Cytokine gene polymorphisms and the inflammatory response to abdominal aortic aneurysm repair

BACKGROUND: Cytokines are key mediators of the inflammatory response to surgery and polymorphic sites in their genes have been shown to affect cytokine production in vitro. The aim of this study was to determine whether cytokine gene polymorphisms affect cytokine production in vivo in patients undergoing abdominal aortic aneurysm (AAA) repair. METHODS: One hundred patients admitted for elective AAA repair had plasma levels of interleukin (IL) 1beta, IL-6, IL-10 and tumour necrosis factor (TNF) alpha measured at induction of anaesthesia and 24 h after operation. Genotypes for each patient were determined using induced heteroduplex genotyping for the following loci: IL-1beta + 3953, IL-6 - 174, IL-10 - 1082/-592 and TNF-alpha - 308. RESULTS: Patients with an IL-10 - 1082 A allele had a significantly higher IL-10 response to surgery than those without an A allele (P = 0.030) and there was also a significant difference in IL-10 response between patients with IL-10 - 1082 AA genotypes and those with GG genotypes (P = 0.030). CONCLUSION: Elective AAA repair results in a measurable cytokine response. In this study the magnitude of this response was not affected by the individual patient's cytokine gene polymorphisms.     

The role of cytokine gene polymorphisms in the pathogenesis of abdominal aortic aneurysms: a case-control study

BACKGROUND: Cytokines are the primary mediators of inflammation and also influence matrix metalloproteinase expression, both of which are important in development of abdominal aortic aneurysm (AAA). A significant, but as yet unknown, familial factor contributes to the pathogenesis of AAA. Many cytokine genes contain polymorphic sites, some of which affect cytokine production in vitro. Cytokine gene polymorphisms may therefore influence the pathogenesis of AAA. The purpose of this study was to determine whether there is any association between cytokine gene polymorphisms and AAA. METHODS AND RESULTS: This case-control study comprised 100 patients with AAA and 100 age-matched and sex-matched control subjects. For each case and control subject in the study, genotypes at the following cytokine gene polymorphic loci were determined: interleukin (IL)-1beta +3953, IL-6 -174, IL-10 -1082, IL-10 -592, and tumor necrosis factors-alpha -308. Allele and genotype frequencies were compared between AAA and control groups, and odds ratios (OR) were calculated for the presence of AAA with each allele at each locus examined as risk factors. The IL-10 -1082 A allele was significantly more common in the AAA group than the control group (P =.03). The OR for the IL-10 -1082 A allele as a risk factor for AAA was 1.8 (95% confidence interval, 0.9-3.6). DISCUSSION: These associations suggest a significant role for IL-10 in the pathogenesis of AAA. This association of AAA with the IL-10 -1082 A allele is also biologically plausible; the IL-10 -1082 A allele is associated with low IL-10 secretion, and it may be that AAA develops in patients who are unable to mount the same anti-inflammatory response as those who do not have AAA.     

Nonimmunologic complications and gene polymorphisms of immunoregulatory cytokines in long-term renal transplants

BACKGROUND: While the influence of cytokine gene polymorphisms on immunologic complications after organ transplantation is widely evaluated, little is known about predictive value of cytokine genotype for the development of nonimmunologic post-transplant complications: hypertension, dyslipoproteinemia, diabetes mellitus, hyperuricemia. METHODS: The -1082IL-10, -308TNF-alpha, transforming growth factor-beta1 (TGF-beta1) (codon 10, 25), -174IL-6, +874IFN-gamma gene single nucleotide polymorphisms (SNP) were studied in 278 long-term renal transplants by polymerase chain reaction-sequence specific primer (PCR-SSP) with respect to nonimmunologic post-transplant complications. RESULTS: Significant association of the TGF-beta (codon 25) GG genotype with hyperuricemia (P= 0.0013) and dyslipoproteinemia (P= 0.0171) was found. The TGF-beta1 (codon 25) CG genotype was detected more frequently in patients with normal uric acid levels. The +874IFN-gamma AA genotype was associated with type 2/steroid-induced diabetes (P= 0.0127). Frequency of the -1082IL-10 AG genotype was significantly higher in hyperuricemic patients versus controls (P= 0.0022). No associations of polymorphisms in the tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), TGF-beta codon 10 genes with hyperuricemia, dyslipoproteinemia, or diabetes were detected. We failed to observe significant differences in cytokine genotype distribution between hypertensive and normotensive patients. CONCLUSION: We established an association of particular cytokine genotypes with nonimmunologic post-transplant complications. This supports an idea that assessment of cytokine SNPs may allow more accurate prediction of nonimmunologic complications and appropriate adjustment of pre-emptive treatments in long-term transplant patients.     

