Frequencies of the common promoter polymorphisms in cytokine genes in a Polish population

The Role of Plasma Interleukin-6 Levels on Atherosclerotic Cardiovascular Disease and Cardiovascular Mortality Risk Scores in Javanese Patients with Chronic Kidney Disease

Interleukin-6 (IL-6) has been identified as an important pro-inflammatory factor involved in mediating the severity of chronic kidney disease (CKD). This study sought to determine the effect of plasma IL-6 levels on atherosclerotic cardiovascular disease (ASCVD) and cardiovascular mortality risk scores in Javanese CKD patients. We also analyzed the frequency of IL-6 G174C single nucleotide polymorphism (SNP) in the population. This study was a cross-sectional study involving seventy-three patients of Javanese ethnic origin with stable chronic kidney disease. We assessed the ASCVD risk score, cardiovascular mortality score, genotyping of IL-6 G174C SNP, and plasma IL-6 levels in these patients. The genotype distribution and allele frequencies of the IL-6 G174C SNP were predominated by the G genotype/allele (GG: 97.26%, GC: 1.37%, CC: 1.37%, G-allele: 97.95%, and C-allele: 2.05%). Despite the fact that plasma IL-6 levels did not directly affect cardiovascular mortality risk, further analysis revealed its direct effect on the ASCVD risk score (path coefficient = 0.184, p = 0.043, 95% CI = 0.018−0.380), which in turn affected cardiovascular mortality risk (path coefficient = 0.851, p = <0.01, 95% CI = 0.714−0.925). In conclusion, plasma IL-6 levels play important roles on ASCVD risk and cardiovascular mortality risk in Javanese patients with CKD.

Interleukin 6 (rs1800795) and pentraxin 3 (rs2305619) polymorphisms-association with inflammation and all-cause mortality in end-stage-renal disease patients on dialysis

Chronic inflammation plays an important role in the progression and outcome of chronic kidney disease (CKD). The circulating levels of the inflammatory biomarkers interleukin 6 (IL6) and pentraxin 3 (PTX3) are enhanced in CKD patients, and are associated with the progression of the disease and with higher risk for cardiovascular events, the major cause of death in CKD patients. Our aim was to study how specific polymorphisms of IL6 and PTX3 encoding genes affect the inflammatory response and outcome of end-stage renal disease (ESRD) patients on dialysis. Methodology included the analysis of two single nucleotide polymorphisms (SNP), namely the IL6 (rs1800795) polymorphism in the promoter region (-174G > C), and the PTX3 (rs2305619) polymorphism in the intron 1 (+ 281A > G), which were analyzed in ESRD patients on dialysis and in a group of heathy individuals. The allelic frequencies, genotype distribution and their association with circulating levels of the inflammatory markers C-reactive protein (CRP), IL6, growth differentiation factor 15 (GDF15) and PTX3, were determined in ESRD patients. Events of death were recorded along one year, to assess the association of the studied SNPs with all-cause mortality and the inflammatory biomarkers, in ESRD patients. Results showed that the allelic frequencies and genotype distribution for IL6 and PTX3 SNPs in the control group and ESRD patients were similar and in agreement with other European reports. For the IL6 polymorphism, we found a trend towards higher levels of high-sensitivity (hs) CRP, IL6 and PTX3 in the homozygous genotypes; the CC genotype also showed the highest levels of GDF15. The mortality rate after the 1-year follow-up was 10.4%. The CC genotype (IL6 SNP) was associated to a higher risk of mortality and deceased patients carrying this genotype also showed the highest levels of hsCRP. Regarding the studied PTX3 SNP, the AA genotype was linked to an enhanced inflammatory response, showing the highest values of hsCRP and IL6. Nevertheless, this genotype had no significant impact on the mortality rate. In conclusion, both studied SNPs seem to modulate the inflammatory response in ESRD and may, therefore, be determinant on disease progression and patients' outcome. Our data also highlights the importance of research on genetic variants that, although less frequent, may have significant biological value.

