Search

Background Coronavirus disease 2019 (COVID-19) is associated with increased morbidity and mortality in older adults. Although the advent of the first vaccines has significantly reduced these rates, data on older adults in clinical trials are scarce. Objectives We quantified and compared the humoral response in individuals with vs. without pre-existing seropositivity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in a cohort of 69 patients living in a nursing home and who had received the recommended two doses of the Comirnaty (Pfizer-BioNTech®) vaccine. Results All 69 patients (100%) tested positive for antibodies against SARS-CoV-2 at 2 months post-vaccination. Residents with a pre-vaccination infection had significantly higher titers of anti-spike 1 IgG than those with no prior infection (median [interquartile range]: 55,726 [14463–78852] vs. 1314 [272–1249] arbitrary units, respectively; p

Background: Bkv-miR-B1-5p is a viral micro-RNA (miRNA) specifically produced during BK polyomavirus (BKPyV) replication. Recent studies have suggested using bkv-miR-B1-5p as a biomarker to monitor viral infection and predict complications in kidney transplant patients. To identify the technical limitations of this miRNA quantification in biological samples, knowledge of its stability and distribution in the extracellular compartment is necessary. Moreover, a proof of concept for using bkv-miR-B1-5p as a biomarker of active replication in chronic infection is still missing in the published literature. Methods: The stability of bkv-miR-B1-5p was evaluated in samples derived from cell cultures and in urine from BKPyV-infected kidney transplant recipients. The miRNA was quantified in different fractions of the extracellular compartment, including exosomes, and protein binding was evaluated. Finally, we developed an in vitro model for chronic culture of BKPyV clinical isolates to observe changes in the bkv-miR-B1-5p level during persistent infections. Results: Bkv-miR-B1-5p is a stable biomarker in samples from humans and in vitro experiments. Marginally associated with the exosomes, most of the circulating bkv-miR-B1-5p is bound to proteins, especially Ago2, so the miRNA quantification does not require specific exosome isolation. The bkv-miR-B1-5p level is predictable of viral infectivity, which makes it a potential specific biomarker of active BKPyV replication after kidney transplantation.

From September 2020, new variants of concern of SARS-CoV-2 were detected in Europe. In this context, our hospital center has led us to be particularly vigilant in the search for and detection of these variants. To this end, two SARS-CoV-2 Mutation Discrimination assays for the detection of 501 and 484 mutations on spike protein were developed. It allowed to quickly identify the United Kingdom variant 20I/501Y.V1 and the south-african variant 20H/501Y.V2 that were circulating in our region and surprisingly identify a mutation of interest (N501T), which reported for the first time the A.28 lineage in France.

BackgroundIn the fight against SARS-COV-2, the development of serological assays based on different antigenic domains represent a versatile tool to get a comprehensive picture of the immune response or differentiate infection from vaccination beyond simple diagnosis.ObjectivesHere we use a combination of the Nucleoprotein (NP), the Spike 1 (S1) and Spike 2 (S2) subunits, and the receptor binding domain (RBD) and N-terminal domain (NTD) of the Spike antigens from the Syrius-CoViDiag® multiplex IgG assay, to follow the immune response to SARS-CoV-2 infection over a long time period and depending on disease severity.ResultsUsing a panel of 209 sera collected from 61 patients up to eight months after infection, we observed that most patients develop an immune response against multiple viral epitope, but anti-S2 antibodies seemed to last longer. For all the tested IgGs, we have found higher titers for hospitalized patients than for non-hospitalized ones. Moreover the combination of the five different IgG titers increased the correlation to the neutralizing antibody titers than if considered individually.ConclusionMultiplex immunoassays have the potential to improve diagnostic performances, especially for ancient infection or mild form of the disease presenting weaker antibody titers. Also the combined detection of anti-NP and anti-Spike-derived domains can be useful to differentiate vaccination from viral infection and accurately assess the antibody potential to neutralize the virus.

