D008562:Membrane Glycoproteins; D018396:Mucin-1; D009077:Mucins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037663:Pulmonary Surfactant-Associated Protein D; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D019014:fas Receptor; D007770:L-Lactate Dehydrogenase