Effects of the IL6 -174G>C promoter polymorphism and IL-6 serum levels on the progression of cutaneous malignant melanoma

Cutaneous malignant melanoma (CMM) is one of the most immunogenic types of cancer, with a 6-fold higher rate of spontaneous regression than any other malignancy. In addition to responsiveness to different immunotherapies, the immunogenicity of CMM highlights the important role of the host immune system in the response to CMM. The present study aimed to explore the role of two functional promoter polymorphisms [IL6 -174G>C (rs1800785) and TNFA -308G>A (rs1800629)] in the regulation of the genes encoding the pro-inflammatory cytokines interleukin (IL)-6 and tumor necrosis factor-α, specifically in patients with CMM. A total of 76 patients with CMM and 200 control subjects were genotyped using PCR-restriction fragment length polymorphism. The genotype frequencies for both single nucleotide polymorphisms (SNPs) did not differ significantly between the patients and controls (P=0.358 and P=0.810 for IL6 and TNFA, respectively). However, compared with carriers of C-allele genotypes (CG+CC), patients with the IL6 -174GG genotype exhibited more advanced melanoma (Clark scale ≥3; P=0.037) and shorter survival times, particularly those who worked outdoors (in conditions with increased sunlight exposure; P=0.016). Furthermore, the serum IL-6 levels of patients with CMM were significantly higher than those of the control subjects, which were associated with unfavorable blood and serum characteristics and tumor progression (development of new distant metastases; P=0.004), and with a shorter overall survival time (P=0.042). Using a Cox proportional hazard model, the IL6 -174GG genotype was found to be an independent prognostic factor for reduced survival time (P=0.030), together with sex (being male; P=0.004) and occupations with higher exposure to sunlight (P=0.047). In conclusion, the results of the present study indicated that the promoter polymorphisms IL6 -174G>C and TNFA -308G>A are not predisposing factors for CMM. However, the IL6 -174G>C SNP and IL-6 serum concentrations are likely to influence the progression of the disease, and the GG genotype and higher IL-6 serum levels may indicate shorter survival.

Association of the Interleukin-6 rs1800795 Polymorphism with Type 2 Diabetes Mellitus in the Population of the Island of Crete, Greece

BACKGROUND

Interleukin 6 (IL-6), a proinflammatory cytokine, is elevated in patients with type 2 diabetes (T2D), and is considered an independent predictor of T2D. IL-6 single-nucleotide polymorphisms (SNPs) have been associated with higher levels of IL-6. This study investigated the role of an IL-6 gene polymorphism and its possible association to T2D in the genetically homogeneous Greek population of the island of Crete.

MATERIALS AND METHODS

A total of 144 patients with T2D and 180 controls, all Cretans, selected from the Diabetes Clinic and the Department of Internal Medicine at the University Hospital of Heraklion, Crete, Greece, were genotyped for the IL-6 -174G>C (rs1800795) SNP by the restriction fragment length polymorphism method.

RESULTS

The G/C genotype and the minor allele C of the IL-6 rs1800795 SNP were more common in individuals with T2D than controls (p = 0.004, odds ratio [OR] = 1.98, 95% confidence interval [CI]: 1.24-3.18 and p = 0.011, OR = 1.59, 95% CI: 1.11-2.26, respectively).

CONCLUSION

An association of the rs1800795 SNP of the IL-6 gene with T2D has been detected for the first time in Cretans. The present results, in combination with those presented previously from different ethnic/racial populations, highlight the necessity of comparative studies among different ethnic/racial populations to detect genetic characteristics and associations with T2D.

Searching for signals of recent natural selection in genes of the innate immune response - ancient DNA study

