Combined analysis of cytokine gene polymorphism and the level of expression with allograft function in kidney transplant recipients

IL17A and IL17F genes polymorphisms are associated with histopathological changes in transplanted kidney

Background

Interleukin 17 is a proinflammatory cytokine involved in immune response after allograft transplantation. IL-17 family of proinflammatory cytokines includes IL-17A and IL-17F. Previous studies have demonstrated that the rs2275913 IL17A and the rs11465553 IL17F gene polymorphism are associated with kidney allograft function. Because of the association between these polymorphisms and post-transplant immune response, we assume that these single nucleotide polymorphisms may affect morphological structure of transplanted kidney.

The aim of this study was to examine the association of rs2275913 IL17A and rs2397084, rs11465553 and rs763780 IL17F gene polymorphisms with histopathological changes in transplanted kidney biopsies such as: glomerulitis, tubulitis, arteritis, cell infilitration and fibrosis.

Methods

The study enrolled 82 patients after renal graft transplantation in whom a kidney biopsy was performed because of impaired graft function. The rs2397084 T > C (Glu126Gly), rs11465553 G > A (Val155Ile) and rs763780 T > C (His167Arg) polymorphisms within the IL17F gene and the rs2275913 A > G (− 197 A > G) polymorphism within the IL17A gene promoter were genotyped using TaqMan genotyping assays on a 7500 FAST Real-Time PCR System (Applied Biosystems, USA).

Results

There was a significant association between the rs2275913 IL17A gene polymorphism and the grade of tubulitis, which was more severe among patients with the A allele, compared to recipients with the GG genotype (GG vs. AG + AA, P = 0.02), and with the grade of arteriolar hyaline thickening and mesangial matrix increase, which were more severe among patients with the G allele compared to recipients with the AA genotype (AA vs. AG + GG, P = 0.01 and P = 0.04, respectively). Tubular atrophy and interstitial fibrosis were more severe among individuals with the C allele at the rs763780 IL17F gene polymorphism (TT vs. TC, P = 0.09 and P = 0.017, respectively). However, it should be taken into account that the statistical significance was achieved without correction for multiple testing, and no significant association would remain significant after such correction.

Conclusions

The results of this study may suggest a possible association between the rs2275913 IL17A and rs2275913 IL17A gene polymorphisms and some histopathological changes in transplanted kidney biopsies.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1308-z) contains supplementary material, which is available to authorized users.

A trial sequential meta-analysis of IFN-γ +874 A>T (rs2430561) gene polymorphism and extrapulmonary tuberculosis risk

Interferon-γ (IFN-γ) plays a crucial role in immunological responses against Mycobacterium tuberculosis (M.tb) infection. The polymorphism at +874 A > T (rs2430561) influences the levels of IFN-γ, which may further influence the susceptibility to extrapulmonary tuberculosis (EPTB). This polymorphism has been investigated with respect to EPTB occurrence in different populations and provided contradictory and conflicting results. This study was performed to meta-statistically analyze the data and draw a more accurate conclusion regarding the association of IFN-γ +874 A > T gene polymorphism and EPTB susceptibility. A quantitative synthesis was executed for the pertinent studies retrieved from online web-databases viz. Google Scholar, PubMed/Medline and EMBASE. The pooled odds ratios (ORs) and confidence intervals (95% CIs) were estimated for all the genetic models by meta-analysis. A total of eight studies were retrieved which included 762 confirmed EPTB cases and 1341 controls. The meta-analysis results revealed reduced association of EPTB in allelic contrast (T vs. A: p = 0.001; OR = 0.668, 95% CI = 0.524 to 0.850), homozygous (TT vs. AA: p = 0.017; OR = 0.450, 95% CI = 0.234 to 0.868), heterozygous (AT vs. AA: p = 0.004; OR = 0.574, 95% CI = 0.395 to 0.835), dominant (TT + AT vs. AA: p = 0.003; OR = 0.536, 95% CI = 0.354 to 0.810) and recessive (TT vs. AA + AT: p = 0.039; OR = 0.662, 95% CI = 0.448 to 0.980) genetic models. Furthermore, re-sampling statistics also revealed reduced risk of EPTB in overall population and Asian subgroup. This meta-analysis concluded that IFN-γ +874 A > T gene polymorphism is meaningfully related with the reduced EPTB risk in overall and Asian population, and further necessitates larger studies to be conducted on this topic in other races.

IL-6 and IL-18 cytokine gene variants of pulmonary tuberculosis patients with co-morbid diabetes mellitus and their household contacts in Hyderabad

PURPOSE

Association of cytokine genes reflects their susceptibility towards infection and disease in household contacts (HHC) of pulmonary tuberculosis (PTB) patients. Hyperglycemia, a common factor in diabetics might influence their risk towards mycobacterium tuberculosis infection and disease development. This study determines the association of IL-6 and IL-18 cytokine gene variants of TB patients with diabetes mellitus (TBDM) and their HHC in Hyderabad.

METHODS

Single nucleotide polymorphisms of IL-6 (-174 G>C and -572 G>C) and IL-18 (-137 G>C and -607 C>A) cytokine genes were genotyped by Amplification Refractory Mutation System and Restriction Fragment Length polymerase chain reaction in total of 705 subjects comprising of TBDM, their HHC, PTB, DM and Healthy controls (HC).

RESULTS

At IL-6 -174G>C variant, GG genotype, G allele in TBDM and TBDM HHC, at -572G>C variant, C allele in TBDM and GG haplotype in TBDM HHC were showing positive association, however DM have not shown any association at IL-6 polymorphic sites. With respect to the IL-18 gene polymorphisms, at -137 G>C variant, GG genotype was positively associated in PTB while at -607 C>A variant positive association was shown with AC genotype in TBDM, their HHC and DM; GACC diplotype in TBDM and GCGC in PTB.

CONCLUSION

Our findings suggest that susceptible combination of IL-6 and IL-18 cytokine genes associated with disease in the HHCs highlight their risk of inclination towards the disease.

Association of UGT2B7, UGT1A9, ABCG2, and IL23R polymorphisms with rejection risk in kidney transplant patients

Despite advances in testing compatibility between donor and recipient, graft rejection remains a current concern. Single-nucleotide polymorphisms (SNPs) that codify altered enzymes of metabolism, drug transport, and the immune system may contribute to graft rejection in transplant patients. This study examined the association between SNPs present in genes of these processes and occurrence of graft rejection episodes in 246 kidney transplant patients, 35% of which were diagnosed with rejection. Genotype-gene expression associations were also assessed. Peripheral blood samples were used for genotyping of 24 SNPs on the following genes: CYP3A4, CYP3A5, CYP2E1, POR, UGT2B7, UGT1A9, ABCB1, ABCC2, ABCG2, SLCO1B1, TNF, IL2, IRF5, TGFB1, NFKBIA, IL10, IL23R, NFAT, and CCR5 by real-time PCR. The analysis of gene expression was performed by RT-qPCR. The association between graft rejection episodes and polymorphic variants was assessed using odds ratios. Polymorphisms rs7662029 (UGT2B7) and rs6714486 (UGT1A9) were associated with occurrence of graft rejection episodes, rs7662029 (UGT2B7) exhibited a protective effect (1.85-fold), and rs6714486 (UGT1A9) an increased 1.6-fold increased risk of graft rejection. Among drug transporter genes, only rs2231142 (ABCG2) demonstrated an association with a 1.92-fold decrease in the risk of graft rejection. The immunological SNP rs10889677 (IL23R) was associated with a 1.9-fold enhanced risk of graft rejection. Association between genotypes and gene expression was not detected. Therefore, SNPs of UGT2B7, UGT1A9, ABCG2, and IL23R genes may be useful as candidate markers for screening of risk graft rejection in renal transplant patients. These markers may improve medical decisions, avoiding adverse effects.

