title: Increased expression of Toll-like receptor 4 in peripheral blood leucocytes and serum levels of some cytokines in patients with ankylosing spondylitis.
abstract: Toll-like receptor 4 (TLR4) is a member of the Toll-like receptor family, which can bridge innate and adaptive immune responses. Activation of the TLR4 signalling pathway may induce the release of proinflammatory cytokines such as tumour necrosis factor (TNF)-alpha and interleukin (IL)-12, which was considered to play an important role in pathogenesis of immune-mediated diseases. Ankylosing spondylitis (AS) is an immune-mediated disease whose aetiology remains unknown. The aim of the study was to investigate the expression of TLR4 and serum TNF-alpha, IL-12 and soluble tumour necrosis factor-related apoptosis-inducing ligand (sTRAIL) level in AS patients. The results indicated that TLR4 protein and mRNA levels were significantly higher in AS patients than in healthy controls; however, there was no significant difference between human leucocyte antigen (HLA)-B27-positive and -negative AS patients, as well as serum levels of TNF-alpha, IL-12 and sTRAIL. In addition, in HLA-B27-positive AS patients, TLR4 level showed close associations with the cytokines and laboratory parameters of disease activity [erythrocyte sedimentation rate (ESR) and plasma C-reactive protein (CRP)], respectively. Similarly, the strong associations between the cytokines or between IL-12 and ESR or CRP were observed in HLA-B27-positive AS patients. Interestingly, in HLA-B27-positive AS patients, TNF-alpha correlated significantly with ESR, but did not with CRP. In contrast, sTRAIL correlated with CRP, but did not with ESR. Among HLA-B27-negative patients, no close correlation was found. In our study, it was suggested that the abnormal activation of TLR4 signalling and serum TNF-alpha, IL-12 and sTRAIL may play a key role in the development and progression of AS, which may be dependent on the status of HLA-B27 antigen.
authors: Department of Laboratory Diagnosis, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors: Z-X
authors: ZX
authors: Yang
authors: Y
authors: Y
authors: Liang
authors: Y
authors: Y
authors: Zhu
authors: C
authors: C
authors: Li
authors: L-Z
authors: LZ
authors: Zhang
authors: X-M
authors: XM
authors: Zeng
authors: R-Q
authors: RQ
authors: Zhong
mesh_terms: D000328:Adult; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000378:metabolism; D016207:Cytokines / Q000097:blood*; D005260:Female; D015796:HLA-B27 Antigen / Q000097:blood; D006801:Humans; D018664:Interleukin-12 / Q000097:blood; D007962:Leukocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D012333:RNA, Messenger / Q000235:genetics; D013167:Spondylitis, Ankylosing / Q000276:immunology*; D051197:Toll-Like Receptor 4 / Q000097:blood* / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D016207:Cytokines; D015796:HLA-B27 Antigen; D012333:RNA, Messenger; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12; D002097:C-Reactive Protein