Alleles 308A and 238A in the tumor necrosis factor alpha gene promoter do not increase the risk of severe malaria in children with Plasmodium falciparum infection in Mali

The hypothesis that tumor necrosis factor (TNF) aggravates malaria in children is supported by observations that TNF polymorphisms and high TNF levels have been associated with cerebral malaria. Nevertheless, severe malaria was not associated with polymorphisms located at positions -308A and -238A in the TNF alpha gene promoter or with a high TNF level in plasma in children from Bamako, Mali.     

Significant association between TNF-alpha (TNF) promoter allele (-1031C, -863C, and -857C) and cerebral malaria in Thailand

We examined a possible association of three single nucleotide polymorphisms (SNPs) of the tumor necrosis factor alpha (TNF) promoter -1031T>C (rs1799964), -863C>A (rs1800630), and -857C>T (rs1799724) with severe malaria in 466 adult patients having Plasmodium falciparum malaria in northwest Thailand. Four TNF promoter alleles comprising these three SNPs were detected in the studied population. The frequency of the TNF U04 allele designated -1031C, -863C, and -857C was found to be significantly greater in patients with cerebral malaria than in patients with mild malaria (12.6%, cerebral malaria vs 5.6%, mild malaria; odds ratio =2.5; P=0.002). The association of U04 with susceptibility to cerebral malaria was not caused by linkage disequilibrium with any specific HLA-B and -DRB1 alleles.     

Genetic susceptibility to SLE is associated with TNF-alpha gene polymorphism -863, but not -308 and -238, in Thai population

The production of cytokine varies among individuals and correlates with the polymorphism of cytokine genes. Three functional single nucleotide polymorphisms (SNPs) at position -863, -308, and -238 in the tumour necrosis factor alpha (TNF-alpha) gene promoter were analysed for association with systemic lupus erythematosus (SLE) (n = 154), and clinical manifestations in a Thai population were compared with 154 ethnically matched controls. The genotyping was determined by polymerase chain reaction-restriction fragment length polymorphism method. The association between these SNPs and SLE was analysed using chi-squared test. The -863A allele and -863A, -308G, -238G haplotype were found to be significantly increased in SLE patients (25%) compared with healthy controls (15.3%) (Pc = 0.009, OR = 1.85, 95% CI = 1.21-2.83). In addition -863A allele was found to be significantly increased in the SLE group with Raynaud's phenomenon compared to SLE without Raynaud's phenomenon (35% vs. 19.4%) (Pc = 0.048, OR = 2.23, 95% CI = 1.21-4.10). The -863A allele of TNF-alpha gene and the extended haplotype of -863A, -308G, -238G can be used as a genetic marker for SLE susceptibility in Thai populations. In addition, the -863A genotype could produce high TNF levels and potentially induce the occurrence of Raynaud's phenomenon.     

No association between the -1031 polymorphism in the TNF-alpha promoter region and type 1 diabetes

Tumor necrosis factor alpha (TNF-alpha) is an important immunomodulator and is believed to be involved in the development or progression of type 1 diabetes. In the following study, we evaluated TNF-alpha promoter polymorphisms at positions -863 and -1031 and their association with type 1 diabetes in a group of 210 diabetic patients from Lebanon. Our results show that in our population, the C allele is predominant at position -863, whereas the A allele is very rare (2%). At position -1031, however, the C and T allele distribution was similar in both the patient (17.8% vs 82.2%, respectively) and the control (21.4% vs 79.6%) groups. No association of TNF-alpha genotype at position 1031 with type 1 diabetes was found as demonstrated by the family-based association test and the transmission disequilibrium test. However, when patient genotypes were compared, the recessive CC genotype was only found in type 1 diabetic males but not in type 1 diabetic females. This observation, however, requires further investigation in a larger sample before conclusive association to gender is suggested. In conclusion, our results demonstrate that no association between TNF-alpha polymorphism and type 1 diabetes seems to exist in our population.     

The tumor necrosis factor-alpha promoter -1031C polymorphism is associated with decreased risk of endometriosis in a Japanese population

BACKGROUND: Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional proinflammatory cytokine, associated with various inflammatory and autoimmune diseases. Elevated TNF-alpha levels in peritoneal fluid have been reported in women with endometriosis, suggesting that TNF-alpha may be involved in the development of endometriosis. In this study, we investigated the possible association between endometriosis and the TNF-alpha gene promoter polymorphisms -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C in a Japanese population. METHODS: We compared the distribution of the -238G/A, -308G/A, -857C/T, -863C/A and -1031T/C polymorphisms in the promoter region of TNF-alpha in 130 endometriosis cases and 185 controls using PCR-RFLP analysis. RESULTS: The allele frequencies of -238A, -308A, -857T, -863A and -1031C in controls were 2.0%, 1.3%, 19.4%, 17.0% and 18.6%, and in the cases 1.1%, 0.3%, 19.6%, 18.6% and 13.6%, respectively. No significant differences in frequencies were found between the crude endometriosis cases and controls. However, when the endometriosis group was divided into a subgroup of women with stage IV disease only, the frequency of the -1031C allele was significantly lower in this subgroup than controls. CONCLUSIONS: The variability of the -1031T/C polymorphism of the TNF-alpha gene may be associated with susceptibility to (AUTHOR: as meant?) endometriosis.     

A reduced risk of infection with Plasmodium vivax and clinical protection against malaria are associated with antibodies against the N terminus but not the C terminus of merozoite surface protein 1

Progress towards the development of a malaria vaccine against Plasmodium vivax, the most widely distributed human malaria parasite, will require a better understanding of the immune responses that confer clinical protection to patients in regions where malaria is endemic. The occurrence of clinical protection in P. vivax malaria in Brazil was first reported among residents of the riverine community of Portuchuelo, in Rond?nia, western Amazon. We thus analyzed immune sera from this same human population to determine if naturally acquired humoral immune responses against the merozoite surface protein 1 of P. vivax, PvMSP1, could be associated with reduced risk of infection and/or clinical protection. Our results demonstrated that this association could be established with anti-PvMSP1 antibodies predominantly of the immunoglobulin G3 subclass directed against the N terminus but not against the C terminus, in spite of the latter being more immunogenic and capable of natural boosting. This is the first report of a prospective study of P. vivax malaria demonstrating an association of reduced risk of infection and clinical protection with antibodies against an antigen of this parasite.     

Analysis of the polymorphism of the tumour necrosis factor (TNF) gene and promoter and of circulating TNF-alpha levels in heart-transplant patients suffering or not suffering from severe rejection

Plasma TNF-α levels are generally higher in heart-graft patients who experience a rejection episode than in those who do not. Because the TNF gene and its promoter are polymorphic, we studied the relationships between genetic variability at the TNF locus, the occurrence of graft rejection and TNF-α plasma levels in 62 heart-transplant patients in order to investigate inter-individual differences in plasma TNF-α levels after allogeneic stimulation. TNF-α was immunoenzymatically measured in blood specimens collected on the same day as endomyocardial biopsy. After PCR amplification of DNA, NcoI and AspHI polymorphisms were characterized by their restriction profiles, TNFa microsatellites by electrophoretic separation on acrylamide and the promoter region by sequencing. Plasma levels and molecular genetic results were compared to the grade of heart graft rejection established according to pathological criteria. In our study, allograft rejection was associated neither with NcoI or AspHI polymorphism nor with nucleotide changes in the TNF-Α promoter. We observed low TNF-α levels in n1/n1 homozygous patients and in subjects with G→A at position – 308 of the promoter sequence. Concerning the polymorphism of the TNFa microsatellite, our results might suggest an association with graft rejection but we have to be very careful in drawing conclusions because of the small size of the sample.     

Analysis of the polymorphism of the tumour necrosis factor (TNF) gene and promoter and of circulating TNF-alpha levels in heart-transplant patients suffering or not suffering from severe rejection.

Plasma TNF-alpha levels are generally higher in heart-graft patients who experience a rejection episode than in those who do not. Because the TNF gene and its promoter are polymorphic, we studied the relationships between genetic variability at the TNF locus, the occurrence of graft rejection and TNF-alpha plasma levels in 62 heart-transplant patients in order to investigate inter-individual differences in plasma TNF-alpha levels after allogeneic stimulation. TNF-alpha was immunoenzymatically measured in blood specimens collected on the same day as endomyocardial biopsy. After PCR amplification of DNA, NcoI and AspHI polymorphisms were characterized by their restriction profiles, TNFa microsatellites by electrophoretic separation on acrylamide and the promoter region by sequencing. Plasma levels and molecular genetic results were compared to the grade of heart graft rejection established according to pathological criteria. In our study, allograft rejection was associated neither with NcoI or AspHI polymorphism nor with nucleotide changes in the TNF-A promote. We observed low TNF-alpha levels in n1/n1 homozygous patients and in subjects with G-->A at position--308 of the promoter sequence. Concerning the polymorphism of the TNFa microsatellite, our results might suggest an association with graft rejection but we have to be very careful in drawing conclusions because of the small size of the sample.     

A promoter polymorphism in the CD14 gene is associated with elevated levels of soluble CD14 but not with IgE or atopic diseases

BACKGROUND: A polymorphism in the promoter region of the CD14 gene, C-159T, has been shown to be associated with increased levels of soluble CD14 (sCD14) and decreased serum immunoglobulin E (IgE) and the expression of a more severe atopic phenotype in previous studies. METHODS: To test if these associations are consistently found in different populations and different age groups, we genotyped 2048 children of different age groups as well as 888 adults from different regions of Germany for the CD14 C-159T polymorphism. RESULTS: While an association between this promoter polymorphism and levels of sCD14 could be confirmed in our study population (CC: 1017 ng/ml vs TT: 1370 ng/ml, P = 0.03), no association between CD14 C-159T genotypes and IgE levels or the prevalence of atopic diseases was seen. CONCLUSIONS: The lack of association between CD14 genotypes and IgE as well as atopic outcomes in this large German study population seems to indicate that CD14 genotypes may not directly be involved in the development of allergies during childhood.     

Cyclooxygenase-2 -765G>C polymorphism is associated with C-reactive protein levels in resistant smokers but not in chronic obstructive pulmonary disease patients

We sought to investigate whether the serum concentrations of several inflammatory biomarkers are related to the cyclooxygenase-2 (COX2) −765G>C polymorphism in chronic obstructive pulmonary disease (COPD) and a control group of non-COPD smokers. Serum inflammatory markers (CRP, SAA, CXCL8, and sICAM-1) were measured by ELISA in 144 patients with COPD and in 55 control subjects. Genomic DNA was extracted from peripheral blood leukocytes, and the COX2 −765G>C (rs20417) polymorphism was genotyped. After adjustment for age and active smoking, CRP and SAA concentrations were associated with the COX2 polymorphism in controls (p = 0.041 and 0.014, respectively) but not in COPD patients. The CXCL8 and sICAM-1 concentrations were not associated with the COX2 polymorphism for either cases or controls. The results of the present study indicate that there is a relationship between the COX2 −765G>C polymorphism and the concentrations of CRP and SAA in non-COPD smokers and that this relationship does not exist in COPD patients.     

The C(-260)>T gene polymorphism in the promoter of the CD14 monocyte receptor gene is not associated with acute myocardial infarction

Abstract. CD surface molecules mediates cell activation and signaling. In particular, CD14 on blood monocytes mediate monocyte/macrophage activation by lipopolysaccharide.Lipopolysaccharide and its receptor, CD14, have been implicated in atherogenesis. It has been recently shown that a C(-260)T polymorphism in the promoter of the CD14 receptor may be a risk factor for coronary artery disease. Recently this association has been questioned because no increased risk was found with the T allele, even in the homozygous state. In the present study we investigated a possible association between the C(-260)T polymorphism in the CD14 promoter and acute myocardial infarction. Two hundred and thrteen patients with and acute myocardial infarction 213 healthy controls were included in the study. Genotype frequencies of the C(-260)T polymorphism in the CD14 promoter were determined by polimerase chain reaction and the amplified product was cleaved with HaeIII. The frequency of the T allele was not significantly different in patients compared with controls. In this study we were not able to detect differences of frequency of the allele T (-260) in the promoter of the CD14 receptor gene in survivors of myocardial infarction and controls.     

The common -318C/T polymorphism in the promoter region of CTLA4 gene is associated with reduced risk of ophthalmopathy in Chinese Graves' patients

Studies in the past have clearly established that CTLA4 is a susceptible gene for Graves' disease (GD). However, association studies between CTLA4 and the risk of developing Graves' ophthalmopathy (GO) in GD patients have shown conflicting results. In this study, associations of five CTLA4 single nucleotide polymorphisms (-1722A/G, -1661A/G, -318C/T, +49G/A, CT60) with GD risk and GO susceptibility in GD patients were investigated in a Chinese population. Our results showed that either +49A/G or CT60 polymorphism was associated with GD susceptibility in the Chinese population. Significant differences in the distribution of the genotypes or alleles evaluated between GD patients with and without clinically evident GO were only found for -318C/T polymorphism (P = 0.03). Multiple logistic regressions revealed that the -318T allele was negatively associated with GO under both additive and dominant genetic models (adjusted OR = 0.56, 95%CI 0.35-0.89, P = 0.014; adjusted OR = 0.51, 95%CI 0.30-0.84, P = 0.009, respectively). Stratification analysis according to gender demonstrated different scenarios concerning the role of the -318T allele in GO risk: a significant protective role for GO was only confirmed in male but not in female GD patients. Haplotype analyses showed that only the haplotypes containing the -318T allele played a protective role in GO. In conclusion, results from this study suggested that the -318T allele might play a protective role in GO susceptibility for GD patients at least in the Chinese population. However, extended analyses with larger sample size should be carried out in patients from different ethnic origins to further verify this association.     

C(-260)T polymorphism in the promoter of CD 14 gene is not associated with myocardial infarction in the Tunisian population

Recent findings suggest that inflammation plays a role in atherosclerosis and its acute complications. Several known mechanisms may play at least a partial role in this process. One of the most likely mechanisms involves lipopolysaccharide (LPS) and its receptor, CD14. The C(− 260)T single nucleotide polymorphism (rs2569190) in the promoter region of the CD14 receptor gene has been reported to be associated with a higher risk of MI. Others studies, however, have not corroborated these findings. Considering the contradictory results, the aim of the present study was to investigate the possible association between the CD14 C(− 260)T polymorphism and the risk of MI in the Tunisian population.A total of 321 Tunisian patients with MI and 344 healthy controls were included in the study. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The frequency of TT homozygous genotype for the CD14 C(− 260)T polymorphism was 26.2% in MI patients and 27.0% in the control group. However, the genotype distribution and allele frequencies were not significantly different between MI and controls subjects. Moreover, the odds ratio for MI associated with the TT genotype failed to reach statistical significance (OR = 1.22; 95% CI: 0.85–1.77; p = 0.272).These results do not support the hypothesis that the C−260T polymorphism of CD14 gene contributes to the genetic susceptibility to MI in the Tunisian population studied.     

Histologic features distinguish microsatellite-high from microsatellite-low and microsatellite-stable colorectal carcinomas, but do not differentiate germline mutations from methylation of the MLH1 promoter

The detection of microsatellite-unstable (microsatellite instability [MSI]) colorectal carcinomas (CRCs) has prognostic value and can help screen for Lynch syndrome. We determined which histologic features are associated with MSI status and presence of germline mutation and/or methylation of MLH1 promoter. Patients diagnosed with CRC were offered participation in the Columbus-area hereditary nonpolyposis colorectal cancer syndrome study regardless of age or family history. Tumors were evaluated for MSI using a modified Bethesda panel of microsatellite markers. Methylation status of the MLH1 promoter was evaluated by methylation-specific polymerase chain reaction and bisulfite PCR followed by restriction digestion of tumor DNA. All patients with microsatellite-unstable tumors underwent mutation analysis of the MLH1, MSH2, and MSH6 genes by full sequencing of genomic DNA and by multiplex ligation probe assay of MLH1 and MSH2. Histologic end points were tumor type, grade, percentage of mucin, border, and lymphoid host response. Of the 482 CRCs, 87 were MSI with 69 MSI high (MSI-H), 18 MSI low (MSI-L), and 395 microsatellite stable (MSS). Of 87 MSI tumors, 12 had germline mutations and 34 had methylation of the MLH1 promoter. Younger age, but not histologic features, was significantly associated with a germline mutation. Percentage of mucin, histologic type, grade, and lymphoid host response differed significantly between MSI-H when compared with MSI-L or MSS. No difference was found between MSI-L versus MSS. Histologic features are associated with MSI-H CRC and are helpful to differentiate MSI-H from MSI-L and MSS. These features are not useful to distinguish MSI-L from MSS carcinomas, and those with a deleterious germline hereditary nonpolyposis colorectal cancer syndrome mutation from those with methylation of the MLH1 promoter region.     

The C(-260)>T gene polymorphism in the promoter of the CD14 monocyte receptor gene is not associated with acute myocardial infarction

CD surface molecules mediates cell activation and signaling. In particular, CD14 on blood monocytes mediate monocyte/macrophage activation by lipopolysaccharide.Lipopolysaccharide and its receptor, CD14, have been implicated in atherogenesis. It has been recently shown that a C(-260)T polymorphism in the promoter of the CD14 receptor may be a risk factor for coronary artery disease. Recently this association has been questioned because no increased risk was found with the T allele, even in the homozygous state. In the present study we investigated a possible association between the C(-260)T polymorphism in the CD14 promoter and acute myocardial infarction. Two hundred and thrteen patients with and acute myocardial infarction 213 healthy controls were included in the study. Genotype frequencies of the C(-260)T polymorphism in the CD14 promoter were determined by polimerase chain reaction and the amplified product was cleaved with HaeIII. The frequency of the T allele was not significantly different in patients compared with controls. In this study we were not able to detect differences of frequency of the allele T (-260) in the promoter of the CD14 receptor gene in survivors of myocardial infarction and controls.