Donor and recipient-transforming growth factor-beta 1 polymorphism and cardiac transplant-related coronary artery disease

The rs1800470 Polymorphism of the TGFB1 Gene Is Associated with Myocardial Fibrosis in Heart Transplant Recipients

The transforming growth factor β1 (TGFβ1), whose level may depend on the polymorphism of the TGFB1 gene, is involved in the formation of myocardial fibrosis. Myocardial fibrosis in a cardiac allograft may lead to a heart's structural and functional remodeling and subsequent dysfunction. The frequency of occurrence of alleles and genotypes of the TGFB1 gene polymorphic regions rs1800469, rs1800470, and rs1800471 in heart transplant recipients and their association with graft myocardial fibrosis were analyzed. Carriers of the CC genotype (p = 0.023, OR = 0.12, 95% CI: 0.017-1.0), and more often the G allele of rs1800471 (p = 0.023, OR = 7.76, 95% CI: 1.0-60.20), were found among heart transplant recipients less frequently than among healthy individuals. In patients with ischemic heart disease (IHD), the GG genotype was less common (p = 0.035, OR = 2.68, 95% CI: 1.061-6.793), while the A allele of rs1800469 was found more frequently (p = 0.035, OR = 0.37 95% CI: 0.148-0.942) than in patients with dilated cardiomyopathy (DCM). In heart transplant recipients with the AA genotype of rs1800470, myocardial fibrosis, verified by endomyocardial biopsy, was detected more often than in carriers of the G allele (OR = 10.4, 95% CI: 1.152-94.538, p = 0.013). The revealed differences suggest a relationship between TGFB1 gene polymorphism and graft myocardial fibrosis. Studies on a larger group of patients would make it possible to characterize the influence of genetic factors on the formation of myocardial fibrosis in heart transplant recipients.

Contribution of the polymorphism rs1800469 of transforming growth factor β in the development of myocardial infarction: meta-analysis of 5460 cases and 8413 controls (MOOSE-compliant article)

Studies investigating the association between transforming growth factor (TGF-β-509C/T, rs1800469) promoter polymorphism and myocardial infarction (MI) risk reported inconsistent results. The aim of our study was to assess the association between the 509C/T polymorphism of the TGF-β gene (rs1800469) and MI risk.A total of 5460 cases and 8413 controls in 7 case-control studies were incorporated in our current meta-analysis. The original studies were selected through searching the databases of the PubMed and EMBASE. The odds ratio (OR) and 95% confidence interval (95% CI) of TGF-β 509C/T (rs1800469) for MI risk were applied to estimate the strength of the association.Our results showed that T allele carriers had a 13% increased risk of MI, when compared with the C allele carriers (OR = 1.13, 95% CI: 1.00-1.27). In the subset analysis by the type of MI, significantly elevated risk of MI was associated with the homozygote TT and heterozygote C/T in no-AMI subjects, when compared with the CC homozygote carriers (OR = 1.12, 95% CI:1.02-1.23).Our meta-analysis shows that the polymorphism with homozygote TT and heterozygote C/T of TGF-β 509C/T (rs1800469) is significantly associated with the increased risk of MI.

Non-HLA Genetic Factors and Their Influence on Heart Transplant Outcomes: A Systematic Review

Supplemental digital content is available in the text.

Background

Improvement of immunosuppressive therapies and surgical techniques has increased the survival rate after heart transplantation. Nevertheless, a large number of patients still experience complications, such as allograft rejection, vasculopathy, kidney dysfunction, and diabetes in response to immunosuppressive therapy. Variants in HLA genes have been extensively studied for their role in clinical outcomes after transplantation, whereas the knowledge about non-HLA genetic variants in this setting is still limited. Non-HLA polymorphisms are involved in the metabolism of major immunosuppressive therapeutics and may play a role in clinical outcomes after cardiac transplantation. This systematic review summarizes the existing knowledge of associations between non-HLA genetic variation and heart transplant outcomes.

Methods

The current evidence available on genetic polymorphisms associated with outcomes after heart transplantation was identified by a systematic search in PubMed and Embase. Studies reporting on polymorphisms significantly associated with clinical outcomes after cardiac transplantation were included.

Results

A total of 56 studies were included, all were candidate gene studies. These studies identified 58 polymorphisms in 36 genes that were associated with outcomes after cardiac transplantation. Variants in TGFB1, CYP3A5, and ABCB1 are consistently replicated across multiple studies for various transplant outcomes.

Conclusions

The research currently available supports the hypothesis that non-HLA polymorphisms are associated with clinical outcomes after heart transplantation. However, many genetic variants were only identified in a single study, questioning their true effect on the clinical outcomes tested. Further research in larger cohorts with well-defined phenotypes is warranted.

Single nucleotide polymorphisms for genes encoding cytokines in the context of cardiac surgery. Part I: Heart transplantation

Cardiovascular diseases remain the leading cause of death in Poland and other countries of the European Union. Patients with end-stage heart failure constitute a patient subgroup for whom the treatment of choice is heart transplantation. Despite advances in immunosuppressive therapy, acute or chronic graft rejection occurs in 20-30% of cases in the first six months after transplantation. The significance of the immune response and inflammation in graft rejection implies the important role of cytokines. Molecular markers are sought to facilitate risk assessment and improve patient care. At present, genetic tests are not used for this purpose, but studies aiming to rectify that have been conducted for years, including studies on single nucleotide polymorphisms of cytokine genes. This paper presents the results of research on the single nucleotide polymorphisms (SNPs) of the IL-2, IL-4, IL-6, IL-10, TGF-β1, PDGF, VEGF, and TNF-α genes in conjunction with heart transplantation. The analyzed data do not allow for reliable application of these genetic tests in clinical practice, but suggest that it is a promising direction which may improve the options of treatment individualization in the future.

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.

Genetic polymorphisms located in TGFB1, AGTR1, and VEGFA genes are associated to chronic renal allograft dysfunction

BACKGROUND

Persistent inflammation and fibrosis have been related to active progression of renal deterioration and reduced survival of kidney transplant. The aim of this study was to determine the impact of single-nucleotide polymorphisms (SNPs) located in regions related to inflammatory and immune processes on the development of chronic renal allograft dysfunction (CRAD).

METHODS

A retrospective study was carried out on 276 patients who received kidney transplant (KT). SNPs were genotyped via the SNPlex platform. Statistical analysis was performed with SNPstat and regression logistic analyses were adjusted by age and gender of recipients and donors, cold ischemia time and the number of human leukocyte antigen (HLA) mismatches.

RESULTS

From 276 patients with KT, 118 were non-CRAD and 158 were CRAD. Three SNPs showed significant associations with CRAD development: rs1800471 in transforming growth factor beta 1 (TGFB1), rs5186 in angiotensin II receptor type 1 (AGTR1), and rs699947 in vascular endothelial growth factor A (VEGFA). GC genotype of rs1800471 was associated with increased odds of CRAD compared to GG genotype (OR=2.65 (95% confidence interval (CI)=1.09; 6.47), p=0.025), as well as AC and AA genotype of rs699947 assuming a dominant model (OR=1.80 (95% CI=1.02; 3.20), p=0.044). Besides, AC and CC genotypes of rs5186 were associated with reduced odds of CRAD assuming a dominant model (OR=0.56 (95% CI=0.33; 0.96), p=0.033).

CONCLUSION

Our findings suggest that three genes related to immunity and inflammation (rs1800471, rs5186 and rs699947) are associated to susceptibility or protection to CRAD, and might have diagnostic utility in predicting the likelihood of developing CRAD.

Transforming growth factor-beta polymorphisms and cardiac allograft rejection

BACKGROUND

Cytokine gene polymorphisms regulate cytokine expression. We analyzed transforming growth factor-beta (TGF-beta) allelic variation in codon 25 in susceptibility to acute rejection episodes in cardiac transplant recipients.

METHODS

Between June 1997 and December 2001, 123 de novo heart transplants were performed at UAB with analysis based on 109 patients. Clinical and laboratory data were recorded at intervals up to 1 year post-transplant. Recipient genotypes for TGF-beta (codon 25) were determined using polymerase chain reaction (PCR) sequence-specific primers. Correlations between TGF-beta genotypes and acute rejection were made using Kaplan-Meier plots and parametric hazard models.

RESULTS

Of the patients enrolled, 72% had at least one rejection and 46% had multiple rejections in the first year post-transplant. Among those > or =55 years of age at transplant, patients with the GG genotype had significantly fewer rejections as compared to those with the CC or GC genotype (1.25 vs 2.5, p < 0.01). There was no difference in risk of rejection between the genotype groups among patients <50 years of age at transplant (p = 0.43). Similar results were observed when we used time to cumulative Grade 2R or greater rejection as the outcome.

CONCLUSION

The GG TGF-beta genotype may protect against acute rejection in older recipients during the first year after transplant.

Genotypic variation and phenotypic characterization of granzyme B gene polymorphisms

BACKGROUND

Granzyme B has been associated with allograft rejection in solid organ transplantation. Single nucleotide polymorphisms (SNPs) in the granzyme B gene might impact its expression. The aims of this study were (1) to establish the frequency of two granzyme B SNPs (A-295G; Q-55R) in pediatric heart transplant (PHTx) recipients and (2) to determine their phenotypic expression in healthy individuals.

METHODS

Three hundred ninety-six PHTx patients (245 white non-Hispanic, 49 black non-Hispanic, 82 Hispanics, and 20 others) and 52 healthy controls were screened for Q-55R and A-295G. For the control samples, we assessed the frequency of granzyme B positive cells by ELISPOT assay after mitogen stimulation.

RESULTS

Among the PHTx recipients, 57% percent of the population carried the Q/Q genotype, whereas 6% were R/R homozygotes. Seven of 49 (14%) black non-Hispanics were R/R homozygotes, whereas 13 of 245 (5%) of white non-Hispanics and 5 of 82 (6%) Hispanics carried the R/R genotype (P=0.02). The A allele frequency of granzyme B A-295G (49.6%) was similar to that of the G allele (50.4%). However, 80% of Black non-Hispanics were A allele carriers compared with 68% of White non-Hispanics (P<0.0001). After mitogen stimulation, the frequency of granzyme B positive cells was higher in the Q/Q homozygotes compared with R/R carriers (P=0.006), whereas a similar frequency of granzyme B positive cells was noticed among the genotypes of A-295G SNP.

CONCLUSIONS

These data indicate that 55 Q/Q genotype is associated with increased in vitro expression of granzyme B.

Clinical impact of cytokine and growth factor genetic polymorphisms in thoracic organ transplantation

Demographic and clinical risk factors may only partially predict short- and long-term outcomes after thoracic transplantation. The interindividual variability seen in rejection profiles could be related to the recipient's or donor's genetic background. Rejection, either acute or chronic, elicits an alloimmune response that involves a complex network of cytokines, growth factors, adhesion molecules, and other molecules, which may modulate the immune response toward rejection or, conversely, mediate graft acceptance. Herein, the authors discuss the current evidence regarding the importance of genetic polymorphisms as independent predictors of allograft outcome. They believe that pretransplant genotype profiling of patients, in combination with other relevant clinical information, might be useful to predict the risk for posttransplant adverse events and also to facilitate the implementation of individualized immunosuppression.

Effect of cytokine and pharmacogenomic genetic polymorphisms in transplantation

Consolidating the information that we have on pharmacogenetics and on cytokine genetics to produce patient-oriented individualized drug regimens is an important challenge in transplantation medicine. Using a multi-variant approach based on genetic profile and other relevant clinical factors a score system may be developed to predict the severity of rejection, infection, or other complications associated with transplantation. The ultimate goal of these studies is to improve patient outcome through individualized drug regimens.

Symptomatic acute myocardial infarction in a patient bearer of heart transplantation following ischemic heart disease

In 2005 Syeda et al. reported that the major factor limiting the long term of cardiac transplantation is the development of accelerated arteriosclerosis that occurs in the coronary arteries of the cardiac allograft. Transplant arteriosclerosis is characterized by diffuse, uniform, concentric narrowing of the artery by a fibrous proliferation of sub-intima cells. This atherosclerosis was estimate to occur in approximately 50% of patients by 5 years after transplantation. Unfortunately, as a consequence of cardiac denervation, symptoms are often atypical or completely absent. When these are present, the symptoms are those typical of effort angina. Very uncommon is the acute coronary syndrome. We present a case of a patient, underwent to a cardiac transplant for ischemic cardiomyopathy that after 10 years from the transplantation, was affected by an anterior myocardial infarct. In our case the presence of a single noncircumferential atherosclerotic plaque makes to think that it is a consequence of a patient's systemic atherosclerotic disease better then the result of the heart transplant's typical atherosclerosis.

Impact of TGFβ1 Gene Polymorphisms on Acute and Chronic Rejection in Pediatric Heart Transplant Allografts

BACKGROUND

The aim of this study was to assess the influence of IL-10 and TGFbeta1 gene polymorphisms on the development of acute rejection and coronary disease in pediatric heart transplant recipients.

METHODS

Patients were classified as either Rejectors or Nonrejectors. Coronary artery disease (CAD) was diagnosed by angiography or on macroscopic examination. Genotyping PCR-SSP were performed for IL-10 and TGFbeta1 (codon 10 and 25) in 111 patients. Thirty-nine were Rejectors and 31 developed CAD.

RESULTS

The proportion of IL-10 low-producers was higher in Rejectors than in Nonrejectors (respectively 46% versus 22%, P=0.009). IL-10 gene polymorphism was not associated with CAD. TGFbeta1-codon10-25 high-producers were 92.3% in Rejectors and 75% in Nonrejectors (P=0.026), 93.5% in patients with CAD and 76.2% in patients free from CAD (P=0.037). TGFbeta1-codon25 high-production separately analyzed correlated with CAD (31/31 high-producers in CAD=100% versus 69/80 in noCAD patients=86.2%, P=0.03). TGFbeta1-codon10 gene polymorphisms were not associated with CAD.

CONCLUSION

IL-10 low-producers have an increased risk of acute rejection. High-expressors of TGFbeta1-codon10-25 have an increased risk of acute rejection and CAD, while TGFbeta1-codon25 high-production is associated with coronary disease. Genetic polymorphism may reveal patients at high-risk in whom therapies and monitoring should be adjusted.