Since December 2019, an emerging infectious viral disease implicating a coronavirus SARS-CoV-2 has caused a global pandemic. Elderly people, being more fragile, are the most affected by the severity and lethality of this disease. The NH and LTCU of the Amiens University Hospital registered their first Covid-19 cases in February 2020, which lead to the opening of a Covid-19 dedicated unit and of specific protocol for confinement. This descriptive study was analyzing the prevalence of Covid-19 seroconversion within the NH and the LTCU of the Amiens University Hospital. Both this screening test and the nasopharyngeal swab PCRs were in order to assess the impact of the Covid-19 epidemic in NH and LTCU. On June 15th and 16th, the serological tests for Covid-19 were positive for 146 (66.1%) of the residents tested. The seroconversion rate was significantly different (p 0.001) between the NH (88.7%) and the LTCU (45.6%). During the epidemic, there was no excess mortality index within the NH and LTCU services of the Amiens University Hospital. Among frail patients, the role of immunosenescence can be discussed to account for the absence of this inflammatory reaction. This study showed that isolating the infected patient in a dedicated unit significantly reduces the risk of seroconversion and contamination compared to isolating them within their own unit.

Background Fourth-generation immunoassays (such as the ADVIA Centaur® HIV Ag/Ab Combo (CHIV) assay) have improved the early diagnosis of human immunodeficiency virus (HIV), and their sensitivity and specificity usually exceed 99%. In regions with a low prevalence of HIV infection, however, the regular occurrence of false positives interferes with a medical laboratory’s workflow. The additional reagent and staff costs associated with false positives can nevertheless be avoided or reduced by gaining a better knowledge of the CHIV assay’s performance. Objectives/study design To improve our HIV diagnosis strategy, we retrospectively analyzed all the Centaur® CHIV assays and confirmatory tests performed at Amiens University Medical Center between 2012 and 2018. We used open-source machine learning software to process this large database, develop a predictive model, and identify a new cut-off for Centaur® CHIV index interpretation. Results A total of 56,682 HIV serological assay results were analyzed. The results of the CHIV assay were initially reactive or indeterminate for 449 samples. After p24 antigen and/or immunoblotting, there were 171 (38%) false positives and 278 (62%) confirmed true positives. The application of a cut-off of 2.12 led to reclassification of 130 of the 171 false positives as true negatives. Combining our predictive model with medical record analysis reduced the number of false positive CHIV assay results from 171 to 12. Conclusions The efficiency of the Centaur® CHIV assay can be increased by adjusting its cut-off for positivity. This adjustment may reduce the number of unnecessary confirmatory tests and accelerate the delivery of HIV test results.

In the context of a second wave of SARS-CoV-2 transmission, the use of saliva sampling has become an issue of real importance. SARS-CoV-2 RNA screening was performed on nasopharyngeal and saliva swabs collected from 501 individuals from residential homes for the elderly. The saliva samples were collected at the same time as the nasopharyngeal samples. Nasopharyngeal samples yielded positive results for 26 individuals, only two of whom also tested positive with saliva swabs. In this context, saliva collected by swabbing the fluid is not an ideal sample.

Background: Kidney transplant recipients (KTRs) are exposed to a high risk of BK polyomavirus (BKPyV) replication, which in turn may lead to graft loss. Although the microRNAs (miRNAs) bkv-miR-B1-3p and bkv-miR-B1-5p are produced during the viral cycle, their putative value as markers of viral replication has yet to be established. In KTRs, the clinical relevance of the changes over time in BKPyV miRNA levels has not been determined. Methods: In a retrospective study, we analyzed 186 urine samples and 120 plasma samples collected from 67 KTRs during the first year post-transplantation. Using a reproducible, standardized, quantitative RT-PCR assay, we measured the levels of bkv-miR-B1-3p and bkv-miR-B1-5p (relative to the BKPyV DNA load). Results: Detection of the two miRNAs had low diagnostic value for identifying patients with DNAemia or for predicting DNAuria during follow-up. Seven of the 14 KTRs with a sustained BKPyV infection within the first year post-transplantation showed a progressive reduction in the DNA load and then a rapid disappearance of the miRNAs. DNA and miRNA loads were stable in the other seven KTRs. Conclusions: After the DNA-based diagnosis of BKPyV infection in KTRs, bkv-miR-B1-3p and bkv-miR-B1-5p levels in the urine might be valuable markers for viral replication monitoring and thus might help physicians to avoid an excessive reduction in the immunosuppressive regimen.

Objectives BK polyomavirus-associated nephropathy is a troublesome disease caused by BK polyomavirus (BKPyV) infection in immunocompromised renal graft recipients. There are no effective treatments available, making immunosuppression reduction the only management option. Thus, pre-graft predictive BKPyV replication markers are needed for identification of patients at high risk of viraemia. Methods We conducted a retrospective study to assess the correlation between pre-transplantation BKPyV serostatus and post-transplantation incidence of BKPyV infection. Sera from 329 recipients and 222 matched donors were tested for anti-BKPyV antibodies against BKPyV serotypes I and IV by using a virus-like particle-based immunoglobulin G enzyme-linked immunosorbent assay, and BKPyV DNA load was monitored for at least 1 year post-transplantation. Results Eighty recipients were viruric and 59 recipients were viraemic post-transplantation. In the post-transplantation period, the probability of developing viraemia for serotype I increased from 4.3% for the D−/R+ group to 12.1% for the D+/R+ group, climbing to 37.5% for the D+/R− group (P Conclusions Determination of both donor and recipient BKPyV seropositivity before transplantation and antibody titre measurements may serve as a predictive tool to manage clinical BKPyV infection by identification of patients at high risk.

International audience; No abstract available

ObjectivesHealthcare workers are more likely to be infected by SARS-CoV-2. In order to assess the infectious risk associated with working in a hospital, we sought to estimate the proportion of healthcare professionals infected with SARS-CoV-2 by screening staff in a University Medical Center in France.SettingA hospital-wide screening campaign (comprising a serological test and a questionnaire) ran from 18 May to 26 July 2020.Primary and secondary outcome measuresThe seroprevalence rate was analysed in a multivariate analysis according to sociodemographic variables (age, sex and profession), exposure to SARS-CoV-2 and symptoms.ResultsA total of 4840 professionals were included, corresponding to 74.5% of the centre’s staff. The seroprevalence rate (95% CI) was 9.7% (7.0% to 12.4%). Contact with a confirmed case of COVID-19 was significantly associated with seropositivity (OR (95% CI: 1.43, (1.15 to 1.78)). The seroprevalence rate was significantly higher among nursing assistants (17.6%) than among other healthcare professionals. The following symptoms were predictive of COVID-19: anosmia (OR (95% CI): 1.55, (1.49 to 1.62)), ageusia (1.21, (1.16 to 1.27)), fever (1.15, (1.12 to 1.18)), myalgia (1.03, (1.01 to 1.06)) and headache (1.03, (1.01 to 1.04)).

Background The emergence of the global SARS-CoV-2 pandemic required the rapid and large-scale deployment of PCR and serological tests in different formats. Objectives Real-life evaluation of these tests is needed. Using 168 samples from patients hospitalized for COVID-19, non-hospitalized patients but infected with SARS-CoV-2, patients participating in screening campaigns, and samples from patients with a history of other seasonal coronavirus infections, we evaluated the clinical performance of 5 serological assays widely used worldwide (WANTAI®, BIORAD®, EUROIMMUN®, ABBOTT® and LIAISON®). Results For hospitalized patients, all these assays showed a sensitivity of 100 % from day 9 after the symptoms onset. On the other hand, sensitivity was much lower for patients who did not require hospitalization for COVID-19 confirmed by PCR (from 91.6 % for WANTAI® to 69 % for LIAISON®). These differences do not seem to be due to the antigens chosen by the manufacturers but more to the test formats (IgG detection versus total antibodies). In addition, more than 50 days after a positive PCR for CoV-2-SARS the proportion of positive patients seem to decrease. We did not observe any significant cross-reactions for these techniques with the four other seasonal coronaviruses. Conclusion In conclusion, the evaluation and knowledge of the serological tests used is important and should require an optimized strategy adaptation of the analysis laboratories to best meet patient’s expectations in the face of this health crisis.

Extracellular vesicles have recently emerged as a novel mode of viral transmission exploited by naked viruses to exit host cells through a nonlytic pathway. Extracellular vesicles can allow multiple viral particles to collectively traffic in and out of cells, thus enhancing the viral fitness and diversifying the transmission routes while evading the immune system. This has been shown for several RNA viruses that belong to the Picornaviridae, Hepeviridae, Reoviridae, and Caliciviridae families; however, recent studies also demonstrated that the BK and JC viruses, two DNA viruses that belong to the Polyomaviridae family, use a similar strategy. In this review, we provide an update on recent advances in understanding the mechanisms used by naked viruses to hijack extracellular vesicles, and we discuss the implications for the biology of polyomaviruses.

