Distinct and dynamic activation profiles of circulating dendritic cells and monocytes in mild COVID-19 and after yellow fever vaccination.

Dysregulation of the myeloid cell compartment is a feature of severe disease in hospitalized COVID-19 patients. Here, we investigated the response of circulating dendritic cell (DC) and monocyte subpopulations in SARS-CoV-2 infected outpatients with mild disease and compared it to the response of healthy individuals to yellow fever vaccine virus YF17D as a model of a well-coordinated response to viral infection. In SARS-CoV-2-infected outpatients circulating DCs were persistently reduced for several weeks whereas after YF17D vaccination DC numbers were decreased temporarily and rapidly replenished by increased proliferation until 14 days after vaccination. The majority of COVID-19 outpatients showed high expression of CD86 and PD-L1 in monocytes and DCs early on, resembling the dynamic after YF17D vaccination. In a subgroup of patients, low CD86 and high PD-L1 expression were detected in monocytes and DCs coinciding with symptoms, higher age, and lower lymphocyte counts. This phenotype was similar to that observed in severely ill COVID-19 patients, but less pronounced. Thus, prolonged reduction and dysregulated activation of blood DCs and monocytes were seen in a subgroup of symptomatic non-hospitalized COVID-19 patients while a transient coordinated activation was characteristic for the majority of patients with mild COVID-19 and the response to YF17D vaccination.

Single nucleotide polymorphism rs5029937 in TNFAIP3 gene is correlated with risk of rheumatoid arthritis.

Background: Rheumatoid arthritis (RA) is a progressive and common autoimmune disease with multifactorial etiology. Several pieces of research show that genetic factors play a major role in the incidence of RA. Several genome-wide association studies (GWAS) have identified the tumor necrosis factor alpha inducible protein 3 (TNFAIP3) genes as one of the candidate loci. The TNFAIP3 gene encoding ubiquitin-editing protein A20 witch restricts B cell survival and prevents autoimmunity. Previous studies have indicated that single nucleotide polymorphisms (SNPs) in the TNFAIP3 gene are correlated with several autoimmune disorders. In the present study, we assessed the possible association between SNP rs5029937 (intronic variant) in the TNFAIP3 gene with RA risk in the Iranian population. Methods: A case-control study using 50 RA patients and 50 control subjects was undertaken to evaluate rs5029937 (G>T) genotypes using real-time PCR high resolution melting method (HRM). The SPSS22 was used for statistical analyses and the significance level was set at P<0.05. Results: Logistic regression analysis demonstrates that homozygous TT + heterozygous TG genotypes compared with GG genotype increase the risk of RA (TT+TG vs GG; P= 0.004, OR= 3.46; 95%CI [1.492-8.075]). Also, individuals with allele T were more frequently affected with RA than subjects with G allele (T vs G; P= 0.004, OR= 2.61; 95%CI [1.382-4.919]). Conclusion: Our findings propose a substantial correlation between rs5029937 (G>T) polymorphism and RA risk in Iranian population.

Mutations in Hepatitis D Virus Allow It to Escape Detection by CD8+ T Cells and Evolve at the Population Level.

BACKGROUND & AIMS: Hepatitis D virus (HDV) superinfection in patients with hepatitis B virus (HBV) is associated with rapid progression to liver cirrhosis and hepatocellular carcinoma. Treatment options are limited, and no vaccine is available. Although HDV-specific CD8+ T cells are thought to control the virus, little is known about which HDV epitopes are targeted by virus-specific CD8+ T cells or why these cells ultimately fail to control the infection. We aimed to define how HDV escapes the CD8+ T-cell-mediated response. METHODS: We collected plasma and DNA samples from 104 patients with chronic HDV and HBV infection at medical centers in Europe and the Middle East, sequenced HDV, typed human leukocyte antigen (HLA) class I alleles from patients, and searched for polymorphisms in HDV RNA associated with specific HLA class I alleles. We predicted epitopes in HDV that would be recognized by CD8+ T cells and corresponded with the identified virus polymorphisms in patients with resolved (n = 12) or chronic (n = 13) HDV infection. RESULTS: We identified 21 polymorphisms in HDV that were significantly associated with specific HLA class I alleles (P < .005). Five of these polymorphisms were found to correspond to epitopes in HDV that are recognized by CD8+ T cells; we confirmed that CD8+ T cells in culture targeted these HDV epitopes. HDV variant peptides were only partially cross-recognized by CD8+ T cells isolated from patients, indicating that the virus had escaped detection by these cells. These newly identified HDV epitopes were restricted by relatively infrequent HLA class I alleles, and they bound most frequently to HLA-B. In contrast, frequent HLA class I alleles were not associated with HDV sequence polymorphisms. CONCLUSIONS: We analyzed sequences of HDV RNA and HLA class I alleles that present epitope peptides to CD8+ T cells in patients with persistent HDV infection. We identified polymorphisms in the HDV proteome that associate with HLA class I alleles. Some variant peptides in epitopes from HDV were only partially recognized by CD8+ T cells isolated from patients; these could be mutations that allow HDV to escape the immune response, resulting in persistent infection. HDV escape from the immune response was associated with uncommon HLA class I alleles, indicating that HDV evolves, at the population level, to evade recognition by common HLA class I alleles.

