Systemic lupus erythematosus with nephritis is strongly associated with the TNFB*2 homozygote in the Korean population

Association of HLA-DR1, HLA-DR13, and HLA-DR16 Polymorphisms with Systemic Lupus Erythematosus: A Meta-Analysis

Objectives

The principal purpose of this meta-analysis was to assess the association between HLA-DRB1 (HLA-DR1, HLA-DR13, and HLA-DR16) polymorphisms and SLE susceptibility.

Methods

We searched published case-control studies on the association between HLA-DRB1 polymorphisms and SLE susceptibility from PubMed and Web of Science databases. The pooled ORs with 95% CIs were utilized to estimate the strength of association of HLA-DR1, HLA-DR13, and HLA-DR16 polymorphisms and SLE susceptibility by fixed effect models. We also performed sensitivity analysis, trial sequential analysis, Begg's test, and Egg's test in this meta-analysis.

Results

A total of 18 studies were included in this meta-analysis. Overall analysis showed that HLA-DR1 and HLA-DR13 polymorphisms were associated with a decreased risk of SLE (OR = 0.76, 95% CI: 0.65-0.90, P < 0.01; OR = 0.58, 95% CI: 0.50-0.68, P < 0.01), and HLA-DR16 polymorphism was associated with an increased risk of SLE (OR = 1.70, 95% CI: 1.24-2.33, P < 0.01). In subgroup analysis of ethnicity, the results were as follows: HLA-DR1 polymorphism in Caucasians (OR = 0.76, 95% CI: 0.58-0.98,P = 0.04) and North Americans (OR = 0.64, 95% CI: 0.42-0.96,P = 0.03); HLA-DR13 polymorphism in Caucasians (OR = 0.62, 95% CI: 0.47-0.82,P < 0.01) and East Asians (OR = 0.44, 95% CI: 0.34-0.57,P < 0.01); and HLA-DR16 polymorphism in East Asians (OR = 2.62, 95% CI: 1.71-4.03,P < 0.01).

Conclusions

This meta-analysis showed that HLA-DR1 and HLA-DR13 are protective factors for SLE, and HLA-DR16 is a risk factor. Due to the limitations of this meta-analysis, the association between HLA-DRB1 polymorphisms and SLE susceptibility needs to be further researched before definitive conclusions are proved.

Haplotypes of TNFα/β Genes Associated with Sex-Specific Paranoid Schizophrenic Risk in Tunisian Population

Several medical research findings have announced a strong association between the biology of cytokines and various brain activities. Since growing evidences suggest the crucial and complex role of the tumor necrosis factor in the CNS, we have hypothesized that functional genetic variants of the LTA and TNFA genes (LTA +252A/G (rs909253) and TNFA -857C/T (rs1799724) and TNFA -238G/A (rs361525)) may be involved in the predisposition to schizophrenia. This research is based on a case-control study. The RFLP-PCR genotyping was conducted on a Tunisian population composed of 208 patients and 208 controls. We found a strong significant overrepresentation of the minor alleles (G, T, and A, respectively) in all patients compared with controls (p = 0.003, OR = 1.55; p = 0.005, OR = 1.78; and p = 0.0001, OR = 1.74, respectively). This correlation was confirmed for male but not for female patients. Interestingly, the frequencies of the minor alleles were significantly more common among patients with paranoid schizophrenia when compared with controls (p = 0.003, OR = 1.75; p = 5 · 10^-6, OR = 3.04; and p = 4 · 10^-6, OR = 2.35, respectively). This potential association was confirmed by a logistic binary regression analysis only for the development of the paranoid form of schizophrenia (p = 0.001/OR = 2.6; p = 0.0002/OR = 3.2; and p = 0.0004/OR = 3.1, respectively) and remained not significant for the other subtypes. Moreover, our study showed an important association between GCA haplotype and the development of this pathological form (p = 10^-4, OR = 3.71). In conclusion, our results proved a significant association between the three polymorphisms and paranoid schizophrenia, at least in the Tunisian population, suggesting a substantially increased risk for paranoid schizophrenia with dominant inheritance of these three minor alleles.

Association of lymphotoxin alpha polymorphism with systemic lupus erythematosus and rheumatoid arthritis: a meta-analysis

AIM

The aim of this study was to perform a meta-analysis of eligible studies to derive precise estimation of the associations of lymphotoxin alpha (LTA) 252 A>G polymorphism (rs909253) with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) risk.

METHOD

Data were collected from the following electronic databases, including EMBASE, PubMed and China National Knowledge Infrastructure (CNKI). A total of 19 studies (13 studies involving 1346 SLE patients and 1951 controls, six studies involving 1079 RA patients and 1057 controls) were included.

RESULTS

This meta-analysis showed no evidence of significant association of the A allele with SLE susceptibility (odds ratio [OR] 1.26; 95% confidence interval [CI] 0.98-1.62, P = 0.073), but it showed a weaker association under an additive model (OR 1.63, 95%CI 1.01-2.65, P = 0.047). Stratification by ethnicity indicated that the variant A allele carriers increased the risk of SLE in Asians (OR 1.91, 95%CI 1.44-2.53, P < 0.001). However, we failed to reveal any association between LTA gene 252 A>G polymorphism and RA risk under all models (for A vs. G: OR 1.02, 95%CI 0.79-1.33, P = 0.853; for AA + AG vs. GG: OR 0.86, 95%CI 0.52-1.41, P = 0.542; for AA vs. AG + GG: OR 1.19, 95%CI 0.80-1.78, P = 0.394, for AA vs. GG: OR 1.03, 95%CI 0.58-1.84, P = 0.919). Similar results were obtained in the subgroup analysis based on ethnicity.

CONCLUSION

The present study suggests that LTA 252 A>G polymorphism is associated with SLE susceptibility in Asians, and there is no significant association between LTA 252 A>G polymorphism and RA.

Tumor necrosis factor B (TNFB) genetic variants and its increased expression are associated with vitiligo susceptibility

Genetic polymorphisms in TNFB are involved in the regulation of its expression and are found to be associated with various autoimmune diseases. The aim of the present study was to determine whether TNFB +252A/G (rs909253) and exon 3 C/A (rs1041981) polymorphisms are associated with vitiligo susceptibility, and expression of TNFB and ICAM1 affects the disease onset and progression. We have earlier reported the role of TNFA in autoimmune pathogenesis of vitiligo, and we now show the involvement of TNFB in vitiligo pathogenesis. The two polymorphisms investigated in the TNFB were in strong linkage disequilibrium and significantly associated with vitiligo. TNFB and ICAM1 transcripts were significantly increased in patients compared to controls. Active vitiligo patients showed significant increase in TNFB transcripts compared to stable vitiligo. The genotype-phenotype analysis revealed that TNFB expression levels were higher in patients with GG and AA genotypes as compared to controls. Patients with the early age of onset and female patients showed higher TNFB and ICAM1 expression. Overall, our findings suggest that the increased TNFB transcript levels in vitiligo patients could result, at least in part, from variations at the genetic level which in turn leads to increased ICAM1 expression. For the first time, we show that TNFB +252A/G and exon 3 C/A polymorphisms are associated with vitiligo susceptibility and influence the TNFB and ICAM1 expression. Moreover, the study also emphasizes influence of TNFB and ICAM1 on the disease progression, onset and gender bias for developing vitiligo.

Interferon-gamma 874A>T genetic polymorphism is associated with infectious complications following surgery in patients with thoracic esophageal cancer

BACKGROUND

Cytokines play a major role in the organization of orchestrated responses to infections, and there is an emerging consensus that cytokine gene polymorphisms mediate individual variations in cytokine expression. Our aim in this study was to assess whether cytokine polymorphisms were associated with infectious complications following esophagectomy in a Japanese population.

METHODS

The study participants were Japanese patients treated with transthoracic esophagectomy without neoadjuvant treatment. DNA was extracted from blood samples, and genetic polymorphisms for interferon (INF)-gamma, tumor necrosis factor-alpha and -beta, transforming growth factor-beta1, interleukin (IL)-1beta, IL-1 receptor antagonist, IL-2, IL-6, IL-6 receptor, IL-10, and IL-12beta were investigated using the polymerase chain reaction-restriction fragment length polymorphism method. We then assessed the association between gene polymorphisms and postoperative infection.

RESULTS

Of the 110 patients studied, 18 (16%) developed a postoperative infection (pneumonia, 14 patients; pyothorax, 5; intraabdominal abscess, 1; neck abscess, 1; sepsis, 2). Although the characteristics of patients who developed postoperative infections did not differ, analysis of the genotypes using the Fisher exact test revealed a significantly (P = .0215) greater incidence of postoperative infections among those carrying the INF-gamma 874 (rs2430561) A/A and A/T genotypes. Moreover, univariate and multivariate logistic regression models showed patients carrying the INF-gamma 874A/T genotype were significantly more likely to develop postoperative infectious complications (odds ratio>3.4).

CONCLUSION

Our findings suggest that the IFN-gamma 874A>T polymorphism is potentially predictive of the likelihood that patients undergoing esophagectomy for thoracic esophageal cancer will develop postoperative infections. This polymorphism may therefore have important clinical relevance and should be considered when treatment regimens are designed.

Extended haplotype analysis reveals an association of TNF polymorphisms with susceptibility to systemic lupus erythematosus beyond HLA‐DR3

OBJECTIVE

To study the relative contribution of tumour necrosis factor (TNF) and HLA-DRB1 polymorphisms to the genetic susceptibility to systemic lupus erythematosus (SLE) via an extended haplotype analysis.

METHODS

We performed an association study in 205 unrelated German Caucasian patients with SLE fulfilling the 1997 revised American College of Rheumatology (ACR) criteria. Healthy age-, ethnically- and sex-matched individuals (n = 157) served as controls. HLA-DRB1 typing was performed by a sequence-specific oligonucleotide hybridisation assay. Two TNF single nucleotide polymorphisms (SNPs) and two multiallelic microsatellites were analysed by mutagenically separated polymerase chain reaction (PCR) or fragment length analysis, respectively. Extended haplotypes were reconstructed with the PHASE software.

RESULTS

Alleles for all polymorphic loci studied and the most frequent haplotypes showed a significantly different distribution between SLE patients and controls. The alleles HLA-DR2, DR3, TNFd1, TNF2, TNFB*1, and TNFa2, designated as risk alleles, and the extended haplotypes DR3-TNFd1-TNF2-TNFB*1-TNFa2 and DR2-TNFd3-TNF1-TNFB*2-TNFa11 prevailed in SLE patients. TNF risk alleles were strongly positively linked with HLA-DR3 and negatively linked with HLA-DR2. Thus, in HLA-DR3 haplotypes individual effects of TNF polymorphisms could not be resolved. By contrast, HLA-DR2 showed an association with SLE independently of TNF risk alleles, while the risk increased further when they were present. In haplotypes lacking HLA-DR2 and DR3, the alleles TNFdl and TNF2 contributed independently to SLE susceptibility.

CONCLUSION

Extended haplotype analysis revealed HLA-DR3 independent associations of TNF polymorphisms with susceptibility to SLE. Haplotypes that have been shown to be associated with different TNF-alpha production capacity may prevail in different disease subgroups.

Systemic lupus erythematosus: multiple immunological phenotypes in a complex genetic disease

Systemic lupus erythematosus (SLE) is a complex polygenic autoimmune disease characterized by the presence of anti-nuclear autoantibodies (ANAs) that are often detectable years prior to the onset of clinical disease. The disease is associated with a chronic activation of the immune system, with the most severe forms progressing to inflammatory damage that can impact multiple organ systems in afflicted individuals. Current therapeutic strategies poorly control disease manifestations and are generally immunosuppressive. Recent studies in human patient populations and animal models have associated elements of the innate immune system and abnormalities in the immature B lymphocyte receptor repertoires with disease initiation. A variety of cytokines, most notably type I interferons, play important roles in disease pathogenesis and effector mechanisms. The genetic basis for disease susceptibility is complex, and analyses in humans and mice have identified multiple susceptibility loci, several of which are located in genomic regions that are syntenic between humans and mice. The complexities of the genetic interactions that mediate lupus have been investigated in murine model systems by characterizing the progressive development of disease in strains expressing various combinations of susceptibility alleles. These analyses indicate that genetic epistasis dramatically impact disease development and support the feasibility of identifying molecular pathways that can suppress disease progression without completely impairing normal immune function.

Genetic contribution of the tumour necrosis factor (TNF) B + 252*2/2 genotype, but not the TNFa,b microsatellite alleles, to systemic lupus erythematosus in Japanese patients

The contribution of the tumour necrosis factor (TNF) B + 252 (TNFB) dimorphism and microsatellite polymorphisms of TNFa and TNFb to the pathogenesis of systemic lupus erythematosus (SLE) was studied in Japanese patients. The TNFB dimorphism was determined using the restriction fragment length polymorphism (RFLP) method with NcoI digestion followed by specific polymerase chain reaction (PCR) amplification. TNFa and TNFb microsatellite polymorphisms were determined using the DNA sequencer and GeneScan program (Applera Corporation, Foster City, CA) followed by specific PCR amplification. HLA-DRB1*15 typing was carried out by the PCR-sequence specific conformational polymorphism (SSCP) method. In SLE, the allele frequency of TNFB*2 significantly increased (68.9%, P < 0.05) and the genotype frequency of TNFB*2/2 also increased (52.8%, P < 0.05). TNFB*2 showed no significant linkage disequilibrium with HLA-DRB1*1501. The prevalence of TNFa13 and TNFb4 showed very slight increases, but these increases were not significant. An association analysis indicated that TNFB*2/2 conferred greater, or at least equal, susceptibility to SLE in Japanese patients in comparison with HLA-DRB1*1501. The TNFB*2/2 genotype may contribute additively with DRB1*1501 to SLE in Japanese patients. No association was observed between auto-antibodies and TNF. TNFB*2 is a genetic marker for SLE in Japanese patients, while TNFa and TNFb microsatellites are not associated with SLE.

Genomic view of systemic autoimmunity in MRLlpr mice

MRLlpr mice develop spontaneous systemic autoimmunity with many hallmarks of the human disease systemic lupus erythematosus. Although a variety of genes have been implicated in this model, disease pathogenesis is still poorly understood. In an effort to identify novel genes and pathways, we performed genome-wide mRNA expression analysis in the spleens and kidneys of MRLlpr mice throughout the disease course. Samples were collected from cohorts of C57BL/6, MRL+/+ and MRLlpr mice, and profiled by flow cytometry and gene expression microarrays. Serum autoantibodies and renal pathology were studied in parallel. We identified 236 genes in MRLlpr spleen that showed significant threefold or greater changes in expression between 6 and 20 weeks. Of interest, a number of interferon-responsive genes were expressed early, and remained dysregulated throughout the disease course. Many chemokines, cell surface proteins, transcription factors and cytokines, including IFN-gamma, also showed altered expression as disease progressed. Analysis of kidneys indicated the presence of severe inflammation that coincided with evidence for changes in kidney function and elevated expression of IFN-inducible genes, complement components and antigen presentation genes. These data provide a unique genomic view of the progression to fatal autoimmunity in MRLlpr mice, and provide new candidate genes and pathways to explore.

Genetic polymorphisms in tumor necrosis factor (TNF)-alpha and TNF-beta in a population-based study of systemic lupus erythematosus: associations and interaction with the interleukin-1alpha-889 C/T polymorphism

Tumor necrosis factor (TNF) is involved in the pathogenesis of systemic lupus erythematosus (SLE), but the role of TNF polymorphisms in SLE susceptibility remains unclear. Previous studies in different populations report an inconsistent association of the TNF-alpha -308A allele with SLE, sometimes depending on the presence of HLA-DR3. We examined the association of polymorphisms in TNF-alpha (-308G/A, -238G/A) and TNFbeta (+252A/G) in a population-based study of SLE in the southeastern United States and considered TNF-SLE associations with respect to HLA-DR3 and DR2 and the interleukin (IL)-1alpha -889C/T polymorphism, previously linked to SLE in this population. Genotypes were analyzed for 230 recently diagnosed SLE patients who met American College of Rheumatology classification criteria and 276 age- and sex-matched controls, randomly selected from driver's license registries. Carriage of the TNF-alpha -308A allele was significantly associated with SLE in Caucasians (OR = 2.3; 95% CI 1.4, 3.9), but not African Americans. Analyses stratified by IL-1alpha -889 genotypes (C/C vs C/T or T/T) revealed independent associations of SLE with TNF-alpha -308A or HLA-DR2 and DR3. This reflected a significant interaction of TNF and IL-1 genotypes in Caucasians, and yielded a strong association (OR = 8.0, p < 0.00001) for the combined "HLA-DR3, TNF-alpha -308A, IL-1alpha -889C/C" genotype. These findings provide evidence of cytokine gene epistasis in SLE susceptibility.

Genetics of human systemic lupus erythematosus: the emerging picture

Systemic lupus erythematosus (SLE) is a systemic autoimmune inflammatory disease with partially understood etiology, which can affect virtually any organ. Despite suggestions to the contrary, SLE is proving to be a reliable phenotype for genetic studies. Similar to many other autoimmune diseases, SLE demonstrates a complex pattern of inheritance that is consistent with the involvement of multiple susceptibility genes as well as environmental risk factors. During the past several years, some new candidate genes have been implicated in induction of SLE through association studies, and multiple susceptibility regions have been detected through genome-wide linkage studies. Many of the susceptibility effects have been confirmed by independent studies.

Immunosuppressive therapy modulates T lymphocyte gene expression in patients with systemic lupus erythematosus

To evaluate the T-cell large-scale differential gene expression in systemic lupus erythematosus (SLE) patients presenting with glomerulonephritis we studied SLE patients before and after immunosuppressive treatment. Large-scale gene expression of peripheral blood mononuclear T cells was evaluated using cDNA microarray nylon membranes containing 5184 cDNAs. Data were analysed using the SAM and Cluster and Treeview software. When untreated patients were compared to healthy individuals, 38 genes, most of them located on chromosomes 1, 3, 6, 17 and 19, were repressed, and when untreated patients were compared to treated ones, 154 genes, located on chromosomes 1, 6, 7, 12 and 17, were induced. In terms of biological function of coded proteins, the differentially expressed genes were associated with apoptosis, cell cycle, chromosomal scaffold, cytokine/chemokine, DNA repair/replication, Golgi/mitochondrial proteins, mRNA processing, signalling molecules and tumour suppressors. Two autoantigen genes related to RNA splicing (small nuclear riboprotein 70,000 MW-U1 SNR, and splicing factor 3a, 60,000 MW), and the tetranectin-plasminogen-binding protein were repressed. The Fc fragment of immunoglobulin G low affinity IIb, apoptotic protease activating factor-1, two subunits of cytochrome c, caspase 8, complement C5a, HLA-DRA, HLA-DQB1, transforming growth factor-beta receptor II, small nuclear ribonucleoprotein polypeptide N (Sm protein N) genes, heterogeneous nuclear riboprotein-C, and argininosuccinate lyase genes, among others, were induced. A total of 10 genes were repressed in untreated patients and induced in treated ones, among them tumour necrosis factor (ligand) superfamily member 9, tumour protein p53, mannosidase alpha class IA, and CD22. Although some of these differentially expressed genes are typically expressed in B cells, CD22 and CD32 have also been reported in T cells and may provide regulatory signals to B cells. Assessment of differential gene expression may provide hybridization signatures that may identify susceptibility, diagnostic and prognostic markers of SLE.

Novel polymorphisms and the definition of promoter ‘alleles’ of the tumor necrosis factor and lymphotoxin α loci: inclusion in HLA haplotypes

Tumor necrosis factor (TNF) and lymphotoxin alpha (LTA) influence a variety of cellular responses and play a complex role in the immune response. Several single nucleotide polymorphisms (SNPs) have been reported in these major histocompatibility complex (MHC)-linked loci; however, a comprehensive examination of polymorphisms in the promoter regions of TNF and LTA has not been carried out and was undertaken here. Seven novel SNPs in LTA were identified by sequence analysis of 69 samples. Eight novel TNF alleles and 16 novel LTA alleles were designated. The TNF alleles clustered into two closely related groups, while the LTA alleles clustered into three distinct groups using phylogenetic and percentage difference analyses. A total of 52 unique TNF-LTA-HLA haplotypes are reported. There appear to be some associations between TNF/LTA alleles and HLA haplotypes, but not with specific HLA alleles. The majority of the SNPs appear to be randomly associated within and between the two loci except for the LTA SNPs at -293, +81 and +369. These observations may provide an explanation for the oftentimes contradictory results of studies associating individual cytokine gene SNPs with expression level phenotypes, HLA and disease.

Role of transforming growth factor-beta 1 gene polymorphisms in childhood idiopathic thrombocytopenic purpura

PURPOSE

To investigate whether transforming growth factor-beta 1 (TGF-beta 1) gene polymorphisms have a role in the development, clinical progress, and treatment response in children with idiopathic thrombocytopenic purpura (ITP).

PATIENTS AND METHODS

Thirty-five children with acute ITP, 40 children with chronic ITP, and 97 healthy children were enrolled. After genomic DNA was extracted, TGF-beta 1 gene 509 (C-->T), codon 25 (Arg-->Pro), and codon 10 (Leu-->Pro) polymorphisms were studied using a coupled polymerase chain reaction-restriction enzyme digestion method.

RESULTS

The genotype and allele frequencies of TGF-beta 1 polymorphisms between acute ITP, chronic ITP, and control group did not differ significantly. No significant association was found between TGF-beta 1 polymorphisms and therapy response.

CONCLUSIONS

These results demonstrate that the frequency of TGF-beta1 gene 509 (C-->T), codon 25 (Arg-->Pro), and codon 10 (Leu-->Pro) polymorphisms and alleles do not play a role as a genetic risk factor in the development and clinical progress of ITP. Different results may be obtained with further studies involving larger patient populations and other TGF-beta 1 gene polymorphisms.

TNFB polymorphism may be associated with schizophrenia in the Korean population

This study was conducted to test the association between the tumor necrosis factor (TNF)-beta gene (B) polymorphism and schizophrenia in the Korean population. 127 patients with schizophrenia according to the DSM-IV criteria and 202 healthy controls were enrolled in this study. Patients and controls were biologically unrelated age and sex-matched native Koreans. Genotyping for the TNFB polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism. Genotype and allele distributions of the TNFB polymorphism in patients with schizophrenia were significantly different from those of the controls. Subjects with the TNFB*2 allele had an increased risk for schizophrenia (Odds Ratio=1.76, 95% CI=1.27-2.45). The present study suggests that the TNFB polymorphism may confer susceptibility to schizophrenia in the Korean population.

Tumor necrosis factor-beta gene polymorphism may not be associated with major depressive disorder in the Korean population

Tumor necrosis factor (TNF)-beta has been implicated in the regulation of immune system. Alterations of the immune system in patients with major depressive disorder (MDD) have been also proposed to date. The present study was undertaken to investigate whether TNF-beta gene polymorphism is associated with MDD in the Korean population. Ninety-five patients with MDD who met the criteria of DSM-IV and 202 gender- and age-matched unrelated volunteers participated in the study. Genotyping for TNF-beta gene was performed by a polymerase chain reaction-restriction fragment length polymorphism method. The genotype and allele distribution in patients with MDD was similar to that of the controls. This study suggests that the TNF-beta gene polymorphism does not confer a susceptibility to MDD in the Korean population. A larger scaled study to examine different races is necessary to determine a role in the pathogenesis of MDD.

Tumour necrosis factor alpha (-238 and -308) and beta gene polymorphisms in pulmonary tuberculosis: haplotype analysis with HLA-A, B and DR genes

SETTING

A study of tumour necrosis factor alpha and beta (TNFalpha and beta) gene polymorphism and haplotype analysis with HLA in pulmonary tuberculosis.

OBJECTIVE

To determine whether TNFalpha (-238 and -308) and TNFbeta (Nco I polymorphism in intron 2) genes either alone or in combination with human leucocyte antigens (HLA) as haplotypes afford susceptibility or resistance to pulmonary tuberculosis as well as bacteriological relapse of the disease.

DESIGN

Tumour necrosis factor alpha -238, -308 (TNFalpha -238, -308) and TNFbeta (Nco I) gene polymorphisms were carried out in HLA-A,B and DR typed pulmonary tuberculosis patients (n=210) and 120 normal healthy control subjects.

RESULTS

No difference in the genotype frequencies of TNFalpha-238 and -308 and TNFbeta was seen between control subjects and pulmonary tuberculosis patients. Of the HLA-TNF haplotypes analysed, the infrequent allele (A) of TNFalpha238 was in strong linkage disequilibrium with HLA-A1 (P corrected: Pc=0.001), B17 (Pc<0.0001) and DR7 (Pc=0.01) in control subjects and with B17 (Pc<0.0001) in pulmonary tuberculosis. The infrequent allele 2 of TNFalpha-308 and the infrequent allele 2 of TNFbeta were in strong linkage disequilibrium with HLA-B21. An increased haplotype frequency of HLA-B17-TNFalpha-238/A (P=0.05), B17-TNFalpha308/2 (P=0.03) and B17-TNFalpha308/2 (P=0.01) was observed in bacteriological relapse patients than quiescent patients.

CONCLUSION

The present study suggests that TNFalpha (-238 and -308) and TNFbeta gene variants are not associated independently with the susceptibility to pulmonary tuberculosis. However, in combination with the HLA genes/gene products such as HLA-A1, B17, B21 and DR7, the TNFalpha and beta genes as haplotypes are associated with protection against the disease as well as an increased susceptibility to bacteriological relapse.

GvHD risk assessment in hematopoietic stem cell transplantation: role of cytokine gene polymorphisms and an in vitro human skin explant model

This present review concentrates on the recent results investigating the role of certain cytokine gene polymorphisms, including tumor necrosis factor alpha, interferon gamma, interleukin-6 (IL-6), IL-10, and IL-1 receptor antagonist, in allogeneic stem cell transplantation. The review discusses their potential role in predicting outcome and the development of a genetic risk index for graft-versus-host disease in human leukocyte antigen matched sibling transplants. By the comparative use of an in vitro human skin explant model, initial results suggest that certain polymorphisms may be associated with more severe disease.

Cytokine polymorphisms in systemic lupus erythematosus and Sjögren's syndrome

Systemic lupus erythematosus (SLE) and Sjögren's syndrome (SS) are defined genetically as complex diseases where multiple genes are involved in their pathogenesis. Among the genes of interest are those coding for the cytokines, molecules involved in immunoregulation that have been shown to play important roles in these diseases. Whether abnormalities in cytokine production are owing to genetic polymorphisms within the genes themselves is a matter of intensive study. The finding of functional polymorphisms within cytokine genes and their potential association with disease will open new avenues in their treatment.

Distribution of seven polymorphic markers and haplotypes within the human TNF gene cluster in Koreans

We examined the distribution of polymorphic elements within the tumor necrosis factor (TNF) gene cluster in 133 normals and in 20 Korean families and compared our data with the results of Caucasians. The genotypes that are shown frequently are TNF a6 (33.8%), TNF b5 (46.6%), TNF c1 (79.3%), TNF d3 (34.6%), TNF e3 (86.5%), TNFB*2 (51.5%), and TNF(-308) A (91.4%). In comparison, TNFa 6 (33.8%), TNFa 13 (4.1%), TNFb 5 (46.6%), TNFd 1 (7.5%), TNFd 3 (34.6%), TNFe 3 (86.5%), TNFe 4 (6.8%), and TNF(-308) A (91.3%) were found more frequently in Koreans than Caucasians (p < 0.01). TNFa 14, TNFa 15, TNFd 8, and TNFe 4 alleles were found only in Korean controls. However, TNFb 6 and TNFb 7 alleles were not found in this study. From the TNF gene of TNFa, TNFb, TNFc, TNFn, TNF(-308), TNFd, and TNFe, 49 different TNF haplotypes were found in 20 Korean families. These data suggest that the TNF microsatellite haplotypes constitute a highly polymorphic system and that will provide useful information on the association between the TNF marker and the immune disease.

Genetics of systemic lupus erythematosus. Clinical implications

Rheumatic diseases have long been recognized as having complex inheritance patterns. It has recently been estimated that over 100 genes may be implicated in the SLE disease process. Identification of these genes has led to a greater understanding of the etiopathogenesis of SLE and is beginning to lead to new types of interventions directed at correcting aberrant biological processes.

TNF-alpha and TNF-beta gene polymorphisms in systemic sclerosis

Tumor necrosis factor (TNF)-alpha and TNF-beta, mediators of inflammatory responses, have been implicated in the pathogenesis of autoimmune diseases. The aim of this investigation was to determine whether two promoter region polymorphisms of the TNF-alpha gene (TNF-alpha -308 and TNF-alpha -238) and a determinant in the first intron of the TNF-beta gene (TNF-beta +252) affect susceptibility to systemic sclerosis (scleroderma) (SSc). Fifty patients and 60 healthy blood donors from Japan were genotyped for these markers by polymerase chain reaction-based methods. Fisher's exact test was used to test for significant associations. Because of very limited variation at the TNF-alpha -308 and TNF-alpha -238 loci in the Japanese people, statistical analyses with sufficient power could not be done for these genotypes. However, the two homozygous genotypes of the TNF-beta +252 locus were found to be significantly associated with SSc. Compared to controls, the frequency of the TNF-1 genotype was decreased, whereas that of TNF-2 was increased in SSc patients. The former implies an association with resistance, while the latter suggests an association with susceptibility to the disease. These results show that the TNF-beta +252 locus plays an important role in the etiopathogenesis of SSc.

Genetic influences on sarcoidosis

To investigate the genetic influences underlying the development of sarcoidosis, HLA class II genotyping was performed in Japanese patients with sarcoidosis and healthy controls using the PCR-RFLP method. The frequencies of both DR52 group antigen-associated alleles (HLA-DRB1*11, -DRB1*12 and -DRB1*14) and DRB1*08 alleles were higher in the patient group, suggesting that the common, specific amino acid residue on the DRB1 molecule of these alleles may determine susceptibility to sarcoidosis. Alternatively, it is possible that another susceptibility gene, linked to these DRB1 alleles, exists within the MHC region. We screened the TNFA, TNFB, HSP70-1 and Hum70t genes around the class III region, as well as the HLA-DMA and -DMB genes in the class II region, for genetic polymorphism in sarcoidosis. None of these genes suggested a susceptibility to sarcoidosis. These studies support the thesis that one of the major genetic factors controlling the development of sarcoidosis is located within the DRB1 locus in the HLA class II region.

Decreased tumour necrosis factor-beta production in TNFB*2 homozygote: an important predisposing factor of lupus nephritis in Koreans

Low TNF production and its association with TNF gene restriction fragment length polymorphism (RFLP) was demonstrated in (NZW/NZB) F1 mice. However, little is known about the significance of TNF production in association with TNF gene polymorphism in human SLE. This study was designed to evaluate the role of TNF production of peripheral blood mononuclear cells (PBMC) and its association with TNFB gene polymorphism in SLE, particularly lupus nephritis. TNFB gene polymorphism was defined by PCR-NcoI RFLP. TNF productions of phytohemagglutinin (PHA)-stimulated PBMC and T cells were examined by bioassay using L929 cell line and ELISA. The PBMC stimulated by PHA from patients with SLE (n = 60) tended to secrete less amounts of TNF by bioassay (1032 +/- 184 pg/ml vs 1524 +/- 224 pg/ml, P = 0.094), and TNF-beta by ELISA (P = 0.0082) than that from normal controls (n = 38). The low TNF-alpha producer was more frequent in nephritis than non-nephritis (34.4% vs 7.1% respectively, P < 0.01). TNF-beta also revealed similar results (53.1% vs 21.4%, P < 0.05). In SLE, mean production of TNF-beta was decreased in TNFB*2 homozygote (n = 18) than that in TNFB*1 homozygote (n = 9) (1126.3 +/- 145 pg/ml) vs 642 +/- 118.4 pg/ml, respectively, P = 0.021), whereas TNF-alpha production showed little difference between the two groups (710.1 +/- 56.4 vs 542.4 +/- 71.1 pg/ml, respectively, P = 0.149). Our results demonstrate that decreased TNF production of PBMC, which was significantly associated with TNFB*2 homozygosity, could be an important predisposing factor of lupus nephritis in Koreans.

Molecular analysis of major histocompatibility complex allelic associations with systemic lupus erythematosus in Taiwan

OBJECTIVE

To investigate the association of HLA class II alleles/haplotypes, type I C2 deficiency gene, and tumor necrosis factor a gene promoter allele (TNF2) with systemic lupus erythematosus (SLE) in the Chinese population in Taiwan.

METHODS

The HLA-DRB1 and DQB1 alleles were studied in 105 SLE patients and 115 controls by the polymerase chain reaction (PCR)/sequence-specific oligonucleotide probe method, the subtyping of DRB1*15/16 and DRB5 by PCR with sequence-specific primers, type I C2 deficiency gene by PCR, and TNF2 by PCR-Nco I restriction fragment length polymorphism.

RESULTS

The frequencies of the HLA class II alleles DRB1*02, DRB1*1502, DRB5*0102, DQB1*0501, and DQB1*0602 and DR2-associated haplotypes DRB1* 1501,DRB5*0101,DQB1*0602 and DRB1*1502,DRB5* 0102,DQB1*0501 were higher among SLE patients than among controls; however, only DQB1*0501 was statistically significantly associated with SLE. No specific allele/haplotype was significantly associated with lupus nephritis. No subject had type I C2 deficiency. SLE patients had a marginally higher percentage of TNF2, which was in linkage disequilibrium with DR3. Since DR3 was not associated with SLE in this Taiwanese Chinese population, TNF2 might play a role in the immunopathogenesis of SLE.

CONCLUSION

Although no HLA-DRB1 allele was found to be significantly associated with SLE, the associations with DQB1*0501 and TNF2 suggest that DQB1 and tumor necrosis factor a may be important genetic factors in SLE susceptibility in the Chinese population in Taiwan.