DNA polymorphisms and mutations of the tumor necrosis factor-alpha (TNF-alpha) promoter in Langerhans cell histiocytosis (LCH)

The effects of genotype on inflammatory response in hippocampal progenitor cells: A computational approach

Cell culture models are valuable tools to study biological mechanisms underlying health and disease in a controlled environment. Although their genotype influences their phenotype, subtle genetic variations in cell lines are rarely characterised and taken into account for in vitro studies. To investigate how the genetic makeup of a cell line might affect the cellular response to inflammation, we characterised the single nucleotide variants (SNPs) relevant to inflammation-related genes in an established hippocampal progenitor cell line (HPC0A07/03C) that is frequently used as an in vitro model for hippocampal neurogenesis (HN). SNPs were identified using a genotyping array, and genes associated with chronic inflammatory and neuroinflammatory response gene ontology terms were retrieved using the AmiGO application. SNPs associated with these genes were then extracted from the genotyping dataset, for which a literature search was conducted, yielding relevant research articles for a total of 17 SNPs. Of these variants, 10 were found to potentially affect hippocampal neurogenesis whereby a majority (n=7) is likely to reduce neurogenesis under inflammatory conditions. Taken together, the existing literature seems to suggest that all stages of hippocampal neurogenesis could be negatively affected due to the genetic makeup in HPC0A07/03C cells under inflammation. Additional experiments will be needed to validate these specific findings in a laboratory setting. However, this computational approach already confirms that in vitro studies in general should control for cell lines subtle genetic variations which could mask or exacerbate findings.

Proteomic identification of allergenic proteins in red oak (Quercus rubra) pollen

BACKGROUND

Red oak pollen is an important cause of allergic respiratory disease and it is widely distributed in North America and central Europe. To date, however, red oak pollen allergens have not been identified. Here, we describe the allergenic protein profile from red oak pollen.

METHODS

Total proteins were extracted from red oak pollen using a modified phenolic extraction method, and, subsequently, proteins were separated by two-dimensional gel electrophoresis (2DE) for both total protein stain (Coomassie Blue) and immunoblotting. A pool of 8 sera from red oak sensitive patients was used to analyze blotted proteins. Protein spots were analyzed by Mass Spectrometry.

RESULTS

Electrophoretic pattern of total soluble proteins showed higher intensity bands in the regions of 26-40 and 47-52 kDa. Two dimensional immunoblots using pool sera from patients revealed four allergenic proteins spots with molecular masses in the range from 50 to 55 kDa. Mass spectrometry analysis identified 8 proteins including Enolase 1 and Enolase 1 chloroplastic, Xylose isomerase (X1 isoform), mitochondrial Aldehyde dehydrogenase, UTP-Glusose-1-phosphate uridylyltransferase, Betaxylosidase/alpha-l-arabinofuranosidase and alpha- and beta subunits of ATP synthase.

CONCLUSIONS

This study has identified for first time 8 IgE binding proteins from red oak pollen. These findings will pave the way towards the development of new diagnostic and therapeutic modalities for red oak allergy.

High levels of plasma interleukin-17A are associated with severe neurological sequelae in Langerhans cell histiocytosis

OBJECTIVE

Langerhans cell histiocytosis (LCH) is a granulomatous inflammatory myeloid neoplasia associated with a cytokine storm in both serum and lesions. Increased levels of plasma interleukin-17A (IL-17A) in LCH patients have been reported, but this finding was not confirmed in all studies. Neurodegeneration is a devastating complication of LCH (ND-LCH). We aimed to revisit the issue of plasma IL-17A levels in LCH, by using a larger number of patients, and also to investigate the relationship between IL-17A and LCH sequelae, especially ND-LCH.

METHODS

Plasma samples from 68 LCH patients and 127 controls were analyzed for IL-17A levels by two ELISAs with different anti-IL-17A capture antibodies: either polyclonal or neutralizing monoclonal antibodies in 17polyAb-ELISA or 17mAb-ELISA, respectively.

RESULTS

Both ELISAs had a similar capacity to specifically detect recombinant or native human IL-17A, as well as plasma IL-17A from LCH patients. We confirmed the finding of higher levels of plasma IL-17A in LCH patients compared to controls (p < 0.0001). The association of IL-17A with LCH was independent of the ELISA used, and of gender, age, disease class activity, and pattern of tissue-organ involvement (single-system versus multi-system). ROC analyses (p < 0.0001) allow to discriminate LCH patients from the control group, supporting the notion that IL-17A may be a potential biomarker for LCH. More interestingly, high IL-17A levels were significantly associated with LCH patients having sequelae, with the highest plasma levels in patients with ND-LCH (p < 0.0001).

CONCLUSION

The association between high levels of IL-17A and LCH was confirmed. IL-17A may be associated with ND-LCH development. This might have therapeutic implications, offering a novel target for precision therapy of ND-LCH.

TNF-α (-308) Gene Polymorphism and Type 2 Diabetes Mellitus in Ethiopian Diabetes Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder resulting from insulin insufficiency or function. Predisposing factors for T2DM are mainly genetic and environmental. Genetic polymorphism of cytokines like tumor necrosis factor-alpha (TNF-α) is suggestive of interference with insulin-sensitive glucose uptake and induces insulin resistance that ultimately could lead to T2DM. In this study, we assessed the effect of TNF-α (-308) G/A gene polymorphism and its association with the development of T2DM in an Ethiopian population.

METHODS

An institutional-based cross-sectional study was conducted on study subjects with T2DM and non-diabetic healthy controls. DNA was extracted and genotyping was carried out by using amplification refractory mutation system polymerase chain reaction. A genetic-polymorphism on TNF-α (-308) G/A with T2DM was evaluated by logistic regression and Student's t-test. A P-value <0.05 was considered as statistically significant.

RESULTS

In the present study, we observed a significant association between T2DM and TNF-α (-308) gene polymorphism's GG genotype [χ2 test P = 0.005, OR (95% CI) =2.667 (1.309-5.45d8)]. In contrast, no statistically significant differences were observed in the frequencies of genotypes AA and AG (χ2 test P=0.132 and 0.067, respectively). Moreover, T2DM individuals had higher concentrations of lipid profiles for those carrying the TNF-α (-308) GG genotype as compared to the control group.

CONCLUSION

TNF-α (-308) genetic polymorphism may be implicated in the genetic susceptibility for, as well as the development of T2DM and lipid metabolism in the Ethiopian population. Therefore, a large-scale study and early screening of TNF-α (-308) genetic polymorphism may help in early management and control of diabetes and related outcomes.

Association of tumor necrosis factor-α (TNF-α) gene promoter polymorphisms with aggressive and chronic periodontitis in the eastern Indian population

Background: Periodontitis is a very common inflammatory oral disease. Tumor necrosis factor-α (TNF-α) is a cytokine that has been involved with the gingival tissue destruction and remodeling occurrence. We investigated the association of single nucleotide polymorphisms (SNPs) in TNF-α gene promoter region with the susceptibility of aggressive and chronic periodontitis in the eastern Indian population.

Methods: A total of 397 DNA samples from venous blood were isolated. 40 individuals were aggressive periodontitis patients, 157 were identified chronic periodontitis patients, and the remaining 200 were healthy individuals. Five SNPs of TNF-α at promoter region (rs361525, rs1800629, rs1799724, rs1800630, and rs1799964) were genotyped by PCR-sequencing in periodontitis patients and control subjects.

Results: rs1800629 (-308G/A) polymorphism was more frequent in both aggressive and chronic periodontitis patients compared with the control population, though the allele frequency was different only in aggressive periodontitis patients. On the other hand, both the genotypic and allelic variation of rs361525 (-238G/A) polymorphism were found significantly less frequently in aggressive and chronic periodontitis than in controls. The other polymorphisms like rs1799724 (-857C/T) and rs1799964 (-1031T/C) were significantly different between chronic periodontitis patients and control subjects.

Conclusion: The findings suggest that the rs1800629 (-308G/A) polymorphism of TNF-α gene is associated with both aggressive and chronic periodontitis while rs1799724 (-857C/T) and rs1799964 (-1031T/C) polymorphisms of TNF-α gene is associated only with the increased susceptibility to chronic periodontitis.

TNF promoter polymorphisms are associated with genetic susceptibility in COPD secondary to tobacco smoking and biomass burning

Background

Smoking and smoke from biomass burning (BB) are the main environmental risk factors for COPD. Clinical differences have been described between COPD related to smoking and related to wood smoke, but no studies have shown genetic differences between patients exposed to these two risk factors.

Methods

To investigate a possible association of tumor necrosis factor (TNF) promoter polymorphisms, we conducted a case–control study. A total of 1,322 subjects were included in four groups: patients with a diagnosis of COPD secondary to smoking (COPD-S, n=384), patients with COPD secondary to biomass burning (COPD-BB, n=168), smokers without COPD (SWOC, n=674), and biomass burning-exposed subjects (BBES n=96). Additionally, a group of 950 Mexican mestizos (MMs) was included as a population control. Three single nucleotide polymorphisms (SNPs) were selected in the TNF gene (rs1800629, rs361525, and rs1800750) and one SNP in the lymphotoxin alpha gene (rs909253).

Results

Statistically significant differences were found with genotype GA of the rs1800629: COPD-S vs SWOC, (p<0.001, odds ratio [OR] =2.55, 95% CI=1.53–4.27); COPD-S vs COPD-BB (p,0.01). When performing the comparison of the less severe (G1: I + II) and the more severe (G2: III + IV) levels, differences were identified in G1 (p<0.05, OR=1.94, 95% CI=1.04–3.63) and G2 (p<0.001, OR=3.68, 95% CI=1.94–3.07) compared with SWOC. Regarding genotype GA of rs361525, it has been associated when comparing COPD-BB vs BBES (p=0.0079, OR=5.99, 95% CI=1.38–53.98).

Conclusion

The heterozygous genotype GA of polymorphisms rs1800629 and rs361525 in the TNF promoter are associated with the risk of COPD.

Single nucleotide polymorphisms in TNF are associated with susceptibility to aspirin-exacerbated respiratory disease but not to cytokine levels: a study in Mexican mestizo population

AIM

To evaluate the association of three single nucleotide polymorphisms in TNF and one in LTA in Mexican patients with aspirin-exacerbated respiratory disease (AERD) and the correlation of those single nucleotide polymorphisms with serum levels of TNF-α.

PATIENTS & METHODS

Case-control study including 133 patients with AERD, 135 patients with asthma (aspirin-tolerant asthmatics) and 182 healthy subjects.

RESULTS

GA genotype of rs1800629 in TNF was found to be associated with the risk of developing AERD (p < 0.05; odds ratio = 2.36) and by dominant model (p < 0.05; odds ratio = 2.51). Furthermore, there was a difference in the serum levels between the aspirin-tolerant asthmatics group and the other groups (p < 0.001).

CONCLUSION

The GA genotype of rs1800629 is associated with genetic susceptibility to AERD, but it does not correlate to protein serum levels.

Red blood cell alloimmunization in patients with sickle cell disease: correlation with HLA and cytokine gene polymorphisms

BACKGROUND

The reason for the difference in susceptibility to red blood cell (RBC) alloimmunization among patients with sickle cell disease (SCD) is not clearly understood and is probably the result of multiple factors. Our hypothesis is that genetic polymorphisms are associated with RBC alloimmunization.

STUDY DESIGN AND METHODS

We investigated the possible association of susceptibility to RBC alloimmunization with polymorphisms of HLA and cytokines genes in 161 SCD patients prior exposed to RBC transfusion. Cytokine gene polymorphisms were analyzed by polymerase chain reaction (PCR) and TaqMan assays. HLA Class I genotyping was performed using PCR-specific sequence of oligonucleotides. Polymorphism frequencies were compared using the Fisher's exact test.

RESULTS

Our results revealed increased percentage of the A allele and the GA genotype of the TNFA -308G/A cytokine among alloimmunized patients when compared to nonalloimmunized patients (A allele, 16.4% vs. 6.8%, p = 0.004; GA genotype, 32.8% vs. 11.7%, p = 0.0021). In addition, the IL1B -511T allele and the IL1B -511TT and CT genotype frequencies were overrepresented among alloimmunized patients (T allele, 53.0% vs. 37.5%, p = 0.0085; CT + TT genotypes, 81.82% vs. 60.87%, p = 0.0071). In relation to HLA Class I, we found a higher frequency of HLA-DRB1*15 among patients alloimmunized to Rh antigens when compared to nonalloimmunized patients (15.63% vs. 6.98%, p = 0.044).

CONCLUSION

Brazilian SCD patients with the TNFA, IL1B, and HLA-DRB1 gene polymorphisms were at increased risk of becoming alloimmunized by RBC transfusions. These findings may contribute to the development of future therapeutic strategies for patients with SCD with higher susceptibility of alloimmunization.

The -308 bp TNF gene polymorphism influences tumor necrosis factor expression in leprosy patients in Bahia State, Brazil

Leprosy or Hansen's disease is a debilitating chronic granulomatous disease caused by Mycobacterium leprae, with high incidence and prevalence in Brazil. The -308 bp G/A single nucleotide polymorphism (SNP rs1800629) in the tumor necrosis factor (TNF) gene promoter is a proposed risk factor for leprosy. In Brazil, Northern India, Egypt and Nepal, the common G allele was associated with leprosy. In Eastern India, Thailand and Malawi the minor A allele was the risk factor. Allele A was previously associated with high TNF. We genotyped rs1800629 in 326 leprosy cases from Bahia State, Brazil, including 72 paucibacillary (PB) and 47 multibacillary (MB) without reactions, and 69 reversal reaction (RR) and 78 erythema nodosum leprosum (ENL) with reactions. Logistic regression was used to compare patient groups with 331 healthy controls. Relative TNF mRNA was determined in peripheral blood leukocytes by QRTPCR, and serum TNF levels measured by ELISA. We found that TNF mRNA expression was higher (P=0.03) in leprosy patients compared to endemic controls, but did not differ significantly between clinical subgroups. Carriage of the minor A allele was associated (P=0.003) with low TNF mRNA across leprosy patients. Nevertheless, we found no evidence for either allele at this SNP as a risk factor for leprosy per se (OR=1.12, 95% CI 0.79-1.60, P=0.52), PB (OR=0.99, 95% CI 0.54-1.81, P=0.97), MB (OR=0.86, 95% CI 0.40-1.83, P=0.70), RR (OR=1.37, 95% CI 0.79-2.38, P=0.27) or ENL (OR=0.76, 95% CI 0.40-1.45, P=0.42) when compared to endemic controls. Further studies are required to determine whether the influence of the minor A allele on TNF mRNA levels determines response to treatment, particularly in the context of ENL reaction treatment with anti-TNF therapies and RR reactions where treatment with prednisolone is known to reduce TNF levels. Our findings contribute to understanding TNF as an important determinant of leprosy immunopathology in Brazil.

Identification of genetic variants in the TNF promoter associated with COPD secondary to tobacco smoking and its severity

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease that arises in response to noxious particles or gases. Associations of genetic polymorphisms in TNF have been reported in Asians and Caucasians, but not in Mestizo populations. A case-control study was conducted in two stages: in the first stage, patients with COPD (COPD group, n=165) and smokers without disease (SNC group, n=165) were included and the TNF promoter sequence was determined using direct sequencing. In the second stage, the identified polymorphisms were validated by real-time polymerase chain reaction (PCR) in COPD (n=260) and SNC (n=506). In the first stage, 11 different sets of “contig” alignments were determined, of which contig 10 was found to be associated with susceptibility (P=5.0E-04, OR [odds ratio] =3.64) and contig 1 with Global Initiative for COPD (GOLD) greater grade (P=1.0E-02, OR =3.82). The single nucleotide polymorphisms found in this region were individually identified; the GA genotypes of rs1800629 (P=0.038, OR =2.07), rs56036015 (P=0.0082, OR =3.18), and rs361525 (P=1.0E-02, OR =4.220) were higher in the COPD group vs the SNC group; after second-stage validation, rs1800629 (P=6.00E-03, OR =2.26) and rs56036015 (P=1.10E-03, OR =2.54) are maintained. There are genetic variants in the TNF promoter associated with increased risk of COPD secondary to smoking and with a higher GOLD grade in the Mexican Mestizo population.

Th1/Th2 cytokines and their genotypes as predictors of hepatitis B virus related hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the predominant type of primary liver cancer, is one of the most serious life-threatening malignancies, worldwide. In majority of the cases, HCC develops after prolonged and persistent chronic liver disease. hepatitis B virus (HBV) or HCV infection is prominent etiological factors, attributing to this condition. It has been well documented that HBV, being the inducer of chronic inflammation, is the main causative agent in causing HCC, particularly in Asian countries. The HBV infection leads to a wide range of clinical symptoms from carrier state to malignancy. Cytokines being immune-modulatory molecules, are the key mediators in the defense mechanism against viral infection. In this regard, this review will detail the substantial role of key Th1: interleukin 1 (IL-1), IL-2, IL-12, tumor necrosis factor-α, interferon-γ; Th2: IL-4, IL-10 and non Th1/Th2: IL-6, transforming growth factor-β1 cytokines genotypes in analyzing the variability in the clinical manifestations in an HBV-afflicted individual, which might finally, culminates into HCC. Since cytokine production is regulated genetically, the cytokine promoter region single-nucleotide polymorphisms induced changes, greatly affects the cytokine production, thus resulting into differential outcome of immune balance.

IFN-γ (+874) and not TNF-α (-308) is associated with HBV-HCC risk in India

Tumor necrosis factor (TNF)-α and interferon (IFN)-γ, the pro-inflammatory Th1 cytokines are the indispensable coordinators of the inflammatory responses involved in hepatitis B virus (HBV) pathogenesis. This study attempted to evaluate any possible association among TNF-α (-308G>A) and IFN-γ (+874T/A) genotypes, the spontaneous blood and mRNA levels and expression of their major signal transducers, namely STAT1 and NF-кB with hepatitis B virus-induced hepatocellular carcinoma (HCC) susceptibility in India. For this, 398 subjects (146 controls, 68 inactive-HBV-carriers, 64 chronic-active HBV patients, 61 HBV-cirrhotics, and 59 HBV-HCC subjects) were enrolled. Polymerase chain reaction-restriction fragment length polymorphism, allele-specific PCR, enzyme-linked immunosorbent assay, reverse transcriptase-PCR, and Western blot analysis were done for assessing polymorphism, blood levels, mRNA expression, and protein expression of signal transducers, respectively, of TNF-α and IFN-γ. The study revealed no significant association of TNF-α (-308) GA genotype, while a significant negative association of IFN-γ (+874) TA and AA genotypes, in HBV-HCC risk. Moreover, blood levels of TNF-α were significantly elevated as disease progresses to HCC, while IFN-γ levels were raised in HCC patients only. Besides, IFN-γ mRNA levels were significantly elevated in cirrhotics, with no change observed in TNF-α transcript levels. Moreover, NF-кB expression also consistently increased during HCC progression. These observations suggest a vital negative association of IFN-γ (+874) with HBV-HCC risk, with no significant association evident in TNF-α (-308). However, the TNF-α and IFN-γ levels markedly increased in HCC development.

Pulmonary Langerhans cell histiocytosis: profiling of multifocal tumors using next-generation sequencing identifies concordant occurrence of BRAF V600E mutations

BACKGROUND

Pulmonary Langerhans cell histiocytosis is a localized proliferation of Langerhans cells in the lung that presents without systemic manifestations as bilateral nodular lung disease in adult cigarette smokers. The molecular basis for this proliferation is unknown.

METHODS

Twenty-two concurrent nodules in five patients were microdissected from formalin-fixed paraffin-embedded tissue and analyzed by next-generation sequencing for mutations in 46 cancer genes with the Ion AmpliSeq Cancer Panel on an Ion PGM (Personal Genome Machine) Sequencer (Life Technologies Corporation). Mutation confirmation was performed by conventional Sanger sequencing or by sensitive coamplification at lower denaturation polymerase chain reaction/fluorescence melting curve analysis.

RESULTS

Small amounts of DNA (10 ng) isolated from nodules were sufficient for successful interrogation of 740 mutational hot spots in 46 cancer genes by the Ion PGM Sequencer, with an average depth of coverage of 2,783 reads per hot spot and with uniformity of coverage of 92%. BRAF V600E mutation was detected in all concurrent nodules studied in two of the five patients, whereas in three of the five patients, no oncogene mutations were found.

CONCLUSIONS

Pulmonary Langerhans cell histiocytosis appears to be a clonal proliferation that may or may not have BRAF V600E mutations. For those with BRAF V600E mutations, new targeted therapies, such as vemurafenib, may be used in progressive cases.

Tumor necrosis factor alpha promoter polymorphism -308 G/A in Brazilian patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antibodies to components of the cell nucleus in association with a diverse array of clinical manifestations. Polymorphisms in cytokines genes may play an important role in the development and clinical manifestation. Due to this, there is a great interest in the identification of biomarkers that which could quantify the susceptibility and disease activity. A case-control study of 98 lupus cases and 76 lupus-free adults controls, was performed to analyze whether or not the polymorphism of the TNF-α gene promoter at positions -308 G/A would alter the risk for SLE and clinical manifestations. Genotyping was carried out by polymerase chain reaction, PCR products were digested by NcoI restriction enzyme and fractionated after on 2% Agarose gel and visualized posteriorly staining by ethidium bromide. There were significant differences in the distribution of the TNF-α gene polymorphism between the SLE and control groups. Individual carriers of the variant allele A had a 3.29 (95% CI: 1.7738-6.1325)-fold increased risk for SLE. Moreover, association was observed between SLE patients and serositis (P=0.0228). This study presents a preliminary evidence of association between TNF-α polymorphism and SLE susceptibility in the Northeast population from Brazil.

Association Between Tumor Necrosis Factor-α Gene Polymorphism and Sasang Constitution in Cerebral Infarction

During the last decade, a growing corpus of evidence has indicated an important role of cytokines in the development of brain damage following cerebral ischemia. Tumor necrosis factor-α (TNF-α), a potent immunomodulator and pro-inflammatory cytokine, has been implicated in many pathological processes. In this study, we examined whether promoter region polymorphism in the TNF-α gene at position –308 affects the odds of cerebral infarction (CI) and whether genetic risk is enhanced by Sasang constitutional classification. Two hundred and twelve CI patients and 610 healthy controls were genotyped and determined according to Sasang constitutional classification. A significant decrease was found for the TNF-α A allele in CI patients compared with controls ( p = 0.033, odds ratio, OR: 0.622). However, there was no significant association between TNF-α polymorphism and Sasang constitution in CI patients. Our finding suggests that TNF-α promoter region polymorphism is responsible for susceptibility to CI in Koreans.

Association between the tumour necrosis factor-α-308G/A polymorphism and chronic obstructive pulmonary disease: an update

BACKGROUND AND OBJECTIVE

Previous studies have suggested that the -308A allele in the tumour necrosis factor-α (TNF-α) gene promoter (rs1800629) may be a potential risk factor for COPD. However, more recent findings have been inconsistent. In the present study, a meta-analysis was performed to assess the association between the TNF-α-308G/A single nucleotide polymorphism (SNP) and the risk of COPD.

METHODS

Published studies were retrieved from PubMed, EMBASE and other databases. All studies assessing the association between the TNF-α-308G/A SNP and the risk of COPD were assessed. Pooled ORs with 95% CIs were calculated.

RESULTS

In the 36 studies that met the inclusion criteria, 4975 patients and 6518 control subjects had been genotyped. The overall results showed that the association between the TNF-α-308G/A SNP and the risk of COPD was statistically significant for Asians (OR = 2.36, 95% CI: 1.84-3.02, P < 0.0001) but not for Caucasians (OR = 1.07, 95% CI: 0.91-1.25, P = 0.438). As smoking is one of the most important risk factors for COPD, a second meta-analysis that included only smokers (3018 patients and 2749 control subjects) was performed. This analysis confirmed that the association between the TNF-α-308G/A SNP and COPD was statistically significant for Asians (OR = 1.72, 95% CI: 1.14-2.61, P = 0.011) but not for Caucasians (OR = 1.16, 95% CI: 0.86-1.56, P = 0.33).

CONCLUSIONS

This meta-analysis suggests that the TNF-α-308A genotype is associated with an increased risk of COPD in Asian but not Caucasian populations. Further studies are necessary to evaluate the relationship between TNF-α polymorphisms and the risk of COPD.

Interaction of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism in the susceptibility to multiple sclerosis

Multiple sclerosis is a multifactorial disorder with complex genetic basis. It is believed that genes encoding HLA molecule and cytokines are involved in the pathogenesis of MS. In this study, we have evaluated the impact of HLA-DRB1*1501 allele and TNF-alpha -308 G/A single nucleotide polymorphism, and their interaction, in the susceptibility to MS in Iranian population. Genomic DNA samples were prepared from whole blood of 366 MS Patients and 414 control subjects. The genotypes were determined by SSP-PCR method. Frequency of alleles and genotypes were compared between the two groups by using Fisher's exact test. HLA-DRB1*1501 allele was more frequent among patients (OR=1.57, P=0.0026). TNF-α -308 G allele and G/G genotype had higher frequency among MS patients than control subjects (G vs. A: OR=1.26, P<0.05); G/G vs. A/A: OR=4.59, P=0.0003). The odds ratio was higher among HLA-DRB1*1501 positive individuals. Co-existence of TNF G and HLA-DRB1*1501 alleles showed higher prevalence among MS patients (OR=7.07, P=0.0007). Our results have shown that HLA-DRB1*1501 allele and TNF-α -308 G/A polymorphism are associated with the risk of multiple sclerosis in Iranian population. We also observed an interaction between these two loci that support the role of HLA alleles and cytokine genes and gene-gene interaction in the development and pathogenesis of MS.

Cell-specific gene expression in Langerhans cell histiocytosis lesions reveals a distinct profile compared with epidermal Langerhans cells

Langerhans cell histiocytosis (LCH) is a rare disease characterized by heterogeneous lesions containing CD207(+) Langerhans cells (LCs) and lymphocytes that can arise in almost any tissue and cause significant morbidity and mortality. After decades of research, the cause of LCH remains speculative. A prevailing model suggests that LCH arises from malignant transformation and metastasis of epidermal LCs. In this study, CD207(+) cells and CD3(+) T cells were isolated from LCH lesions to determine cell-specific gene expression. Compared with control epidermal CD207(+) cells, the LCH CD207(+) cells yielded 2113 differentially expressed genes (false discovery rate < 0.01). Surprisingly, the expression of many genes previously associated with LCH, including cell-cycle regulators, proinflammatory cytokines, and chemokines, were not significantly different from control LCs in our study. However, several novel genes whose products activate and recruit T cells to sites of inflammation, including SPP1 (osteopontin), were highly overexpressed in LCH CD207(+) cells. Furthermore, several genes associated with immature myeloid dendritic cells were overexpressed in LCH CD207(+) cells. Compared with the peripheral CD3(+) cells from LCH patients, the LCH lesion CD3(+) cells yielded only 162 differentially regulated genes (false discovery rate < 0.01), and the expression profile of the LCH lesion CD3(+) cells was consistent with an activated regulatory T cell phenotype with increased expression of FOXP3, CTLA4, and SPP1. Results from this study support a model of LCH pathogenesis in which lesions do not arise from epidermal LCs but from accumulation of bone marrow-derived immature myeloid dendritic cells that recruit activated lymphocytes.

Transcriptional control of the TNF gene

The cytokine TNF is a critical mediator of immune and inflammatory responses. The TNF gene is an immediate early gene, rapidly transcribed in a variety of cell types following exposure to a broad range of pathogens and signals of inflammation and stress. Regulation of TNF gene expression at the transcriptional level is cell type- and stimulus-specific, involving the recruitment of distinct sets of transcription factors to a compact and modular promoter region. In this review, we describe our current understanding of the mechanisms through which TNF transcription is specifically activated by a variety of extracellular stimuli in multiple cell types, including T cells, B cells, macrophages, mast cells, dendritic cells, and fibroblasts. We discuss the role of nuclear factor of activated T cells and other transcription factors and coactivators in enhanceosome formation, as well as the contradictory evidence for a role for nuclear factor kappaB as a classical activator of the TNF gene. We describe the impact of evolutionarily conserved cis-regulatory DNA motifs in the TNF locus upon TNF gene transcription, in contrast to the neutral effect of single nucleotide polymorphisms. We also assess the regulatory role of chromatin organization, epigenetic modifications, and long-range chromosomal interactions at the TNF locus.

Genomic variants associated with primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an autoimmune hepatobiliary disease characterized by immune-mediated injury of small and medium-sized bile ducts, eventually leading to liver cirrhosis. Several studies have addressed PBC immunopathology, and the data support an immune activation leading to autoantibodies and autoreactive T cells acting against the lipoylated 2-oxoacid dehydrogenase complexes. The causes of the disease remain unknown, but environmental factors and genetic susceptibility both contribute to its onset. Over the past two decades several association studies have addressed the role of genetic polymorphisms in PBC pathogenesis and have reported multiple associations. However, only a few studies had sufficient statistical power, and in most cases results were not independently validated. A genome-wide association study has recently been reported, but this too awaits independent confirmation. The aim of this present work is to critically review the numerous studies dedicated to revealing genetic associations in PBC, and to predict the potential for future studies based on these data.

A critical assessment of the factors affecting reporter gene assays for promoter SNP function: a reassessment of -308 TNF polymorphism function using a novel integrated reporter system

One of the greatest challenges facing genetics is the development of strategies to identify functionally relevant genetic variation. The most common test of function is the reporter gene assay, in which allelic regulatory regions are used to drive the expression of a reporter gene, and differences in expression in a cell line after transient transfection are taken to be a reflection of the polymorphism. Many studies have reported small differences in single nucleotide polymorphism (SNP)-specific reporter activity, including the tumor necrosis factor (TNF) G-308A polymorphism. However, we have established that many variables inherent in the reporter gene approach can account for the reported allelic differences. Variables, such as the amount of DNA used in transfection, the amount of transfection control vector used, the method of transfection, the growth history of the host cells, and the quality and purity of DNA used, all influence TNF -308 SNP-specific transient reporter gene assays and serve as a caution for those researchers who apply this method to the functional assessment of polymorphic promoter sequences. We have developed an integrated reporter system that obviates some of these problems and shows that the TNF G-308A polymorphism is functionally relevant in this improved assay, thus confirming that the -308A allele expresses at a higher level compared with the -308G allele.

Lack of TNFα mRNA expression in cervical cancer is not associated with loss of heterozygosity at 6p21.3, inactivating mutations or promoter methylation

Infection with oncogenic human papillomavirus (HPV) is considered to be the major etiologic event for cervical cancer. Tumor necrosis factor alpha (TNFalpha), a proinflammatory cytokine, may be involved in orchestrating an antitumor immune response against human papillomavirus expressing cervical cancer cells. Hence, loss of TNFalpha could be advantageous for tumor cells to escape immune clearance. The aim of our study was to investigate TNFalpha gene expression and epigenetic characteristics associated with the loss of TNFalpha expression in cervical cancer. To this end, we examined TNFalpha expression, loss of heterozygosity (LOH) at 6p21.3, the locus of TNFalpha, mutational status of the TNFalpha locus, loss of the TNFalpha promoter variant 2 allele and CpG hypermethylation of the TNFalpha promoter. RNA in situ hybridization showed absence of TNFalpha expression in 45% of 63 tumors. LOH occurred in 57% of the tumors and was not concordant with absence of TNFalpha mRNA. No mutations in the TNFalpha gene were identified in 15 cases deficient in TNFalpha expression exhibiting LOH. Furthermore, lack of TNFalpha expression did not correlate with promoter methylation. In conclusion, TNFalpha mRNA expression is absent in nearly half of the cervical tumors analyzed. Neither promoter methylation nor genetic causes for lack of expression were evident.

Relationship between iris constitution analysis and TNF-alpha gene polymorphism in hypertensives

Iridology is a complementary and alternative medicine that involves the diagnosis of medical conditions by noting irregularities of the pigmentation in the iris. Iris constitution has a strong hereditary component. Tumor necrosis factor-alpha (TNFalpha), a pleiotropic cytokine, has been implicated in many pathological processes including hypertension. In this paper, the relationship between iris constitution and TNFalpha gene polymorphism in those with hypertension is investigated. Eighty seven hypertensive individuals and 79 controls were classified according to iris constitution and the TNFalpha genotype of each individual determined. Compared to the controls, the frequency of the TNFalpha GA heterozygote was lower in the hypertensive group, although the statistical significance was marginal (p = 0.08). This result implies an association with resistance to the disease. In addition, the frequency of the cardio-renal connective tissue weakness type was significantly higher in the hypertensive group with the TNFalpha GG genotype, as compared to the controls (p = 0.001). An association is demonstrated among TNFalpha gene polymorphism, Koreans with hypertension, and iris constitution.

Combination of Helicobacter pylori strain and tumor necrosis factor-alpha polymorphism of the host increases the risk of peptic ulcer disease in children

BACKGROUND

Helicobacter pylori infection is probably acquired in childhood and causes a vigorous immune response. It is unclear why only a subgroup of infected children develops peptic ulcer disease. We have previously reported that iceA1 strains tend to be associated with duodenal disease in children. However, the pathogenesis probably does not depend solely on the H pylori strain but also on the variability of the host response.

OBJECTIVES

The aim of this study was to assess the significance of tumor necrosis factor-alpha (TNF-alpha) promoter polymorphism in relation to infection with H pylori strains in children.

METHODS

A total of 113 antral biopsies of H pylori-positive children (ages 2-18 years) were analyzed. Of these, 23 had duodenal disease, including erosive duodenitis and/or duodenal ulceration, and 90 had gastritis only. H pylori infection was diagnosed by bacterial culture and histology. Patient genomic DNA extracted from the antral biopsy was used to characterize the genetic polymorphism of TNF-alpha promoter at nucleotide positions -308 and -238 by polymerase chain reaction-based restriction fragment-length polymorphism. All H pylori strains were examined for cytotoxin-associated gene A and induced-by-contact-with-epithelium gene (iceA1).

RESULTS

A total of 31% of children with duodenal disease were infected with iceA1 positive strains and had the -238 G to A polymorphism in the TNF-alpha gene vs only 1.6% of children with gastritis alone (P < 0.0005).

CONCLUSIONS

The combination of bacterial iceA1 and TNF-alpha 238 G to A polymorphism may be a risk factor for peptic ulcer disease in children infected with H pylori. Larger studies are needed to confirm this association.

Contribution for new genetic markers of rheumatoid arthritis activity and severity: sequencing of the tumor necrosis factor-alpha gene promoter

The objective of this study was to assess whether clinical measures of rheumatoid arthritis activity and severity were influenced by tumor necrosis factor-alpha (TNF-alpha) promoter genotype/haplotype markers. Each patient's disease activity was assessed by the disease activity score using 28 joint counts (DAS28) and functional capacity by the Health Assessment Questionnaire (HAQ) score. Systemic manifestations, radiological damage evaluated by the Sharp/van der Heijde (SvdH) score, disease-modifying anti-rheumatic drug use, joint surgeries, and work disability were also assessed. The promoter region of the TNF-alpha gene, between nucleotides -1,318 and +49, was sequenced using an automated platform. Five hundred fifty-four patients were evaluated and genotyped for 10 single-nucleotide polymorphism (SNP) markers, but 5 of these markers were excluded due to failure to fall within Hardy-Weinberg equilibrium or to monomorphism. Patients with more than 10 years of disease duration (DD) presented significant associations between the -857 SNP and systemic manifestations, as well as joint surgeries. Associations were also found between the -308 SNP and work disability in patients with more than 2 years of DD and radiological damage in patients with less than 10 years of DD. A borderline effect was found between the -238 SNP and HAQ score and radiological damage in patients with 2 to 10 years of DD. An association was also found between haplotypes and the SvdH score for those with more than 10 years of DD. An association was found between some TNF-alpha promoter SNPs and systemic manifestations, radiological progression, HAQ score, work disability, and joint surgeries, particularly in some classes of DD and between haplotypes and radiological progression for those with more than 10 years of DD.

Tumor necrosis factor-alpha genetic predisposing factors can influence clinical severity in nephropathia epidemica

Severe human infection with Hantavirus is characterized by high fever, cold chills, thrombocytopenia, arterial hypotension, acute renal failure, and/or adult respiratory distress syndrome (ARDS)-like pulmonary involvement, but the clinical course varies greatly between individuals. We investigated whether genetically determined differences in tumor necrosis factor (TNF)-alpha production can influence the severity of Hantavirus disease. We studied a TNF-alpha single-nucleotide promoter polymorphism (SNP) at position -238 (a guanine [G]-to-adenine [A] transition) and ex vivo TNF-alpha production in a recall study of 36 Belgian patients who had a serologically proven form of Puumala virus-induced Hantavirus infection with the kidney as main target organ. In our study, the highest creatinine levels were found in patients with the lowest ex vivo TNF-alpha production. Creatinine levels correlated inversely with TNF-alpha production (R = -0.35, p < 0.05). The number of thrombocytes was significantly lower in patients with the GA-238 genotype (low TNF-alpha producers) compared with patients with the GG-238 genotype. In our study, genetically determined low production of TNF-alpha was associated with some parameters indicating a more severe clinical course of Puumala Hantavirus infection in humans, possibly by impaired activation of TNF-alpha-dependent antiviral mechanisms, which could in turn result in decreased clearance of Hantavirus.

Inflammation-related gene polymorphisms and colorectal adenoma

Chronic inflammation has been reported to be a risk factor for colorectal neoplasia. The propensity to mount an inflammatory response is modified by germ line variation in cytokine and other inflammation-related genes. We hypothesized that a proinflammatory genotype would be positively associated with colorectal adenoma, a precursor of colorectal cancer. We investigated the association of colorectal adenoma with 19 single nucleotide polymorphisms in a range of important proinflammatory (IL1B, IL6, IL8, TNF, and LTA) and anti-inflammatory (IL4, IL10, and IL13) cytokines and other inflammation-related genes (PTGS2 and PPARG) in a case-control study of risk factors for colorectal polyps in which all participants (ages 18-74 years) had undergone colonoscopy or sigmoidoscopy. The study sample comprised 244 cases of colorectal adenoma and 231 polyp-free controls. Compared with being homozygous for the common allele, heterozygosity at the IL1B -31 (C>T) locus was associated with an odds ratio (OR) for colorectal adenoma of 1.8 [95% confidence interval (95% CI), 1.2-2.9]. Homozygous carriers of the IL8 -251-A allele were at 2.7-fold increased risk of adenoma (95% CI, 1.5-4.9) compared with homozygosity for the common T allele, whereas carriage of at least one IL8 -251-A allele conferred a 1.5 increased odds of disease (95% CI, 1.0-2.4). Among non-nonsteroidal anti-inflammatory drug users, there was a statistically significant association between the IL10 -819-T/T genotype and adenoma compared with the common IL10 -819-C/C genotype (OR, 3.9; 95% CI, 1.1-13.6), which was not evident among nonsteroidal anti-inflammatory drug users (OR, 0.7; 95% CI, 0.3-1.5; P(interaction) = 0.01). These exploratory data provide evidence that polymorphic variation in genes that regulate inflammation could alter risk for colorectal adenoma.

Tumor necrosis factor-alpha -308G>A allelic variant modulates iron accumulation in patients with hereditary hemochromatosis

BACKGROUND

In vitro and animal studies suggest that tumor necrosis factor alpha (TNF-alpha) modulates intestinal iron transport. We hypothesized that the effect of TNF-alpha might be particularly relevant if iron absorption is not effectively controlled by the HFE gene.

METHODS

In patients with homozygous C282Y hemochromatosis, we investigated the influence of TNF-alpha -308G>A allelic variant on total body iron overload, determined in all patients by measuring iron removed during depletion therapy, and hepatic iron index and need for phlebotomy to prevent iron reaccumulation, measured in patient subgroups.

RESULTS

Of 86 patients with hereditary hemochromatosis, 16 (19%) were heterozygous carriers and 1 (1%) was a homozygous carrier of the TNF-alpha promoter -308A allele. Mean (SD) total body iron overload was increased 2-fold in TNF-alpha -308A allele carriers [10.9 (7.6) g] compared with homozygous carriers of the G allele [5.6 (5.0) g, P<0.001]. Hepatic iron index differed markedly between TNF-alpha -308A allele carriers [5.6 (3.5) micromol/g/year] and homozygous G allele carriers [3.1 (2.2) micromol/g/year, P=0.040, n=30]. After iron depletion, the need for phlebotomy to prevent iron reaccumulation (maintenance therapy) was substantially higher in TNF-alpha -308A allele carriers than in homozygous G allele carriers (P=0.014, n=73). We used multiple regression analyses to exclude possible confounding effects of sex, age, family screening, body-mass index, and meat or alcohol intake.

CONCLUSION

TNF-alpha -308G>A allelic variant modulates iron accumulation in patients with hereditary (homozygous C282Y) hemochromatosis, but the effect of the TNF-alpha -308A allele on clinical manifestations of hemochromatosis was less accentuated than expected from the increased iron load associated with this allele.

Oral Manifestations of Langerhans Cell Histiocytosis in a Pediatric Population

Langerhans Cell Histiocytosis is a rare and protean disease of unknown etiology, clinically characterized by single or multiple osteolytic and/or soft tissue lesions. Oral involvement may predate systemic manifestations or mimic infectious/inflammatory disorders. In the present series, oral involvement characterized eight cases of pediatric Langerhans Cell Histiocytosis and oral symptoms represented a very early sign of this disease in four patients. A careful clinical investigation and a proper histologic analysis were required for achieving a definite diagnosis and for confirming clinical suspicion of disease relapse. Immunohistochemistry, that nowadays represents a reliable and accessible ancillary histological technique, allowed the definite diagnosis in all cases of our series.

Genes and (auto)immunity in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a chronic autoimmune cholestatic liver disease most commonly encountered in postmenopausal women; it is characterized by high-titer serum autoantibodies to mitochondrial antigens, elevated serum IgM, progressive destruction of intrahepatic bile ducts, and ultimately liver cirrhosis and failure. The cytopathic mechanisms leading to the selective destruction of intrahepatic cholangiocytes are still largely unknown. The current theory on the pathogenesis of PBC indicated that environmental factors might trigger autoimmunity in genetically susceptible individuals. In fact, genetic predisposition is critical to disease onset and progression, yet peculiar among autoimmune diseases, as indicated by the lack of a strong association with major histocompatibility complex haplotypes. Further, the recently reported concordance rate among monozygotic twins strengthens the importance of genetic factors, while also indicating that additional factors, possibly infectious agents or xenobiotics, intervene to trigger the disease. In this review, the available data regarding the genetic factors associated with PBC susceptibility and progression, as well as the available evidence regarding the immunomediated pathogenesis of PBC, will be critically illustrated and discussed.

GCF2/LRRFIP1 represses tumor necrosis factor alpha expression

Tumor necrosis factor alpha (TNF-alpha) is an important mediator of inflammation, apoptosis, and the development of secondary lymphoid structures. Multiple polymorphic microsatellites have been identified in and around the gene, and there are also multiple single-base pair biallelic polymorphisms in the introns and promoter. The TNF-alpha -308 promoter polymorphism is a G-to-A transition which has been statistically associated with various autoimmune disorders. Some studies have found that it may directly mediate the increased transcription of TNF-alpha in some circumstances. This study characterizes proteins interacting at the polymorphic promoter site. Affinity purification of binding proteins and confirmatory chromatin immunoprecipitation assays were used to identify the proteins. Electrophoretic mobility shift analyses and surface plasmon resonance were used to define binding characteristics. Proteins interacting at this site include GCF2/LRRFIP1 and Ets-1. GCF2/LRRFIP1 appears to act as a repressor and occupies the -308 site in cells that do not make TNF-alpha. Cells competent to produce TNF-alpha have Ets-1 bound to the -308 promoter site. Active transcription is accompanied by NF-kappaB and c-Jun binding to the proximal promoter. Thus, dynamic changes on the TNF-alpha promoter, particularly at the -308 site, accompany the transition from repressed to active transcription. GCF2/LRRFIP1 is the first TNF-alpha repressor identified.

From bases to basis: linking genetics to causation in primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is a multifactorial autoimmune disease with inherited and environmental components in pathogenesis. It is exceptional among autoimmune diseases in showing strong heritability according to familial occurrence and monozygotic twins concordance, yet with weak associations with the usual genetic risk elements for autoimmunity, such as the HLA alleles. Among the latter, there is risk (at least in some populations) conferred by HLA DRB1*08 and possibly some protection by DRB1*11. However, the inconsistency among studies on HLA is surprising, given that PBC is a relatively homogenous disease entity. Among non-HLA genes, some studies implicate polymorphisms of genes for cytotoxic T-lymphocyte antigen-4, interleukin-2, or interleukin-10; polymorphisms of the vitamin D receptor could synergize with low sunlight exposure to create deficiency of the immunoregulatory factor, activated vitamin D. A new lead is available from the finding in female subjects with PBC of an increase in the degree of monosomy of the X chromosome that is presumed to carry immune response genes. A further suggested source of inquiry is the apparent protection of African-American women from PBC. Finally, data on inheritance should be sought in PBC by descent methodology, rather than by cross-sectional association studies in cases and control subjects, and based on analysis of a large number of families with an affected member through a worldwide effort.

Is there a future for TNF promoter polymorphisms?

The in vitro study of TNF promoter polymorphism (SNP) function was stimulated by the numerous case-control (association) studies of the polymorphisms in relation to human disease and the appearance of several studies claiming to show a functional role for these SNPs provided a further impetus to researchers interested in the role of TNF in their disease of interest. In this review we consider case-control studies, concentrating on the autoimmune and inflammatory diseases rheumatoid arthritis, multiple sclerosis, ankylosing spondylitis, and asthma, and on infectious diseases including malaria, hepatitis B and C infection, leprosy and sepsis/septic shock. We also review the available evidence on the functional role of the various TNF promoter polymorphisms. In general, case-control studies have produced mixed results, with little consensus in most cases on whether any TNF polymorphisms are actually associated with disease, although results have been more consistent in the case of infectious diseases, particularly malaria. Functional studies have also produced mixed results but recent work suggests that the much studied -308G/A polymorphism is not functional, while the function of other TNF polymorphisms remains controversial. Studies of the TNF region are increasingly using extended haplotypes that can better capture the variation of the MHC region.

Tumor necrosis factor, interleukin 11, and leukemia inhibitory factor produced by Langerhans cells in Langerhans cell histiocytosis

OBJECTIVES

: The etiology and pathophysiology of Langerhans cell histiocytosis (LCH) remain elusive. The 3-year survival in pediatric multisystem LCH is still around 80%, and children with risk organ involvement (i.e., liver, spleen, hematopoietic system, or lungs) have a less favorable outcome. To further elucidate the pathogenesis of LCH in the search for a rationale cure, the authors investigated intracellular synthesis of tumor necrosis factor (TNF), interleukin (IL)-11, and leukemia inhibitory factor (LIF) from biopsied lesions.

METHODS

: Lesional cells were obtained by fine-needle aspiration biopsy from nine children with LCH. The study was accomplished by the use of an immunofluorescence staining method that allowed cytokine-producing cells to be differentiated from cytokine-binding cells.

RESULTS

: All patients had histiocytes expressing TNF. Seven patients had histiocytes expressing IL-11 and six patients had histiocytes expressing LIF. The two children with the highest proportion of histiocytes displaying TNF and the three with the highest proportion of histiocytes expressing IL-11 and LIF all had risk organ involvement. Two-color staining revealed that histiocytes expressing TNF, IL-11, and LIF co-expressed CD1a molecules.

CONCLUSIONS

: These observations suggest that LCH represents a cytokine-driven condition partially mediated by TNF, IL-11, and LIF. These three cytokines are all osteoclastogenic, suggesting a pathogenetic pathway for the osteolytic lesions in LCH. Furthermore, thrombocytosis in LCH may be explained by IL-11 and LIF activity.

Frequencies of the tumor necrosis factor gene polymorphisms in the Korean population

Tumor necrosis factor (TNF), a potent immuno-modulator and pro-inflammatory cytokine, has been implicated in many pathological processes. The TNFA and the TNFB genes, which encode TNFalpha and TNFbeta, respectively, are both located on the short arm of chromosome 6 between the class I and class II regions of the HLA complex. A striking feature of the entire HLA complex is a high degree of genetic variation. Two biallelic polymorphisms in the TNFA (- 308G/A) and TNFB (+ 252A/G) genes have been reported to be associated with TNF production and with susceptibility to inflammatory diseases. Population information on polymorphisms is essential for the study of genetic diseases. The aim of this study is to obtain accurate information about polymorphisms in the TNF genes in the Korean population. Allele frequencies of TNFA (- 308G/A) and TNFB (+ 252A/G) were measured in 581 unrelated Korean individuals by PCR-RFLP. Allele frequencies of each polymorphism were determined and compared with those previously reported in other populations. A significant difference was found for the allele frequencies of TNFA and TNFB gene in Koreans compared with Europeans. The - 308/A allele in the TNFA gene was very rare in Asians (0.008-0.096). The frequency of the - 308/A allele in Koreans was considerably lower than in Europeans (0.120-0.189). Contrary to lower frequency of the -308/A allele, that of + 252/G allele in the TNFB gene was higher than in Koreans (0.445) compared with Europeans (0.29-0.39). The polymorphisms and allele frequencies obtained in this study will be useful for genetic studies of common inflammatory diseases.

Tumor necrosis factor alpha gene polymorphism is associated with cerebral infarction

We examined whether promoter region polymorphism in the tumor necrosis factor-alpha (TNFalpha) gene at position -308 affects the odds of cerebral infarction (CI). We genotyped 366 CI patients and 610 healthy controls for the same polymorphism. A significant decrease was found for the TNFalpha A allele in CI patients compared with controls (P=0.003). Our finding suggests that TNFalpha promoter region polymorphism is responsible for susceptibility to CI in Koreans.

TNF-alpha and TNF-beta gene polymorphisms in cerebral infarction

Tumor necrosis factor (TNF) is an important cytokine in the inflammation process of atherosclerosis. Two biallelic polymorphisms in the TNF-alpha (TNF-alpha -308) and TNF-beta (TNF-beta +252) genes have been reported to be associated with TNF production and susceptibility to inflammatory diseases. We investigated two genetic polymorphisms in the TNF locus (TNF-alpha -308 G-->A and TNF-beta +252 A-->G) as risk factors for cerebral infarction (CI) by determining its prevalence in 294 survivors of CI, and in 581 age-, gender-, and race-matched controls. A significant association was found for the TNF-alpha and TNF-beta genotypes in CI patients compared with controls. A significant increase was found for the TNF-alpha A allele in controls compared with CI patients (chi2 = 7.593, p = 0.006, odds ratio = 1.74, confidence interval = 1.17-2.59). In addition, the TNF-alpha GG genotype increased the relative risk for CI in subjects with the TNF-beta AA genotype (chi2 = 4.998, p = 0.025). As a result, compared to controls, the frequency of the TNF-alpha AA genotype was decreased, whereas that of TNF-beta AA was increased in CI patients. The former implies an association with resistance, whereas the latter suggests an association with susceptibility to the disease. These results show that the TNF-alpha -308 and TNF-beta +252 locus plays an important role in the etiopathogenesis of CI.

Langerhans cell histiocytosis patients have HLA Cw7 and DR4 types associated with specific clinical presentations and no increased frequency in polymorphisms of the tumor necrosis factor alpha promoter

BACKGROUND

Current theory on the etiology of Langerhans cell histiocytosis (LCH), formerly Histiocytosis-X, is that abnormality(ies) of the immune system are responsible for dysregulation of Langerhans cells (LC) in patients' lesions. Among the known abnormalities in LCH patients are increased amounts of tumor necrosis factor alpha (TNF-alpha) and other cytokines in the lesions.

PROCEDURE

We investigated the human leukocyte antigen (HLA) phenotypes of 29 patients and 37 healthy family members to determine if any haplotypes segregate with the presence or locations of the disease. The lymphocyte subsets for 22 patients and 11 family members were also determined.

RESULTS

Patients with single bone, multiple bone, or multi-system LCH had different relative proportions of HLA types. Patients presenting with single bone disease had an especially high frequency of the DR4 type. In this patient group, every Caucasian patient had either Cw7 or DR4. Lymphopenia was documented in patients who had been off therapy as well as those who only had surgical curetage of their lesions. Family members also had low numbers of T lymphocytes. There were fewer mutations of the TNF-alpha promoter in patients than in the general population.

CONCLUSIONS

Although there is an increased percentage of LCH patients with DR4 and/or Cw7 there was also an increased prevalence of this antigen as well as lymphopenia among unaffected family members. Additional genetic and/or environmental factors are necessary to explain this association. TNF-alpha promoter mutations are not responsible for the increased production of this cytokine.

Tumor necrosis factor-alpha gene promoter polymorphisms in chronic schizophrenia

BACKGROUND

Alterations in cytokine levels in patients with schizophrenia have been documented. Polymorphisms in these cytokine genes are thus potential genetic markers for schizophrenia. The aim of this study was to investigate four biallelic polymorphisms in the tumor necrosis factor-alpha (TNFalpha) gene promoter in relation to susceptibility to schizophrenia.

METHODS

Three hundred two patients and 152 control subjects were genotyped and frequencies of genotypes and alleles were compared for the -1031T/C, -863C/A, -857C/T, and -308G/A polymorphisms. Genotype and allele frequencies were compared between controls and patients.

RESULTS

There were statistically significant differences in genotype distribution and allele frequencies for the -308 polymorphism (p <.001). Genotype distribution and allele frequencies of the other three polymorphisms were not different between patients and reference controls.

CONCLUSIONS

The -308 polymorphism or another genetic variant in linkage disequilibrium with it could be a susceptibility factor for chronic schizophrenia.

Maxillofacial manifestations of Langerhans cell histiocytosis: a clinical and therapeutic analysis of 10 patients

The definition of Langerhans cell histiocytosis (formerly known as histiocytosis X) includes the clinical syndromes Hand-Schueller-Christian syndrome, Abt-Letterer-Siwe syndrome, and eosinophilic granuloma. The paper gives an overview of current diagnostic and treatment strategies of LCH. Furthermore, records and clinical data of 10 patients with LCH were evaluated retrospectively. Patients' age ranged from 13 years to 42 years. The mandible was more frequently involved than the maxilla. Three patients (30%) had systemic manifestations of LCH in addition to their oral lesions. The longest follow-up period was 12 years. During follow-up six patients (60%) developed recurrent LCH and received adjuvant chemo- or radiation therapy. For solitary bone lesions, surgical curettage is the recommended treatment. Those patients with multi-organ involvement or recurrent LCH should be included into clinical trials initiated by the Histiocyte Society.

Congenital self-healing langerhans cell histiocytosis with atrophic recovery of the skin: clinical correlation of an immunologic phenomenon

The pathophysiology and pathogenesis of congenital self-healing Langerhans cell histiocytosis (CSHLCH) as well as that of the other types of Langerhans cell histiocytosis is not well understood. Some authors postulate deregulated immunologic mechanisms that result in overproduction of cytokines. We examined a neonate with disseminated papulonodular eruptions containing lymphoid aggregates of B lymphocytes in the chorial layer. The diagnosis of a CSHLCH was made and the follow-up showed a complete involution of the eruptions, leaving atrophic lesions in the sites corresponding to the initial findings. We discuss a possible imbalance of the immune response as a pathogenetic mechanism.

Langerhans cell histiocytosis: an evaluation of histopathological parameters, demonstration of proliferation by Ki-67 and mitotic bodies

PURPOSE

Langerhans cell histiocytosis (LCH) is a disease with a variable clinical manifestation, being localised (SS) or disseminated (MS). The etiology and pathogenesis of LCH is unknown. It is a proliferative disorder of monoclonal origin, but not necessarily neoplastic. In our study we evaluated histopathological parameters and proliferative activity in LCH.

MATERIALS AND METHODS

Infiltrates from 43 patients with LCH were investigated (nSS=32, nMS=11). We evaluated different histopathological parameters semiquantitatively, demonstrating proliferation using immunohistochemistry for Ki-67.

RESULTS

Overall, the histopathological picture of LCH was heterogeneous. The degree of eosinophilia and presence of necroses was significantly higher in SS-infiltrates compared to MS-infiltrates. Mitotic figures were detected in more than half the infiltrates. The Langerhans origin was verified by CD1a. Ki-67 was highly expressed in all but one infiltrate.

CONCLUSIONS

The presence of necrosis and the degree of eosinophilia are related to SS-disease in our study. Ki-67 expression and the presence of mitotic figures indicate that local proliferation contributes to the accumulation of Langerhans cells. Supported by the histopathological appearance of the lesions and a level of Ki-67 expression lower than that of neoplastic tissue, we suggest that LCH is a reactive condition, possibly induced by immunostimulation caused by unknown agents.

p53 expression in biopsies from children with Langerhans cell histiocytosis

PURPOSE

Langerhans cell histiocytosis (LCH) is a rare pediatric and adult disease causing skin rashes, osteolytic bone lesions, tumorous growth in various organs, and in some patients, organ dysfunction. The cause of the disease is obscure, and it is not yet understood why some patients develop single-system lesions only without relapse, whereas others develop fatal multiorgan disease. The expression of p53 tumor suppressor gene product detected immunohistochemically can be used as a guideline to alterations in DNA repair control and apoptosis. The authors have chosen to analyze p53 expression in biopsies from children with LCH and correlate it with clinical manifestation and outcome in a broad range of organs.

PATIENTS AND METHODS

The study was performed on 50 specimens from 32 children (19 boys and 13 girls), median age 3 1/4 years, range 5 months to 12 1/3 years with a definite diagnosis of LCH based on CD1a positivity. The slides were stained with p53 antibody and semiquantitatively evaluated using a grading system from 1 to 5 as an estimate for 0% to 20%, 20% to 40%, 40% to 60%, 60% to 80%, and 80% to 100% p53-positive for pathologic Langerhans cells (pLC), respectively.

RESULTS

The p53 protein was expressed in various degrees in pLC in all lesions. The degree of p53 expression could not be correlated to either clinical manifestation or outcome.

CONCLUSIONS

An increased expression of p53 in pLC indicates an altered DNA repair control with or without abnormal control of apoptosis.