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OBJECTIVE: Systemic sclerosis (SSc) is an orphan disease that can lead to severe involvement of the gastrointestinal tract with a significant impact on patients' quality of life (QoL). The Mediterranean diet (MD) was consistently demonstrated to have beneficial effects on chronic diseases based on biological bases. We aimed to evaluate the adherence to the MD of Italian patients with SSc to preliminarily assess its association with gastrointestinal symptoms and other disease features, mood, and QoL. METHODS: In this cross-sectional study, adherence to the MD was measured in 387 patients from four SSc Italian referral centers through the 14-item Mediterranean Diet Adherence Screener (14-MEDAS) questionnaire. We also registered patients' reported outcomes related to the QoL and mood. RESULTS: Overall, an optimal adherence to MD was observed in 14.7% of patients with SSc, a moderate adherence in 71.3%, and a low adherence in 14.0%. In univariate analysis, poor adherence to the MD was associated with a more prominent depressive mood, time missed at work, and perception of more severe Raynaud's phenomenon and digital ulcers, whereas the 14-MEDAS score inversely correlated with depression score and reflux. CONCLUSION: In our cohort of patients with SSc, overall adherence to MD was moderate. Patients with lower adherence to MD also reported worse outcomes related to QoL and mood. Administration of the 14-MEDAS could be a reasonable choice to assess adherence to the MD in patients with SSc. Future initiatives to study the role of MD in the management of patients with SSc are warranted.
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Objectives: Behçet's syndrome (BS) is a chronic multisystemic inflammatory disorder of unclear aetiology. The predominant BS susceptibility locus was identified within HLA-B*51. HLA-B*51 subtypes were previously studied as disease susceptibility markers. Few data are now available about the relationship between B*51 subtypes and clinical phenotype. The aim of this study was to genotype HLA-B*51 subtypes in a series of Italian BS patients and to test the association with clinical manifestations and disease severity (Krause's index). Methods: HLA-B*51 subtype genotyping for 63 alleles (B*51:01-B*51:63) was performed by PCR after DNA extraction from whole blood of BS patients. The correlation of disease clinical manifestations and severity (Krause's index) with the HLA-B*51 allele and its subtypes was analysed. Results: We enrolled 241 (140 male and 101 female) BS patients, and HLA-B*51 frequency was 62.7% (151 of 241). One hundred and eight of the HLA-B*51-positive patients carried the B*51:01 subtype (108 of 151, 71.5%), 39 of 151 (25.8%) the B*51:08 subtype, 2 of 151 (1.3%) the B*51:02 subtype, 1 of 151 (0.7%) the B*51:05 subtype, and 1 of 151 (0.7%) the B*51:07 subtype. We found that ocular involvement was statistically associated with HLA-B*51 positivity and with B*51:01 and B*51:08 subtypes (P < 0.05). We also found that disease severity was higher in HLA-B*51-positive patients than in negative patients, but without statistical significance (median Krause's index 5.1 vs 4.1, P > 0.05). Conclusion: Here, we confirm a high frequency of the HLA-B*51 allele in our group of BS patients. B*51:01 and B*51:08 were found to be the most common subtypes, and an association of both subtypes with ocular involvement was also underlined.
ABSTRACT
Tumor Necrosis Factor-alpha (TNFα) rs1800629 (-308G>A) is a single nucleotide polymorphism (SNP) related to variable responses to anti-TNFα therapy. This therapy is efficient in severe and refractory manifestation of Behçet syndrome (BS), an auto-inflammatory systemic vasculitis. We investigated (1) the association between rs1800629 genotypes and responses to therapy and (2) the correlation between SNP and clinical patterns in a cohort of 74 BS Italian patients receiving anti-TNFα therapy with a follow-up of at least 12 months. The rs1800629 was genotyped through amplification, direct sequencing and bioinformatics analyses. The rs1800629 GG and GA genotypes were assessed as predictors of outcomes dividing the patients between therapy responders and non-responders. The rs1800629 GG and GA genotypes were found, respectively, in 59/74 (79.7%) and 15/74 BS patients (21.3%) (p < 0.05). We identified 16/74 (21.9%) non-responder patients, of which 9/16 (56.3%) showed the GG genotype and 7/16 (43.7%) the GA genotype. A total of 50/58 (86.2%) responder patients showed the GG genotype, and 8/58 (13.8%) the GA genotype (p < 0.05). The percentage of non-responder females (68.8%) was significantly higher than non-responder males (31.2%) (p < 0.05). No correlation between SNP and clinical patterns was observed. To successfully include rs1800629 as a predictive biomarker of TNFα inhibitor response, genome-wide association studies in larger, well-characterised cohorts are required.
ABSTRACT
Spondyloarthritis are chronic inflammatory diseases affecting spine, peripheral joints and enthesis, as well as extra-articular sites (bowel, eyes, skin). Diagnosis of spondyloarthritis often is slow and requires a multidisciplinary approach. The "Early SpA Clinic" project aimed at improving the patient care and journeys, by solving some organizational issues existing in Rheumatology Clinics. The "Early SpA Clinic" involved 19 Italian Rheumatology Centers using in-depth organizational analyses to identify areas for improvement. From the results of the analyses, some organizational solutions were suggested, and their impact measured at the end of the project through specific KPI. With the implementation of the suggested organizational solutions, Centers achieved relevant results, positively impacting on all the phases of the patient journey: decrease in waiting lists (-23%) and in the time length to transit the Center (-22%), increase in the percentage of new diagnoses (+20%), in the saturation of outpatient clinic capacity (+16%), and in the patient satisfaction (+4%). Centers involved in the "Early SpA Clinic" implemented several organizational actions based on an overall assessment of their activities and on solutions that required no additional resources. Overall, the Centers achieved the "Early SpA Clinic" objectives in terms of better management of resources, personnel, spaces, equipment, in relation to the volumes of patients.
ABSTRACT
Paradoxical psoriatic arthritis (PPsA) may be associated with guselkumab treatment. We describe a patient in whom PPsA required a change from guselkumab to ixekizumab. The pathophysiology of this paradoxical reaction is most likely a cytokine imbalance.
Subject(s)
Arthritis, Psoriatic , Psoriasis , Antibodies, Monoclonal, Humanized , Arthritis, Psoriatic/drug therapy , Humans , Psoriasis/complications , Psoriasis/drug therapy , Severity of Illness Index , Treatment OutcomeABSTRACT
OBJECTIVE: Early diagnosis of autoimmune rheumatic diseases (ARDs) is key to achieving effective treatment and improving prognosis. The coronavirus disease 2019 (COVID-19) pandemic has led to major changes in clinical practice on a global scale. We aimed to evaluate the impact of the COVID-19 pandemic on rheumatological clinical practice and autoimmunity testing demands. METHODS: Data regarding the first rheumatological visits and new diagnoses, together with the autoimmunity laboratory testing volumes related to the COVID-19 pandemic phase (January-December 2020), were collected from medical records and the laboratory information system of a regional reference hospital (Basilicata, Italy) and compared with those obtained during the corresponding period in 2019. RESULTS: A significant decrease in the 2020 autoimmunity laboratory test volume was found when compared with the same period in 2019 (9912 vs 14,100; P < 0.05). A significant decrease in first rheumatological visits and diagnosis (1272 vs 2336; P < 0.05) was also observed. However, an equivalent or higher percentage of positive autoimmunity results from outpatient services was recorded during 2020 when compared to the prepandemic state. Of note, COVID-19-associated decline in new diagnoses affected mainly less severe diseases. In contrast, ARDs with systemic involvement were diagnosed at the same levels as in the prepandemic period. CONCLUSION: The COVID-19 pandemic has affected access to health services. However, our study highlighted that during the outbreak, greater appropriateness of the requests for laboratory tests and visits emerged, as shown by a greater percentage of positive test results and new diagnoses of more severe ARDs compared to the prepandemic period.
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COVID-19 , Rheumatic Diseases , Ambulatory Care , Humans , Pandemics , Rheumatic Diseases/diagnosis , Rheumatic Diseases/epidemiology , SARS-CoV-2ABSTRACT
Dactylitis - a hallmark clinical feature of psoriatic arthritis (PsA) - that occurs in 30-50% of PsA patients, is a marker of disease severity for PsA progression, an independent predictor of cardiovascular morbidity and impairs the motor functions of PsA patients. There is a paucity of evidence for the treatment due to the absence of randomized controlled trials assessing dactylitis as a primary endpoint and current practice arises from the analysis of dactylitis as a secondary outcome. Corticosteroid (CS) injections for dactylitis in PsA patients are a therapeutic treatment option for patients with isolated dactylitis or for patients with flares in tendon sheaths, despite stable and effective systemic treatment. The aim of this narrative review is to briefly illustrate the clinical aspects of dactylitis in PsA, the imaging and clinimetric tools used to diagnose and monitor dactylitis, the current treatment strategies and principally to provide a comprehensive picture of the clinical efficacy and safety with ultrasound-guide and blind techniques of CS injections for dactylitis in PsA patients.
ABSTRACT
OBJECTIVE: The University of California Los Angeles Scleroderma Clinical Trials Consortium Gastrointestinal Tract 2.0 (GIT 2.0) instrument is a self-report tool measuring gastrointestinal (GI) quality of life in patients with systemic sclerosis (SSc). Scarce data are available on the correlation between patient-reported GI symptoms and motility dysfunction as assessed by esophageal transit scintigraphy (ETS). METHODS: We evaluated the GIT 2.0 reflux scale in patients with SSc admitted to our clinic and undergoing ETS, and correlated their findings. RESULTS: Thirty-one patients with SSc undergoing ETS were included. Twenty-seven were female, and 9 had diffuse cutaneous SSc. Twenty-six of 31 (84%) patients had a delayed transit and an abnormal esophageal emptying activity (EA); they also had a higher GIT 2.0 reflux score (P = 0.04). Mean EA percentage was higher in patients with none to mild GIT 2.0 reflux score (81.1 [SD 11.5]) than in those with moderate (55.7 [SD 17.8], P = 0.003) and severe to very severe scores (55.8 [SD 19.7], P = 0.002). The percentage of esophageal EA negatively correlated with the GIT 2.0 reflux score (r = -0.68, P < 0.0001), but it did not correlate with the other GIT 2.0 scales and the total GIT 2.0 score. CONCLUSION: SSc patients with impaired ETS findings have a higher GIT 2.0 reflux score. The GIT 2.0 is a complementary tool for objective measurement of esophageal involvement that can be easily administered in day-to-day clinical assessment.
Subject(s)
Gastroesophageal Reflux/diagnostic imaging , Gastrointestinal Tract , Scleroderma, Systemic , Female , Gastroesophageal Reflux/etiology , Gastrointestinal Tract/diagnostic imaging , Humans , Male , Quality of Life , Radionuclide Imaging , Reproducibility of Results , Scleroderma, Systemic/complications , Scleroderma, Systemic/diagnostic imaging , Severity of Illness IndexABSTRACT
Behçet syndrome (BS) is a vasculitis characterized by several clinical manifestations including the rare neurological involvement (neuro-BS, NBS). The aim of our pivotal study was to investigate the mutational status of several inflammation-related genes in a cohort of Italian patients with and without the neurological involvement (20 NBS vs 40 no-NBS patients). The preliminary in silico single nucleotide polymorphism (SNP) selection and primer design were performed by NCBI Primer-Blast tool. Genomic DNA was isolated and amplified using PCR. PCR amplicons were sequenced and bioinformatically analysed. Twelve tagSNPs were selected and genotyped: ERAP1 rs30187, rs17482078, and rs27044; IL10 rs1800872 and rs1518111, IL12A rs17810546, IL23R rs17375018, IL23R-IL12RB2 rs924080, STAT4 rs7572482, CCR1 rs7616215, KLRC4 rs2617170, and UBAC2 rs3825427. ERAP1 and IL23R SNPs showed statistically significant higher frequencies in NBS group than no-NBS. ERAP1 rs30187 AA was more common in no-NBS patients (20.0% NBS vs 47.5% no-NBS; p < 0.05), while rs17482078 GA frequency was higher in NBS patients (55.0% NBS vs 22.5% no-NBS; p < 0.05, OR: 4.21). IL23R rs17375018 GG was more frequent in NBS group (65.0% NBS vs 40.0% no-NBS; p < 0.05), according to a previous finding. No other statistically significant differences were found. In conclusion, ERAP1 and IL23R SNPs were found associated with neurological involvement of BS. Additional and larger analyses were required to verify our preliminary findings.
Subject(s)
Aminopeptidases/genetics , Behcet Syndrome/genetics , Interleukins/genetics , Minor Histocompatibility Antigens/genetics , Polymorphism, Single Nucleotide , Adult , Behcet Syndrome/pathology , Female , Humans , Male , Middle Aged , NK Cell Lectin-Like Receptor Subfamily C/genetics , Receptors, CCR1/genetics , STAT4 Transcription Factor/genetics , Ubiquitin-Activating Enzymes/geneticsABSTRACT
Serum amyloid A (SAA) is a family of acute-phase reactants. The rise of SAA concentration in blood circulation during the acute-phase response is a clinical marker of active inflammation. Despite its practical and analytical advantages, SAA measurement by enzyme-linked immunosorbent assay (ELISA) has been used mainly as a research tool rather than for the routine laboratory testing. This may be partly explained by the lack of robust reference data in the literature for the different commercially available immunoassays. Using the recommended procedures for the production of reference intervals published by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), we developed the SAA reference interval for a well-defined Italian healthy population and investigated the correlation among SAA and C-reactive protein (CRP), the commonly used acute-phase marker. After data normalization, the reference cutoff was calculated as 225 ng/ml. A good correlation between SAA and CRP was found (P < .05). No statistically significant differences was found between males and females when the means of SAA values were compared, suggesting that not gender-partitioned reference range is recommended for this analyte. This study allowed to define a widely accepted reference cutoff for the SAA detected by ELISA, responding to an unmet need of laboratory medicine.
Subject(s)
C-Reactive Protein/analysis , Enzyme-Linked Immunosorbent Assay , Serum Amyloid A Protein/analysis , Adult , C-Reactive Protein/standards , Enzyme-Linked Immunosorbent Assay/standards , Female , Healthy Volunteers , Humans , Male , Reference Values , Serum Amyloid A Protein/standardsSubject(s)
Arthritis , Autoimmune Diseases , Antibodies, Antinuclear , Arthritis/drug therapy , Biological Therapy , HumansABSTRACT
To investigate the association between a functional drug-response tumor necrosis factor (TNF)α gene polymorphism (at the positions of -308; rs1800629; NG_007462.1:g.4682G>A) and both disease susceptibility and clinical manifestations in a cohort of 130 Italian patients with Behçet syndrome (BS). A group of 100 ethnically, age, and gender matched healthy controls (HC) was also recruited. Genotyping was performed using molecular (amplification and direct sequencing) and in silico methods. The genotype distribution of BS patients and HC underlined a lower percentage of wild-type GG genotype in BS patients versus HC (106/130 patients, 81.5% vs. 91/100 HC, 91%; p < 0.05), while the heterozygous genotype (GA) was identified in 24/130 patients (18.5%) versus 9/100 HC (9%) (p < 0.05). GA genotype was significantly associated with the disease (odds ratio = 2.29, 95% confidence interval 1.01-5.18). No significant association was recognized between the single nucleotide polymorphism (SNP) and the BS clinical manifestations, as well as with disease severity (Krause's index). We found statistically significant higher frequency of TNFα rs1800629 GA genotype in patients than in controls. No significant association was recognized between the polymorphism and the clinical parameters, as well as between the SNP and the disease severity. Our data need to be confirmed in larger cohort of patients and matched controls.
Subject(s)
Behcet Syndrome/genetics , Genetic Predisposition to Disease/genetics , Polymorphism, Single Nucleotide , Tumor Necrosis Factor-alpha/genetics , Case-Control Studies , Female , Humans , Italy , Male , Middle AgedABSTRACT
Background: Anti-dense fine speckled 70 (DFS70) autoantibodies have more often been described in apparently healthy individuals than in patients with systemic autoimmune rheumatic diseases (SARD). The aim of this study was to explore the link between anti-DFS70 autoantibodies and vitamin D (25(OH)D) levels in an Italian adult cohort.Methods: Serum samples from 34 (five males and 29 females) anti-DFS70 positive patients (index cases), 34 ANA-negative healthy controls, 34 ANA-positive anti-DFS70 negative SLE patients, both groups age- and gender-matched with the index cases, 23 ANA-positive anti-DFS70 negative healthy blood donors and six female SARD patients showing mixed DFS positive pattern were collected and tested for 25(OH)D levels. Relevant demographics and lifestyle practices, body mass index (BMI), comorbidities, and use of medication were recorded for patients and healthy controls.Results: Mean serum levels of 25(OH)D were significantly higher in anti-DFS70 positive subjects (mean ± SD: 22.1 ± 9.8 ng/ml) than in ANA-negative healthy controls (mean ± SD: 17.3 ± 6.7 ng/ml; p = .03), ANA-positive healthy controls (mean ± SD: 15.2 ± 6.8 ng/ml; p = .01), SLE patients (16.6 ± 11.0 ng/ml; p = .01) and in patients with SARD (15.0 ± 5.6 ng/ml; p = .01). No statistically relevant differences in BMI, clinical, or demographic parameters were found.Conclusions: Our findings showed higher levels of vitamin D in anti-DFS70 positive subjects than in the controls, which is compatible with the hypothesis of the "benign" nature of anti-DFS70 antibodies.
Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Autoantibodies/blood , Rheumatic Diseases/blood , Rheumatic Diseases/immunology , Transcription Factors/immunology , Vitamin D/blood , Adult , Autoimmune Diseases/blood , Autoimmune Diseases/immunology , Body Mass Index , Cohort Studies , Female , Fluorescent Antibody Technique, Indirect/methods , Humans , Male , Middle AgedABSTRACT
INTRODUCTION: ERAP1 has been recently proposed as risk marker of Behçet syndrome (BS). Gene single nucleotide polymorphisms (SNPs) could affect the enzymatic activity and the conserved active site is pivotal for the aminopeptidase function. This study aims to characterize the ERAP1 active site in a cohort of BS patients vs healthy controls (HC) integrating genomics, transcriptomics and bioinformatics approach. MATERIALS AND METHODS: We recruited 109 consecutive Italian BS patients (63M:46 F; mean age: 45.07 ± 12.28 years) and 106 matched HC (55M:51 F; mean age: 42.57 ± 12.29 years). DNA was isolated and amplified using PCR with home made-primer pairs. PCR products were directly sequenced and computational analyses were performed to search active site SNPs (NCBI-BlastN tool), to predict SNPs functional effect (PolyPhen-2 software) and to obtain protein 3D modelling (Protean3D software). In a second phase of analysis, RNA was extracted and reverse transcribed. Quantitative Real-Time PCR (qPCR) was performed to assess ERAP1 mRNA level in presence (target) and in absence (control) of gene polymorphisms. The Fold change was calculated for the relative quantification of gene expression. RESULTS: A novel coding variation (NG_027839.1:g.25637 T > G; NP_057526.3:p.Phe360Cys, HGSV nomenclature) was found in heterozygosity state in 5/109 BS patients (4.59 % of cases) and none of HC. It was recognized in association with rs2287987, rs30187, rs17482078, and rs27044 BS-related polymorphisms for 4 out of 5 patients. All patients carrying the novel SNP were HLA-B*51-positive. The novel SNP was released in GenBank database with MK140632.1 ID. The SNP was predicted to be damaging and resides within the Zn-binding HEXXH(X)18E region of the active site, changing the structurally conserved region for the amminopeptidase function. In fact, the change in energy (ΔE) score between wild-type and SNP-containing protein showed a less stable protein in presence of p.Cys360 (ΔE:3.584) (Protean3D prediction). Preliminary qPCR results underlined a significant difference in fold change value when target and control values were compared (p < 0.05), suggesting a reduced expression of ERAP1 mRNA in presence of the novel SNP. CONCLUSIONS: Our study strengthens the association between ERAP1 and BS. The most significant point was the localization of the novel p.Phe360Cys SNP within the Zn-binding region of protein active site that was predicted to affect its function, causing protein destabilization. Our findings need to be tested in larger genetic studies.
Subject(s)
Aminopeptidases/chemistry , Aminopeptidases/genetics , Behcet Syndrome/genetics , Minor Histocompatibility Antigens/chemistry , Minor Histocompatibility Antigens/genetics , Adult , Catalytic Domain/physiology , Female , Genetic Predisposition to Disease , Genotype , Humans , Italy , Male , Middle Aged , Polymorphism, Single Nucleotide , Structure-Activity RelationshipABSTRACT
A novel nonsynonymous variation of NLRP3 was identified in an Italian patient with Behçet syndrome using both bioinformatics and molecular methods. This variation was a thymine to guanine polymorphism responsible for the isoleucine to serine amino acid change at position 348. The novel variation was predicted to be a pathogenic allele.
Subject(s)
Behcet Syndrome/diagnosis , Behcet Syndrome/genetics , Genetic Association Studies , Genetic Predisposition to Disease , Genetic Variation , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Alleles , Base Sequence , DNA Mutational Analysis , Genetic Association Studies/methods , Genotype , Humans , Italy , Male , Middle Aged , Polymorphism, GeneticABSTRACT
The Endoplasmic reticulum aminopeptidase protein 1 (ERAP1) trims N-terminal amino acids from epitope precursors for Major Histocompatibility Complex class I presentation. Genome-wide association studies demonstrated that ERAP1 gene single nucleotide polymorphisms (SNPs) are associated with Behçet's syndrome (BS). This study was conducted on the two most consistently BS-associated ERAP1 polymorphisms, rs17482078 (NG_027839.1:g.35983G>A) and rs27044 (NG_027839.1:g.35997C>G) to analyse their distribution in 55 Italian BS patients and 65 ethnically matched controls (healthy controls, HC) and to test their association with BS risk. SNPs were detected by isolation, amplification of genomic DNA and direct sequencing. SNPs functional effects were predicted by bioinformatics software. The odds ratio (OR) with 95% confidence intervals was calculated to assess the strength of BS association for genotypes and alleles, also validated by logistic regression (LR). LR was used to test the association between both SNPs and patients HLA genetic data. Bonferroni correction was also applied. Comparing patients and controls, we found a significant higher frequency of rs17482078 A allele (32.73% BS vs 17.69% HC, p = 0.007) and AA genotype (18.18% BS vs 0% HC; p = 0.0003) and rs27044 G allele (63.64% BS vs 46.92% HC; p = 0.0096) in BS group after Bonferroni correction. No association was found between HLA-B*51 and both ERAP1 SNPs. Although preliminary, our data show a stronger association of rs17482078 with BS compared to rs27044 by means of case-control genetic analysis and bioinformatics prediction of protein structure change. A larger series of patients and controls is required to confirm our preliminary findings.
Subject(s)
Aminopeptidases/analysis , Behcet Syndrome/genetics , Minor Histocompatibility Antigens/analysis , Polymorphism, Genetic/genetics , Adult , Case-Control Studies , Chi-Square Distribution , Computer Simulation , Female , Genome-Wide Association Study/methods , Humans , Italy , Logistic Models , Male , Middle Aged , Odds Ratio , Prospective StudiesABSTRACT
Anti-Dense Fine Speckled 70 (DFS70) antibodies are a common finding in clinical laboratory referrals. High prevalence of DFS70 autoantibodies in healthy population and usual negative association with Antinuclear Antibody (ANA)-associated autoimmune rheumatic diseases (AARD) were reported. The aim of this study was to evaluate the prevalence of DFS70 autoantibodies and their association with other autoantibodies in the context of a routine ANA referral cohort. Consecutive sera submitted for ANA screening were analyzed for anti-DFS70 antibodies by indirect immunofluorescence (IIF) (n = 3175, 1030 men and 2145 women) then confirmed by immunoblotting. Anti-DFS70 positive samples were also assayed for a large spectrum of other circulating autoantibodies. The prevalence of anti-DFS70 antibodies was 1.7% in the whole population and 4.6% in the ANA-positive samples. Comparison between DFS70 IIF and immunoblotting showed an excellent correlation between the two methods. The prevalence of anti-DFS70 positive was significantly higher in females (2.1%, 45/2145) than in males (1.0%, 10/1030). Of note, no concomitant autoantibodies were found in the DFS70-positive male group compared with DFS70-positive females group that showed other serum autoantibodies in the 51% of cases. Anti-DFS70 reactivity in male population may represent an useful biomarker predicting the absence of other autoantibodies. On the contrary, the serological profile of DFS70-positive females required further investigations in order to define the presence of concomitant disease-marker autoantibodies.
Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Antibodies, Antinuclear/blood , Autoantibodies/blood , Transcription Factors/immunology , Adult , Aged , Antibody Specificity , Autoimmune Diseases/blood , Autoimmune Diseases/immunology , Biomarkers/blood , Cohort Studies , Female , Fluorescent Antibody Technique, Indirect , Healthy Volunteers , Humans , Immunoblotting , Male , Middle Aged , Phenotype , Prevalence , Rheumatic Diseases/blood , Rheumatic Diseases/immunology , Seroepidemiologic StudiesABSTRACT
The endoplasmic reticulum aminopeptidase protein 1 gene (ERAP1) is related to several human diseases, including Behçet syndrome (BS), a multisystemic disorder with unknown etiology. ERAP1 is involved in immune response and its role can be influenced by gene single nucleotide variations (SNVs). We genotyped the ERAP1 whole structure in 50 consecutive BS patients and 50 ethnically-matched healthy controls using both bioinformatics and molecular methodologies. We identified two novel heterozygous missense SNVs of ERAP1 exon3 responsible for the p.Glu183Val and p.Phe199Ser changes. The first variation was recognized in 7/50 (14%) BS patients and involved the substrate binding site (p.Glu183) required for the anchorage of the peptide N-terminal group. The SNV was predicted to be a damaging variation, as well as the p.Phe199Ser substitution (PolyPhen-2 and SIFT on line software). 3D protein structure prediction showed a change in energy score when the wild-type and the variant states were compared, probably influencing the substrate binding and the protein folding. The first variation was associated to a more stable protein chain, while the second polymorphism was related to a less stable protein chain. Our data need to be tested in larger genetic studies.