In order to fight the SARS-CoV-2 pandemic infection, there is a growing need and demand for diagnostic tools that are complementary and different from the RT-PCR currently in use. Multiple serological tests are or will be very soon available but need to be evaluated and validated. We have thus tested 4 immunochromatographic tests for the detection of antibodies to SARS-CoV-2. In addition, we assessed the kinetics of antibody appearance using these assays in 22 patients after they were tested positive by RT-PCR. We observed great heterogeneity in antibody detection post-symptom onset. The median antibody detection time was between 8 and 10 days according to the manufacturers. All the tests showed a sensitivity of 60 to 80% on day 10 and 100% on day 15. In addition, a single cross-reaction was observed with other human coronavirus infections. Thus, immunochromatographic tests for the detection of anti-SARS-CoV-2 antibodies may have their place for the diagnostic panel of COVID-19.

Aims Coronavirus disease 2019 (COVID‐19) is a rapidly progressing pandemic, with four million confirmed cases and 280,000 deaths at the time of writing. Some studies have suggested that diabetes is associated with a greater risk of developing severe forms of COVID‐19. The primary objective of the present study was to compare the clinical features and outcomes in hospitalized COVID‐19 patients with vs. without diabetes. Methods All consecutive adult patients admitted to Amiens University Hospital (Amiens, France) with confirmed COVID‐19 up until April 21st, 2020, were included. The composite primary endpoint comprised admission to the intensive care unit (ICU) and death. Both components were also analyzed separately in a logistic regression analysis and a Cox proportional hazards model. Results A total of 433 patients (median age: 72; 238 (55%) men; diabetes: 115 (26.6%)) were included. Most of the deaths occurred in non‐ICU units and among older adults. Multivariate analyses showed that diabetes was associated neither with the primary endpoint (odds ratio (OR): 1.12; 95% confidence interval (CI): 0.66‐1.90) nor with mortality (hazard ratio: 0.73; 95%CI: 0.40‐1.34) but was associated with ICU admission (OR: 2.06; 95%CI 1.09‐3.92, p=0.027) and a longer length of hospital stay. Age was negatively associated with ICU admission and positively associated with death. Discussion Diabetes was prevalent in a quarter of the patients hospitalized with COVID‐19; it was associated with a greater risk of ICU admission but not with a significant elevation in mortality. Further investigation of the relationship between COVID‐19 severity and diabetes is warranted. This article is protected by copyright. All rights reserved.

Aims To describe the characteristics of patients hospitalized with COVID-19 (including their long-term at-home medication use), and compare them with regard to the course of the disease. To assess the association between renin–angiotensin system inhibitors (RASIs) and disease progression and critical outcomes. Methods and results All consecutive hospitalized patients with laboratory-confirmed COVID-19 in a university hospital in Amiens (France) were included in this study. The primary composite endpoint was admission to an intensive care unit (ICU) or death before ICU admission. Univariable and multivariable logistic regression models were used to identify factors associated with the composite endpoint. Between 28 February 2020 and 30 March 2020, a total of 499 local patients tested positive for SARS-CoV-2. Of these, 231 were not hospitalized {males 33%; median [interquartile range (IQR)] age: 44 (32–54)}, and 268 were hospitalized [males 58%; median (IQR) age: 73 (61–84)]. A total of 116 patients met the primary endpoint: 47 died before ICU admission, and 69 were admitted to the ICU. Patients meeting the primary endpoint were more likely than patients not meeting the primary endpoint to have coronary heart disease and to have been taking RASIs; however, the two subsets of patients did not differ with regard to median age. After adjustment for other associated variables, the risk of meeting the composite endpoint was 1.73 times higher (odds ratio 1.73, 95% confidence interval 1.02–2.93) in patients treated at baseline with a RASI than in patients not treated with this drug class. This association was confirmed when the analysis was restricted to patients treated with antihypertensive agents. Conclusions We highlighted a potential safety signal for RASIs, the long-term use of which was independently associated with a higher risk of severe COVID-19 and a poor outcome. Due to the widespread use of this important drug class, formal proof based on clinical trials is needed to better understand the association between RASIs and complications of COVID-19.