Cytokine-related genotypic differences in peak interleukin-6 blood levels of patients with SIRS and septic complications

BACKGROUND: The aim of the present study was to investigate whether tumor necrosis factor (TNF), interleukin (IL)-1, and IL-6-related genotypic differences affect IL-6 blood levels in patients with systemic inflammatory response syndrome (SIRS) in an intensive care unit (ICU). METHODS: Seven polymorphisms of TNF, IL-1, and IL-6-related polymorphisms were studied with an allele-specific polymerase chain reaction. One hundred and thirteen patients diagnosed with SIRS whose sequential organ failure assessment scores were > or =5 at the time when their daily measured IL-6 blood level peaked during the ICU stay (IL-6 max) were examined. IL-6 max, survival, and septic complications were compared between carriers and non-carriers of less frequent alleles, indicated as allele*2, in each polymorphism. RESULTS: In single nucleotide polymorphism (SNP) at position -238 site of TNF-alpha (TNF-alpha-238*G/A), IL-6-596*G/A, and IL-6-174*C/T, allele*2 frequencies were much lower in the Japanese than in the Caucasian population. IL-6 max was significantly higher in allele*2 carriers of IL-1beta-511*C/T. Associations were found between susceptibility to septic shock and allele*2 carriage for both IL-1beta-511*C/T and TNF-alpha-308*G/A, and also between poor prognosis and allele*2 carriage in both IL-1 receptor antagonist second intron various number of tandem repeats polymorphism (IL-1raRN*1-5) and TNF-alpha-308*G/A. IL-1beta-511*C/T and IL-1raRN*1-5 were in linkage disequilibrium in this study population. CONCLUSIONS: Carriers of less frequent alleles in IL-1-related polymorphisms appear to have significant vulnerability to production of excessive IL-6 blood levels and to deterioration in septic shock.     

Promoter polymorphisms of the TNF-alpha (G-308A) and IL-6 (C-174G) genes predict the conversion from impaired glucose tolerance to type 2 diabetes: the Finnish Diabetes Prevention Study

High levels of cytokines are risk factors for type 2 diabetes. Therefore, we investigated whether the promoter polymorphisms of the tumor necrosis factor-alpha (TNF-alpha; G-308A) and interleukin 6 (IL-6; C-174G) genes predict the conversion from impaired glucose tolerance (IGT) to type 2 diabetes in the Finnish Diabetes Prevention Study. Altogether, 490 overweight subjects with IGT whose DNA was available were randomly divided into one of the two treatment assignments: the control group and the intensive, individualized diet and exercise intervention group. The -308A allele of the TNF-alpha gene was associated with an approximate twofold higher risk for type 2 diabetes compared with the G-308G genotype (odds ratio 1.80, 95% CI 1.05-3.09; P = 0.034). Subjects with both the A allele of the TNF-alpha gene and the C-174C genotype of the IL-6 gene had a 2.2-fold (CI 1.02-4.85, P = 0.045) higher risk of developing type 2 diabetes than subjects without the risk genotypes. We conclude that the -308A allele of the promoter polymorphism (G-308A) of the TNF-alpha gene is a predictor for the conversion from IGT to type 2 diabetes. Furthermore, this polymorphism seems to have a gene-gene interaction with the C-174C genotype of the IL-6 gene.     

Genetic polymorphisms and the risk of infection following esophagectomy. positive association with TNF-alpha gene -308 genotype

OBJECTIVE: To examine the association of single nucleotide polymorphisms (SNPs) in inflammation-related genes in the development of infections following esophagectomy. SUMMARY BACKGROUND DATA: Genetic polymorphisms for immunoregulatory cytokines may explain individual variation in response to trauma. Esophagectomy is associated with a high risk of postoperative infection and sepsis, and this study explored a number of SNPs in cytokine genes and their relationship to postoperative infection. METHODS:: In a prospective analysis of 197 patients with esophageal cancer undergoing resection, 55 developed postoperative infections. DNA was extracted and genotyping was performed for polymorphisms in genes encoding TNF-alpha, IL-1beta, IL-1 receptor antagonist, IL-10, and Toll-like receptor 4 (TLR-4) using Taqman chemistry and PCR/RFLP. In a blinded analysis, the cohort with infections was compared with the no complication cohort (n = 114) and a cohort that had noninfective complications (n = 28). RESULTS: No differences in polymorphisms for IL-1beta, IL-1 RN, IL-10, and TLR-4 genes were observed across groups. The frequency of TNF-alpha -308 GG homozygotes was significantly (P = 0.021) higher in the postoperative infection group. The G allele was significantly higher in the postoperative infection group compared with the no complication group (P = 0.017) and other complication group (P = 0.013). By multivariate analysis, this polymorphism as well as age and body mass index were predictors of infection. CONCLUSION: The TNF-alpha -308A allele has been shown to be associated with higher circulating levels of TNF-alpha and the -308 G allele is a comparative low secretor allele. We propose that the polymorphism in the promotor region of TNF-alpha gene may lead to altered expression and a possible suboptimal activity of TNF-alpha in persons with GG genotypes, and these data suggest a link with infection following major surgery.     

Cytokine gene polymorphisms in hemodialysis patients: association with comorbidity, functionality, and serum albumin

BACKGROUND: Cytokine-orchestrated chronic inflammation plays a major role in long-term morbidity and mortality in patients with end-stage renal disease (ESRD) on hemodialysis (HD). In this cross-sectional study, we evaluated the association between specific alleles/genotypes and combinations of genotypes of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and IL-10 with indices of comorbidity, functional status, and other biological markers in a cohort of 183 ESRD patients recruited to the Hemodialysis (HEMO) Study from two Boston centers. METHODS: Genotyping was performed for single nucleotide polymorphisms in the promoter region of IL-6 (-174 G-->C), TNF-alpha (-308 G-->A), and IL-10 (-1082 G-->A). The relationship of specific genotypes to the index of coexistent disease (ICED) score (an index of comorbidity), Karnofsky Index (a measure of functional status), serum albumin, and nutritional indices (anthropometric measurements, body mass index, normalized protein catabolic ratio) were studied. Plasma IL-6 levels, as well as TNF-alpha and IL-10 production by endotoxin-stimulated peripheral blood mononuclear cells (PBMC), were also measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Patients with the high producer genotypes for the proinflammatory cytokines IL-6 (G/G and G/C) and TNF-alpha (G/A and A/A) had significantly higher comorbidity (ICED scores of > or =2) and lower functional scores (Karnofsky Index) compared with patients with the low producer genotypes for these cytokines (C/C and G/G, respectively). In contrast, patients with the high and intermediate producer genotypes (G/G and G/A) for the anti-inflammatory cytokine IL-10 had a higher Karnofsky Index compared with those with the low producer genotype (A/A). Serum albumin levels were lower in patients with the TNF-alpha high producer genotype (G/A and A/A) compared with those with the low producer genotype (G/A and A/A). On multivariate analysis, the IL-6 high producer genotypes were associated with an odds ratio (OR) of 4.87 for higher comorbidity (ICED scores > or =2) (P= 0.02), and 4.9 for lower Karnofsky Index (lower functional status) (P= 0.04) compared with patients with the low IL-6 producer genotypes. Similarly, the TNF-alpha high producer genotype was associated with increased odds for a higher ICED score, lower Karnofsky Index, and lower serum albumin compared with patients with the low producer genotype for this cytokine. In contrast, the IL-10 high/intermediate producer genotype was associated with increased odds for a higher Karnofsky Index (P= 0.05). Cytokine genotype combinations-the TNF-alpha high producer and IL-6 high producer genotype combination, and the IL-6 high producer and IL-10 low producer genotype combination-were independently associated with a higher ICED score. These genotype combinations, as well as the TNF-alpha high producer and IL-10 low producer genotype combination, were also associated with a lower Karnofsky Index. CONCLUSION: In ESRD patients on long-term HD, single nucleotide polymorphisms in the promoter region of the proinflammatory cytokines IL-6 and TNF-alpha, and the regulatory monokine IL-10, show a strong association with indices of comorbidity and function, and biological and nutritional markers.     

Cytokine polymorphisms in men with chronic prostatitis/chronic pelvic pain syndrome: association with diagnosis and treatment response

PURPOSE: The chronic pelvic pain syndrome is a common disorder of unknown etiology. Elevated cytokines in prostate fluid and semen are frequent findings. We studied genetic polymorphisms that can alter cytokine gene expression in men with the chronic pelvic pain syndrome. MATERIALS AND METHODS: Genomic DNA was extracted from blood from 36 men with the chronic pelvic pain syndrome. Reversed sequence specific oligonucleotide probing was used to genotype the polymorphisms for cytokine promoter sites, namely tumor necrosis factor (TNF)-alpha 308, transforming growth factor (TGF)-beta 25, TGF-beta 10, interleukin (IL)-10 1082 and IL-6 174. Genotype frequencies were compared with 252 controls as well as among groups of patients with the chronic pelvic pain syndrome according to diagnostic category and treatment response. RESULTS: There were no differences in men with the chronic pelvic pain syndrome and control patients in the frequency of TNF-alpha, TGF-beta or IL-6 alleles, although those with the chronic pelvic pain syndrome were more likely to express the genotype associated with low IL-10 production (30.6% versus 12.1%, p = 0.007). When comparing National Institutes of Health diagnoses, category IIIa patients were more likely to have the low TNF-alpha genotype (categories II, IIIa and IIIb 33%, 100% and 18%, respectively, p = 0.04). All 11 of the 28 patients treated with the anti-inflammatory quercetin in whom treatment failed had the low TNF-alpha genotype versus 29.4% of those in whom treatment succeeded (p = 0.0003). Similarly men with quercetin treatment failure were much less likely to have the low IL-10 genotype than those with treatment success (9.1% versus 47.1%, p = 0.04). CONCLUSIONS: Patients with the chronic pelvic pain syndrome are more likely to have a low IL-10 producing genotype, suggesting autoimmunity as a potential etiology. Anti-inflammatory phytotherapy failure was associated with low TNF-alpha and high IL-10 phenotypes, which may help define a subset of patients with the chronic pelvic pain syndrome without an inflammatory etiology.     

Influence of cytokine genes polymorphisms on long-term outcome in renal transplantation

BACKGROUND: Recently, polymorphisms of cytokine genes have been associated with modified gene expression and increased cytokine production. We evaluated the influence of interleukin-10 (IL-10) gene G-1082A, tumour necrosis factor alpha (TNFalpha) gene G-308A and IL-6 gene G-174C polymorphisms on the rejection rate, renal function and long-term outcome in renal transplantation. PATIENTS AND METHODS: We studied n = 224 consecutive patients, who underwent renal transplantation at our centre from 1998 to 2001 (cadaveric: n = 175, living related: n = 49) followed up for 4.9 +/- 2.0 yr and n = 100 healthy volunteers. IL-10 gene G-1082A, TNFalpha gene G-308A and IL-6 gene G-174C polymorphisms were determined by polymerase chain reaction (PCR) amplification. RESULTS: The genotype distribution of the investigated polymorphisms was similar in patients and controls (ns). The age of donor and the recipient, the number of HLA mismatches and cold and warm ischemic time did not differ among patients with different genotypes (ns). No association between cytokine polymorphisms and the incidence of acute rejection episodes was detected (ns). The cytokine genotypes did not correlate with serum creatinine or creatinine clearance at any time during follow up (ns). Furthermore, there was no significant difference in the genotype frequencies among patients experiencing graft failure (ns). Patients with different cytokine gene polymorphisms showed similar outcomes in the Kaplan-Meier analysis of graft survival (ns). Finally, cytokine polymorphisms had no influence on the acute rejection rate or graft outcome also in the subgroup of HLA-DR mismatched grafts (ns). CONCLUSION: Our results suggest that IL-10 gene G-1082A, TNFalpha gene G-308A and IL-6 gene G-174C polymorphisms are no major risk factors in renal transplantation.     

Influence of cytokine gene polymorphisms on erythropoetin dose requirements in chronic haemodialysis patients.

BACKGROUND: Chronic inflammation influences renal anaemia and reduce erythropoetin effectiveness. Chronic kidney disease and haemodialysis (HD) induce elevated cytokine and C-reactive protein (CRP) levels at an inter-individually variable extent. These differences are in part due to polymorphisms within cytokine genes, e.g. for pro-inflammatory interleukin-6 (IL-6) and anti-inflammatory interleukin-10 (IL-10). We hypothesized that these polymorphisms influence erythropoetin effectiveness. METHODS: Genotyping for polymorphisms of IL-6 (-174G/C) and IL-10 (-1082G/A) genes was done in 460 prevalent HD patients. Erythropoetin requirements were determined after three months of stable dosing of erythropoesis stimulating proteins (ESP). The effect of the cytokine genotypes was evaluated by multiple regression analysis. RESULTS: The presence of the IL-6 -174G allele (found to be related with higher secretion of IL-6) was associated with a 26% higher ESP dose compared with individuals without the G allele (P = 0.008). The IL-10 -1082 G/A polymorphism was not associated with ESP needs. Multivariate analysis detected a predictive value for ESP dose of the IL-6 polymorphism (P = 0.022), the haemoglobin level and the dose of i.v. iron, but not of age, gender, dialysis vintage, ferritin or the CRP value. CONCLUSIONS: Presence of the IL-6 allele -174G is related to higher ESP doses in chronic HD patients. The polymorphism of the anti-inflammatory IL-10 does not influence ESP dose, probably due to the fact that this cytokine has directly inhibitory effects on haematopoiesis in addition to its beneficial effects on inflammation.     

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.     

TNF Alpha−308 Genotype and Renin–Angiotensin System in Hemodialysis Patients: An Effect on Inflammatory Cytokine Levels?

BACKGROUND: Renin-angiotensin system (RAS) was suggested to modulate inflammatory cytokine production. Angiotensin II was consistently shown to increase production of tumor necrosis factor alpha (TNF-alpha). However, inflammatory cytokines and RAS were modulated by genetic polymorphisms such as TNF-alpha-308 G > A and angiotensin-converting enzyme (ACE) I/D gene polymorphisms. The aim of this study was to investigate the effects of ACE and TNF-alpha genotypes on inflammatory cytokines in hemodialysis (HD) patients. METHODS: ACE I/D and TNF-alpha-308 G > A genotypes, pre- and postdialysis plasma renin activity (PRA), serum ACE, interleukin-1 beta (IL-1beta), and TNF-alpha levels were determined in 22 HD patients. RESULTS: Predialysis serum ACE activity is correlated with TNF-alpha (r = 0.63; P = 0.01), and PRA was correlated with IL-1beta levels (r = 0.49; P = 0.02). Pre/postdialysis IL-1beta and TNF-alpha were similar in DD and II/ID ACE genotypes. Predialysis TNF-alpha and IL-1beta (32.4 +/- 5; 35.1 +/- 4.2 vs. 28.1 +/- 3.7; 26.5 +/- 6.2 pg/mL; P < 0.05) and postdialysis TNF-alpha levels (30.4 +/- 1.4 vs. 28.4 +/- 0.82 pg/mL; P < 0.05) were significantly higher in TNF1/2 than TNF1/1 patients. CONCLUSION: ACE and TNF-alpha-308 G > A (1/2) gene polymorphisms may contribute to modulation of proinflammatory cytokine production and hence chronic inflammation in HD patients.     

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 patterns in patients after major vascular surgery, hemorrhagic shock, and severe blunt trauma. Relation with subsequent adult respiratory distress syndrome and multiple organ failure.

OBJECTIVE: This study investigates the course of serum cytokine levels in patients with multiple trauma, patients with a ruptured abdominal aortic aneurysm (AAA), and patients undergoing elective AAA repair and the relationship of these cytokines to the development of adult respiratory distress syndrome (ARDS) and multiple organ failure (MOF). SUMMARY BACKGROUND DATA: Severe tissue trauma, hemorrhagic shock, and ischemia-reperfusion injury are pathophysiologic mechanisms that may result in an excessive uncontrolled activation of inflammatory cells and mediators. This inflammatory response is thought to play a key role in the development of (remote) cell and organ dysfunction, which is the basis of ARDS and MOF. METHODS: The study concerns 28 patients with multiple trauma, 20 patients admitted in shock because of a ruptured AAA, and 18 patients undergoing elective AAA repair. Arterial blood was serially sampled from admission (or at the start of elective operation) to day 13 in the intensive care unit, and the serum concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1 beta, and IL-6 were determined. RESULTS: Twenty-two patients died, 15 within 48 hours and 7 after several weeks, as a result of ARDS/MOF. At hospital admission and after 6 hours, these nonsurvivors had significantly higher plasma TNF-alpha and IL-1 beta levels than did the survivors. At the same measuring points, TNF-alpha and IL-1 beta were significantly more elevated in patients with ruptured AAA than in traumatized patients. However, IL-6 was significantly higher in the traumatized patients. In 10 patients, ARDS/MOF developed, and 41 had an uncomplicated course in this respect. Those with ARDS/MOF exhibited significantly different cytokine patterns in the early postinjury phase. TNF-alpha and IL-1 beta levels were higher mainly on the first day of admission; IL-6 concentrations were significantly elevated in patients with ARDS/MOF from the second day onward. The latter cytokine showed a good correlation with the daily MOF score during the whole 2-week observation period. CONCLUSIONS: In the early postinjury phase, higher concentrations of these cytokines are associated, not only with an increased mortality rate, but also with an increased risk for subsequent ARDS and MOF. These data therefore support the concept that these syndromes are caused by an overwhelming autodestructive inflammatory response.     

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.     

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.     

Association of IL-10 polymorphism with severity of illness in community acquired pneumonia

BACKGROUND: The influence of genetic polymorphisms of interleukin (IL)-10, tumour necrosis factor (TNF)-alpha, and IL-6 gene promoters on severity of systemic inflammatory response syndrome (SIRS) associated with community acquired pneumonia (CAP) was studied. METHODS: Using PCR-RFLP analysis we analysed a -1082G/A single nucleotide polymorphism (SNP) of the anti-inflammatory IL-10 gene, a -308G/A SNP of the pro-inflammatory TNF-alpha gene and a -174G/C SNP of the IL-6 gene. Illness severity was stratified according to SIRS score, calculated by presence of up to four physiological indices: temperature, white blood cell count, heart rate and respiratory rate (non-SIRS, SIRS 2, SIRS 3, and SIRS 4). RESULTS: A statistically significant stepwise increase in frequency of the IL-10 G allele, associated with higher expression of the gene, was observed in patients with increasing severity of illness from non-SIRS (n=19) to SIRS 2 (n=17), SIRS 3 (n=33) and SIRS 4 (n=24). This was primarily due to a higher frequency of the GG genotype with increasing severity from non-SIRS through to SIRS 4. IL-10 G allele frequency was also increased in patients who died as a result of CAP (n=11) compared with CAP survivors (n=82) (p=0.01). No association was seen between the TNF-alpha -308G/A and IL-6 -174G/C SNPs and disease. Additionally, no interaction between all three SNP genotypes and disease severity was observed. CONCLUSIONS: A polymorphism affecting IL-10 expression may influence the severity of illness in patients with CAP.     

Cytokine gene polymorphisms predict acute graft rejection following renal transplantation.

BACKGROUND: The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of acute rejection, while animal models suggest a role for interleukin-10 (IL-10) in promoting graft survival. It has also been shown that polymorphisms in the TNFA gene promoter (position -308) and in the IL-10 gene promoter (position -1082) correlate with differential production of these cytokines in vitro. The aim of this study was to determine whether TNF-alpha and IL-10 gene polymorphisms influence the incidence and severity of acute rejection in the first six months following renal transplantation. METHODS: The cytokine genotypes of 115 consecutive first cadaveric kidney allograft recipients and their donors were screened. The rejection episodes (REs) were defined clinically and confirmed histologically where possible and further classified according to severity (RS), namely steroid-resistant or responsive REs. The genotypes were then correlated with the REs and RS. RESULTS: The recipient TNF-alpha high producer genotype and IL-10 high producer genotype were significantly associated with multiple REs (>/=2) in human leukocyte antigen (HLA)-DR mismatched transplants (P = 0.0047 and P = 0.045, respectively), whereas only the TNF-alpha high producer genotype was associated with steroid-resistant REs (P = 0.025). When recipient cytokines were analyzed together, the TNF-alpha high/IL-10 high producer genotype had the worst prognosis, whereas TNF-alpha low/IL-10 low producer genotype was protective. CONCLUSIONS: We conclude that recipient TNF-alpha and IL-10 gene polymorphisms are determinants of REs and RS following kidney transplantation. Routine screening of these gene polymorphisms may have a clinical role in identifying patients at risk of multiple REs and severe rejections.     

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.