NUDCD3 deficiency disrupts V(D)J recombination to cause SCID and Omenn syndrome.

Inborn errors of T cell development present a pediatric emergency in which timely curative therapy is informed by molecular diagnosis. In 11 affected patients across four consanguineous kindreds, we detected homozygosity for a single deleterious missense variant in the gene NudC domain-containing 3 (NUDCD3). Two infants had severe combined immunodeficiency with the complete absence of T and B cells (T -B- SCID), whereas nine showed classical features of Omenn syndrome (OS). Restricted antigen receptor gene usage by residual T lymphocytes suggested impaired V(D)J recombination. Patient cells showed reduced expression of NUDCD3 protein and diminished ability to support RAG-mediated recombination in vitro, which was associated with pathologic sequestration of RAG1 in the nucleoli. Although impaired V(D)J recombination in a mouse model bearing the homologous variant led to milder immunologic abnormalities, NUDCD3 is absolutely required for healthy T and B cell development in humans.

CYLD in health and disease.

CYLD lysine 63 deubiquitinase (CYLD) is a ubiquitin hydrolase with important roles in immunity and cancer. Complete CYLD ablation, truncation and expression of alternate isoforms, including short CYLD, drive distinct phenotypes and offer insights into CYLD function in inflammation, cell death, cell cycle progression and cell transformation. Research in diverse model systems has shown that these are mediated via CYLD regulation of cellular pathways including the NF-κB, Wnt and TGF-ß pathways. Recent biochemical advances and models have offered new insights into the regulation and function of CYLD. In addition, recent discoveries of gain-of-function germline pathogenic CYLD variants in patients with a neurodegenerative phenotype contrast with the more widely known loss-of-function mutations seen in patients with CYLD cutaneous syndrome and with sporadic cancers. Here, we provide a current review of mechanistic insights into CYLD function gained from CYLD animal models, as well as an update on the role of CYLD in human disease.

SOCS3 deregulation contributes to aberrant activation of the JAK/STAT pathway in precursor T-cell neoplasms.

Despite the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway being frequently altered in T-ALL/LBL, no specific therapy has been approved for T-ALL/LBL patients with constitutive signalling by JAK/STAT, so there is an urgent need to identify pathway members that may be potential therapeutic targets. In the present study, we searched for JAK/STAT pathway members potentially modulated through aberrant methylation and identified SOCS3 hypermethylation as a recurrent event in T-ALL/LBL. Additionally, we explored the implications of SOCS3 deregulation in T-ALL/LBL and demonstrated that SOCS3 counteracts the constitutive activation of the JAK/STAT pathway through different molecular mechanisms. Therefore, SOCS3 emerges as a potential therapeutic target in T-ALL/LBL.

Can Music Decrease Anxiety and Pain During Dental Implant Surgery? A Randomized Clinical Trial.

PURPOSE: Music has proven to be an effective tool in the management of anxiety during some surgical procedures. The aim of this study was to test the effect of baroque (BM) and classical era music (CM) as a nonpharmacological therapy on the control of anxiety and pain levels among patients undergoing dental implant placement surgery. METHODS: A randomized controlled clinical trial of patients attending a dental clinic was conducted. Patients with psychiatric disorders were excluded. Twenty six patients of Spanish nationality requiring single-tooth dental implant were included. Each patient was assigned to 1 of the 3 experimental groups, which acted as an independent variable: Group I (n = 8) listened to BM; Group II (n = 10) listened to CM; and Group III (n = 8) did not listen to music and was the control group (C). The dependent variables were divided into physiological variables and psychological variables. The physiological dependent variables analysed were systolic and diastolic blood pressure, heart rate, and oxygen saturation, recorded at 4 different times during surgery. The Kruskal-Wallis test compared each of these variables between the 3 experimental groups. The psychological dependent variable analyzed was the degree of anxiety, measured by the self-completed Modified Dental Anxiety Scale and Visual Analog Scale (measured before and after surgery). The Wilcoxon statistical test compared degree of anxiety before and after surgery. In all cases, the level of statistical significance was set at P < .05. RESULTS: The mean age of the sample was 46.5 ± 10.6 (range, 24-69 years), 50% male and 50% female. Statistically significant differences in degree of anxiety before and after surgery were found in the BM (P = .027, confidence interval [CI] = 0.146-6.104; BM before = 4.25 ± 3.91 and BM after = 1.13 ± 1.45) and CM groups (P = .044, CI = 0.161-3.039; CM before = 3.10 ± 2.88 and CM after = 1.50 ± 1.43) and were not found in group C (P = .180, CI = 1.104-3.604; C before = 2.63 ± 3.62 and C after = 1.38 ± 1.99). When comparing the perceived pain after the intervention among the 3 groups (C, BM, and CM), no significant differences were observed between them (P = .319; CI = -0.58-1.96; C = 0.75 ± 1.75, BM = 1.25 ± 1.75, and CM = 1.70 ± 1.70). CONCLUSION: Listening to BM and CM reduces anxiety in patients undergoing dental implant placement surgery. Musical flow should be applied in this practice.