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), causing the COVID-19, has been declared as pandemic by the World Health Organization. Epidemiological and clinical characteristics of patients with COVID-19 have been largely reported but biological risk factors have not yet been well described. In this retrospective and monocentric study, we explored 35 hematological and biochemical parameters, routinely measured at the Amiens University Hospital laboratory, between February 21, 2020 and March 30, 2020 for patients diagnosed with COVID-19. 154 patients were included in this study. We compared biological parameters collected at hospital admission between patients who survived or not after hospitalization. Non survivor patients displayed lower hemoglobin (p=0.02) and bicarbonate concentrations (p=0.03) and higher potassium concentration (p=0.03) compared to the survivors. We then compared these biological parameters between patients hospitalized in conventional care units and patients hospitalized in intensive care units (ICU). Numerous biological examinations had significant variations, including lymphocyte and neutrophil counts, bicarbonate, calcium and C Reactive Protein concentrations. In multivariate Cox analysis, risk factors for aggravation (defined as ICU admission or death) included low bicarbonate levels and hyponatremia. A significant worse overall survival was associated with hyponatremia, hyperkaliemia and prothrombin time > 16.8 seconds. We then proposed a prognostic score, to be validated in a future prospective study. Thus, these biological parameters, easily available, could help clinicians to identify high risk patients at an early stage of infection.

SummaryObjectiveThe objective of this study was to monitor the anti-SARS-CoV-2 antibody response in infected patients.MethodsIn order to assess the time of seroconversion, we used 151 samples from 30 COVID-19 inpatients and monitored the detection kinetics of anti-S1, anti-S2, anti-RBD and anti-N antibodies with in-house ELISAs. We also monitored the presence of neutralizing antibodies in these samples as well as 25 asymptomatic carrier samples using retroviral particles pseudotyped with the spike of the SARS-CoV-2.ResultsWe observed that specific antibodies were detectable in all inpatients two weeks post-symptom onset. The detection of the SARS-CoV-2 Nucleocapsid and RBD was more sensitive than the detection of the S1 or S2 subunits. Neutralizing antibodies reached a plateau two weeks post-symptom onset and then declined in the majority of inpatients. Furthermore, neutralizing antibodies were undetectable in 56% of asymptomatic carriers.ConclusionsOur results raise questions concerning the role played by neutralizing antibodies in COVID-19 cure and protection against secondary infection. They also suggest that induction of neutralizing antibodies is not the only strategy to adopt for the development of a vaccine. Finally, they imply that anti-SARS-CoV-2 neutralizing antibodies should be titrated to optimize convalescent plasma therapy.HighlightsSpecific antibodies are detectable in 100% COVID-19 inpatients two weeks post-symptom onset.The detection of the SARS-CoV-2 Nucleocapsid and Receptor Binding Domain is more sensitive than the detection of the S1 or S2 subunits.Neutralizing antibodies reach a plateau two weeks post-symptom onset and then decline in the majority of inpatients.Neutralizing antibodies are undetectable in the majority of asymptomatic carriers.

Reactivation of BKPyV is responsible for nephropathies in kidney transplant recipients, which frequently lead to graft loss. The mechanisms of persistence and immune evasion used by this virus remain poorly understood, and a therapeutic option for transplant patients is still lacking. Here, we show that BKPyV can be released into EVs, enabling viral particles to infect cells using an alternative entry pathway. This provides a new view of BKPyV pathogenesis. Even though we did not find any decreased sensitivity to neutralizing antibodies when comparing EV-associated particles and naked virions, our study also raises important questions about developing prevention strategies based on the induction or administration of neutralizing antibodies. Deciphering this new release pathway could enable the identification of therapeutic targets to prevent BKPyV nephropathies. It could also lead to a better understanding of the pathophysiology of other polyomaviruses that are associated with human diseases., Most people are asymptomatic carriers of the BK polyomavirus (BKPyV), but the mechanisms of persistence and immune evasion remain poorly understood. Furthermore, BKPyV is responsible for nephropathies in kidney transplant recipients. Unfortunately, the sole therapeutic option is to modulate immunosuppression, which increases the risk of transplant rejection. Using iodixanol density gradients, we observed that Vero and renal proximal tubular epithelial infected cells release two populations of infectious particles, one of which cosediments with extracellular vesicles (EVs). Electron microscopy confirmed that a single vesicle could traffic tens of viral particles. In contrast to naked virions, the EV-associated particles (eBKPyVs) were not able to agglutinate red blood cells and did not use cell surface sialylated glycans as an attachment factor, demonstrating that different entry pathways were involved for each type of infectious particle. However, we also observed that naked BKPyV and eBKPyV were equally sensitive to neutralization by the serum of a seropositive patient or commercially available polyvalent immunoglobulin preparations, which occurred at a postattachment step, after endocytosis. In conclusion, our work shows a new mechanism that likely plays a critical role during the primary infection and in the persistence, but also the reactivation, of BKPyV. IMPORTANCE Reactivation of BKPyV is responsible for nephropathies in kidney transplant recipients, which frequently lead to graft loss. The mechanisms of persistence and immune evasion used by this virus remain poorly understood, and a therapeutic option for transplant patients is still lacking. Here, we show that BKPyV can be released into EVs, enabling viral particles to infect cells using an alternative entry pathway. This provides a new view of BKPyV pathogenesis. Even though we did not find any decreased sensitivity to neutralizing antibodies when comparing EV-associated particles and naked virions, our study also raises important questions about developing prevention strategies based on the induction or administration of neutralizing antibodies. Deciphering this new release pathway could enable the identification of therapeutic targets to prevent BKPyV nephropathies. It could also lead to a better understanding of the pathophysiology of other polyomaviruses that are associated with human diseases.

