Association of interleukin‐15 single nucleotide polymorphisms with resistance to brucellosis among Iranian patients

Abstract

Interleukin (IL)-15, a Th1-related cytokine, triggers inflammatory cells' recruitment and increases the expression of interferon gamma (IFN-γ), which is an important cytokine in the immunity against brucellosis. Different single-nucleotide polymorphisms (SNPs) have been observed in the IL-15 gene, so this study aimed to investigate the probable association between these SNPs and susceptibility to brucellosis among Iranian patients. A total of 190 patients with brucellosis and 83 healthy milk farmers who consumed contaminated raw milk and dairy products from animals involved with brucellosis were included in this study. All the patients and the controls were genotyped for four IL-15 polymorphisms at positions 267, 367, 13687 and 14035 using polymerase chain reaction-restriction fragment length polymorphisms. The 267C and 13687A alleles, haplotypes CGCT and CAAA and the 267CC and 13687AA genotypes were significantly more frequent in the controls than in the patients (P = 0.014, 0.03, 0.006, 0.024, 0.026 and 0.01, respectively), so the variation in the IL-15 gene may be one of the factors affecting the resistance to brucellosis. In contrast, the frequency of haplotypes CGCA and TACT was significantly higher in patients compared with controls (P = 0.015 and 0.007, respectively), and interestingly the last one was observed only in the patients; therefore, it may serve as a predictive factor for brucellosis. In conclusion, it could be suggested that IL-15 genetic variants can affect resistance or susceptibility to human brucellosis among Iranian patients.

Association Between Cytokine Gene Polymorphisms and Human Susceptibility to Brucellosis

“…In our study, three genotypes of IL-15 (-367), AA/GG and GA had nearly the same distribution in both groups of patient and control, while the GG genotype of IL-15 (-592) was significantly higher in the patient group compared to the control group. In the study by Kalani et al, no significant difference was observed between the frequency of alleles and genotype polymorphisms of IL-15 (-367) in the controls and patients, suggesting that there is not a significant relationship between IL-15 (-367) gene polymorphisms and susceptibility and/or resistance to brucellosis (22).…”

“…There are several genetic polymorphic sites which are known to be associated with the production of TNF, including TNF-α (-308 G/A, -238 G/A) and TNF-β (+252 A/G) (22,23). In some previous studies, TNF-α polymorphisms at positions -308 and -238 have been associated with susceptiArch Pediatr Infect Dis.…”

Association of Interleukin-18 Gene Polymorphism with Susceptibility to Visceral Leishmaniasis in Endemic Area of Bihar, an Indian Population

“…Such studies clearly point towards possibility of the gene polymorphisms in affecting susceptibility or protection towards the same disease in different individuals [12–14]. Recently, Moravej et al has found the association of IL-18 gene polymorphism with VL in Iranian population [15].…”

IL15 polymorphism is associated with advanced fibrosis, inflammation‐related biomarkers and virological response in human immunodeficiency virus/hepatitis C virus coinfection

“…Apart from the well‐known single nucleotide polymorphisms (SNPs) around interleukin 28B ( IL28B) gene , other SNPs around immune‐related genes have also demonstrated to have an important role. In this setting, IL15 SNPs have been implicated in infectious diseases , immune diseases and cancers . To date, there are no data about the influence of IL15 SNPs on CHC progression and we only found an article showing a relationship with response to pegIFNα/RBV therapy .…”