The last decade has seen sharp progress in the field of human evolutionary genetics and a great amount of genetic evidence of natural selection has been provided so far. Since host-pathogen co-evolution is difficult to trace due to the polygenic nature of human susceptibility to microbial diseases, of particular interest is any signal of natural selection in response to the strong selective pressure exerted by pathogens. Analysis of ancient DNA allows for the direct insight into changes of a gene pool content over time and enables monitoring allele frequency fluctuations. Among pathogenic agents, mycobacteria are proved to have remained in an intimate, long-lasting relation with humans, reflected by the current high level of host resistance. Therefore, we aimed to investigate the prevalence of several polymorphisms within innate immune response genes related to susceptibility to mycobacterial diseases (in SLC11A1, MBL2, TLR2, P2RX7, IL10, TNFA) in time series data from North and East Poland (1st-18th century AD, n = 207). The comparison of allele frequencies over time revealed a predominant role of genetic drift in shaping past gene pool of small, probably isolated groups, which was explained by the high level of population differentiation and limited gene flow. However, the trajectory of frequency fluctuations of two SNPs suggested the possibility of their non-neutral evolution and the results of applied forward simulations further strengthened the hypothesis of natural selection acting on those loci. However, we observed an unusual excess of homozygosity in the profile of several SNPs, which pinpoints to the necessity of further research on temporally and spatially diverse samples to support our inference on non-stochastic evolution, ideally employing pathway-based approaches. Nevertheless, our study confirms that time series data could help to decipher very recent human adaptation to life-threatening pathogens and assisting demographic events.

Effect of G(-174)C polymorphism in interleukin-6 gene on cardiovascular disease in type 2 diabetes patients

Interleukin-6 (IL-6) is an important pro-inflammatory cytokine of relevance to cardiovascular diseases. The aim of this case-control study was to evaluate the association between the G(-174)C functional polymorphism in the IL-6 gene and risk of cardiovascular disease (CVD) in type 2 diabetes patients. We examined 1090 patients with T2DM and 612 controls. All subjects were genotyped for the G(-174)C polymorphism by polymerase chain reaction (PCR) and restriction analysis. There were no significant differences in the distribution of genotypes and alleles between T2DM patients and healthy controls. Significantly higher C allele frequency was observed in CVD+ patients compared to CVD- subgroup (53% vs. 32%, p<0.0001). The odds ratio for C allele was 2.4 (95% CI 1.99-2.9, p<0.0001) and for CC genotype 4.55 (95% CI 3.12-6.63, p<0.000). When the distribution of G(-174)C polymorphism was compared in subgroups with different clinical phenotypes of CVD, a significant association of CC genotype with myocardial infarction was observed. Forty eight percent of patients with MI had the CC genotype compared to 22% of patients without MI (p<0.0001). In conclusion, type 2 diabetes patients carrying the C allele of the IL-6 G(-174)C polymorphism have a significantly increased risk of CVD.

Association between CRP gene polymorphism 717A/G, C-reactive protein and neurological deficit in ischemic stroke

Inflammatory components play an important role in the pathogenesis of arteriosclerosis, one of the main causes of stroke. Blood C-reactive protein (CRP) level is connected with the severity of neurological deficit and disability after stroke. Production of CRP depends on CRP gene polymorphism. This study enrolled 125 patients with ischemic stroke. CRP 717A/G polymorphism was tested in all patients along with an assay of CRP levels measured on the first and tenth day after stroke onset. Neurological deficit on admission and before discharge from hospital was evaluated according to National Institutes of Health Stroke Scale (NIHSS), and then associated with CRP levels and the CRP polymorphism. The CRP 717AA genotype was the most frequent, observed in 53.6% of patients; AG genotype in 40%, and GG genotype in 6.4%. Carriers of the 717GG genotype had a significantly higher CRP level on the first day after stroke versus heterozygotes (p=0.023). The improvement in neurological state evaluated with the NIHSS was significantly better in CRP 717AA patients in comparison with other CRP 717 genotypes (p=0.035). A higher level of CRP on the first day after ischemic stroke was slightly associated with the CRP 717AG genotype. The CRP 717AA genotype promotes improvement of neurological state in patients with ischemic stroke.

Cytokine gene polymorphisms: methods of detection and biological significance

In recent years, several functional polymorphisms, particularly, SNPs have been identified in cytokines and their receptor genes that regulate levels of cytokine expression. These have been implicated as immune prognostic markers in diseases, including differential response to therapy and as biomarkers of graft outcome following organ and stem cell transplantation. Population distribution of cytokine gene polymorphisms (CGPs) reveals significant variations in allele frequencies in different ethnic groups and this might explain, to some extent, the observed differences in SNP associations with various diseases and immune-pathologies. A number of molecular methods are available for defining CGPs. These include PCR-SSP, AFLP, Taqman probe assays as well as sequencing based typing. Of these, the PCR-based sequence-specific primer based test is the most widely accepted technique. This chapter describes steps involved in this procedure along with sources for procuring essential reagents. An important aspect of CGP analyses is the correct interpretation of results particularly determination of their multilocus haplotypes.

Is interleukin-10 gene polymorphism a predictive marker in HCV infection?

The clinical outcome of hepatitis C virus (HCV) infection varies between individuals - from spontaneous viral clearance and persistence without complication, to chronic hepatitis, cirrhosis and hepatocellular carcinoma. Also patterns of response to interferon-based anti-HCV therapy are different from person to person. This diversity may be affected by host genetic factors, including alterations in genes encoding cytokines. Interleukin-10, as an anti-inflammatory cytokine and immune response modulator, may influence on HCV infection susceptibility as well as spontaneous and treatment-induced HCV eradication. Moreover, it is stated that IL-10 has antifibrotic properties and play a role in progression of liver disease. This review summarized studies on interleukin-10 gene polymorphisms (mainly promoter SNPs at positions -1082(G/A), -819(C/T) and -592(C/A)), which may determine IL-10 production, regarding susceptibility to HCV infection, course of HCV-related liver disease (fibrosis, cirrhosis, hepatocellular carcinoma, ALT abnormalities), spontaneous viral elimination as well as hepatitis C treatment outcomes. Analysis of hereby summarized studies shows that it is difficult to unambiguously determine the importance of IL-10 polymorphism as a predictor of clinical outcome of hepatitis C and response to anti-HCV therapy before its beginning. Thus, future larger studies need to address these issues. Continuation of studies on interleukin-10 polymorphisms as well as identification of other candidate predictive markers in HCV infection has important practical implications and there is a chance that may contribute to reduce the scale of hepatitis C problem.

Maternal interleukin-6 (-174) C/C polymorphism is associated with chorioamnionitis and cystic periventricular leucomalacia of the preterm infant

OBJECTIVE

To evaluate the association between maternal interleukin (IL)-6 G(-174)C polymorphism and cystic periventricular leukomalacia (cPVL) of the preterm newborn.

STUDY DESIGN

After searching a local database, we recruited 132 preterm infants with diagnosis of cPVL, 44 Caucasian mothers were also recruited to participate in this candidate gene-association study at a single teritary care center. Data related to maternal IL-6 G(-174)C polymorphisms were compared with 41 controls, and furthermore compared with data from umbilical cord blood samples from a consecutive birth cohort of 395 healthy newborns, and published data from Caucasian populations including 1104 adults, respectively. In addition, subgroup analysis was performed in cases with either history of preterm premature rupture of the membranes (PPROM) or clinical chorioamnionitis (CCA). IL-6 genotyping was performed using an allele-specific polymerase chain reaction technique.

RESULT

Frequencies of the IL-6 G(-174)C polymorphisms did not differ between cases (GG, 29.5%; GC, 54.5% and CC, 15.9%) and controls (GG, 34.2; GC, 51.2 and CC, 14.6%). Subgroup analysis of 31 cases with history of PPROM (GG, 25.8; GC, 54.8 and CC 19.4%) and controls did not reveal significant differences, but a significantly higher frequency of the CC genotype was found in 23 cases with a history of CCA (34.8%) compared with controls by either univariate (P=0.032; odds ratio 3.11, 95% confidence interval (CI) 1.11 to 8.68) or multivariate analysis (P=0.049, odds ratio 2.54, 95% CI 1.01 to 6.45). These data were confirmed by a comparing the CC genotype frequency to 395 term controls (CC 14.7%, P=0.005) and to the mean CC genotype frequency of 1104 Caucasian adults (CC 15.6%, P<0.0001).

CONCLUSION

Frequencies of the IL-6 G(-174)C polymorphisms did not differ between groups. Subgroup analysis revealed an association of the CC genotype with CCA and cPVL in the preterm newborn.

The association of IL-1beta, IL-2, and IL-6 gene polymorphisms with bone mineral density and osteoporosis in postmenopausal women

OBJECTIVE

Osteoporosis is a common disorder with a strong genetic component. The genetics of osteoporosis impacts on the prediction, diagnosis, prognosis, and treatment of the disease.

STUDY DESIGN

The aim of the present study was to examine associations between cytokine gene polymorphisms (IL-1beta, IL-2, IL-6) and bone mineral density (BMD) values in postmenopausal women. The study included 226 postmenopausal women with a diagnosed BMD T-score lower than -2.5 SD (mean: -3.02+/-.053) and 224 postmenopausal women with a BMD T-score greater than -2.5 SD (mean: -1.33+/-0.51).

RESULTS

Among the women with T-scores below -2.5 SD, the BMD values were significantly lower in the carriers of the IL-6 GG genotype compared with those with the CC and GC genotypes (0.70+/-0.38 vs. 0.73+/-0.25 and 0.74+/-0.23 for the lumbar spine, 0.54+/-0.18 vs. 0.56+/-0.15 and 0.58+/-0.22 for the femoral neck). There were no statistically significant associations between the IL-1beta and IL-2 genotypes and BMD values in the group of women with T-scores below -2.5 SD.

CONCLUSION

The results of the present study suggest an association of the IL-6 -174 G/C polymorphism with osteoporosis in postmenopausal women.

The G/G genotype of transforming growth factor beta 1 (TGF-beta1) single nucleotide (+915G/C) polymorphism coincident with other host and environmental factors is associated with irreversible bronchoconstriction in asthmatics

Irreversible airflow obstruction may develop in some cases of asthma even in absence of known risk factors such as smoking and environmental insults and despite implementing apparently appropriate therapy. This implies that genetic factors may significantly contribute to determining the severity in the course of the disease. The published reports on genetic predisposition to irreversible bronchoconstriction in asthma, however, are relatively scarce, and disregard its potential association with transforming growth factor (TGF)-beta1 gene polymorphism despite established role that TGF-beta1 plays in airway remodelling. We tested TGF-beta1 single-nucleotide polymorphisms (SNPs) at position +869 of codon 10 (leucine or proline) and position +915 of codon 25 (arginine or proline) for association with irreversible bronchoconstriction in a case-control study involving 110 patients with asthma and 109 controls. Multivariate logistic regression analysis revealed that genotype G/G at codon 25 was significantly associated with irreversible bronchoconstriction in asthmatics (odds ratio = 4.44; 95% confidence interval: 1.00-19.61; P = 0.05), but only after adjustment for gender, disease duration and smoking index. The influence of SNPs at codon 10 on irreversible airway obstruction was not significant. Our results suggest that presence of SNP (+915G/G) at codon 25 in TGF-beta1 gene may predispose to the development of irreversible bronchoconstriction in asthmatic patients, but only when coincident with the male gender, habitual smoking and relevant duration of the disease.

IL-1beta, IL-6, and TNF gene polymorphisms do not affect the treatment outcome of rheumatoid arthritis patients with leflunomide

Leflunomide is an isoxazole derivative that is structurally and functionally unrelated to other known immunomodulatory drugs. Previous studies have revealed that therapy with leflunomide causes decreased production of mediators such as IL-1beta, IL-6, and TNF-alpha, which are involved in inflammatory process. The aim of the present study was to examine whether the polymorphisms in genes IL1B, IL6, and TNF may affect treatment outcomes in RA patients treated with leflunomide. The study was carried out on 129 patients (106 women, 23 men, mean age 52.9 +/- 11.03) diagnosed with RA and treated with leflunomide 20 mg daily. Clinical improvement was evaluated according to the American College of Rheumatology (ACR) 20% and 50% response criteria. There were no statistically significant associations between the studied genotypes and improvement of disease activity parameters. The results of the present study suggest that IL1beta, IL6, and TNF gene polymorphisms are not significant factors influencing the therapy outcome of RA patients with leflunomide.

Strain and model dependent differences in inflammatory cell recruitment in mice

OBJECTIVE AND DESIGN

The objective of this study was to determine genetic differences in inflammation in these distinct inbred mouse strains.

METHODS

Peritoneal leukocyte recruitment, matrix metalloproteinases and cytokines were quantified in A/J, 129/svJ, C57BL/6J, using thioglycollate or biomaterial implants as inflammatory stimuli.

RESULTS

In response to thioglycollate, A/J had significant decreases compared to C57BL/6J in both neutrophil (86 %) and macrophage (62 %) recruitment, and 129/svJ had a significant (43 %) decrease compared to C57BL/6J in macrophage recruitment. The reduced leukocyte recruitment corresponded to reduced matrix metalloproteinase-9. In the bioimplant model, 129/svJ had a 2-fold increase in neutrophil and macrophage recruitment compared to C57BL/6J, and the increased leukocyte recruitment corresponded to elevated cytokines, monocyte inhibitory protein-2 and monocyte chemoattractant protein-1, in the lavage compared to the values for C57BL/6J.

CONCLUSION

Not only was leukocyte recruitment strain dependent, but the three strains had marked differences in metalloproteinases and cytokine response. In addition, there were model specific differences in the metalloproteinase and cytokine response to the two inflammatory stimuli. Thus, inflammatory cell recruitment is genetically determined and stimulus specific and may determine the susceptibility to complex diseases.

Interleukin-10 (IL10) and tumor necrosis factor alpha (TNF) gene polymorphisms in Parkinson's disease patients

Recent studies revealed that inflammatory processes might play an important role in the pathogenesis of Parkinson's disease (PD). We hypothesized that genetically determined differences in the immune response, especially in anti- and pro-inflammatory cytokines production might influence the risk for the development and/or onset of sporadic PD. In the present study, we investigated the genetic polymorphisms of the IL10 (-1082 and -519) and TNF (-308) genes in relation to the risk of PD, and their associations with age of PD onset in a group of 316 patients, divided into two subgroups: Group 1: patients with early onset PD (EOPD), i.e. before 50 years of age (102 patients), and group 2: patients with onset of PD after 50 years of age comprising 214 subjects. Control samples were obtained from 300 randomly selected healthy individuals from the same geographical region with no signs of Parkinsonism as evaluated by a neurologist. PCR-RFLP methods were used for genotyping. No statistically significant differences between PD patients and controls were found in the frequency of a single locus of IL10 promoter. We found TNF -308A allele significantly more frequent in EOPD patients compared to the controls (p=0.007). The overrepresentation of the A allele was reflected by a significant increase in AA homozygous individuals in EOPD patients compared to the controls (p=0.0021). The results from our study revealed that the TNF -308AA genotype might increase the risk of early onset of PD.

Interleukin-10 gene polymorphism in Parkinson's disease patients

BACKGROUND

The etiology of sporadic Parkinson's disease (PD) is not well established. Recent studies revealed that inflammatory processes might also play an important role in the pathogenesis of PD. We hypothesized that genetically determined differences in the immune response, especially in anti-inflammatory cytokines production, might influence the risk of sporadic PD development and/or onset. To prove this hypothesis, two DNA polymorphisms at IL-10 promoter (-1082 and -519) were examined in sporadic PD patients.

METHODS

The study enrolled 341 patients with diagnosed idiopathic PD. All cases of secondary parkinsonism were excluded from the study. For the purpose of this study the patients were also divided into two subgroups: group 1: patients with onset of Parkinson's disease, i.e., <50 years of age (early onset) included 60 patients, as well as group 2: patients with onset of Parkinson's disease >50 years of age (late onset) comprising 281 subjects. Control samples were from 315 randomly selected healthy individuals from the same geographical region who were free from signs of parkinsonism as evaluated by consultant neurologists. PCR-RFLP methods were used for genotyping.

RESULTS

No statistically significant differences between PD patients and controls were found in the frequency of a single locus (-1082, -519) of IL-10 promoter. Likewise, haplotype analysis did not demonstrate any significant differences between evaluated groups. The frequency of the evaluated IL-10 genotypes was also similar in EOPD and LOPD patients.

CONCLUSIONS

Results from our study revealed that the IL-10 (-1082G>A, -592C>A) polymorphism is not a risk factor of sporadic Parkinson's disease in a Polish population.

Single nucleotide polymorphisms of cytokine genes in the healthy Slovak population

Cytokines are molecules that control and modulate the activities of numerous target cells via binding to specific receptors. The observed differences in the cytokine production among individuals can be, at least partially, explained by gene polymorphisms. Several cytokine gene polymorphisms have been identified to play a role in susceptibility to various diseases, including autoimmune, infectious, allergic or cardiovascular diseases. The aim of the current study was to determine allele and genotype frequencies of 22 polymorphisms in 13 cytokine genes in the healthy Slovak population and to compare them with data available from six populations from Central and Southern Europe. A polymerase chain reaction with sequence-specific primers was used to genotype polymorphisms within genes encoding IL-1alpha, IL-1beta, IL-1R, IL-1RA, IL-4Ralpha, IL-12, IFN-gamma, TGF-beta, TNF-alpha, IL-2, IL-4, IL-6 and IL-10 in a sample of 140 unrelated Slovak subjects. The allelic distribution of all polymorphisms in the Slovak population was very close to that in the geographically and historically closest populations in Central Europe--the Czech and the Polish. However, several differences were found between the Slovak and four populations from Southern Europe. The obtained data represent a basis for further studies on association of cytokine gene polymorphisms with some diseases.

Cytokine gene polymorphisms in the Dutch population

Numerous studies have shown that variations in the production and activity of cytokines influence the susceptibility and/or resistance to various infectious agents, autoimmune diseases, and cancer, as well as the predisposition to allograft rejection. Differences in the production of cytokines between individuals are often caused by single nucleotide polymorphisms (SNP) in the promoter or coding regions of cytokine genes. The cytokine polymorphisms of 107 unrelated Caucasian individuals originating from various parts of the Netherlands were studied and compared with the results of two European (Czech and Italian) populations. Twenty-two SNPs of 13 different cytokine genes were analysed. To test the Hardy-Weinberg equilibrium, allele frequencies were estimated by direct gene counting. Evaluation of the allele frequencies of the Dutch, Italian and Czech populations showed that five SNPs were significantly different between the Dutch and the Italians, while these SNPs did not vary between the Dutch and the Czechs. This analysis, in combination with other types of immune profiling, may be helpful for prediction of the clinical outcome of various infectious and immune-related disorders, as well as for estimation of the risk for rejection and graft vs. host disease after organ or stem cell transplantation.

Frequency distribution of cytokine gene polymorphisms in the healthy North Indian population

The allelic and genotype frequencies corresponding to 22 single nucleotide polymorphisms (SNPs) in 13 cytokine genes interleukin (IL) 1-alpha (T/C -889), IL1-beta (C/T -511, T/C +3962), IL12 (C/A -1188), interferon-gamma (A/T UTR 5644), transforming growth factor-beta (C/T codon 10, G/C codon 25), tumour necrosis factor-alpha (G/A -308, G/A -238), IL2 (T/G -330, G/T +160), IL4 (T/G -1098, T/C -590, T/C -33), IL6 (G/C -174, G/A nt 565), IL10 (G/A -1082, C/T -819, C/A -592), IL1R (C/T pst11970), IL1RA (T/C mspa111100) and IL4RA (G/A +1902) were determined in 130 healthy North Indian subjects. All genomic typings were performed with polymerase chain reaction with sequence-specific assays. An analysis of the allelic and haplotype frequencies in the North Indian population showed a good fit with the Hardy-Weinberg equilibrium for most of the SNPs. The data can be used for anthropological comparisons, as well as for association studies with different diseases and for use in transplant situations involving acute and chronic rejection.

Distribution of 22 cytokine gene polymorphisms in the healthy Czech population

Cytokine gene polymorphisms (CGP) have been implicated in the pathogenesis of immune-mediated diseases including transplant complications via their effect on cytokine production and regulation. This study aimed to determine population frequencies of selected cytokine single nucleotide polymorphisms in the healthy Czech population and compare them with the data from other selected European populations. CGP were genotyped by polymerase chain reaction with sequence-specific primers (PCR-SSP) using the Heidelberg kit in 120 unrelated Czech healthy individuals. Chi-squared analysis was used to test for a deviation from Hardy-Weinberg equilibrium. Allelic and genotype frequencies and carriage rates were determined for 22 CGP located within 13 cytokine genes in total. The frequencies observed in this study were similar to those available from the other two geographically close Central European centres, but they differed for several CGP from the data reported in south European populations. The data on the distribution of 22 CGP in the healthy Czech population reported here may be utilized to investigate possible associations of CGP with diseases or transplantation outcome.