Background Genetic and environmental factors are known to play a role in the pathogenesis of ankylosing spondylitis (AS) which is the most severe subgroup of patients of spondyloarthritis. Killer Cell Immunoglobulin-like receptors (KIR) are the molecules regulating the cytotoxic response of Naturel Killer (NK) cells. KIR genes have polymorphic structures and comprise a high difference between the populations. KIR genes have been shown to be associated with the pathogenesis of several autoimmune and inflammatory diseases.
Objectives The relationship between the KIR genes and AS predisposition was already shown in previous studies in different populations. In this particular study, we aimed to assess the relationship of the KIR genes in the develepoment of AS in a group of Turkish patients.
Methods Study includes 68 patients with AS (31 female, 37 male, mean age: 38.27) and 75 healthy subjects (34 women, 41 men, mean age: 38.6) as a control group. Typing of sixteen different KIR genes was performed by the method of Spesific Sequence Oligonucleotide Probes (SSOP). The distribution of KIR genotypes were obtained from the data base of “www.allelefrequencies.net”. The rates of the KIR genes of the both groups were found by direct counting method and the comparision of the groups is made by Fisher's Exact test.
Results The frame genes KIR2DL4, 3DL2, 3DL3 and the 3DP1 were present in all patients and controls. KIR3DS1 which is one of the activating KIR genes, was found to be significantly higher in the AS cases (39.7%) than that of the control group (16%) (p=0.002), (Figure 1). In addition, there was no significant difference between AA and Bx genotypes in the patient and control groups. In the meta-analysis published by Zuo and colleagues in 2014; seven different studies conducted in Iran, Chinese, Spanish, English, Russian and Polish populations between the years of 2009-2012 were examined and it was reported that several KIR genes such as KIR2DL1, KIR2DS4, KIR2DS5 and KIR3DS1 were found to be associated with AS susceptibility. This is the first study from Turkey about the relationship between AS and KIR genes. We found KIR3DS1 gene significantly higher in Turkish AS patients as similar to the results of this meta-analysis study.
Conclusions These results show that KIR3DS1 gene activating NK cell cytotoxicity may trigger AS development and suggesting that it is related with the disease predisposition. Our result is compatible with other Caucasian populations.
Yu-Lian Jiao et al.: Polymorphisms of KIRs Gene and HLA-C Alleles in Patients with Ankylosing Spondylitis: Possible Association with Susceptibility to the Disease. J Clin Immunol (2008) 28:343–349
Hai-Ning Zuo et al.: Genetic variations in the KIR gene family may contribute to susceptibility to ankylosing spondylitis: a meta-analysis, Mol Biol Rep (2014) 41:5311–5319
Disclosure of Interest None declared