Relationship between in vitro lipopolysaccharide-induced cytokine response in whole blood, angiographic in-stent restenosis, and toll-like receptor 4 gene polymorphisms.
BACKGROUND
In coronary in-stent restenosis (ISR), a substantial contribution of inflammation is assumed. We evaluated the association between polymorphisms in the Toll-like receptor 4 (TLR4) gene and cytokine response after lipopolysaccharide (LPS) challenge and the development of ISR.


METHODS
Patients were included after successful elective stent placement in a native coronary artery and were scheduled for follow-up angiography after 6 months. Quantitative coronary analysis was performed off-line. Patient whole blood was challenged with LPS for 24 h. Baseline and stimulated concentrations of interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha, and IL-10 were assessed by ELISA. Two cosegregating single-nucleotide polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) were analyzed by allele-specific PCR amplification of genomic DNA.


RESULTS
A total of 236 consecutive patients were included, and 40 (17%) developed ISR. Median baseline and stimulated cytokine concentrations did not differ between patients with and without ISR. In multivariate analysis, male sex, unstable angina, hypertension, and chronic total occlusion were predictors of ISR. TLR4 genotypes were not associated with baseline or stimulated cytokine concentrations or with angiographic variables at follow-up.


CONCLUSIONS
In vitro cytokine response to LPS challenge is not increased in patients with ISR. Functionality of the TLR4 Asp299Gly polymorphism could not be demonstrated in this setting, and this polymorphism was not associated with angiographic outcome, calling into question its role in the progression of neointimal tissue growth.
Rittersma
Saskia Z H
SZ
Department of Cardiology, Academic Medical Center, Amsterdam, The Netherlands. z.h.rittersma@amc.uva.nl
Kremer Hovinga
Johanna A
JA
Koch
Karel T
KT
Boekholdt
S Matthijs
SM
van Aken
Benien E
BE
Scheepmaker
Arko
A
Bax
Matthijs
M
Schotborgh
Carl E
CE
Piek
Jan J
JJ
Tijssen
Jan G P
JG
Reitsma
Pieter H
PH
de Winter
Robbert J
RJ
D000328:Adult; D017023:Coronary Angiography; D023903:Coronary Restenosis / Q000097:blood* / Q000209:etiology; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D011956:Receptors, Cell Surface / Q000235:genetics*; D015607:Stents / Q000009:adverse effects*; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors
D016207:Cytokines; D008070:Lipopolysaccharides; D008562:Membrane Glycoproteins; D011956:Receptors, Cell Surface; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors