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Panagiotis Pantelidis

Publications and source records attributed to Panagiotis Pantelidis.

14 recordsLinked to original sources
PubMed2006

Endothelin axis polymorphisms in patients with scleroderma.

OBJECTIVE: To evaluate the distribution of polymorphisms in the endothelin 1 (EDN1), endothelin receptor A (EDNRA) and endothelin receptor B (EDNRB) genes in systemic sclerosis (SSc; scleroderma) and SSc subsets. METHODS: Two hundred five patients with SSc and 255 healthy controls were screened for polymorphisms in EDN1, EDNRA, and EDNRB, using sequence-specific primer-polymerase chain reaction. The polymorphisms studied were at the following positions: for EDN1, -1370 (T-1370G) of the promoter, +138 of exon 1 (+138 A/-), +85 of exon 3 (E106E), and +23 of exon 5 (K198N); for EDNRA, -231 of exon 1 (G-231A), and +69(H323H) and +105 (E335E) of exon 6; for EDNRB, +2841 of exon 2 (EDNRB-3), -2547 of exon 3 (EDNRB-2), and -2446 of exon 3 (EDNRB-1). RESULTS: No significant differences between the SSc group as a whole and control subjects were observed for any of the investigated polymorphisms in EDN1, EDNRA, and EDNRB. However, compared with patients with limited cutaneous SSc, patients with diffuse skin involvement had an increased frequency of allele carriage of EDNRB-1A (76.8% versus 54.4%; P = 0.002), EDNRB-2A (79.7% versus 60.2%; P = 0.006), and EDNRB-3G (79.7% versus 56.6%; P = 0.001). Significantly increased carriage frequencies for EDNRA alleles H323H/C and E335E/A were observed in SSc patients with anti-RNA polymerase (anti-RNAP) antibodies, compared with both anti-RNAP-negative SSc patients (P < 0.05) and control subjects (P < 0.005). CONCLUSION: The finding of associations between endothelin receptors A and B and distinct clinical and immunologic SSc subsets supports the role of endothelin and its receptors in the pathogenesis of SSc. However, these findings and their functional significance need to be confirmed and investigated in future studies.

Endothelins↗
PubMed2004

Monitoring the progress of BK virus associated nephropathy in renal transplant recipients.

BACKGROUND: Nephropathy associated with BK virus (BKVAN) has recently emerged as an important cause of allograft failure following renal transplantation. The aim of this study was to evaluate the effectiveness of laboratory markers in the follow-up of patients with BKVAN. METHODS: Serial samples from seven renal transplant recipients with biopsy proven BKVAN were studied. The median follow-up time from diagnosis was 76 weeks. Intervention after the diagnosis of BKVAN included immunosuppression dose reduction, alternative immunosuppressive agents and/or antiviral therapy with cidofovir. Serial urine samples (n = 127) were collected for electron microscopy (EM), decoy cell detection and quantitative urine BK viral load using real-time polymerase chain reaction. Serum BK viral load was also measured serially (n = 72). RESULTS: All patients showed a reduction in serum and urine viral load during the period of follow-up co-incident with the loss of decoy cells and negative urine EM. Urine samples that were negative for decoy cells or polyomavirus by EM had a urine viral load <10(6) copies/ml and a corresponding serum viral load <10(3) copies/ml. In paired serum/urine samples, there was a proportional relationship between serum and urine viral load with each urine viral load approximately 1000-fold higher than the corresponding serum level. Serum and urine viral loads that decreased to <200 and < 10(6) copies/ml, respectively, correlated with histological improvement. CONCLUSION: Negative EM and absence of decoy cells could be used as broad indicators of a response to intervention. However, measurement of BK virus DNA level provided a wider dynamic range and could be a better choice for determining the extent of viral control.

Adult↗
PubMed2004

The TNF-863A allele strongly associates with anticentromere antibody positivity in scleroderma.

OBJECTIVE: Scleroderma is characterized by the presence of 3 predominant, yet almost mutually exclusive, antibodies: anticentromere antibody (ACA), antitopoisomerase antibody, and anti-RNA polymerase antibody. The purpose of this study was to investigate tumor necrosis factor (TNF) polymorphisms in scleroderma, with the specific aim of determining whether TNF polymorphisms would prove to be stronger markers for ACA than class II major histocompatibility complex (MHC). METHODS: We studied 214 UK white scleroderma patients and 354 healthy controls. All subjects were investigated for 5 TNF promoter region polymorphisms by sequence-specific polymerase chain reaction. RESULTS: We showed that an NF-kappaB binding site polymorphism (known to be functionally relevant) in the TNF promoter region was present in 51.8% of patients with ACA and 16.3% of patients without ACA (chi(2) = 25.1, P = 0.000004 [corrected P = 0.00002]). Using haplotype mapping, we showed that this was a primary TNF association that could explain the previous weak links between ACA production and class II MHC alleles. In marked contrast to our ACA results, HLA class II (especially DRB1*11) appeared to be primary in that it could explain the weaker TNF association with antitopoisomerase production. Further, we observed a separate TNF haplotype to be associated with scleroderma per se, although the level of significance was much lower (chi(2) = 8.7, P = 0.003 [corrected P = 0.02]). CONCLUSION: We believe these findings may have importance both for the directional pathogenesis of scleroderma progression and for the treatment of scleroderma with anti-TNF agents.

Alleles↗
PubMed2003

Analysis of IL-12 p40 subunit gene and IFN-gamma G5644A polymorphisms in Idiopathic Pulmonary Fibrosis.

BACKGROUND: Genes encoding cytokine mediators are prime candidates for genetic analysis in conditions with T-helper (Th) cell disease driven imbalance. Idiopathic Pulmonary Fibrosis (IPF) is a predominantly Th2 mediated disease associated with a paucity of interferon-gamma (IFN-gamma). The paucity of IFN-gamma may favor the development of progressive fibrosis in IPF. Interleukin-12 (IL-12) plays a key role in inducing IFN-gamma production. The aim of the current study was to assess whether the 1188 (A/C) 3'UTR single nucleotide polymorphism (SNP) in the IL-12 p40 subunit gene which was recently found to be functional and the 5644 (G/A) 3' UTR SNP of the IFN-gamma gene were associated with susceptibility to IPF. METHODS: We investigated the allelic distribution in these loci in UK white Caucasoid subjects comprising 73 patients with IPF and 157 healthy controls. The SNPs were determined using the polymerase chain reaction in association with sequence-specific primers incorporating mismatches at the 3'-end. RESULTS: Our results showed that these polymorphisms were distributed similarly in the IPF and control groups CONCLUSION: We conclude that these two potentially important candidate gene single nucleotide polymorphisms are not associated with susceptibility to IPF.

3' Untranslated Regions↗
PubMed2003

Analysis of IL6 and IL1A gene polymorphisms in UK and Dutch patients with sarcoidosis.

BACKGROUND: Proinflammatory cytokines are a major determinant in the inflammatory events leading to sarcoidosis. Genetic variations in the genes encoding these cytokines might contribute to sarcoidosis susceptibility, disease severity and outcome. METHODS: In the present study we genotyped two clinically well-defined cohorts of Caucasian sarcoidosis patients from different European countries (each with their own controls) for the following polymorphisms using SSP-PCR: IL6 -174(G/C), IL6 intron 4(A/G) and IL1A-889(C/T). In total, 516 individuals were studied (147 UK + 102 Dutch patients, 101 UK + 166 Dutch controls). Disease severity data at presentation included chest radiographic stage, FVC, DL(CO), and extrapulmonary manifestations. Disease progression was evaluated on follow-up chest radiographs and sequential lung function measurements (2, 4 years). RESULTS: No differences in genotype, carriage and allele frequencies of the investigated polymorphisms were found in either of the populations. Analysis of genotype data in relation to disease severity data, however, showed a slightly increased carrier frequency of the rarer-174C allele in patients with Stage IV sarcoidosis (p = 0.03, Pc = 0.09). Pulmonary function progression analysis did not reveal significant associations. CONCLUSIONS: Although the investigated polymorphisms are unlikely to contribute to sarcoidosis susceptibility, the IL6-174C allele might have a role in the genetics underlying sarcoidosis severity or the progression towards pulmonary fibrosis in a particular subgroup.

Adult↗
PubMed2002

Interstitial vascularity in fibrosing alveolitis.

The aim of this study was to evaluate interstitial vascularity in cryptogenic fibrosing alveolitis (CFA) and in fibrosing alveolitis associated with systemic sclerosis (FASSc). Open lung biopsies from eight patients with CFA, nine patients with FASSc, and normal lung from 12 patients undergoing surgery for lung cancer were studied. Markers for endothelial cells (CD34) and cell proliferation (proliferating cell nuclear antigen) were localized by sequential immunohistochemistry and quantified using computer-assisted analysis. Vascular distribution was evaluated at increasing distances (up to 160 microm) from the airspaces. Vessel density was markedly reduced in both FASSc (3.9%) and in CFA (4.5%) compared with control samples (20.4%, p < 0.0001). The percentage of tissue occupied by vessels decreased with increasing distance from alveoli in control samples but not in CFA or FASSc samples. Endothelial cell proliferation indices were increased in FASSc but not in CFA, compared with control samples (p = 0.006). In conclusion, there is net vascular ablation and redistribution of blood vessels in areas of interstitial thickening in both CFA and FASSc, which may contribute to gas exchange impairment.

Adult↗
PubMed2002

Increased frequency of the uncommon tumor necrosis factor -857T allele in British and Dutch patients with sarcoidosis.

Interindividual variation in the expression of tumor necrosis factor (TNF)-alpha suggests the existence of functionally distinct TNF alleles, which might play a role in sarcoidosis. We investigated five potentially functional biallelic TNF promoter polymorphisms at nucleotide positions -1,031(T/C), -863(C/A), -857(C/T), -307(G/A), and -237(G/A) in two clinically well-defined groups of white patients (British [UK] and Dutch [NL]) with sarcoidosis, each with their own control subjects. Polymorphisms were determined using SSP-PCR. A total of 772 individuals were studied (96 UK patients, 354 UK control subjects, 100 NL patients, 222 NL controls). A significant increase in the rarer TNF -857T allele was found in both sarcoidosis populations. In total 25.5% of the sarcoid patients carried the TNF -857T allele versus 14.1% of the control subjects (p = 0.003, p(c) = 0.02). In the sarcoidosis group the allele frequency of this polymorphism was 13.5% versus 7.3% in the control subjects (p = 0.0003, p(c) = 0.002). Subgroup analysis showed a significant increase in the rarer TNF -307A (TNF-2) allele in patients with Löfgren's syndrome (p = 0.006, p(c) = 0.03). Our finding does not necessarily imply that the two polymorphisms relate to different functions; it may be that one or both are in linkage disequilibrium with the causal site. This requires further studies of functionality and linkage disequilibrium.

Gene Frequency↗
PubMed2002

Nuclear factor-kappaB activation in alveolar macrophages requires IkappaB kinase-beta, but not nuclear factor-kappaB inducing kinase.

Cytokine mediated activation of alveolar macrophages (AMs) is an important event in the pathogenesis of fibrosing alveolitis (FA). Through membrane-associated antigens, cytokines (e.g., tumor necrosis-factor-alpha and interleukin-1) are believed to activate a common kinase cascade that initiates the cytoplasmic degradation of IkappaB and nuclear translocation of "nuclear factor-kappaB" (NF-kappaB). In the nucleus, NF-kappaB promotes the transcription of genes encoding chemokines and cytokines involved in chronic inflammation. Preventing cytokine-mediated NF-kappaB activation is a potential strategy for attenuating the lung injury that occurs in FA. Previously, we have demonstrated that, unlike AMs from healthy volunteers, AMs from patients with inflammatory lung diseases express the coxsackie/adenovirus receptor and the alphav integrins required for adenovirus (Adv) infection. This property allows Adv-mediated transgene delivery to diseased, but not normal, AMs and analysis of molecular pathways involved in gene transcription. In this study, AMs were infected with Adv constructs expressing a defective beta subunit of IkappaB kinase (AdvIKKbetakd) and a defective NF-kappaB inducing kinase (AdvNIKkd) to investigate the contribution of these molecules to NF-kappaB activation. We observed that IKKbeta, but not NIK, was required for NF-kappaB activation. The results of this study identify IKKbeta, but not NIK, as a potential therapeutic target in diseases that involve NF-kappaB-dependent gene transcription.

Adenoviridae↗
PubMed2002

Interleukin-1 gene cluster polymorphisms in sarcoidosis and idiopathic pulmonary fibrosis.

Members of the interleukin-1 (IL-1) family are implicated in the pathogenesis of sarcoidosis and idiopathic pulmonary fibrosis (IPF). We have, therefore, performed a case-control study to investigate a plausible association between sarcoidosis and the polymorphisms in the IL-1alpha, IL-1beta, and IL-1 receptor antagonist (IL-1Ra) genes. Further, as a separate question, we explored whether the aforementioned genes of the IL-1 cluster are associated with IPF. Using PCR with sequence-specific primers, IL-1alpha -889, IL-1beta -511, IL-1beta +3953, and IL-1Ra intron 2 VNTR polymorphisms were determined in 348 white subjects of West Slavonic ancestry (95 patients with sarcoidosis, 54 patients with IPF, and 199 healthy control subjects). The IL-1alpha -889 1.1 genotype was significantly overrepresented in patients with sarcoidosis in comparison with control subjects (60.0 versus 44.2%, p = 0.012, p(corr) = 0.047). The distribution of IL-1beta -511, IL-1beta +3953, and IL-1Ra VNTR genotypes and alleles did not significantly differ between the cases and controls. No association between IPF and the investigated polymorphisms was found. Strong linkage disequilibrium between pairs of polymorphic loci was observed. Further population studies are warranted to confirm the observed association between sarcoidosis and the IL-1alpha polymorphism and also to explore mechanisms of IL-1alpha -889 participation in aberrant immune response in sarcoidosis.

Adolescent↗
PubMed2002

HLA-DQB1*0201: a marker for good prognosis in British and Dutch patients with sarcoidosis.

Human leukocyte antigen (HLA)-DQB1 is one of the intriguing candidate genes in sarcoidosis. We performed high resolution molecular HLA-DQB1 typing on two groups of white patients (British [UK] and Dutch [NL]) in order to investigate the relationship between 19 DQB1 alleles and disease severity and progression. A total of 803 individuals were studied (133 UK and 102 NL patients, and 354 UK and 214 NL control subjects). Disease severity data included extrapulmonary disease, chest X-ray stage, lung diffusing capacity for carbon monoxide, and FVC. Progression was evaluated on follow-up chest radiographs (2 and 4 yr). The results showed DQB1*0201 to be strongly protective against severe sarcoidosis in both populations; in other words, it localized to Stage I at all time points (P < 0.0001, P(corrected) (P(c)) = 0.002), whereas another DQB1 allele, *0602, tended to have opposite effects. Further, a clear association was found between the *0201 allele and Löfgren's syndrome (P < 0.0001, P(c) = 0.001). More importantly, carriage of this allele reduced the risk of disease progression. In contrast, the other common split of DQB1*02, *0202, did not affect disease severity but was mildly protective against sarcoidosis in the UK population (P = 0.02, p(c) not significant). In conclusion, this study shows that DQB1*0201 is a strong marker for mild sarcoidosis. Additional mapping across the DQB1*0201-DRB1*0301 haplotype, including specific alleles at genes such as DRB3, tumor necrosis factor, lymphotoxin-alpha, I-kappa-B-like protein, and B-associated transcript 1, is necessary for a final localization of the protective effect on this haplotype.

ATP-Binding Cassette Transporters↗
PubMed2001

Surfactant gene polymorphisms and interstitial lung diseases.

Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs). Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

Animals↗