In the last 20 years, the management of BK polyomavirus (BKPyV) reactivation in kidney transplant patients has become a true challenge for the transplant community. The only treatment option is based on the early identification of at-risk patients. The number of reported risk factors for BKPyV reactivation has increased markedly in the literature last years, although they are sometimes in an unclear or contradictory manner. Our purpose is to provide a systematic review and meta-analysis of risk factors for BKPyV viremia and nephropathy described in multivariate analyses. The PubMed database was searched for prospective or prospectively-based observational studies on risk factors for BKPyV viremia and/or nephropathy. Our qualitative assessment of risk factors was based on the odds ratios and hazard ratios calculated in multivariate regression analyses. Of the 241 publications screened, 34 were included in the qualitative analysis. In all, 144 and 19 distinct factors were analyzed for BKPyV viremia and for BKPyV nephropathy, respectively. Our evaluation highlighted eight risk factors for BKPyV viremia: a tacrolimus regimen, a deceased donor, a male recipient, a history of previous transplant, age at transplantation, ureteral stent use, delayed graft function, and acute rejection episodes increased the risk of BKV viremia to varying extents. Tacrolimus and acute rejection episodes were also associated with a higher incidence of BKPyV nephropathy. BKPyV reactivation is a serious complication after renal transplantation. With a view to combating this problem, existing data should be published in full, and new prospective international multicenter studies should be performed.

International audience; The major histocompatibility complex class I polypeptide-related sequence A (MICA) glycoprotein mediates the activation of the natural killer group 2D receptor (NKG2D) expressed on NK and CD8+ T cells. A methionine or valine at position 129 in exon 3 results in strong (MICA129 met) or weak (MICA129 val) binding to NKG2D. The MICA A5.1 allele causes a premature stop codon. Various NKG2D polymorphisms are associated with low (NKC3 C/C and NKC4 C/C) or high (NKC3 G/G and NKC4 T/T) levels of NK cell cytotoxic activity. In 162 patients with spondyloarthritis (115 with ankylosing spondyloarthritis, 46 with psoriatic arthritis and 1 with reactive arthritis) compared to 124 healthy controls, MICA-129 with methionine allele was more frequent in patients with spondyloarthritis (odds ratio (OR) (95% confidence interval) = 4.84 (2.75-8.67)), whereas MICA-129 val/val, MICA A5.1 and NKC3 C/C variants were less frequent (OR = 0.20 (0.11-0.37), 0.15 (0.06-0.36) and 0.24 (0.13-0.44), respectively). After adjustment for HLA-B*27 status, only NKC3 C/C remained linked to spondyloarthritis (adjusted OR = 0.14 (0.06-0.33)). Homozygosity for MICA A5.1 is linked to ankylosing spondyloarthritis, and NKC3 C/C and MICA-129 val/val to psoriatic arthritis. MICA and NKC3 polymorphisms (related to a low NK cell cytotoxic activity) constituted a genetic association with spondyloarthritis.

Highlights • The respiratory viral profile varied with age. • The distribution of viruses is variable over the year depending on the species. • Persistence of non-enveloped viruses throughout the year. • