Cytokine gene polymorphism in liver allograft recipients

The association between cytokine gene polymorphisms and graft rejection in liver transplantation: a systematic review and meta-analysis

We investigated the contribution of polymorphisms in cytokine genes (TNFa-308, IL10-1082 and -592, TGFb1-c10 and c25, and IFNg+874) on the risk of graft rejection in liver transplantation. We performed a systematic review by identifying relevant studies and applied meta-analysis to pool gene effects. In total, 12 studies were eligible and included in the study. Data extraction and assessments for risk of bias were independently performed by two reviewers. Data for allele frequencies, allelic, and genotypic effects were pooled. Heterogeneity and publication bias were assessed. Pooled minor allele frequencies for TNFa-308, IL10-1082, TGFb1-c10, TGFb1-c25, IFNg+874, and IL10-592 were 0.140 (95% CI: 0.083, 0.198), 0.432 (95% CI: 0.392, 0.472), 0.387 (95% CI: 0.307, 0.467), 0.090 (95% CI: 0.056, 0.123), 0.460 (95% CI: 0.392, 0.528), and 0.224 (95% CI: 0.178, 0.269), respectively. OnlyTNFa-308 and IL10-1082 polymorphisms were significantly associated with graft rejection. Patients who carried minor homozygous genotypes for these two polymorphisms were at 3.5 and 1.69 times higher risk of graft rejections than patients who carried major homozygous genotypes. The estimated lambdas were 0.41 and 0.47, suggesting an additive mode of effect was most likely. However, we could not detect the associations of TGFb1at c10 and c25, INFg+874, and IL10-592 polymorphisms and graft rejection. In summary, our systematic review has demonstrated that TNFa-308 and IL10-1082 are potential risk factors of poor outcomes in liver transplantation. Future updated meta-analysis studies to confirm the power of these genotypes in association with allograft rejection are needed.

Interleukin-10-1082G/A polymorphism and acute liver graft rejection: A meta-analysis

AIM: To investigate the association between interleukin (IL)-10-1082 (G/A) promoter polymorphism and acute rejection (AR) in liver transplant (LT) recipients.

METHODS: Two investigators independently searched the Medline, Embase, China National Knowledge Infrastructure, and Chinese Biomedicine Databases. Summary odds ratios (ORs) and 95% CIs for IL-10-1082 G/A polymorphism and AR were calculated in a fixed- and a random-effects model as appropriate.

RESULTS: This meta-analysis included seven case-control studies, which comprised 652 cases of LT recipients in which 241 cases developed AR and 411 cases did not develop AR. Overall, the variant A allele was not associated with AR risk when compared with the wild-type G allele (OR = 0.94, 95% CI: 0.64-1.39). Moreover, similar results were observed when the AA genotype was compared with the AG/GG genotype (OR = 1.05, 95% CI: 0.55-2.02). When stratifying for ethnicity, no significant association was observed among either Caucasians or Asians. Because only one study was performed in Asian patients, the result of subgroup analysis by ethnicity would not be reliable for Asians. Limiting the analysis to the studies with controls in the Hardy-Weinberg equilibrium, the results were persistent and robust. No publication bias was found in the present study.

CONCLUSION: This meta-analysis suggests that IL-10-1082 G/A polymorphism may be not associated with AR risk in LT recipients among Caucasians.

Polymorphisms in cytokine genes and their association with acute rejection and recurrence of hepatitis B in Chinese liver transplant recipients

BACKGROUND

Acute rejection (AR) and hepatitis B virus (HBV) recurrence after liver transplantation (LT) are the two major complications leading to chronic graft dysfunction. Genomic polymorphisms in interleukin (IL)-10, tumor necrosis factor (TNF)alpha and transforming growth factor (TGF)beta1 genes have been found to affect the susceptibility to certain diseases. However, the relationship between cytokine gene polymorphisms and risk of AR as well as HBV recurrence after LT in Han Chinese has not been reported. The objective of the present study was to investigate the association of polymorphisms within these cytokine genes with the risk of AR as well as HBV recurrence.

METHODS

One hundred eighty six Chinese LT recipients in which 41 patients developed AR and 29 patients experienced HBV recurrence were enrolled; 151 age- and gender-matched healthy individuals were selected as controls. Single-nucleotide polymorphisms (SNPs) at loci of IL-10 -1082, -819, -592, and TNFalpha -308, -238, as well as TGFbeta1 -988, -800, -509, +869, and +915 were determined by using DNA sequencing and then confirmed by restriction fragment length polymorphism (PCR-RFLP). Analyses of linkage disequilibrium and haplotype frequency were performed using Haploview program.

RESULTS

The -819 and -592 polymorphisms in the IL-10 gene were in complete linkage (r(2) = 1). Another linkage was found at -509 and +869 in the TGFbeta1 gene (r(2) = 0.66). A significant difference was observed in the distribution of allelic frequencies at position -819 and -592 in the IL-10 gene between ARs and non-ARs (p = 0.036, OR = 1.134, 95% CI 0.999-1.287 and p = 0.036, OR = 1.134, 95% CI 0.999-1.287, respectively). After adjustment for a Bonferroni correction, there was no significant difference between the polymorphism and AR (p >0.05). Furthermore, the overall genotype distribution between HBV recurrence patients and non-HBV recurrence patients was also not significantly different (p >0.05).

CONCLUSIONS

Our study suggests that gene polymorphisms of IL10, TNFalpha, and TGFbeta1 do not have a major independent role in AR and HBV recurrence after LT and may not be risk factors of AR and HBV recurrence after LT in Chinese liver transplant recipients.

Antibodies against glutathione S-transferase T1 (GSTT1) in patients with GSTT1 null genotype as prognostic marker: long-term follow-up after liver transplantation

An objective to improve the evolution of transplants is to identify risk biomarkers of morbidity and loss of allograft. In liver transplant (LTX) recipients, an association has been demonstrated between the presence of mismatch for glutathione S-transferase T1 (GSTT1) and the development of de novo immune hepatitis (IH). In 419 LTX patients we analyzed, for a period of 1 to 14 years, the development of "atypical" autoantibodies directed against GSTT1 and their relationship with the mismatch for GSTT1 genotype and with the risk for developing de novo IH. A total of 6.9% LTX recipients had "atypical" autoantibodies and 24 showed mismatch (recipient/donor) for GSTT1 genotype. From this last group, up to 70% developed de novo IH and graft dysfunction after LTX (95% confidence interval: 17.4-37.5 months). In LTX recipients with a GSTT1 null genotype, the evaluation of "atypical" autoantibodies is useful for monitoring the development of de novo IH.

Cytokine gene polymorphism and early graft rejection in liver transplant recipients

Cytokines, which play important roles in allograft rejection, show variable production among individuals. These variations may be related to genetic polymorphisms within the regulatory regions of the cytokine genes. We investigated the association between the role tumor necrosis factor alpha (TNF-alpha), transforming growth factor-beta (TGF-beta), interferon gamma (IFN-gamma), interleukin (IL)-10 and IL-6 gene polymorphisms and early graft rejection among liver transplant recipients. Forty-three liver transplant recipients enrolled in this study were divided into 2 groups based on events in the first 2 months posttransplantations, namely, those experiencing at least 1 rejection episode (n = 26) or those without any episode (n = 17). The allele or genotype frequencies of cytokine gene polymorphisms showed no difference between liver recipients with or without nonrejection. In conclusion, there was no significant correlation between early graft rejection and cytokine gene polymorphism of TNF-alpha, TGF-beta, IL-10, IL-6, and IFN-gamma in liver transplant recipients.