The Polymorphism -308G/A of Tumor Necrosis Factor-α Gene Modulates the Effect of Immunosuppressive Treatment in First Kidney Transplant Subjects Who Suffer an Acute Rejection

The -308G/A SNP of tumor necrosis factor-alpha (TNF-α) gene affects TNF-α production. As its impact on transplant outcome remains open to debate, we decided to genotype it in a cohort of transplant subjects. A retrospective analysis of 439 first kidney recipients randomly divided into two subgroups (discovery and validation cohorts) was performed to identify the best predictors of acute rejection (AR). The effect on transplant outcome was analyzed by an adjusted logistic regression model. Carriers of the A allele, associated with elevated TNF-α production, presented a higher risk of AR (OR = 2.78; 95% CI = 1.40-5.51). Logistic regression analyses for AR showed an interaction between the polymorphism and treatment with thymoglobulin (p-interaction = 0.03). In recipients who did not receive thymoglobulin, carriers of A allele had higher risk of AR (OR = 4.05; 95% CI = 1.76-9.28). Moreover, carriers of A allele not treated with thymoglobulin presented higher risk of AR than those who received thymoglobulin (OR = 13.74; 95% CI = 1.59-118.7). The AUC of the model in the discovery cohort was 0.70 and in the validation cohort was 0.69. Our findings indicate that the -308G/A TNF-α polymorphism is associated with AR risk and it modulates the effectiveness of thymoglobulin treatment. This pharmacogenetic effect lets us propose this SNP as a useful predictor biomarker to tailor immunosuppressive regimens.

Genetic Association Between IL-21 Polymorphisms and Cryptorchidism in a Chinese Han Population

AIMS

Increasing evidence suggests an association between interleukin gene polymorphisms and cryptorchidism. To investigate the relationship between IL-21 gene polymorphisms and cryptorchidism susceptibility, a comprehensive genetic association study in a Chinese Han population was conducted.

METHODS AND RESULTS

A total of 328 men were enrolled in a case-control study (116 cases and 212 healthy controls). Three SNPs (rs907715, rs2055979, and rs12508721) of the IL-21 gene were genotyped using the TaqMan(®) genotyping assay. For the rs2055979 C>A polymorphism, A allele carriers had significantly decreased cryptorchidism susceptibility (p = 0.021, odds ratios [OR] = 0.58, 95% confidence intervals [CI] = 0.37-0.93) in a dominant model (AA+CA vs. CC), a codominant model (AC vs. CC; p = 0.029, OR = 0.52, 95% CI = 0.31-0.85), and an overdominant model (AC vs. CC/AA; p = 0.0087, OR = 0.53, 95% CI = 0.33-0.86). However, no associations were identified for the rs907715 C>T and rs12508721 C>A polymorphisms. In the haplotype analyses, the C-C-T haplotype of rs907715-rs2055979-rs12508721 significantly increased the risk of cryptorchidism (p < 0.0001, OR = 5.251, 95% CI = 2.528-10.906).

CONCLUSIONS

The rs2055979 C>A polymorphism of the IL-21 gene is associated with cryptorchidism susceptibility, and the C allele increases the risk of cryptorchidism in a Chinese Han population.

Association between cytokine gene polymorphisms and tuberculosis in a Chinese population in Shanghai: a case-control study

BACKGROUND

Polymorphisms in cytokine genes are known to influence cytokine levels, which may influence susceptibility to tuberculosis (TB) infection and disease. Differences in cytokine expression probably determine whether TB progresses, resolves, or becomes latent. In particular, the balance between the Th1 and Th2 cytokine responses influences the expression of disease in individuals with pulmonary TB (PTB). We performed a case-control study of 120 patients diagnosed with PTB, 240 with latent TB infection (LTBI), and 480 healthy controls (HC), to explore the association between polymorphisms in cytokine genes and a predisposition to Mycobacterium tuberculosis infection and TB disease.

RESULTS

A single-gene analysis showed a dominant association between the AA genotype or A allele at nucleotide -874 of the interferon γ (IFN-γ) gene and LTBI. The A allele at nucleotide -1082 of the interleukin 10 (IL-10) gene was significantly more common in PTB patients than in LTBI subjects. Moreover, the polymorphisms at IFN-γ -874 and IL10 - 1082 were associated with protein levels of IFN-γ and IL-10, respectively, in the PTB group. The genotype frequencies of other polymorphisms did not differ between the PTB patients, LTBI and HC subjects. Furthermore, combinations of polymorphisms with IFN-γ -874 were associated with LTBI, whereas combinations with IL10 - 1082 were more likely associated with PTB.

CONCLUSIONS

There are positive associations between the IFN-γ -874 polymorphism and TB and between the IL10 - 1082 polymorphism and LTBI. Our data provide genetic evidence of the multiple disease hypothesis that many cytokine genes are involved in TB susceptibility.