Background/Purpose: IL-33, through binding to its receptor ST2 (suppression of tumorigenicity 2), encoded by the interleukin 1 receptor-like 1 (IL1RL1) gene, activates mast cells and Th2 lymphocytes. Additionally, IL-33 acts as an activator of endothelial cells promoting angiogenesis and vascular permeability. Different studies have supported a pathogenic role of IL-33 axis in autoimmunity. Interestingly, an increased expression of this cytokine and its receptor has been detected in the inflamed arteries of GCA patients, mainly in endothelial cells of newly formed vessels, thus suggesting a possible role of IL-33 in the angiogenesis-dependent inflammation in GCA. The aim of the present study was to investigate for the first time the potential influence of the IL33 and IL1RL1 loci on GCA predisposition.
Methods: A total of 1,363 biopsy-proven GCA patients and 3,908 healthy controls from four European case/control sets (Spanish cohort: 894 cases and 2,047 controls, German cohort: 103 cases and 444 controls, Italian cohort: 255 cases and 1,141 controls, and Norwegian cohort: 111 cases and 276 controls) were combined in a meta-analysis. Six genetic variants: rs3939286, rs7025417 and rs7044343, within the IL33 gene, and rs2058660, rs2310173 and rs13015714, within the IL1RL1 gene, previously associated with autoimmunity, were genotyped using predesigned TaqMan® assays.
Results: A consistent association between the rs7025417 polymorphism and GCA was evident in the overall meta-analysis, under both allele (PMH=0.041, OR=0.88, CI 95% 0.78-0.99) and recessive (PMH=3.40E-03, OR=0.53, CI 95% 0.35-0.80) models. No statistically significant differences between allele or genotype frequencies for the other IL33 and IL1RL1 genetic variants were detected in this pooled analysis.
Conclusion: Our results clearly evidenced the implication of the IL33 locus in the genetic network underlying GCA. This study, together with previous findings, supports an important role of this cytokine in the inflammatory process occurring in GCA.
Disclosure:
A. Márquez,
None;
R. Solans,
None;
J. Hernández-Rodríguez,
None;
M. C. Cid,
None;
S. Castañeda,
None;
M. Ramentol,
None;
L. Rodriguez-Rodriguez,
None;
J. Narváez,
None;
R. Blanco,
None;
N. Ortego-Centeno,
None;
Palm,
None;
A. P. Diamantopoulos,
None;
N. Braun,
None;
F. Moosig,
None;
T. Witte,
None;
L. Beretta,
None;
C. Lunardi,
None;
M. A. Cimmino,
None;
A. Vaglio,
None;
C. Salvarani,
None;
M. A. Gonzalez-Gay,
None;
J. Martin,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-candidate-gene-approach-identifies-il33-as-a-novel-genetic-risk-factor-for-gca/