The expression of transmembrane and soluble CXCL16 and the relation with interferon-alpha secretion in patients with Behçet's disease

CER6690
2013 Vol.31, N°3 ,Suppl.77
PI 0084, PF 0087
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PMID: 24064021 [PubMed]

Received: 11/06/2013
Accepted : 19/08/2013
In Press: 09/09/2013
Published: 09/09/2013

Abstract

OBJECTIVES:
CXCL16 is a member of CXC chemokine, which is synthesised in plasmacytoid dendritic cell as a transmembrane molecule. Transmembrane CXCL16 on plasmacytoid dendritic cell plays a role in binding, uptaking and accumulation of CpG D ODN in early endosomes rather then lysosomal vesicles, thereby causing a high level of interferon-alpha secretion. Previously, we disclosed pronounced interferon-alpha production from these cells in patients with Behçet`s disease. The aim of this study was to investigate the relation between the secretion of IFN-α and the expression of CXCL16 on surface of plasmacytoid dendritic cell from patients with Behçet`s disease, and compare it with patients with ankylosing spondylitis and healthy controls.
METHODS:
The study population consisted of 73 cases (35 with Behçet`s disease, 19 with ankylosing spondylitis and 19 controls). We investigated the expression of CXCL16 on surface of plasmacytoid dendritic cells by flow cytometry, and the serum levels of IFN-α and CXCL16 with ELISA.
RESULTS:
Serum levels of IFN-α in patients with Behçet`s disease were significantly higher than the controls (p=0.009), and than patients with ankylosing spondylitis, but not statistically significant (p=0.124). Serum levels of CXCL16 in patients with Behçet`s disease and patients with ankylosing spondylitis were significantly higher than controls (p=0.009, p=0.003, respectively). We found no difference in the percentage and MFI of plasmacytoid dendritic cells and CD123+CXCL16+ cells determined by flow cytometry among the study and control groups. In patients with Behçet`s disease, a positive correlation was found between the percentage of plasmacytoid dendritic cells and CD123+CXCL16+ cells (p<0.001). Furthermore, there was also a positive correlation between the percentage of plasmacytoid dendritic cells and serum levels of CXCL16 in patients with ankylosing spondylitis (p=0.001). In addition, there was a positive correlation between the percentage of CD123+CXCL16+ cells and serum levels of IFN-α in Behçet`s disease group (p=0.034). We could not find any significant difference in other comparisons.
CONCLUSIONS:
We suggested that the expression of transmembrane CXCL16 on surface of plasmacytoid dendritic cell might contribute to high serum IFN-α levels seen in patients with BD.