Cytokine gene polymorphisms and risks of acute rejection and delayed graft function after kidney transplantation

BACKGROUND: Pretransplantation identification of patients at an increased risk for adverse events would allow more individualized treatment strategies possibly improving long-term outcome. We studied cytokine gene polymorphisms of kidney allograft recipients and their donors to identify factors predisposing for acute rejection (AR) and delayed graft function (DGF). METHODS: A total of 291 adult cadaver kidney recipients transplanted at a single transplantation centre between 1999 and 2002 were investigated. Recipients and donors were typed for TNF-alpha(-308G/A), TGF-beta1(codon 10T/C, codon 25C/G), IL-10(-1082G/A, -819C/T, -592C/A), IL-6(-174C/G), and IFN-gamma(+874T/A) polymorphisms using a SSP-PCR kit. An AR episode was defined based on clinical and histological findings (Banff criteria). RESULTS.: The incidence of AR was 17%. In univariate statistical analyses recipients with TNF-alpha -308AA-genotype were found to be at a significantly increased risk for rejection (odds ratio [OR] 5.0, 95% CI 3.0-8.3, P = 0.003). The association was independent from the patient-donor HLA-mismatch status. In addition, patients with IL-10 ACCACC, ATAATA, GCCATA (-1082A/G, -819C/T, -592C/A, respectively) haplotypes were predisposed to rejection (OR 1.9, 95% CI 1.1-3.1, P = 0.016). Further, the combination of recipient TGF-beta1 25GG-genotype and donor IL-10 -819T-allele was associated with rejection (OR 1.8, 95% CI 1.1-3.0, P = 0.027). These variables remained significant risk factors also in a multivariate logistic regression analysis. The incidence of DGF was 22%. The risk was increased by a donor TNF-alpha -308GA-genotype (OR 1.6, 95% CI 1.1-2.6, P = 0.040). CONCLUSIONS: Our results confirm that cytokine gene polymorphisms influence the outcome of kidney transplantation. Our data especially identify the TNF-alpha -308AA-genotype as a factor predisposing for AR episodes.     

Cytokine gene polymorphism in kidney transplantation--impact of TGF-beta 1, TNF-alpha and IL-6 on graft outcome

Chronic allograft nephropathy (CAN) is one of the main causes of graft loss in renal transplantation. Polymorphisms with functional significance in the promoter and coding regions of cytokine genes have been suggested as a possible factor for graft rejection. The aim of this study was to investigate the impact of cytokine gene polymorphism of pro and anti-inflammatory cytokines on development of CAN in a group of renal transplant patients and donors. Eight single nucleotide polymorphisms (SNPs) including TNFA (-308), TGFB1 (cdns10, 25), IL-10 (-1082, -819, -592), IL-6 (-174) and IFNG (+874) were analyzed in 56 patients with stable graft function (SGF), 10 with CAN and 28 kidney donors by PCR-SSP method. CAN was significantly associated with the recipient TGFB1 cod10 T/T and combination of cods10, 25 T/T G/G genotypes (high producer), (p<0.05). Influence of patient's TNFA genotype correlated with high level of gene expression on the development of CAN was further demonstrated when the patients were stratified according to the HLA mismatches (HLA-DRB MMs). Additionally donor TNFA-308 G/A (high) and IL-6-174 CC (low) genotypes were increased in cases with CAN. No statistically significant differences in distribution of IL-10, IL-6 and IFNG genotypes between recipients with SGF and CAN were found. In conclusion our data suggest that the high producer genotype of profibrogenetic TGF-beta1, pro-inflammatory TNF-alpha and genetically determined low production of immunoregulatory IL-6 cytokine might be risk factors for CAN development.     

The effect of cytokine gene polymorphisms on pediatric heart allograft outcome.

BACKGROUND: Cytokines play a major role in the inflammatory and immune responses that mediate allograft outcome. Several studies have shown that the production of cytokines varies among individuals and these variations are determined by genetic polymorphisms, most commonly within the regulatory region of the cytokine gene. The aim of this study was to assess the effect of these allelic variations on acute rejection after pediatric heart transplantation. METHODS: We performed cytokine genotyping using polymerase chain reaction-sequence specific primers in 93 pediatric heart transplant recipients and 29 heart donors for the following functional polymorphisms: tumor necrosis factor-alpha (TNF-alpha) (-308), interleukin (IL)-10 (-1082, -819, and -592), TGF-beta1 (codon 10 and 25), IL-6 (-174), and interferon-gamma (INF-gamma) (+874). The distribution of polymorphisms in this population did not differ from published controls. The patients were classified as either non-rejecters (0 or 1 episode) or rejecters (> 1 episode) based on the number of biopsy proven rejection episodes in the first year after transplantation. RESULTS: Forty-two of the 69 TNF-alpha patients (61%) in the low producer group were non-rejecters, while 9 of the 24 (37.5%) with high TNF-alpha were non-rejecters (p = 0.047). In contrast, IL-10 genotype showed the opposite finding. Forty-two of the 66 patients (64%) in the high and intermediate IL-10 group were non-rejecters, while 9 of the 26 (35%) in the low IL-10 group were non-rejecters (p = 0.011). The combination of low TNF-alpha with a high or intermediate IL-10 genotype was associated with the lowest risk of rejection (34/49 or 69% non-rejecters). Neither the distribution of the IL-6, INF-gamma, and TGF-beta1 genotype in recipients nor the donor genotype showed any association with acute rejection. CONCLUSION: Genetic polymorphisms that have been associated with low TNF-alpha and high IL-10 production are associated with a lower number of acute rejection episodes after pediatric heart transplantation.     

Genetic association of interleukin-4, interleukin-10, and transforming growth factor-beta gene polymorphism with allograft function in renal transplant patients

Despite advances in immunosuppressive therapy in the past decade, allograft rejection remains the primary cause for kidney graft failure. Cytokines are known to be important mediators in renal allograft outcome. The aim of the present study was to ascertain whether interleukin (IL)-4, IL-10, and transforming growth factor (TGF)-beta cytokine gene polymorphisms contributed to kidney graft outcome. We evaluated single nucleotide polymorphism in IL-4 (-1098G/T, -590C/T, -33C/T), IL-10 (-1082A/G, -819C/T, -592A/C), and TGF-beta (codon 10 and 25) in 100 renal transplant recipients and 139 normal healthy control using polymerase chain reactions based on sequence-specific primers. Recipients were clinically characterized as rejection episode (RE) versus stable graft function (SGF). The results showed the frequencies of IL-4 -33 T allele in the RE, SGF, and control group to be 7%, 73%, and 28%, respectively. IL-10 -592 A allele frequency was 39% in RE, 26% in SGF, and 28% in the control group. TGF-beta codon 10 T allele was 39% in RE, 35% in SGF, and 53% in control group. In conclusion, this study suggested that some cytokine gene alleles reflected SGF among kidney transplant recipients.     

Association of TNF‐α, TGF‐β1, IL‐10, IL‐6, and IFN‐γ gene polymorphism with acute rejection and infection in lung transplant recipients

Infection and rejection are common complications faced by lung transplant recipients (LTRs) and have become major impediments to long‐term survival. Cytokines may play an important role in the development of these complications. In this study, we explored the correlation between TNF‐α (?308 A/G), TGF‐β1 (+869 T/C, +915 G/C), IL‐10 (?592 C/A, ?819 T/C, ?1082 G/A), IL‐6 (?174 G/C), and IFN‐γ (+874 T/A) gene polymorphisms and the incidence of acute rejection and infection. Transplant outcomes were reviewed in a retrospective cohort of 113 LTRs from a single center between December 2004 and November 2012. Cytokine polymorphisms were measured using sequence‐specific primer‐based PCR. HLA typing was performed for the donors and recipients. We found that the LTRs with the IL‐10 ?819 CC and ?592 CC genotypes had a significantly decreased risk of infection (p = 0.017, OR = 0.177, 95% CI = 0.04–0.85). However, we found no significant association between cytokine polymorphisms and acute rejection. Furthermore, the data revealed that the occurrence of acute rejection was strongly associated with infection episodes (χ² = 8.5256, p < 0.01). These results suggest that LTRs possessing the IL‐10 ?819 CC and ?592 CC genotype may be protected from the occurrence of infection. Our results demonstrated that infection is an important cause of acute rejection for LTRs.     

Impact of cytokine gene polymorphism on cardiovascular risk in renal transplant recipients

Cardiovascular events are the leading causes of morbidity and mortality in renal transplant recipients (RTR). Given the role of inflammation in atherosclerosis, the contribution of functional polymorphisms of cytokines to cardiovascular diseases (CVD) was assessed in RTR in this study. Polymorphisms of tumour necrosis factor alpha (TNF-alpha) gene [-308 (G-->A), -238 (G-->A)], interleukin-10 (IL-10) gene [-1082(A-->G), -819 (T-->C), -592 (A-->C)], transforming growth factor beta 1 (TGF-beta1) gene [codon 10 (T-->C), codon 25 (G-->C)], carotis intima media thickness (CIMT), left ventricular mass index (LVMI), 24-h ambulatory blood pressure and serum lipoprotein homocysteine level, erythrocyte sedimentation rate, serum C-reactive protein (CRP) and serum fibrinogen level of RTR were determined. Seventy-two RTR (26 cadaveric allograft, 46 living-related allograft, 43 male, 29 female) were included in this study. LVMI were similar in TNF-alpha, IL-10 and TGF-beta1 genotypes. Right and left CIMT were higher in TT genotype (n = 16) than CT (n = 46) and CC (n = 10) genotypes of TGF-beta1 codon 10 (T-->C) gene polymorphism (RCIMT, 7.7 +/- 2.2 mm vs. 7.0 +/- 1.4 mm vs. 5.9 +/- 1.4 mm, P = 0.025; LCIMT, 8.5 +/- 2.5 mm vs. 7.0 +/- 1.3 mm vs. 6.1 +/- 1.2 mm, P = 0.002). Lipoprotein (a) level of TT genotype (35.5 +/- 22.5 mg/dl) was higher than CC (4.1 +/- 2.8 mg/dl) and CT (20.4 +/- 11.2 mg/dl) genotypes of TGF-beta1 codon 10 (T-->C) gene polymorphism (P = 0.037). High producers of cytokine IL-10 -1082 [GG (n = 22) vs. AA + AG (n = 50)] and low producers of TGF-beta codon 25 [GC + CC (n = 17) vs. GG (n = 55)] had lower IMT of carotid artery but the difference did not reach statistical significance (P > 0.05). The CIMT of renal transplant patients was similar in IL-10 (-819, -592) and TNF-alpha (-308, -238) genotypes. No difference was observed in 24-h ambulatory blood pressure levels, serum lipoproteins, plasma homocysteine level, erythrocyte sedimentation rate, serum CRP, serum fibrinogen level in IL-10, TNF-alpha and TGF-beta1 genotypes. Besides the well-known factors, TGF-beta1 gene polymorphisms might play a role in CVD in RTR even at early stages of asymptomatic atherosclerosis.     

Cytokine gene polymorphism and postreperfusion syndrome during orthotopic liver transplantation

The molecular basis underlying the clinical response to acute liver stress remains to be clarified. Postreperfusion syndrome (PRS) occurring after the meeting of grafted liver with the recipient blood is characterized by hemodynamic instability that develops immediately after reperfusion of an orthotopic liver transplantation (OLT). Cytokines have a role during PRS. The aim of this study was to evaluate the role of some cytokine gene polymorphisms on PRS in patients. MATERIALS AND METHODS: Forty-six patients who underwent OLT were divided into two groups: with versus without PRS. Cytokine genotyping using patient blood was determined by the PCR-SSP method. RESULTS: Liver transplant patients as a whole are usually characterized as low producers of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10, high producers of transforming growth factor (TGF)-beta1 and IL-6 and intermediate producers of interferon (IFN)-gamma. However no significant relationship was shown between the development of PRS and cytokine gene polymorphisms of TNF-alpha (-308 G/A), TGF-beta1 (C/T codon 10, C/G codon 25), IL-10 (-1082 G/A, -819 T/C, -592 A/C), IL-6 (-174 G/C), or IFN-gamma (+874 A/T). CONCLUSION: It seemed that our limited data did not substantiate a role of certain cytokine gene polymorphisms on PRS occurence during OLT. A larger study population may be required to examine this relationship.     

Cytokine gene polymorphisms in heart transplantation: association of low IL-10 production genotype with Quilty effect.

BACKGROUND: Cytokines are important modulators of post-transplant, allogeneic immune responses. In heart transplantation, endomyocardial biopsies allow monitoring of histologic and immunologic events that occur inside the graft; their correlation with risk factors condition graft outcome. Recent reports indicate that various cytokine gene allelic polymorphisms control the number of cytokines produced and may be associated with graft outcome. METHODS: We studied 71 heart transplant recipients between December 1985 and December 2000. We used sequence-specific primers (SSP) polymerase chain reaction to study interleukin-10 (IL-10) polymorphisms at -1082 (G/A), -819 (C/T), and -592 (C/A); tumor necrosis factor alpha (TNF-alpha) at -308 (G/A) and -238 (G/A); transforming growth factor beta (TGF-beta) variants at codon 10 (C/T) and codon 25 (G/C); and interferon-gamma (IFN-gamma) polymorphisms at +874 (T/A). We determined the association of allele, genotype, and haplotype frequencies with the presence of histologically proven rejection episodes (according to International Society for Heart and Lung Transplantation criteria) and the presence of Quilty lesions in endomyocardial biopsy specimens. RESULTS: We found no association between the polymorphisms studied and the frequency and severity of acute and chronic rejection episodes. However, the gene frequency of allele A at IL-10 -1082, associated with decreased IL-10 production, was increased in patients with Quilty lesions (p = 0.0027, odds ratio = 2.98). Similarly, we found more AA homozygous individuals, compared with AG heterozygous and GG homozygous individuals (p = 0.0017), among patients with Quilty effect. The ATA and ACC IL-10 haplotypes also were associated with Quilty effect (p = 0.0051). CONCLUSIONS: These results suggest that genetically controlled decreased IL-10 production predisposes to the development of Quilty lesions. The decreased negative regulatory effect of IL-10 on T cells and macrophages may result in enhanced graft infiltration.     

Cytokine polymorphisms do not influence acute rejection in renal transplantation under tacrolimus-based immunosuppression

INTRODUCTION: Acute rejection remains an important cause of graft loss after renal transplantation. It has been suggested that cytokine genotyping may play a predictive role in identifying individuals who are at higher risk of acute rejection with a view to individualizing their immunosuppression. The aim of this study was to investigate any possible associations between acute rejection and certain cytokine polymorphisms. METHODS: We genotyped 91 cadaveric renal transplant recipients on tacrolimus-based immunosuppression and 84 of their donors. The cytokine polymorphisms studied were the following: tumor necrosis factor (TNF)-alpha-1032 T/C, TNF-alpha-865 C/A, TNF-alpha-859 G/A, interleukin (IL)1-R1-970 C/T, IL-10 haplotype [-1082, -819, -592], and IL-6-174 C/G. RESULTS: We found no association between any polymorphism and the incidence of acute rejection. This was true for both the recipient and donor population. CONCLUSION: Cytokine polymorphisms did not influence acute rejection in our study. We conclude that in the modern era of immunosuppression cytokine genotyping is not a significant predictor of acute rejection in renal transplantation.     

供者细胞因子基因多态性对肾移植受者急性排斥反应发生的影响

目的 研究供者的细胞因子和细胞因子受体基因多态性对肾移植受者急性排斥反应发生的影响.方法 (1)将126例肾移植受者分成急性排斥组和无排斥组,比较可能影响发生急性排斥反应的因素在两组中的分布情况;比较两组受者中供者的13种细胞因子及受体22个位点的基因型及部分细胞因子表达型的分布情况.(2)根据HLA-DR配型分成0～1个HLA-DR位点错配、HLA-DR完全错配两种情况,分别比较阳性基因多态性在急性排斥组和无排斥组中的分布情况.结果 (1)急性排斥组的HLA-DR错配数明显高于无排斥组;无排斥组供者的白细胞介素(IL)-1α889 C/C、IL-1Ra raspI 11100 T/T、IL-4Rd+1902 A/A、转化生长因子(TGF)-β1密码子10 C/C、IL-10-1082A/A、IL-10低表达型的频率明显较高,IL-12～1 188 A/A、IL-2-330 G/G、IL-10 GCC/ATA频率明显较低;(2)HLA-DR 0～1个位点错配时,两组供者中IL-1Rα msp I 11100 T/T、IL-4Rα+1902 A/A、TGF-β1密码子10 C/C、IL-2-330 G/G、IL-10低表达型频率明显不同,而在HLA-DR完全错配时,只有IL-12-1188 A/A表达频率明显不同.结论 供者的IL-1α-889 C/C、IL-1Rα msp I 11100 T/T、IL-4Rα+1902 A/A、TGF-β1,密码子10 C/C、IL-10-1082 A/A和IL-10低表达型是不发生肾移植急性排斥反应的遗传学指标,而IL-12-1188 A/A、IL-2-330 G/G则是发生急性排斥反应的遗传学危险因素.HLA-DR错配状况可干扰供者细胞因子基因多态性对急性排斥反应发生的影响.     

Influence of interleukin-10 polymorphism on the development of coronary vasculopathy following cardiac transplantation

BACKGROUND: Interleukin-10 (IL-10), an important anti-inflammatory cytokine has been implicated in the pathogenesis of acute rejection and long term graft tolerance. Polymorphism in the IL-10 promoter at positions -1082, -819 and -592, correlates with IL-10 production. Haplotype inheritance of these alleles determines whether individuals are high, intermediate, or low producers of IL-10. We investigated the effect of this polymorphism on the development of cardiac transplant vasculopathy (CV). METHODS: CV was defined at routine surveillance coronary angiography as any abnormality in 1 or more epicardial vessels. Recipient and donor DNA was amplified by PCR using primers to the 3 allele sites. After identifying the phenotype by electrophoresis, freedom from CV was analysed by Kaplan-Meier and the log rank test. RESULTS: One hundred and forty eight recipients and 135 donors were studied. High, intermediate and low producers made up 26.4, 47.3 and 26.3% of recipients and 35.6, 48.2 and 16.2% of donors (P=0.42). No significant differences were noted between the phenotype groups. The recipient and donor genotypes, when considered in isolation, had no effect on the freedom from CV; recipients: P=0.85; donors: P=0.52. When the recipient and donor genotypes were combined for an individual patient the freedom from CV was again unaffected; high producing IL-10 allele in donor or recipient: P=0.76, low producing IL-10 allele in donor or recipient: P=0.51. Increasing donor age and acute rejection episodes and the presence of a high producing TGF-beta1 phenotype were independent risk factors for CV. CONCLUSIONS: Polymorphism of the IL-10 promoter region fails to predict the development of CV and cannot be used as a genetic risk marker. This may be due to the effects of immunosuppressive treatment.     

Study of the cytokine polymorphisms in correlation to rejection and graft survival in renal allograft donors and recipients from a homogenous Saudi population

ObjectivesAllograft outcome can be improved with the discovery of risk factors that influence adverse events and may allow individualization of patients' treatment. Rejection is the main hurdle to successful transplantation and the immune response is the key effecter to rejection development. Hence, the major objective of the present study was to assess the relationship between single nucleotide polymorphisms (SNPs) in 5 cytokine genes, HLA mismatch and graft outcome in a cohort of 100 Saudi kidney transplant recipients and 100 living related donors at a single transplant center.Materials & methodsGenotyping of the following positions: TNFA (? 308 G/A), TGFB1 (codon 10 T/C, codon 25 C/G), IL-10 (? 1082 G/A, ? 819 C/T, ? 592 C/A), IL-6 (? 174 C/G), and IFNG (+ 874 T/A) were performed.ResultsThe majority of the donors whose recipients presented with either cellular or antibody mediated graft rejection (90% and 100%) respectively were found to be significantly (p = 0.0351) associated with intermediate or high IL-10 producing haplotypes, compared to those with stable grafts (58.66%). Haplotypes linked with lower IL-10 production were not detected in the donors or their recipients with antibody mediated graft rejection compared to donors with stable graft (41.33%). The distribution of donor IL-10-1082 haplotypes (GG, GA, AA) showed a statistically significant association of IL-10-1082 GA genotype (p = 0.0351) with rejection, when grouped according to patients' rejection status. No other statistically significant deviations were observed in the donors' genotypes. Analyses of cytokine polymorphisms in the recipients revealed no significant association. Multivariate logistic regression analyses showed that only HLA-DRB1 mismatch significantly influenced graft loss (p = 0.0135).ConclusionThis study demonstrates that the donor IL-10 genotypes and HLA-DRB1 mismatch are key determinants in graft outcome after renal transplantation.     

Interleukin-6 and interferon-gamma gene polymorphisms in the development of bronchiolitis obliterans syndrome after lung transplantation

BACKGROUND: A number of genetic polymorphisms have been shown to regulate the production and secretion of tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1, interferon (IFN)-gamma, interleukin (IL)-6, and IL-10. Several of these genetic polymorphisms have been shown to be associated with either acute or chronic rejection of kidney, liver, and heart allografts and with development of allograft fibrosis after lung transplantation. The aim of this study was to assess the effect of these genetic polymorphisms on the development of bronchiolitis obliterans syndrome (BOS) after lung transplantation. METHODS: Genetic polymorphisms were detected by means of polymerase chain reaction in 93 lung allograft recipients for functional polymorphisms in the TNF-alpha (-308), TGF-beta1 (+869 and +915), IL-6 (-174), IFN-gamma (+874), and IL-10 (-1082, -819, and -592) genes. Then, a correlation between BOS development and the presence of these cytokine genotypes was determined using Kaplan-Meier actuarial analysis. RESULTS: A significant correlation was detected between the presence of high-expression polymorphisms of the IL-6 and IFN-gamma genes and BOS development after lung transplantation (P =0.045 and 0.039, respectively). Also, patients with high-expression polymorphisms in both genes developed BOS significantly earlier than patients with low-expression polymorphisms in one or both genes, suggesting a synergistic effect of the alleles during BOS pathogenesis (P =0.016). No correlation was detected between polymorphisms of the TNF-alpha, TGF-beta1, and IL-10 genes and development of BOS after lung transplantation. CONCLUSIONS: The presence of high-expression polymorphisms at position -174 of the IL-6 gene and position +874 of the IFN-gamma gene significantly increases the risk for BOS development after lung transplantation.     

Renal allograft immune response is influenced by patient and donor cytokine genotypes

This study investigated the impact of specific cytokine genotypes on the incidence of acute rejection episodes (ARE), chronic graft dysfunction (CGD), and anti-HLA donor-specific antibody (DS-Ab) production in 86 renal transplant recipients and 70 cadaveric donors. A PCR-SSP method was performed for the analysis of polymorphisms in TNF-alpha, IL-6, TGF-beta, IL-10, and IFN-gamma cytokines. DS-Ab monitoring of sera was performed using a FCXM analysis. Observed cytokine frequencies for patients and donors were not significantly different from the expected frequencies under Hardy-Weinberg equilibrium conditions. The evaluation in recipients revealed a higher frequency of DS-Ab-positive patients among the TNF-alpha high (50.0% vs 25.7%), and for the IL-10 cytokine a greater incidence of ARE-positive patients (35.8% vs 18.2%) with the high + intermediate, compared with the low genotype. The combined effect of these 2 genotypes predisposed to DS-Abs (71.4% vs 25.3%; P = 0.02; odds ratio [OR] = 7.37). As for the TGF-beta1 cytokine, we observed a higher number of CGD-positive patients among high compared with intermediate producers (14.3% vs 0%; P = .050). The analysis of donors revealed a significantly lower incidence of ARE-positive patients among recipients whose donors were carriers of the high IL-6 G/G-genotype compared with the G/C+C/C-genotypes (16.7% vs 41.2%; P = .03), suggesting a protective effect of the G/G genotype on ARE and a predisposing role of donor (-174)allele C. In addition, we noted an association between the IFN-gamma low A/A-genotype and a higher incidence of ARE (42.1% vs 0%; P = .002) and DS-Ab production (47.4% vs 12.5%; P = .02) compared with high producers.     

The interleukin-6 -174promoter polymorphism is associated with long-term kidney allograft survival

BACKGROUND: Th1-dependent effector mechanisms may be responsible for allograft rejection. Recently, interleukin-6 (IL-6) has been shown to antagonize CD4+ T cells to effector Th2 cells and, in the process, differentiate them into Th1 cells. METHODS: To assess the role of IL-6 in long-term allograft survival, 158 patients after first cadaveric kidney transplantation were analyzed for the biallelic -174G-->C promoter polymorphism of the IL-6 gene. RESULTS: Carriers of the -174C-allele (genotype GC/CC) had an inferior three-year graft survival (71/104 = 68.3%; P = 0.0059) with a 3.7-fold increased relative risk of graft loss compared to carriers of the -174GG-genotype (48/54 = 88.9%). The -174GC/CC-genotype retained its negative impact on graft survival when other established prognostic factors and further cytokine polymorphisms (-308TNF-alpha, TGF-beta1 codon 10 & 25, -592/-819/-1082IL-10 and +874IFN-gamma) were considered simultaneously. CONCLUSIONS: Since the clinical impact on transplant outcome seems as important as matching for histocompatibility antigens, genotyping of the IL-6 -174polymorphism may offer a new method for identifying patients at increased risk of allograft loss.     

A study of cytokine gene polymorphisms and protein secretion in renal transplantation

Although there is evidence that cytokine gene polymorphisms are associated with varying quantities of cytokine protein production, the exact role of these polymorphisms in allograft rejection remains unclear. In a previous study, we demonstrated a significant association between high IL-10 secretion in mixed lymphocyte culture (MLC), together with HLA mismatching for at least 4-6 antigens, with the occurrence of acute rejection following renal transplantation. We, therefore, wished to ascertain whether cytokine gene polymorphisms are associated with varying levels of protein secretion and/or allograft rejection in the same group of patients. Cytokine protein secretion in MLC for IL-4, IL-6, IL-10 and IFN-gamma was measured by ELISA in 49 patient-donor pairs. Protein secretion for the above cytokines was also measured in phytohaemagglutinin (PHA) stimulated cultures in 30 normal controls. In both patient and control groups, single nucleotide polymorphism analysis for IL-4 G(-590)T, IL-6 G(-174)C, IL-10 G(-1082)A, IL-10 C(-819)T, IL-10 C(-592)A, TNF-alpha G(-308)A and microsatellite analysis for IFNG (CA repeat) was performed. No correlation was found between cytokine gene polymorphisms and cytokine protein secretion in either mitogen stimulated cultures (control group) or MLC (patient group). In addition, no correlation was demonstrated between cytokine gene polymorphisms and renal allograft rejection.     

Frequencies at three polymorphic sites of interleukin-10 gene promoter in Brazilian renal recipients

We genotyped by PCR-RFLP 141 renal patients (77 men and 64 women with ages between 12 and 58, predominantly Caucasians) for allelic variants of three polymorphic sites of the interleukin-10 gene promoter, previously showed to be associated with different production of IL-10 cytokine: -1082 (G/A), -819 (C/T), and -592 (C/A). These polymorphisms may confer flexibility in the common immune responses and influence the outcome of allo-responses after transplantation. Our aim was to determine the frequencies of three functional polymorphic sites -1082, -819, and -592 of the interleukin-10 gene promoter in renal recipients of Curitiba, Paraná. Paraná State is located in southern Brazil, and its capital is Curitiba with approximately 1.5 million inhabitants. Genotypes were classified as follows: "low" IL-10 producer genotypes (ATA/ATA, ACC/ATA, ACC/ACC), "intermediate" genotypes (GCC/ACC, GCC/ATA), and "high" IL-10 producer genotype (GCC/GCC). In our population we observed linkage disequilibrium between alleles -819C and -592C and this haplotypic combination was more frequent (65%) than -819T and -592A. We found significantly reduced frequency of the genotype and haplotype responsible for high production of interleukin-10, maybe because we have a selected group (only renal patients) or maybe because Brazilian people are very heterogeneous (miscegenational), which may differ from other groups.     

Genetic polymorphisms impact the risk of acute rejection in pediatric heart transplantation: a multi-institutional study

OBJECTIVE: The objective of this study was to determine the association between the genetic polymorphisms of proinflammatory and regulatory cytokines and long-term rates of repeat and late acute rejection episodes in pediatric heart transplant (PHTx) recipients. METHODS: Three hundred twenty-three PHTx recipients: 205 White non-Hispanic, 43 Black non-Hispanic, and 75 Hispanic were analyzed for time to first repeat and late acute rejection episodes by race, age at transplantation, and gene polymorphism (interleukin [IL]-6, -174 G/C, IL-10, -1082 G/A, -819 C/T, 592 C/A; vascular endothelial growth factor (VEGF) -2578 C/A, -460 C/T, +405 C/G; tumor necrosis factor alpha (TNF-alpha)-308 G/A). RESULTS: Recipient black race and older age at transplant were risk factors for both repeat and late rejections, though black race was more significantly related to late rejection (P=0.006). Individually, TNF-alpha high, IL-6 high, VEGF high, and IL-10 low phenotypes did not impact the risk of repeat or late rejection. However, the combination VEGF high/IL-6 high and IL-10 low was associated with increased estimated risk of late rejection (P=0.0004) and only marginally with repeat rejection (P=0.051). In a multivariate analysis, adjusting for age and race, VEGF high/IL-6 high and IL-10 low still remained an independent risk factor for late acute rejection (RR=1.91, P<0.001). CONCLUSION: This is the largest multicenter study to document the impact of genetic polymorphism combinations on PHTx recipients' outcome. The high proinflammatory (VEGF high/IL-6 high) and lower regulatory (IL-10 low) cytokine gene polymorphism profile exhibited increased risk for late rejection, irrespective of age and race/ethnicity.     

Evidence for genetic susceptibility towards development of posttransplant lymphoproliferative disorder in solid organ recipients

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication after organ transplantation. The identification of risk factors for PTLD development is important for disease management. It has been shown that cytokine gene polymorphisms are associated with lymphoma and Epstein-Barr virus (EBV)-associated diseases in nonimmunosuppressed patients. In the present case-control study, we analyzed the impact of -1082 interleukin (IL)-10, -308 tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1 (codon 10, 25), and +874 interferon (IFN)-gamma gene single-nucleotide polymorphisms on the late onset EBV-associated PTLD. METHODS: Out of 1,765 solid organ recipients, 38 patients with late-onset EBV-associated PTLD and 408 matched solid organ recipients were selected and enrolled in the study. Single nucleotide polymorphisms (SNPs) for -1082IL-10, -308TNF-alpha, TGF-beta1 (codon 10, 25), and +874IFN-gamma genes were analyzed by a sequence specific primer polymerase chain reaction and were related to the PTLD development, and the disease course and outcome. RESULTS: The TGF-beta1 (codon 25) GG genotype was detected more frequently in controls than in PTLD patients (odds ratio=0.34, 95% confidence interval: 0.17-0.69, P=0.0022). The frequency of -1082 IL-10 GG genotype was also significantly higher in controls than in PTLD patients (odds ratio=0.5, 95% confidence interval: 0.25-1.0, P=0.044). There were no associations between -308TNF-alpha, TGF-beta1 codon 10, and +874IFN-gamma SNPs and PTLD. Disease course and outcome were not associated with any cytokine SNPs. CONCLUSIONS: Polymorphisms in two key anti-inflammatory cytokines, IL-10 and TGF-beta, are associated with susceptibility to EBV-associated PTLD, suggesting that a shift in pro-/anti-inflammatory response is involved in the pathogenesis of PTLD.