Amino Acid Substitutions within HLA-B*27-Restricted T Cell Epitopes Prevent Recognition by Hepatitis Delta Virus-Specific CD8+ T Cells.

Virus-specific CD8 T cell response seems to play a significant role in the outcome of hepatitis delta virus (HDV) infection. However, the HDV-specific T cell epitope repertoire and mechanisms of CD8 T cell failure in HDV infection have been poorly characterized. We therefore aimed to characterize HDV-specific CD8 T cell epitopes and the impacts of viral mutations on immune escape. In this study, we predicted peptide epitopes binding the most frequent human leukocyte antigen (HLA) types and assessed their HLA binding capacities. These epitopes were characterized in HDV-infected patients by intracellular gamma interferon (IFN-γ) staining. Sequence analysis of large hepatitis delta antigen (L-HDAg) and HLA typing were performed in 104 patients. The impacts of substitutions within epitopes on the CD8 T cell response were evaluated experimentally and by in silico studies. We identified two HLA-B*27-restricted CD8 T cell epitopes within L-HDAg. These novel epitopes are located in a relatively conserved region of L-HDAg. However, we detected molecular footprints within the epitopes in HLA-B*27-positive patients with chronic HDV infections. The variant peptides were not cross-recognized in HLA-B*27-positive patients with resolved HDV infections, indicating that the substitutions represent viral escape mutations. Molecular modeling of HLA-B*27 complexes with the L-HDAg epitope and its potential viral escape mutations indicated that the structural and electrostatic properties of the bound peptides differ considerably at the T cell receptor interface, which provides a possible molecular explanation for the escape mechanism. This viral escape from the HLA-B*27-restricted CD8 T cell response correlates with a chronic outcome of hepatitis D infection. T cell failure resulting from immune escape may contribute to the high chronicity rate in HDV infection.IMPORTANCE Hepatitis delta virus (HDV) causes severe chronic hepatitis, which affects 20 million people worldwide. Only a small number of patients are able to clear the virus, possibly mediated by a virus-specific T cell response. Here, we performed a systematic screen to define CD8 epitopes and investigated the role of CD8 T cells in the outcome of hepatitis delta and how they fail to eliminate HDV. Overall the number of epitopes identified was very low compared to other hepatotropic viruses. We identified, two HLA-B*27-restricted epitopes in patients with resolved infections. In HLA-B*27-positive patients with chronic HDV infections, however, we detected escape mutations within these identified epitopes that could lead to viral evasion of immune responses. These findings support evidence showing that HLA-B*27 is important for virus-specific CD8 T cell responses, similar to other viral infections. These results have implications for the clinical prognosis of HDV infection and for vaccine development.

Genetic diversity of hepatitis D virus genotype-1 in Europe allows classification into subtypes.

Hepatitis delta virus (HDV) is an RNA virus which leads to both acute and chronic forms of hepatitis. At present, HDV isolates have been classified into eight major genotypes distributed over different geographical regions. Recent increase in HDV sequences in Europe and worldwide has enabled us to revisit the taxonomic classification of HDV. A total of 116 large hepatitis delta antigen (L-HDAg) nucleotide sequences and 13 full-length HDV genome sequences belonging to genotype-1 from our European cohort, as well as 621 L-HDAg nucleotide sequences belonging to genotype-1 to genotype-8 retrieved from the GenBank NCBI were included in this study. All 116 isolates of our cohort and 341 of 621 isolates (60%) account for genotype-1, while the remaining 40% of isolates were unevenly distributed across genotype-2 to genotype-8. Phylogenetic analysis of 98 L-HDAg sequences selected after elimination of redundant sequences of all 737 isolates was performed to identify plausible subtypes within HDV genotype-1. Pairwise genetic distances for L-HDAg sequences were calculated to estimate the inter-genotype and inter-subtype differences. The HDV genotype-1 isolates phylogenetically formed five distinct clusters (genotype 1a-1e), each of them corresponding to a distinct geographic region. Two distinct subtypes for HDV genotype-2 and -4 (ie -2a and -2b; -4a and -4b, respectively) could be identified based on isolate sequences from GenBank. The previously defined genotype-1 to genotype-8 have an inter-genotypic difference of ≥10%, while the newly defined subtypes of genotype-1, -2 and -4 show an inter-subtype difference of ≥3% to <10% from the average diversity. In addition, we identified unique amino acid residues, known as specificity-determining positions, amongst the proposed subtypes.

Variants of hepatitis B virus surface antigen observed during therapy with nucleic acid polymer REP 2139-Ca have no influence on treatment outcome and its detection by diagnostic assays.

The treatment of patients suffering from HBeAg-positive chronic hepatitis B with REP 2139-Ca resulted in potent reductions in HBsAg and HBV DNA, seroconversion to anti-HBs and the establishment of functional control of infection. In this cohort of 12 patients, we investigated whether differences between HBsAg sequences might explain the lack of response to REP 2139-Ca observed in 3 of 12 patients. We also assessed if the reduction or complete loss of HBsAg in serum observed during therapy were caused by mutations in the "a" determinant preventing the detection of HBsAg by standard diagnostic assays. The complete pre-S/S open reading frame (ORF) was sequenced and pre-S1, pre-S2 and S amino acid sequences were analysed. We found no major differences between pre-S1, pre-S2 and S sequences in responders and nonresponders correlated with low reduction in HBsAg. In addition, we found no mutations in the "a" determinant that would significantly affect the reactivity of HBsAg in diagnostic assays. These results demonstrate that the amino acid sequence of complete pre-S/S ORF has no direct influence on response to REP 2139-Ca therapy.

Kinetics of hepatitis B surface antigen quasispecies during REP 2139-Ca therapy in HBeAg-positive chronic HBV infection.

Chronic HBV infection results in various clinical manifestations due to different levels of immune response. In recent years, hepatitis B treatment has improved by long-term administration of nucleos(t)ide analogues (NUCs) and peg-interferon. Nucleic acid polymers (NAPs; REP 2139-Ca and REP 2139-Mg) are new antiviral drugs that block the assembly of subviral particles, thus preventing the release of HBsAg and allowing its clearance and restoration of functional control of infection when combined with various immunotherapies. In the REP 102 study (NCT02646189), 9 of 12 patients showed substantial reduction of HBsAg and seroconversion to anti-HBs in response to REP 2139-Ca, whereas 3 of 12 patients did not show responses (>1 log reduction of HBsAg and HBV DNA from baseline). We characterized the dynamic changes of HBV quasispecies (QS) within the major hydrophilic region (MHR) of the 'pre-S/S' open reading frame including the 'a' determinant in responders and nonresponders of the REP 102 study and four untreated matched controls. HBV QS complexity at baseline varied slightly between responders and nonresponders (P = .28). However, these responders showed significant decline in viral complexity (P = .001) as REP 2139-Ca therapy progressed but no significant change in complexity was observed among the nonresponders (P = .99). The MHR mutations were more frequently observed in responders than in nonresponders and matched controls. No mutations were observed in 'a' determinant of major QS population which may interfere with the detection of HBsAg by diagnostic assays. No specific mutations were found within the MHR which could explain patients' poor HBsAg response during REP 2139-Ca therapy.

Interferon-induced protein 44-like gene promoter is differentially methylated in peripheral blood mononuclear cells of systemic lupus erythematosus patients.

BACKGROUND: The objectives of this study were to compare the interferon-induced protein 44-like (IFI44L) promoter methylation level between systemic lupus erythematosus (SLE) patients and healthy controls and to evaluate its diagnostic value in SLE. MATERIALS AND METHODS: The IFI44L promoter methylation level was measured in 49 patients with SLE and 50 healthy controls. Quantitative analysis of promoter methylation IFI44L gene in genomic DNA samples extracted from peripheral blood mononuclear cells was examined in SLE patients and healthy controls. The level of DNA methylation was compared between SLE patients and healthy controls as well as within SLE patient groups based on the presence of renal involvement. Moreover, diagnostic values of IFI44L were calculated. RESULTS: The IFI44L promoter methylation level in SLE patients was significantly lower than healthy controls (median, 43.8 vs. 57, respectively; P = 0.008). The level of IFI44L promoter methylation was not significantly different between SLE patients with renal involvement and SLE patients without renal involvement (84.6% vs. 92.7%, respectively; P = 0.774). The IFI44L promoter methylation level ≤94.3% was the best cutoff point with a sensitivity of 91.8% and a specificity of 38% to distinguish patients with SLE from healthy individuals. CONCLUSION: The level of IFI44L promoter methylation from whole peripheral blood in Iranian SLE patients was significantly lower than healthy controls. Furthermore, the DNA methylation level of IFI44L promoter was not associated with renal damage in patients with SLE.

Molecular evolution and phylodynamics of hepatitis B virus infection circulating in Iran.

Previous local and national Iranian publications indicate that all Iranian hepatitis B virus (HBV) strains belong to HBV genotype D. The aim of this study was to analyze the evolutionary history of HBV infection in Iran for the first time, based on an intensive phylodynamic study. The evolutionary parameters, time to most recent common ancestor (tMRCA), and the population dynamics of infections were investigated using the Bayesian Monte Carlo Markov chain (BMCMC). The effective sample size (ESS) and sampling convergence were then monitored. After sampling from the posterior distribution of the nucleotide substitution rate and other evolutionary parameters, the point estimations (median) of these parameters were obtained. All Iranian HBV isolates were of genotype D, sub-type ayw2. The origin of HBV is regarded as having evolved first on the eastern border, before moving westward, where Isfahan province then hosted the virus. Afterwards, the virus moved to the south and west of the country. The tMRCA of HBV in Iran was estimated to be around 1894, with a 95% credible interval between the years 1701 and 1957. The effective number of infections increased exponentially from around 1925 to 1960. Conversely, from around 1992 onwards, the effective number of HBV infections has decreased at a very high rate. Phylodynamic inference clearly demonstrates a unique homogenous pattern of HBV genotype D compatible with a steady configuration of the decreased effective number of infections in the population in recent years, possibly due to the implementation of blood donation screening and vaccination programs. Adequate molecular epidemiology databases for HBV are crucial for infection prevention and treatment programs.

Correlation between Vitamin D3 level and extrahepatic manifestation in chronic hepatitis type-C virus patients.

BACKGROUND: Chronic hepatitis type-C virus (HCV) infection is one of the most common worldwide viral disorders, which leads to various clinical complications as well as extrahepatic manifestations. Furthermore, Vitamin D3 has also been reported to have relationship with the mentioned complications. The aim is to evaluate the correlation between Vitamin D3 level and extrahepatic manifestation in chronic HCV patients. MATERIALS AND METHODS: This cross-sectional study has been carried out on 90 patients with chronic hepatitis C. The level of Vitamin D3 was assessed in plasma of 90 patients with chronic HCV. Genotyping was done and clinical and sign and symptoms of recruited patients were gathered. Extrahepatic manifestations were evaluated and the correlation of blood, hepatic, and immunological factors and the level of Vitamin D3 were assessed. RESULTS: Most of our patients were male (92% vs. 8%). Twenty-nine percent had the insufficient amount of Vitamin D3 (21-30 ng/ml), and the remains had the Vitamin D3 level between 13-20 ng/ml. Furthermore, our assessment demonstrated that deficiency of Vitamin D3 was associated with the extrahepatic manifestations such as purpura (odds radio [OR] [95% confidence interval (CI) 95%] = 8.80 [1.74-44.47], P = 0.004), vasculitis (OR [95% CI] = 11.70 [3.01-45.41], P < 0.001), arthralgia (OR [95% CI] = 20.26 [4.21-97.47], P < 0.001), myalgia (OR [95% CI] = 4.00 [1.01-17.27], P = 0.048), and glomerulonephritis (P = 0.021). CONCLUSION: According to our results, the extrahepatic manifestation in the patients with sufficient levels of Vitamin D3 would be less possible. In fact, it could be stated that deficiency in the Vitamin D3 can have a significant relationship with these manifestations.

Ultrasonographic findings of rheumatoid arthritis patients who are in clinical remission.

BACKGROUND: The aim of this study was to recognize the findings of ultrasonography (US) in remitted rheumatic arthritis (RA) patients for detection subclinical arthritis. MATERIALS AND METHODS: This descriptive study was conducted during 2016 in a rheumatology center. A total of 70 patients with remitted RA were included in the study. Sonography was performed on all 70 patients who did not show any clinical arthritis in clinical examination to find synovitis and effusion were evaluated with gray scale and hyperemia with power Doppler US. RESULTS: Nearly 44.3% (n = 31) of our patients had positive sonography results including 20% synovitis, 21.4% hyperemia, and 18.6% (n = 13) effusion. A total of 1960 joints of 70 patients were evaluated, in which 3.2% (n = 63) of joints had positive sonography findings including 1.2% synovitis, 1.5% hyperemia, and 1.1 with effusion. CONCLUSION: US can diagnosis subclinical arthritis in patients with remitted RA who does not show any joint involvement in clinical examination.

The effect of Vitamin D supplementation in disease activity of systemic lupus erythematosus patients with Vitamin D deficiency: A randomized clinical trial.

BACKGROUND: The aim of this study was to check the effectiveness of Vitamin D supplementation on the disease activity of Vitamin D-deficient systemic lupus erythematosus (SLE) patients. MATERIALS AND METHODS: In this randomized, double-blind, placebo-controlled trial, 45 Vitamin D-deficient SLE patients were studied in two groups, namely interventional and placebo groups. The interventional group patients were treated with Vitamin D (50,000 unit/weekly Vitamin D for 12 weeks and then 50,000 unit/monthly for 3 months) and placebo group patients were only administered the placebo. The level of Vitamin D and the level of disease activity using SLE disease activity index (SLEDAI) were measured before and after intervention period in each group, and for intra- and between-groups comparison, we used t-test and repeated measure ANOVA. RESULTS: A total of 90 patients were enrolled in this study. The mean of Vitamin D was increased significantly after therapy in interventional group (17.36 ± 4.26 ng/ml vs. 37.69 ± 5.92 ng/ml, P < 0.001). The mean of Vitamin D had no significant difference before and after intervention in placebo group (16.78 ± 4.39 ng/ml vs. 16.62 ± 4.61 ng/ml, P = 0.53). The mean of disease activity (SLEDAI) was not different significantly before and after Vitamin D administration in interventional group (3.09 vs. 1.62 ± 1.25, P = 0.39). The mean of disease activity (SLEDAI) was not different significantly before and after intervention in placebo group (3.09 vs. 1.98 ± 2.47, P = 0.42). CONCLUSION: According to our study, it is suggested that using Vitamin D in patients with SLE could not have better outcomes in this regard. However, there are many unknown environmental or biological factors which are associated with the disease activity of SLE and have not been identified yet.

Agreement of clinical examination and ultrasound methods for detection of joints involvements in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis is a chronic autoimmune disease characterized by synovial tissue inflammation and destruction of articular components which if not controlled properly, can cause disability in patients. For this reason, evaluation of disease activity and its control is very important. In recent years using sonography is promising for the evaluation of disease activity. This study aimed to compare "clinical examination" and "ultrasonography" methods in the detection of disease activity in patients with rheumatoid arthritis. MATERIALS AND METHODS: This cross-sectional study was conducted during 2015 in Al-Zahra Hospital of Isfahan. Based on the American College of Rheumatology 2010 criteria, ninety patients with rheumatoid arthritis who diagnosed by rheumatologist entered into the study. All patients, collaborator by radiologists were subjected to sonography of specific joints structures using two methods, i.e., high-resolution ultrasonography and power Doppler. RESULTS: A total of 2520 joints from ninety patients were examined by physical examination and ultrasonography that 244 joints (9.7%) in physical examination and 348 joints (13.4%) in ultrasonography were involved and the difference between the two groups was statistically significant (P < 0.001). CONCLUSION: Probably, ultrasonography can diagnose joint involvement better than physical examination in patients with Rheumatoid arthritis.

Comparison the percentage of detection of periarthritis in patients with rheumatoid arthritis using clinical examination or ultrasound methods.

BACKGROUND: This study aimed to compare the percentage of detection of periarthritis in patients with rheumatoid arthritis using clinical examination and ultrasound methods. MATERIALS AND METHODS: This study is a cross-sectional study which was conducted in Al-Zahra Hospital (Isfahan, Iran) during 2014-2015. In our study, ninety patients were selected based on the American College of Rheumatology 2010 criteria. All patients were examined by a rheumatologist to find the existence of effusion, and the data were filled in the checklist. The ultrasonography for detecting effusion in periarticular structures was done by an expert radiologist with two methods, including high-resolution ultrasonography and power Doppler. The percentage of effusion existence found by physical examination was compared by sonography, and the Chi-square and t-tests were used for data analysis. RESULTS: The percentage of effusion found in areas with physical examination by rheumatologist was lower than the frequency distribution of effusions found by sonography (8.3% VS 14.2%) (P < 0.001). In sonography, rotator cuff tendonitis is the most common periarthritis. Other findings in sonography were biceps tendinitis (10 cases), wrist tendonitis (13 cases), olecranon bursitis (9 cases), golfers elbow (4 cases), tennis elbow (4 cases), trochanteric bursitis (6 cases), anserine bursitis (6 cases), prepatellar bursitis (11 cases), and ankle tendonitis (7 cases). Tenderness on physical examination was found in 15% of the cases, and the evidence of periarthritis was found in 21/7% through sonography (P < 0.001) and 34% through Doppler sonography (P < 0.001). CONCLUSION: The percentage of periarthritis detection by ultrasonography and power Doppler sonography was higher than clinical examination. Hence, the ultrasonography is more accurate than physical examination.

The association of body mass index with disease activity and clinical response to combination therapy in patients with rheumatoid arthritis.

BACKGROUND: The role of obesity in clinical curse of rheumatoid arthritis (RA) is not clear. We investigated the association of obesity and adiposity with disease activity and clinical response to combination therapy in RA patients. MATERIALS AND METHODS: Active RA patients with the disease activity score using 28 joint counts (DAS28) > 2.6 were studied. Height, weight, and waist and hip circumferences were measured and body mass index (BMI) and waist to hip ratio were calculated. Patients were treated with methotrexate (7.5 to 10 mg/week) plus hydroxychloroquine (200 to 400 mg/day) and prednisolone (2.5 to 10 mg/day) and were followed by DAS28 for up to 24 weeks. RESULTS: One hundred and six patients were studied; age = 48.5 ± 13.8 years, 87.7% female, disease duration = 4.4 years [SE = 0.48]. DAS28 was decreased from 4.5 ± 1.6 to 2.9 ± 1.4 (P < 0.001) after 24 weeks of treatment. Only in patients with disease duration of ≤2 years, BMI (r = -0.415, P = 0.005) and waist circumference (r = -0.296, P = 0.05) were correlated with baseline DAS28. Although BMI (r = -0.337, P = 0.025) and waist circumference (r = -0.315, P = 0.038) were correlated with change in DAS28 after therapy, these correlations were disappeared after controlling for baseline DAS28. CONCLUSION: Obesity and adiposity are associated with less severe disease activity in early stage of RA, but are not associated with response to combination therapy with methotrexate plus hydroxychloroquine in RA patients.

Prior flavivirus immunity skews the yellow fever vaccine response to cross-reactive antibodies with potential to enhance dengue virus infection.

The yellow fever 17D vaccine (YF17D) is highly effective but is frequently administered to individuals with pre-existing cross-reactive immunity, potentially impacting their immune responses. Here, we investigate the impact of pre-existing flavivirus immunity induced by the tick-borne encephalitis virus (TBEV) vaccine on the response to YF17D vaccination in 250 individuals up to 28 days post-vaccination (pv) and 22 individuals sampled one-year pv. Our findings indicate that previous TBEV vaccination does not affect the early IgM-driven neutralizing response to YF17D. However, pre-vaccination sera enhance YF17D virus infection in vitro via antibody-dependent enhancement (ADE). Following YF17D vaccination, TBEV-pre-vaccinated individuals develop high amounts of cross-reactive IgG antibodies with poor neutralizing capacity. In contrast, TBEV-unvaccinated individuals elicit a non-cross-reacting neutralizing response. Using YF17D envelope protein mutants displaying different epitopes, we identify quaternary dimeric epitopes as the primary target of neutralizing antibodies. Additionally, TBEV-pre-vaccination skews the IgG response towards the pan-flavivirus fusion loop epitope (FLE), capable of mediating ADE of dengue and Zika virus infections in vitro. Together, we propose that YF17D vaccination conceals the FLE in individuals without prior flavivirus exposure but favors a cross-reactive IgG response in TBEV-pre-vaccinated recipients directed to the FLE with potential to enhance dengue virus infection.

Impact of Single Nucleotide Polymorphism in the ANKRD55 Gene on Occurrence and Clinical Characteristics of Rheumatoid Arthritis.

Background: Rheumatoid Arthritis (RA) has multifactorial etiology and numerous genetic and environmental factors have been related to an increased risk of RA. Recently, Genome-Wide Association Studies (GWAS) suggested a large number of Single Nucleotide Polymorphisms (SNPs) loci affecting the susceptibility to RA. One of these loci is rs6859219 (C>A), a functional polymorphism in the ANKRD55 gene which was associated with the expression of ANKRD55 and IL6ST. In the current study, we evaluated the possible association between rs6859219 (intronic variant) in the ANKRD55 gene with RA risk in the Iranian population. Methods: A case-control study using 118 RA patients and 115 healthy counterparts was undertaken in order to determine rs6859219 genotypes using real-time polymerase chain reaction High-Resolution Melting (HRM) method. Results: There was a significant difference in the genotype and allele frequencies of rs6859219 between patients and controls (p<0.001). Logistic regression analysis demonstrates that CC genotype and C allele increased the risk of RA (OR for CC genotype= 7.12; 95%CI [3.51-15.05]/OR for C allele=4.16; 95%CI [2.78-6.28]). Furthermore, regarding the dominant and recessive model of inheritance, RA patients indicated obvious association of the rs6859219 variant compared to healthy controls (p<0.001). Moreover, in the patient group, there was a significant correlation between C-Reactive Protein (CRP) concentration with rs6859219 polymorphism (p<0.001). Conclusion: Our findings propose a substantial correlation between rs6859219 polymorphism and RA risk and clinical characteristics of this disease in the Iranian population.

Single Nucleotide Polymorphism rs6445975 in the PXK Gene Is Correlated with Susceptibility and Clinical Characteristics of Systemic Lupus Erythematosus.

Background: Recently, genome-wide association studies (GWAS) have discovered several single nucleotide polymorphisms (SNPs) and loci associated with the risk of systemic lupus erythematosus (SLE). rs6445975 (T>G; intronic variant) polymorphism in the PXK gene is one of these loci. However, there was an inconsistency between the results of replicative studies on European and Asia ancestry. This study aimed to assess the possible association between rs6445975 polymorphism with SLE risk in the Iranian population. Methods: Genotype and allele distribution of rs6445975 polymorphism were investigated in 110 patients with SLE and 115 healthy controls in Isfahan University of Medical Sciences, Isfahan, Iran in 2019 via real-time PCR high resolution melting method (HRM). Results: GG and TG genotypes, but not TT genotype, were associated with increased risk of SLE (GG vs TT; OR= 7.538; 95%CI [3.47, 17.066] and TG vs TT; OR=2.21; 95%CI [1.06, 4.72]). Inheritance analysis revealed that TG + GG was correlated with the increased risk of SLE disease in the dominant model (OR=3.928; 95%CI [2.056, 7.74]). Moreover, subjects with the G allele were more frequently affected with SLE than individuals with the T allele (OR= 3.55; 95%CI [2.37, 5.36]). The G allele in patients was correlated with serum concentration of CRP, ESR, anti-dsDNA antibody, C3, and C4 and presentation of some clinical manifestations such as kidney involvements and skin lesions (P<0.05). Conclusion: Our findings suggest a substantial association between rs6445975 polymorphism in the PXK gene with susceptibility and clinical characteristics of SLE in the Iranian population.

Efficacy and safety of the biosimilar denosumab candidate (Arylia) compared to the reference product (Prolia®) in postmenopausal osteoporosis: a phase III, randomized, two-armed, double-blind, parallel, active-controlled, and noninferiority clinical trial.

BACKGROUND/OBJECTIVE: Osteoporosis is a global health concern with an increasing prevalence worldwide. Denosumab is an antiresoptive agent that has been demonstrated to be effective and safe in osteoporotic patients. This study aimed to compare the efficacy and safety of the biosimilar denosumab candidate (Arylia) to the originator product (Prolia®) in postmenopausal osteoporotic patients. METHODS: In this randomized, double-blind, active-controlled, noninferiority trial, postmenopausal osteoporotic patients received 60 mg of subcutaneous Arylia or Prolia® at months 0, 6, and 12 and were followed up for 18 months. The primary endpoint was the noninferiority of the biosimilar product to the reference product in the percentage change of bone mineral density (BMD) in 18 months at the lumbar spine (L1-L4), total hip, and femoral neck. The secondary endpoints were safety assessment, the incidence of new vertebral fractures, and the trend of bone turnover markers (BTMs). RESULTS: A total of 190 patients were randomized to receive either biosimilar (n = 95) or reference (n = 95) denosumab. In the per-protocol (PP) analysis, the lower limits of the 95% two-sided confidence intervals of the difference between Arylia and Prolia® in increasing BMD were greater than the predetermined noninferiority margin of - 1.78 at the lumbar spine, total hip, and femoral neck sites (mean differences [95% CIs] of 0.39 [- 1.34 to 2.11], 0.04 [- 1.61 to 1.69], and 0.41 [- 1.58 to 2.40], respectively). The two products were also comparable in terms of safety, new vertebral fractures, and trend of BTMs. CONCLUSION: The efficacy of the biosimilar denosumab was shown to be noninferior to that of the reference denosumab, with a comparable safety profile at 18 months. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03293108 ; Registration date: 2017-09-19.

A High-Throughput Yellow Fever Neutralization Assay.

Quick and accurate detection of neutralizing antibodies (nAbs) against yellow fever is essential in serodiagnosis during outbreaks for surveillance and to evaluate vaccine efficacy in population-wide studies. All of this requires serological assays that can process a large number of samples in a highly standardized format. Albeit being laborious, time-consuming, and limited in throughput, the classical plaque reduction neutralization test (PRNT) is still considered the gold standard for the detection and quantification of nAbs due to its sensitivity and specificity. Here, we report the development of an alternative fluorescence-based serological assay (SNTFLUO) with an equally high sensitivity and specificity that is fit for high-throughput testing with the potential for automation. Finally, our novel SNTFLUO was cross-validated in several reference laboratories and against international WHO standards, showing its potential to be implemented in clinical use. SNTFLUO assays with similar performance are available for the Japanese encephalitis, Zika, and dengue viruses amenable to differential diagnostics. IMPORTANCE Fast and accurate detection of neutralizing antibodies (nAbs) against yellow fever virus (YFV) is key in yellow fever serodiagnosis, outbreak surveillance, and monitoring of vaccine efficacy. Although classical PRNT remains the gold standard for measuring YFV nAbs, this methodology suffers from inherent limitations such as low throughput and overall high labor intensity. We present a novel fluorescence-based serum neutralization test (SNTFLUO) with equally high sensitivity and specificity that is fit for processing a large number of samples in a highly standardized manner and has the potential to be implemented for clinical use. In addition, we present SNTFLUO assays with similar performance for Japanese encephalitis, Zika, and dengue viruses, opening new avenues for differential diagnostics.