Tocilizumab in refractory Caucasian Takayasu's arteritis: a multicenter study of 54 patients and literature review.

OBJECTIVE: To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu's arteritis (TAK) in clinical practice. METHODS: A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZMONO) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZCOMBO) was performed. RESULTS: The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5-50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0-31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5-50.0) to 5.0 (0.0-5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0-14.0) months. Twenty-three (42.6%) patients were on TCZMONO and 31 (57.4%) on TCZCOMBO: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZCOMBO were younger [38.0 (27.0-46.0) versus 45.0 (38.0-57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0-38.0) versus 6.0 (1.0-23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7-5.6) versus 1.3 (0.3-3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal. CONCLUSION: TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin.

Exploiting the passenger ACO1-deficiency arising from 9p21 deletions to kill T-cell lymphoblastic neoplasia cells.

Precursor T-cell lymphoblastic neoplasms are aggressive malignancies in need for more effective and specific therapeutic treatments. A significant fraction of these neoplasms harbor deletions on the locus 9p21, targeting the tumor suppressor CDKN2A but also deleting the aconitase 1 (ACO1) gene, a neighboring housekeeping gene involved in cytoplasm and mitochondrial metabolism. Here we show that reducing the aconitase activity with fluorocitrate decreases the viability of T-cell lymphoblastic neoplasia cells in correlation to the differential aconitase expression. The consequences of the treatment were evidenced in vitro using T-cell lymphoblastic neoplasia cell lines exhibiting 9p21 deletions and variable levels of ACO1 expression or activity. Similar results were observed in melanoma cell lines, suggesting a true potential for fluorocitrate in different cancer types. Notably, ectopic expression of ACO1 alleviated the susceptibility of cell lines to fluorocitrate and, conversely, knockdown experiments increased susceptibility of resistant cell lines. These findings were confirmed in vivo on athymic nude mice by using tumor xenografts derived from two T-cell lines with different levels of ACO1. Taken together, our results indicate that the non-targeted ACO1 deficiency induced by common deletions exerts a collateral cellular lethality that can be used as a novel therapeutic strategy in the treatment of several types of cancer.

Colonization history and population differentiation of the Honey Bees (Apis mellifera L.) in Puerto Rico.

Honey bees (Apis mellifera L.) are the primary commercial pollinators across the world. The subspecies A. m. scutellata originated in Africa and was introduced to the Americas in 1956. For the last 60 years, it hybridized successfully with European subspecies, previous residents in the area. The result of this hybridization was called Africanized honey bee (AHB). AHB has spread since then, arriving to Puerto Rico (PR) in 1994. The honey bee population on the island acquired a mosaic of features from AHB or the European honey bee (EHB). AHB in Puerto Rico shows a major distinctive characteristic, docile behavior, and is called gentle Africanized honey bees (gAHB). We used 917 SNPs to examine the population structure, genetic differentiation, origin, and history of range expansion and colonization of gAHB in PR. We compared gAHB to populations that span the current distribution of A. mellifera worldwide. The gAHB population is shown to be a single population that differs genetically from the examined populations of AHB. Texas and PR groups are the closest genetically. Our results support the hypothesis that the Texas AHB population is the source of gAHB in Puerto Rico.

FADD in Cancer: Mechanisms of Altered Expression and Function, and Clinical Implications.

FADD was initially described as an adaptor molecule for death receptor-mediated apoptosis, but subsequently it has been implicated in nonapoptotic cellular processes such as proliferation and cell cycle control. During the last decade, FADD has been shown to play a pivotal role in most of the signalosome complexes, such as the necroptosome and the inflammasome. Interestingly, various mechanisms involved in regulating FADD functions have been identified, essentially posttranslational modifications and secretion. All these aspects have been thoroughly addressed in previous reviews. However, FADD implication in cancer is complex, due to pleiotropic effects. It has been reported either as anti- or protumorigenic, depending on the cell type. Regulation of FADD expression in cancer is a complex issue since both overexpression and downregulation have been reported, but the mechanisms underlying such alterations have not been fully unveiled. Posttranslational modifications also constitute a relevant mechanism controlling FADD levels and functions in tumor cells. In this review, we aim to provide detailed, updated information on alterations leading to changes in FADD expression and function in cancer. The participation of FADD in various biological processes is recapitulated, with a mention of interesting novel functions recently proposed for FADD, such as regulation of gene expression and control of metabolic pathways. Finally, we gather all the available evidence regarding the clinical implications of FADD alterations in cancer, especially as it has been proposed as a potential biomarker with prognostic value.

S194-P-FADD as a marker of aggressiveness and poor prognosis in human T-cell lymphoblastic lymphoma.

T-cell lymphoblastic lymphoma is a haematological disease with an urgent need for reliable prognostic biomarkers that allow therapeutic stratification and dose adjustment. The scarcity of human samples is responsible for the delayed progress in the study and the clinical management of this disease, especially compared with T-cell acute lymphoblastic leukaemia, its leukemic counterpart. In the present work, we have determined by immunohistochemistry that S194-P-FADD protein is significantly reduced in a cohort of 22 samples from human T-cell lymphoblastic lymphoma. Notably, the extent of such reduction varies significantly among samples and has revealed determinant for the outcome of the tumour. We demonstrate that Fas-associated protein with death domain (FADD) phosphorylation status affects protein stability, subcellular localization and non-apoptotic functions, specifically cell proliferation. Phosphorylated FADD would be more stable and preferentially localized to the cell nucleus; there, it would favour cell proliferation. We show that patients with higher levels of S194-P-FADD exhibit more proliferative tumours and that they present worse clinical characteristics and a significant enrichment to an oncogenic signature. This supports that FADD phosphorylation may serve as a predictor for T-cell lymphoblastic lymphoma aggressiveness and clinical status. In summary, we propose FADD phosphorylation as a new biomarker with prognostic value in T-cell lymphoblastic lymphoma.

Association of objectively measured physical activity and sedentary time with arterial stiffness in women with systemic lupus erythematosus with mild disease activity.

OBJECTIVES: To examine the association of objectively measured physical activity (PA) intensity levels and sedentary time with arterial stiffness in women with systemic lupus erythematosus (SLE) with mild disease activity and to analyze whether participants meeting the international PA guidelines have lower arterial stiffness than those not meeting the PA guidelines. METHODS: The study comprised 47 women with SLE (average age 41.2 [standard deviation 13.9]) years, with clinical and treatment stability during the 6 months prior to the study. PA intensity levels and sedentary time were objectively measured with triaxial accelerometry. Arterial stiffness was assessed through pulse wave velocity, evaluated by Mobil-O-Graph® 24h pulse wave analysis monitor. RESULTS: The average time in moderate to vigorous PA in bouts of ≥10 consecutive minutes was 135.1±151.8 minutes per week. There was no association of PA intensity levels and sedentary time with arterial stiffness, either in crude analyses or after adjusting for potential confounders. Participants who met the international PA guidelines did not show lower pulse wave velocity than those not meeting them (b = -0.169; 95% CI: -0.480 to 0.143; P = 0.280). CONCLUSIONS: Our results suggest that PA intensity levels and sedentary time are not associated with arterial stiffness in patients with SLE. Further analyses revealed that patients with SLE meeting international PA guidelines did not present lower arterial stiffness than those not meeting the PA guidelines. Future prospective research is needed to better understand the association of PA and sedentary time with arterial stiffness in patients with SLE.

Deregulated FADD expression and phosphorylation in T-cell lymphoblastic lymphoma.

In the present work, we show that T-cell lymphoblastic lymphoma cells exhibit a reduction of FADD availability in the cytoplasm, which may contribute to impaired apoptosis. In addition, we observe a reduction of FADD phosphorylation that inversely correlates with the proliferation capacity and tumor aggressiveness. The resultant balance between FADD-dependent apoptotic and non-apoptotic abilities may define the outcome of the tumor. Thus, we propose that FADD expression and phosphorylation can be reliable biomarkers with prognostic value for T-LBL stratification.

Influence of the IL6 gene in susceptibility to systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is a genetically complex autoimmune disease; the genetic component has not been fully defined. Interleukin 6 (IL-6) plays a crucial role in immunity and fibrosis, both key aspects of SSc. We investigated the influence of IL6 gene in the susceptibility and phenotype expression of SSc. METHODS: We performed a large metaanalysis including a total of 2749 cases and 3189 controls from 6 white populations (Germany, The Netherlands, Norway, Spain, Sweden, and United Kingdom). Three IL6 single-nucleotide polymorphisms (SNP; rs2069827, rs1800795, and rs2069840) were selected by SNP tagging and genotyped using TaqMan(®) allele discrimination technology. RESULTS: Individual SNP metaanalysis showed no evidence of association of the 3 IL6 genetic variants with the global disease. Phenotype analyses revealed a significant association between the minor allele of rs2069840 and the limited cutaneous SSc clinical form (Bonferroni p = 0.036, OR 1.14, 95% CI 1.04-1.25). A trend of association between the minor allele of the rs1800795 and the diffuse cutaneous SSc clinical form was also evident (Bonferroni p = 0.072, OR 0.86, 95% CI 0.77-0.96). In the IL6 allelic combination analyses, the GGC allelic combination rs2069827-rs1800795-rs2069840 showed an association with overall SSc (Bonferroni p = 0.016, OR 1.13, 95% CI 1.04-1.23). CONCLUSION: Our results suggest that the IL6 gene may influence the development of SSc and its progression.

Lack of association between IFNGR1 gene polymorphisms and biopsy-proven giant cell arteritis.

OBJECTIVES: Since IFN-gamma plays a pivotal role in the pathogenesis of giant cell arteritis (GCA), a polygenic primary systemic vasculitis involving elderly people from Western countries, in the present study we analysed for first time the implication of three IFN-gamma receptor (IFNGR) 1 gene variants in the susceptibility to and clinical expression of GCA. METHODS: Two hundred and sixteen biopsy-proven GCA patients and 460 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for three single nucleotide polymorphisms (SNPs) rs1327474 (-611A/G), rs11914 (+189G7C) and rs7749390 (+95C/T) of the IFNGR1 gene using a pre-designed TaqMan allele discrimination assay. Post PCR, the genotype of each sample was attributed automatically by measuring the allelic specific fluorescence on the ABI PRISM 7900 sequence. RESULTS: No significant differences in the genotype or allele distribution between GCA patients and controls for the three IFNGR1 gene variants were found. Furthermore, no significant differences in the genotype distribution were observed when GCA patients were stratified according to the presence of specific clinical features of the disease such as polymyalgia rheumatica or severe ischemic complications including visual ischemic manifestations. CONCLUSIONS: Our results do not show an implication of IFNGR1gene polymorphisms in the susceptibility to and clinical expression of GCA.

Lack of association between hypoxia inducible factor-1 alpha gene polymorphisms and biopsy-proven giant cell arteritis.

OBJECTIVES: Since the transcription factor hypoxia-inducible factor 1 (HIF-1) is a key early mediator of the response to ischemia and giant cell arteritis (GCA) is a polygenic disease leading to severe ischemic complications, in the present study we analysed for first time the implication of two HIF-1alpha gene polymorphisms in the susceptibility to and clinical expression of GCA. METHODS: Two hundred and fifteen biopsy-proven GCA patients and 470 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for two single nucleotide polymorphisms, rs11549465 (C/T) and rs11549467 (G/A), using a pre-designed TaqMan allele discrimination assay. Post PCR, the genotype of each sample was attributed automatically by measuring the allelic specific fluorescence on the ABI PRIM 7900 sequence. RESULTS: The HIF-1alpha, rs11549465 TT genotype was extremely uncommon in both GCA patients (2.3%) and controls (2.1%). Although the frequency of individuals carrying the CT or TT genotypes was increased in GCA patients (25.1%) compared to controls (20.4%) the difference was not statistically significant (OR 1.30 [95% CI: 0.89- 1.91]; p=0.17). Also, all GCA patients and most controls (98.9%) were homozygous for the rs11549467 GG genotype. GCA patients carrying the rs11549465 CT or TT genotypes had a slight increased risk of developing visual ischemic complications (33.1%) compared to the remaining GCA patients (22.8%); OR 1.60 (95% CI: 0.81- 3.16); p=0.18. CONCLUSIONS: Our results do not confirm an implication of HIF-1alpha gene polymorphisms in the susceptibility to and clinical expression of GCA.

Lack of association between the rs6920220 (G/A) polymorphism of the 6q23 region and biopsy-proven giant cell arteritis.

OBJECTIVE: Recently, 2 independent studies have identified an association between several single-nucleotide polymorphisms (SNP) located in the 6q23 chromosomal region and rheumatoid arthritis (RA). Like RA, giant cell arteritis (GCA) is also a complex polygenic disease in which more than 1 genetic locus is likely to contribute to disease susceptibility and clinical expression. We analyzed the involvement of the rs6920220 (G/A) polymorphism from the 6q23/TNFAIP3 gene region in susceptibility to GCA. METHODS: Two hundred twenty patients with biopsy-proven GCA and 490 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were geno-typed for the 6q23 region rs6920220 using a TaqMan allele discrimination assay and by polymerase chain reaction (PCR) amplification. After PCR, the genotype of each sample was attributed automatically by allelic-specific fluorescence using the ABI Prism 7900 sequence detection system. RESULTS: No significant differences in the genotype distribution between patients with GCA and controls for the rs6920220 (G/A) polymorphism were found. No significant differences were observed when patients with GCA were stratified according to the presence of specific clinical features of the disease such as polymyalgia rheumatica or severe ischemic manifestations or specific visual ischemic complications. CONCLUSION: Our results show no involvement of this 6q23/TNFAIP3 gene region SNP in the susceptibility to or clinical expression of GCA.

Association between IL-18 gene polymorphisms and biopsy-proven giant cell arteritis.

INTRODUCTION: The objective was to investigate the potential implication of the IL18 gene promoter polymorphisms in the susceptibility to giant-cell arteritis (GCA). METHODS: In total, 212 patients diagnosed with biopsy-proven GCA were included in this study. DNA from patients and matched controls was obtained from peripheral blood. Samples were genotyped for the IL18-137 G>C (rs187238), the IL18-607 C>A (rs1946518), and the IL18-1297 T>C (rs360719) gene polymorphisms with polymerase chain reaction, by using a predesigned TaqMan allele discrimination assay. RESULTS: No significant association between the IL18-137 G>C polymorphism and GCA was found. However, the IL18 -607 allele A was significantly increased in GCA patients compared with controls (47.8% versus 40.9% in patients and controls respectively; P = 0.02; OR, 1.32; 95% CI, 1.04 to 1.69). It was due to an increased frequency of homozygosity for the IL18 -607 A/A genotype in patients with GCA (20.4%) compared with controls (13.4%) (IL18 -607 A/A versus IL18 -607 A/C plus IL18 -607 C/C genotypes: P = 0.04; OR, 1.59; 95% CI, 1.02 to 2.46). Also, the IL18-1297 allele C was significantly increased in GCA patients (30.7%) compared with controls (23.0%) (P = 0.003; OR, 1.48; 95% CI, 1.13 to 1.95). In this regard, an increased susceptibility to GCA was observed in individuals carrying the IL18-1297 C/C or the IL18-1297 C/T genotypes compared with those carrying the IL18-1297 T/T genotype (IL18-1297 C/C plus IL18-1297 T/C versus IL18-1297 T/T genotype in GCA patients compared with controls: P = 0.005; OR, 1.61; 95% CI, 1.15 to 2.25). We also found an additive effect of the IL18 -1297 and -607 polymorphisms with TLR4 Asp299Gly polymorphism. The OR for GCA was 1.95 for combinations of genotypes with one or two risk alleles, whereas carriers of three or more risk alleles have an OR of 3.7. CONCLUSIONS: Our results show for the first time an implication of IL18 gene-promoter polymorphisms in the susceptibility to biopsy-proven GCA. In addition, an additive effect between the associated IL18 and TLR4 genetic variants was observed.

Lack of association between IRF5 gene polymorphisms and biopsy-proven giant cell arteritis.

OBJECTIVE: Interferon (IFN) regulatory factors (IRF) are transcriptional mediators of IFN-induced signaling pathways and are involved in immune response. We have analyzed for the first time the association of 2 IRF5 gene variants in the susceptibility to giant cell arteritis (GCA). METHODS: Two hundred twenty patients with biopsy-proven GCA and 520 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the IRF5 rs2004640 and for the IRF5 CGGGG insertion/deletion polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification, followed by an ABI3100 sequencer, respectively. RESULTS: A genotyping rate of 96% was achieved in this series of GCA patients. No significant differences were found in the genotype distribution between GCA patients and controls for both IRF5 gene variants. In this regard, similar genotype frequencies were found in GCA patients and controls. No significant differences were observed when GCA patients were stratified according to the presence of specific clinical features of the disease such as polymyalgia rheumatica or severe ischemic complications. CONCLUSION: Our results showed no association of IRF5 rs2004640 and CGGGG insertion/deletion polymorphisms in the susceptibility to and clinical expression of GCA.

3D liver segmentation in preoperative CT images using a level-sets active surface method.

In this work we propose an active surface method to segment complete liver volumes from preoperative CT abdominal images. The method finds the surface that minimizes an energy function combining intensity inside and outside the surface, gradient information and curvature restrictions. The implementation is based on a level set technique following a multi-resolution strategy to reduce computing time. It requires only a single seed point inside the liver to initialize the active surface. The algorithm has been validated on a set of previously diagnosed livers. Resulting segmentations have been supervised by clinicians and radiologists, and numerically evaluated in terms of volume measurements with respect to those obtained from radiologists' manual segmentations. Additionally, radiologists analyzed the necessity of additional corrections on segmenting volumes.

Association between toll-like receptor 4 gene polymorphism and biopsy-proven giant cell arteritis.

OBJECTIVE: Dendritic cells localized at the adventitia-media border of the normal medium-sized arteries play a pivotal role in the initiation of giant cell arteritis (GCA). These cells express a singular surface receptor profile, including a series of Toll-like receptors (TLR). Ligands of TLR-4 promote activation and differentiation of adventitial dendritic cells and are directly implicated in the pathogenesis of GCA. We aimed to assess the potential implication of the TLR4-(+896 A/G) gene polymorphism in the susceptibility to GCA. METHODS: A total of 210 patients diagnosed with biopsy-proven GCA and 678 matched controls were included in our study. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the TLR4-(+896 A/G) (rs4986790) gene polymorphism by polymerase chain reaction, using a predesigned TaqMan allele discrimination assay. RESULTS: The TLR4 +896 G allele was significantly increased in biopsy-proven GCA patients compared to controls [p = 0.01; odds ratio (OR) 1.65; 95% confidence interval (CI) 1.08-2.52]. The increase was due to a significantly increased frequency of heterozygosity for the TLR4 -896 A/G genotype in the group of patients with biopsy-proven GCA compared to controls (TLR4 -896 A/G heterozygous in patients with GCA 18.1% compared to 11.4% in controls: p = 0.01; OR 1.72; 95% CI 1.10-2.69). However, no significant differences were observed when patients with GCA were stratified according to the presence of specific clinical features of the disease. CONCLUSION: Our results show for the first time an association of TLR4-(+896 A/G) gene polymorphism with susceptibility to biopsy-proven GCA.