Variation in the CXCR1 gene (IL8RA) is not associated with susceptibility to chronic periodontitis

Similar distribution of the allelic and genotypic frequencies were observed between the groups (p > 0.05).The polymorphism rs2234671 in the CXCR1 gene was not associated with the susceptibility to chronic periodontitis in the studied Brazilian population.The human chemokine receptor CXCR-1 (or IL8R-alpha) is a specific receptor for the chemokine interleukin 8 (IL-8) [1]. Initially identified as a chemoattractant for neutrophils, IL-8 has been demonstrated to have pro-inflammatory effects including stimulation of neutrophil degranulation [2]. Cellular activities of IL-8 are mediated by CXCR-1 and CXCR-2 (IL8R-beta), which maintain 78% of amino acid similarity and are encoded by two single-copy genes that are located on chromosome 2q34-35 [3]. However, CXCR-1 is more specific for IL-8 in comparison with CXCR-2 [4].The involvement of IL-8, CXCR-1 and CXCR-2 has been extensively investigated in different diseases such as pyelonephritis [5,6], hepatitis B [7], rapid disease progression of HIV-1+ [8], lung diseases, such as chronic obstructive pulmonary disease and asthma [9], bronchiectasis [10], systemic sclerosis [11] and lung cancer [12]. Some of these studies have reported positive associations between the diseases and single nucleotide polymorphisms (SNPs) in the CXCR1 gene [8,9]. Indeed, a significant association was demonstrated between the 860G > C (S276T) SNP in the CXCR1 gene with decreased lung cancer risk [12]. Haplotypes formed by SNPs in the CXCR1 and CXCR2 genes where also previously identified [7].The 860G > C (S276T) SNP in CXCR1 gene was identified by comparison of multiple sequences deposited in the GenBank/EMBL data banks [11,13]. These authors named this polymorphism differently: +2607 (position 6334 of sequence accession number [GenBank: L19592.1]) in exon 2, and +827 (starting from the initiation of the ATG codon in exon 2 of [GenBank: L19592.1]), respectively. The variant position 860G > C is based on the [NCBI: NM000634.2] exon 2 initiations, how