Association of IL-6 promoter and IFN-γ gene polymorphisms with acute rejection of liver transplantation

Interleukin 6 and interleukin 17A serum levels and gene- polymorphisms in the development of early allograft rejection in living donor liver transplant recipients

The aim of this study is to evaluate the role of serum level of Interleukin 6(IL-6) and Interleukin 17 (IL-17) in liver transplantation outcome for living recipients, Analyze the relation between the gene polymorphism and the occurrence of rejection after liver transplantation and Study the relation between the gene polymorphism and the occurrence of different infectious complications. The study was conducted in March 2023 and included 60 healthy volunteers from the National Liver Institute (NLI) blood bank at Menoufia University and 120 live donation liver recipient patients at NLI. During one month of liver transplantation, the cytokine levels (IL-17, IL-6 proteins, IL-6 G-174C, and IL-17 A rs2275913 gene polymorphism) and CD4 levels for 60 patients of 120 live donation liver recipient patients whom early reject transplanted tissue and the same parameters were measured after 6 months follow up for non-reject group. The main finding of this study was that the post-transplant rejection group and the post-transplant non-rejection and control groups differed significantly in the genotype frequency (CC, CG, and GG) or alleles of IL-6 G-174C (p = 0.011). On the other hand IL-17A rs2275913 gene polymorphism and its alleles (p = 0.71) showed no statistically significant difference. We also observed that serum IL-17 levels, with 100% specificity and 100% sensitivity threshold, will be more sensitive and specific than serum IL-6 and CD4 count in differentiating post-transplant rejection from non-rejection patients. The results showed that there was no significant relationship between the genotypes and serum levels of interleukins and the type and degree of rejection. Proinflammatory cytokines might be useful indicators for distinguishing and early identifying unfavorable outcomes after transplantation, allowing for prompt and effective treatment intervention. To evaluate these findings, prospective clinical trials are required.

C-reactive protein-to-albumin ratio is a predictor of 1-year mortality following liver transplantation

BACKGROUND

Considering the importance of the inflammatory status of recipients on outcomes following liver transplantation (LT), we investigated the association between C-reactive protein-to-albumin ratio (CAR) and one-year mortality following LT and compared it with other parameters reflecting patients' underlying inflammatory status.

METHODS

A total of 3,614 consecutive adult LT recipients were retrospectively evaluated. Prognostic parameters were analyzed using area under the receiver operating characteristic curve (AUROC) analysis, and subsequent cutoffs were derived. For survival analysis, Cox proportional hazards and Kaplan-Meier analyses were performed.

RESULTS

The AUROC for CAR to predict one-year mortality after LT was 0.68 (0.65-0.72), which was the highest compared with other inflammatory parameters, with the best cutoff of 0.34. A CAR ≥ 0.34 was associated with a significantly higher one-year mortality rate (13.3% vs. 5.8 %, log-rank P < 0.001) and overall mortality rate (24.5% vs. 12.9%, log-rank P = 0.039). A CAR ≥ 0.34 was an independent predictor of one-year mortality (hazard ratio, 1.40 [1.03-1.90], P = 0.031) and overall mortality (hazard ratio 1.39 [1.13-1.71], P = 0.002) after multivariable adjustment.

CONCLUSIONS

Preoperative CAR (≥ 0.34) was independently associated with a higher risk of one-year and overall mortality after LT. This may suggest that CAR, a simple and readily available biomarker, maybe a practical index that may assist in the risk stratification of liver transplantation outcomes.

Prediction of Liver Transplant Rejection With a Biologically Relevant Gene Expression Signature

BACKGROUND

Noninvasive biomarkers distinguishing early immune activation before acute rejection (AR) could more objectively inform immunosuppression management in liver transplant recipients (LTRs). We previously reported a genomic profile distinguishing LTR with AR versus stable graft function. This current study includes key phenotypes with other causes of graft dysfunction and uses a novel random forest approach to augment the specificity of predicting and diagnosing AR.

METHODS

Gene expression results in LTRs with AR versus non-AR (combination of other causes of graft dysfunction and normal function) were analyzed from single and multicenter cohorts. A 70:30 approach (61 ARs; 162 non-ARs) was used for training and testing sets. Microarray data were normalized using a LT-specific vector.

RESULTS

Random forest modeling on the training set generated a 59-probe classifier distinguishing AR versus non-AR (area under the curve 0.83; accuracy 0.78, sensitivity 0.70, specificity 0.81, positive predictive value 0.54, negative predictive value [NPV] 0.89; F-score 0.61). Using a locked threshold, the classifier performed well on the testing set (accuracy 0.72, sensitivity 0.67, specificity 0.73, positive predictive value 0.48, NPV 0.86; F-score 0.56). Probability scores increased in samples preceding AR versus non-AR, when liver function tests were normal, and decreased following AR treatment (P < 0.001). Ingenuity pathway analysis of the genes revealed a high percentage related to immune responses and liver injury.

CONCLUSIONS

We have developed a blood-based biologically relevant biomarker that can be detected before AR-associated graft injury distinct from LTR never developing AR. Given its high NPV ("rule out AR"), the biomarker has the potential to inform precision-guided immunosuppression minimization in LTRs.

Donor-derived cell-free DNA levels predict graft injury in liver transplant recipients

Donor-derived cell-free DNA (dd-cfDNA) has been evaluated as a rejection marker in organ transplantation. This study sought to assess the utility of dd-cfDNA to diagnose graft injury in liver transplant recipients (LTR) and as a predictive biomarker prior to different causes of graft dysfunction. Plasma from single and multicenter LTR cohorts was analyzed for dd-cfDNA. Phenotypes of treated biopsy-proven acute rejection (AR, N = 57), normal function (TX, N = 94), and acute dysfunction no rejection (ADNR; N = 68) were divided into training and test sets. In the training set, dd-cfDNA was significantly different between AR versus TX (AUC 0.95, 5.3% cutoff) and AR versus ADNR (AUC 0.71, 20.4% cutoff). Using these cutoffs in the test set, the accuracy and NPV were 87% and 100% (AR vs. TX) and 66.7% and 87.8% (AR vs. ADNR). Blood samples collected serially from LTR demonstrated incremental elevations in dd-cfDNA prior to the onset of graft dysfunction (AR > ADNR), but not in TX. Dd-cfDNA also decreased following treatment of rejection. In conclusion, the serial elevation of dd-cfDNA identifies pre-clinical graft injury in the context of normal liver function tests and is greatest in rejection. This biomarker may help detect early signs of graft injury and rejection to inform LTR management strategies.

IL-6 Directed Therapy in Transplantation

Purpose of Review

IL-6 is a pleiotropic, pro-inflammatory cytokine that plays an integral role in the development of acute and chronic rejection after solid organ transplantation. This article reviews the experimental evidence and current clinical application of IL-6/IL-6 receptor (IL-6R) signaling inhibition for the prevention and treatment of allograft injury.

Recent Findings

There exists a robust body of evidence linking IL-6 to allograft injury mediated by acute inflammation, adaptive cellular/humoral responses, innate immunity, and fibrosis. IL-6 promotes the acute phase reaction, induces B cell maturation/antibody formation, directs cytotoxic T-cell differentiation, and inhibits regulatory T-cell development. Importantly, blockade of the IL-6/IL-6R signaling pathway has been shown to mitigate its harmful effects in experimental studies, particularly in models of kidney and heart transplant rejection. Currently, available agents for IL-6 signaling inhibition include monoclonal antibodies against IL-6 or IL-6R and janus kinase inhibitors. Recent clinical trials have investigated the use of tocilizumab, an anti-IL-6R mAb, for desensitization and treatment of antibody-mediated rejection (AMR) in kidney transplant recipients, with promising initial results. Further studies are underway investigating the use of alternative agents including clazakizumab, an anti-IL-6 mAb, and application of IL-6 signaling blockade to clinical cardiac transplantation.

Summary

IL-6/IL-6R signaling inhibition provides a novel therapeutic option for the prevention and treatment of allograft injury. To date, evidence from clinical trials supports the use of IL-6 blockade for desensitization and treatment of AMR in kidney transplant recipients. Ongoing and future clinical trials will further elucidate the role of IL-6 signaling inhibition in other types of solid organ transplantation.

Profiling the liver graft

PURPOSE OF REVIEW

Achieving operational tolerance remains a priority in liver transplantation. Although several biomarkers of tolerance and rejection have been identified, few have been reproducible and validated across centers, and therefore have yet to reach clinical practice. Here we summarize findings from prior seminal studies and review current developments in profiling the liver allograft.

RECENT FINDINGS

Substantial efforts and progress have been made in the recent years towards the discovery of reliable biomarkers that can predict and guide successful immunosuppression withdrawal. Recent studies have also investigated the transcriptomic signatures underlying not only acute rejection but also subclinical inflammation and chronic allograft injury.

SUMMARY

As new genomic and sequencing technologies continue to develop, clinical trials are underway to validate biomarkers of tolerance, as well as better understand the mechanisms of both acute and subclinical rejection, with the goal of maximizing allograft survival. Altogether, this will hopefully enable the implementation of immunosuppression withdrawal protocols into clinical practice and make operational tolerance reliably attainable in the near future.

Advances in Rejection Management: Prevention and Treatment

Extended survival of liver transplant recipients has brought rejection management to the forefront of liver transplant research. This article discusses T-cell-mediated rejection, antibody-mediated rejection, and chronic rejection. We focus on the prevention and then discuss treatment options. Future directions of rejection management include biomarkers of rejection, which may allow for monitoring of patients who are considered high risk for rejection and detection of rejection before there is any clinical evidence to improve graft and patient survival. With improved graft life and survival of liver transplant recipients, the new frontier of rejection management focuses on immunosuppression minimization, withdrawal, and personalization.

Discovery and validation of a novel blood-based molecular biomarker of rejection following liver transplantation

Noninvasive biomarker profiles of acute rejection (AR) could affect the management of liver transplant (LT) recipients. Peripheral blood was collected following LT for discovery (Northwestern University [NU]) and validation (National Institute of Allergy and Infectious Diseases Clinical Trials in Organ Transplantation [CTOT]-14 study). Blood gene profiling was paired with biopsies showing AR or ADNR (acute dysfunction no rejection) as well as stable graft function samples (Transplant eXcellent-TX). CTOT-14 subjects had serial collections prior to AR, ADNR, TX, and after AR treatment. NU cohort gene expression (46 AR, 45 TX) was analyzed using random forest models to generate a classifier training set (36 gene probe) distinguishing AR vs TX (area under the curve 0.92). The algorithm and threshold were locked and tested on the CTOT-14 validation cohort (14 AR, 50 TX), yielding an accuracy of 0.77, sensitivity 0.57, specificity 0.82, positive predictive value (PPV) 0.47, and negative predictive value (NPV) 0.87 for AR vs TX. The probability score line slopes were positive preceding AR, and negative preceding TX and non-AR (TX + ADNR) (P ≤ .001) and following AR treatment. In conclusion, we have developed a blood biomarker diagnostic for AR that can be detected prior to AR-associated graft injury as well a normal graft function (non-AR). Further studies are needed to evaluate its utility in precision-guided immunosuppression optimization following LT.

Neutrophil-to-lymphocyte ratio is a predictor of early graft dysfunction following living donor liver transplantation

BACKGROUND & AIMS

Early allograft dysfunction (EAD) is predictive of poor graft and patient survival following living donor liver transplantation (LDLT). Considering the impact of the inflammatory response on graft injury extent following LDLT, we investigated the association between neutrophil-to-lymphocyte ratio (NLR) and EAD, 1-year graft failure, and mortality following LDLT, and compared it to C-reactive protein (CRP), procalcitonin, platelet-to-lymphocyte ratio and the Glasgow prognostic score.

METHODS

A total of 1960 consecutive adult LDLT recipients (1531/429 as development/validation cohort) were retrospectively evaluated. Cut-offs were derived using the area under the receiver operating characteristic curve (AUROC), and multivariable regression and Cox proportional hazard analyses were performed.

RESULTS

The risk of EAD increased proportionally with increasing NLR, and the NLR AUROC was 0.73, similar to CRP and procalcitonin and higher than the rest. NLR ≥ 2.85 (best cut-off) showed a significantly higher EAD occurrence (20.5% vs 5.8%, P < 0.001), higher 1-year graft failure (8.2% vs 4.9%, log-rank P = 0.009) and higher 1-year mortality (7% vs 4.5%, log-rank P = 0.039). NLR ≥ 2.85 was an independent predictor of EAD (odds ratio, 1.89 [1.26-2.84], P = 0.002) after multivariable adjustment, whereas CRP and procalcitonin were not. Increasing NLR was independently associated with higher 1-year graft failure and mortality (both P < 0.001). Consistent results in the validation cohort strengthened the prognostic value of NLR.

CONCLUSIONS

Preoperative NLR ≥ 2.85 predicted higher risk of EAD, 1-year graft failure and 1-year mortality following LDLT, and NLR was superior to other parameters, suggesting that preoperative NLR may be a practical index for predicting graft function following LDLT.

Association between CXCL9/10 polymorphisms and acute rejection of liver allograft

While increased serum concentrations of CXCL9/10 are associated with acute cellular rejection (ACR) occurrence, the association between CXCL9/10 single nucleotide polymorphisms (SNPs) and ACR after liver transplantation (LT) remains unknown.In the present case-control study, polymorphisms of CXCL9 (rs10336) and CXCL10 (rs3921) were determined by polymerase chain reaction in 215 liver transplant recipients. ACR was defined as biopsy proven within 6 months after LT. As selected SNPs were in 3'-UTR region, their possible association with protein synthesis was assessed by measuring the plasma concentration of CXCL9/10 in a cohort of 40 new transplant patients using ELISA.There was no association between CXCL9/10 genotypes and overall incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier than patients with GG genotype (P = .003), with similar results for CXCL10 gene (CC vs GG; P = .005). There was no statistically significant difference in plasma concentrations of CXCL9/10 between the rejectors and the non-rejectors. Of note, patients with AA CXCL9 genotype had significantly higher CXCL9 plasma concentrations than patients with AG (P = .01) or GG genotype (P = .045).In conclusion, the SNPs of CXCL9 (rs10336) and CXCL10 (rs3921) are not associated with the incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier and the same genotype was associated with greater plasma concentrations suggesting the involvement of CXCL9 mediated processes in ACR development.

Serum interleukin-6 and tumor necrosis factor-α are associated with early graft regeneration after living donor liver transplantation

Background

Liver graft regeneration is orchestrated by specific and sequential stimuli, including hepatocyte growth factors, cytokines, and catecholamines. We evaluated the association between preoperative serum cytokines and early liver graft regeneration in human living donor liver transplantation (LDLT).

Patients and methods

We retrospectively reviewed the data of adult patients who underwent LDLT from January 2010 to December 2014. Serum cytokines, including interleukin (IL)-2, 6, 10, 12, 17, interferon (IFN)-γ and tumor necrosis factor (TNF)-α were measured in the recipients 1 day before surgery and on postoperative day (POD) 7. Liver graft volume was estimated using abdominal computed tomography images of the donors and recipients.

Results

In total, 226 patients were analyzed in this study. Median preoperative levels of serum cytokines were as follows: IL-2, 0.1 (0.1–1.6) pg/mL; IL-6, 7.3 (0.1–30.2) pg/mL; IL-10, 0.5 (0.1–11.0) pg/mL; IL-12, 0.1 (0.1–0.1) pg/mL; IL-17, 2.0 (0.1–16.4) pg/mL; IFN-γ, 3.2 (0.1–16.0) pg/mL; and TNF-α, 9.8 (5.4–17.9) pg/mL. Higher preoperative serum levels of IL-6, IL-10, and TNF-α, dichotomized at the median, were associated with increased relative liver volumes by POD 7. Multivariate analysis revealed that higher levels of serum IL-6 and TNF-α were independently associated with increased graft volume during the first 1 week after LDLT, based on the lower levels of those cytokines.

Conclusions

IL-6 and TNF-α were important mediators of the success of early graft regeneration in patients who underwent LDLT.

Donor interleukin 6 gene polymorphisms predict the recurrence of hepatocellular carcinoma after liver transplantation

BACKGROUND

Application of the Milan criteria is an effective strategy to select patients with hepatocellular carcinoma (HCC) for liver transplantation, but HCC recurrence is still a major concern. The aim of this study was to determine whether interleukin 6 (IL6) polymorphisms and clinical variables are potential predictors for HCC recurrence and prognosis after transplantation.

METHODS

A total of 110 consecutive patients with HCC undergoing liver transplantation were enrolled in the study. Six tag single nucleotide polymorphisms in IL6 were genotyped in both the donors and recipients. Demographic characteristics, HCC features, and IL6 polymorphisms were assessed against HCC recurrence.

RESULTS

Pretransplant hepatitis B virus DNA (P = 0.014), pretransplant serum alpha-fetoprotein (P = 0.035), number of nodules (P = 0.011), diameter of main nodule (P = 0.001), macrovascular invasion (P = 0.001), microvascular invasion (P = 0.001), HCC exceeding the Milan criteria (P < 0.001), and donor rs2069852 AA genotype (P = 0.010) were associated with HCC recurrence. Recurrence-free survival rate and overall survival rate were significantly lower (P = 0.011 and P = 0.026, respectively) in patients whose donor had the rs2069852 AA genotype than in those whose donor had the AG and GG genotypes. Independent risk factors for recurrence-free survival and overall survival were microvascular invasion (P = 0.003; P = 0.002), HCC exceeding the Milan criteria (P < 0.001; P = 0.001), and donor rs2069852 AA genotype (P = 0.002; P = 0.010).

CONCLUSIONS

Our data suggest that donor IL6 rs2069852 polymorphisms may be a potential genetic marker for HCC recurrence after liver transplantation in the Han Chinese population.

Association of the Interleukin-27 Gene Expression and Hepatitis B Virus Infection in Liver Transplanted Patients

OBJECTIVES

Hepatitis B viral infection is among the most common causes of cirrhosis and hepatocellular carcinoma and a frequent viral indication for liver transplant. Cytokine-mediated immunity plays a critical role in introducing and promoting hepatitis B virus outcomes and in graft microenvironment. Interleukin 27 is a heterodimeric cytokine and a member of interleukin-6/interleukin-12 family. Interleukin-27 shows a broad range of pro- and antiinflammatory properties and plays a determining role during immune responses in combating hepatitis B virus. Therefore, in this study, the possible association between expressions of interleukin-27 gene with hepatitis B virus infection was evaluated in liver transplant patients.

MATERIALS AND METHODS

In a cross-sectional study from liver transplant patients with the risk of hepatitis B virus infection who admitted to Namazi Hospital affiliated to Shiraz University of Medical Sciences, 50 patients were selected and subgrouped to 25 hepatitis B virus-infected and 25 noninfected ones between years 2011 and 2013. The 25 healthy controls also were enrolled in this study. The presence of hepatitis B virus infection was assessed using polymerase chain reaction and enzyme-linked immunosorbent assay protocols in liver transplant patients. In addition, the interleukin-27 gene expression level was analyzed using an in-house-SYBER Green real time polymerase chain reaction method. The rate of interleukin-27 gene expression level was statistically analyzed in studied patient groups and controls using the Livak (2-▵▵CT) method.

RESULTS

The expression level of interleukin-27 gene was increased 10.27- and 2.36-fold in hepatitis B virus-infected and uninfected liver transplanted patients compared with healthy controls.

CONCLUSION

Hepatitis B virus infection can lead to overexpression of interleukin-27 gene in liver transplant patients compared with uninfected ones and controls. However, further studies are needed to characterize the effective antihepatitis B virus effects of interleukin-27 in liver transplant patients.

The Impact of IFN-γ Gene Polymorphisms on Spontaneous Clearance of HCV Infection in Fars Province, Southern of Iran

BACKGROUND

Certain polymorphisms in cytokine genes such as IFN-γ may influence the outcome of hepatitis C virus (HCV) infection. Here the frequency of the genotype, allele, and haplotype of IFN-γ gene at some loci is investigated in HCV-infected patients.

METHODS

Totally 255 patients with chronic HCV infection and 44 spontaneously cleared individuals were included. The chronic or clearance states were confirmed using enzyme-linked immunosorbent assay (ELISA) and two different qualitative reverse transcriptase polymerase chain reaction (RT-PCR) techniques. IFN-γ gene polymorphisms were performed by PCR using sequence-specific primers and PCR-RLFP on extracted genomic DNA.

RESULTS

The frequency of GG genotype (P = 0.0001, OR: 5.69 and CI: 2.21-14.62) and allele (P = 0.0003, OR: 2.73 and CI: 1.54-4.83) of IFN-γ gene at +2109 locus was significantly higher in cases that spontaneously cleared the infection. Haplotype analysis showed the association of AG haplotype (P = 0.0046, OR = 6.14 and CI = 1.56-25) with spontaneous clearance of the infection.

CONCLUSION

Our finding indicated that individuals with GG genotype at +2109 loci of IFN-γ gene and also AG haplotype (A allele at +874 loci and G allele at +2109 loci) may clear HCV infection more frequently than those with AA and AG genotype at +2109 loci and AA, TA, and TG haplotype.

Association of cytokine/costimulatory molecule polymorphism and allograft rejection: a comparative review

One reason for genetic variations among human individuals is SNP which may confer diverse disease susceptibility or resistance in a population. Genetic variations in a key immunoregulatory agent can manifest various immunological responses, such as graft rejection. In fact, the outcome of organ transplantation can be impacted by several genetic causes including polymorphisms in genes encoding cytokines and costimulatory molecules in the donor or recipient. Thus, it can be helpful to contemplate the SNPs relating to these immunological determinants in order to achieve an improved transplantation therapy.

Association between transforming growth factor beta-1 +869T/C polymorphism and acute rejection of solid organ allograft: A meta-analysis and systematic review

BACKGROUND

Transforming growth factor beta-1(TGFB1) is involved in the acute rejection (AR) episodes of solid organ transplant recipients. However, results from published studies on the association between donor/recipient TGFB1 +869T/C polymorphism and AR risk are conflicting and inconclusive.

METHODS

PUBMED, EMBASE, CNKI and Wanfang Database were searched to identify eligible studies investigating the association between donor/recipient TGFB1 +869T/C polymorphism and AR risk. Statistical analysis was performed by using STATA 10.0.

RESULTS

A total of 29 studies were included. Overall, the donor TGFB1 +869T/C polymorphism was significantly associated with AR risk in heterozygote comparison (CT vs. TT: OR = 1.67, 95%CI, 1.17-2.39; P heterogeneity=0.285) and dominant model (CC vs.

TC/TT

OR = 1.47, 95%CI, 1.05-2.06; P heterogeneity=0.445). In addition, subgroup analysis revealed that CT variant (CT vs. TT: OR = 1.97, 95%CI, 1.20-3.25; P heterogeneity = 0.777) and CC/CT genotype (CC/CT vs. TT: OR = 1.72, 95%CI, 1.07, 2.78; P heterogeneity = 0.619) within donors contributed to higher risk of AR in recipients administrated with CsA or FK506, compared with those applied only CsA. On the other hand, no significant association between recipient TGFB1 +869T/C polymorphism and AR was detected in all genetic models.

CONCLUSIONS

This meta-analysis and systematic review suggested that donor TGFB1 +869T/C polymorphism was significantly associated with AR of solid organ transplant recipients, and especially among patients in CsA/FK 506 group compared with those in CsA group.

The Role of Interferon Gamma Gene Polymorphism (+874A/T, +2109A/G, and -183G/T) in Response to Treatment Among Hepatitis C Infected Patients in Fars Province, Southern Iran

BACKGROUND

Hepatitis C virus (HCV) infection as a worldwide health problem is associated with cirrhosis and hepatocellular carcinoma. With current treatment regimen, pegylated interferon (PEG-IFN) plus ribavirin, sustain virological response (SVR) is achieved in only 50% of infected individuals. In HCV infection, an inappropriate ratio of cytokines may affect the benefit of antiviral therapy. Given the polymorphisms in regulatory regions of cytokines genes may influence cytokines production.

OBJECTIVES

We aimed to investigate both the frequency of genotypes and alleles of interferon gamma (IFN-γ) gene at +874A/T, +2109A/G, and -183G/T loci in HCV-infected patients and their associations with response to therapy.

PATIENTS AND METHODS

A total of 158 patients were included and treated with PEG-IFN plus ribavirin. The presence of HCV infection in patients was confirmed by reverse transcription polymerase chain reaction, and genomic DNA was extracted from peripheral leukocytes using salting out method. IFN-γ gene polymorphisms were identified by polymerase chain reaction using sequence specific primers and restriction fragment length polymorphism analysis on genomic DNA.

RESULTS

Of 158 patients, 110 (69.5%) subjects achieved SVR and 48 (30.5%) subjects did not respond to therapy. The frequency of AA genotype (P = 0.001; OR: 11.2; CI: 2.26-63.21) and A allele (P = 0.01; OR: 3.23; CI: 1.23 8.56) of IFN-γ gene at +2109 locus were significantly different between the responder and non-responder subjects infected with genotype 1. Regardless of HCV genotype, the frequency of AG genotype was also higher in responder group than those who did not respond to therapy (P = 0.041; OR: 05.05; CI: 1.05-33.25)). In case of IFN-γ gene at +874 locus, there was no difference in genotypes and alleles frequencies between the responder and non-responder subjects infected with HCV genotypes 1 and 3. Haplotype analysis showed no association between haplotypes and response to therapy. All participants had G/T genotype at -183 locus.

CONCLUSIONS

Our findings indicate that heterogeneity at +2109 locus of IFN-γ gene but not at +874 locus could interfere with successful therapy in patients infected with HCV genotype 1.

Recipient IL-6-572C/G genotype is associated with reduced incidence of acute rejection following liver transplantation

OBJECTIVE

Acute rejection resulting from alloimmune responses is a major risk factor affecting patient survival following liver transplantation. Since interleukin (IL)-6 can mediate acute rejection, the association between IL-6 gene single nucleotide polymorphisms (SNPs) and incidence of acute rejection in liver transplant recipients was investigated.

METHODS

Patients who received liver transplant between January 2005 and December 2010 were typed for IL6-572C/G (rs1800796) polymorphisms using the snapshot technique. Association between genotype and acute rejection was analysed using the SNP Statistics website: http://bioinfo.iconcologia.net/snpstats/start.htm. Allelic and genotypic distributions for rs1800796 were compared among 335 patients with or without acute rejection within the first 6 months following liver transplant.

RESULTS

Incidence of acute rejection was 11.94%. A heterozygous CG genotype for IL6-572C/G was associated with a lower acute rejection rate compared with homozygous CC or GG genotypes.

CONCLUSION

IL6-572 CG genotype may be related to protection from acute rejection following liver transplant in Han Chinese patients.

Gene silencing of 4-1BB by RNA interference inhibits acute rejection in rats with liver transplantation

The 4-1BB signal pathway plays a key role in organ transplantation tolerance. In this study, we have investigated the effect of gene silencing of 4-1BB by RNA interference (RNAi) on the acute rejection in rats with liver transplantation. The recombination vector of lentivirus that contains shRNA targeting the 4-1BB gene (LV-sh4-1BB) was constructed. The liver transplantation was performed using the two-cuff technique. Brown-Norway (BN) recipient rats were infected by the recombinant LVs. The results showed that gene silencing of 4-1BB by RNAi downregulated the 4-1BB gene expression of the splenic lymphocytes in vitro, and the splenic lymphocytes isolated from the rats with liver transplantation. LV-sh4-1BB decreased the plasma levels of liver injury markers including AST, ALT, and BIL and also decreased the level of plasma IL-2 and IFN-γ in recipient rats with liver transplantation. Lentivirus-mediated delivery of shRNA targeting 4-1BB gene prolonged the survival time of recipient and alleviated the injury of liver morphology in recipient rats with liver transplantation. In conclusion, our results demonstrate that gene silencing of 4-1BB by RNA interference inhibits the acute rejection in rats with liver transplantation.

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.

Recipient interleukin-28B Rs12979860 C/T polymorphism and acute cellular rejection after liver transplantation: role of the calcineurin inhibitor used

BACKGROUND

Interleukin-28 (IL-28B) rs12979860 C/T polymorphism is known to predict the outcome of antiviral therapy in hepatitis C. In addition to its interferon-like and antiviral functions, IL-28B possesses the ability to modulate CD8 T cells function. This study aimed to investigate whether recipient IL-28B polymorphism may have a role in predicting the occurrence of acute cellular rejection (ACR) after liver transplantation (LT).

METHODS

Two hundred fifty-one consecutive LT recipients were enrolled. All the patients underwent per protocol liver biopsies at 1, 3, and 12 months after LT. ACR episodes in the first post-LT year were recorded and graded according to the Banff score.

RESULTS

At least one moderate to severe (Banff score ≥ 5) ACR episode was reported in 75 patients (29.9%). ACR was associated with IL-28B polymorphism: C/C=21/102 (20.6%), C/T=43/126 (34.1%), and T/T=11/23 (47.8%) (P=0.003). At logistic regression analysis, IL-28B polymorphism was found to be a predictor of ACR (P=0.012) together with cytomegalovirus reactivation (P=0.023). The association between IL-28B polymorphism and ACR occurrence was evident in tacrolimus but not in cyclosporine-treated patients. ACR episodes occurred more frequently from hepatitis C virus (HCV) negatives carrying the IL-28B C/C genotype (17.8%) to HCV negatives carrying at least one T allele or HCV positives carrying at least one C allele (33.3%) to HCV positives carrying the T/T genotype (50.0%, P=0.002).

CONCLUSIONS

HCV etiology in association with the carriage of IL-28B T/T genotype predicted the highest frequency of ACR. Recipient's IL-28B genotyping could be a useful tool in individualizing immunosuppressive therapy according to the risk of ACR occurrence.

Interleukin-6 up-regulates the expression of interleukin-15 is associated with MAPKs and PI3-K signaling pathways in the human keratinocyte cell line, HaCaT

Interleukin (IL)-15 is an important inflammatory cytokine and plays a key role in autoimmune disease. At present, IL-15 gene expression and regulation related to many innate immunity trigger signals have been clarified in some specific cell types, but the relationship of IL-6 and IL-15 in the human keratinocyte cell line (HaCaT) is unknown. In this study, we investigated the effect of IL-6 on the expression of IL-15 and selected signaling pathways in HaCaT cells. Results demonstrated that IL-6 up-regulated the expression of IL-15 both at the mRNA and protein levels. Meanwhile, IL-6 was able to activate MAPKs-ERK1/2 and PI3K-AKT signaling pathways. Furthermore, the high expression of IL-15 induced by IL-6 was down-regulated while MAPKs-ERK1/2 and PI3K-AKT signaling pathways were, respectively, blocked by PD98059 and LY294002. These findings indicate that the expression of IL-15 up-regulated by IL-6 is associated with MAPKs-ERK1/2 and PI3K-AKT signaling pathways in HaCaT cells.

Cytokine gene polymorphism and asthma susceptibility, progress and control level

Asthma is a multifactor inflammatory disorder, and its management requires understanding of its various pathogenesis and control mechanisms. Cytokines and other inflammatory mediators are important factors in asthma pathophysiology. In this study, we evaluated the role of cytokine polymorphisms in the asthma susceptibility, progress, control, and lung functions. IL-4-C590T polymorphism by PCR-RFLP method, IFN-γ T+874A, TNF-α-A308G, IL-6 G-174C and TGF-β T+869C variants by ARMS-PCR method and IgE serum level by ELISA technique were determined in 81 asthmatic patients and 124 normal subjects. Asthma diagnosis, treatment and control levels were considered using standard schemes and criteria. TNF-α-308GA genotype was more frequent in asthmatics (P = 0.025, OR 3.352), and polymorphisms between different asthma control levels (P > 0.05) were not different. IFN-γ+874AT genotype had a positive correlation with the familial history of asthma (P = 0.034, OR 2.688). IL-6-174C allele (P = 0.045), TNF-α-308GG genotype (P = 0.002) and TNF-α-308G allele (P = 0.004) showed reduced values, and TNF-α-308GA genotype (P = 0.002) increased FEF25-75 value in asthmatics. IFN-γ+874AA genotype caused a decrease in FVC factor (P = 0.045). This study showed that TNF-α-308GA is a risk factor for asthma, but cytokine gene variants do not affect asthma control and IgE serum levels. Variants producing lower levels of IL-6, TNF-α and IFN-γ are associated with reduced pulmonary capacities. To achieve an appropriate schema for asthma management, further studies with consideration of different aspects in a larger group of patients would be more elucidative.

A study of the impact of cytokine gene polymorphism in acute rejection of renal transplant recipients

Acute rejection is a common phenomenon in transplantation. Inflammatory and anti-inflammatory mediators affect the graft microenvironment. Th1 responses cause acute rejection while Th2 immune responses help the survival of the graft. In this study, we evaluated gene polymorphisms of IL-6 G-174C, TGF-β T+869C, IL-4 C-590T, and IFN-γ T+874A cytokines in renal transplant patients. ARMS-PCR method was used to characterize IL-6 G-174C (rs76144090), TGF-β T+869C (rs1800471), and IFN-γ T+874A (rs2430561) polymorphisms and PCR-RFLP, for characterization of IL-4 C-590T (rs2243250) in 100 renal transplant patients. Acute rejection episodes were diagnosed according to the standard criteria. Analysis of the results showed that IL-6-174 GG genotype (P=0.018, OR=3.023, 95% CI=1.183-7.726) and IL-6-174G allele (P=0.046, OR=2.114, 95% CI=1.005-4.447) were more frequent, but IL-6-174GC genotype was less frequent in acute rejection of kidney transplantation in comparison with control group (P=0.024, OR=0.302, 95% CI=0.103-0.883). IFN-γ+874 T allele was associated with a higher risk of acute rejection (P=0.019, OR=2.088, 95% CI=1.124-3.880) while IFN-γ+874 AA genotype was associated with a lower risk of rejection (P=0.023, OR=0.318, 95% CI=0.115-0.875). Frequencies of TGF-β T+869C and IL-4 C-590T were not significantly different (P>0.05). Consequently, our results show that IL-6 G-174C and IFN-γ T+874A gene polymorphisms have predictive values for acute rejection after renal transplantation in Iranian patients.