An Association Study of Interleukin 18 Receptor Genes (IL18R1 and IL18RAP) in Lumbar Disc Degeneration
Ahmad Omair*, 1, Benedicte Alexandra Lie2, Olav Reikeras1, Jens Ivar Brox1
Identifiers and Pagination:Year: 2012
First Page: 164
Last Page: 171
Publisher Id: TOORTHJ-6-164
Article History:Received Date: 23/1/2012
Revision Received Date: 22/3/2012
Acceptance Date: 23/3/2012
Electronic publication date: 20/4/2012
Collection year: 2012
open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
To examine association of candidate genetic variants in structural, inflammatory, matrix modifying, vitamin D receptor genes and variants associated with osteoarthritis, with surgical candidates and surgical patients with lumbar disc degeneration (LDD), in light of their previously reported susceptibility for LDD.
Genotyping of 146 Norwegian LDD patients and 188 Norwegian controls was performed for 20 single-nucleotide polymorphisms (SNPs) from collagen, aggrecan, interleukin, VDR, MMP3 and COX2 genes and 7 SNPs from osteoarthritic genes.
The neighboring genes IL18R1 and IL18RAP polymorphisms (rs2287037 and rs1420100), showed a statistically non-significant risk for developing LDD (OR 1.36 [95 % CI 0.99 – 1.87]; p=0.06 and OR 1.33 [95 % CI 0.98-1.81]; p=0.07). Homozygosity of these risk alleles was associated with LDD (p=0.023 and p=0.027). The non-risk alleles at these SNPs were situated on a haplotype negatively associated with LDD (p=0.008). Carriage of at least one non-risk allele at both loci also reduces the risk of developing LDD (OR 0.51 [95 % CI 0.33-0.80]; p=0.003).
Our findings support the polygenic nature of LDD and suggest that variation in interleukin 18 receptor genes could affect the risk of severe LDD and associated low back pain.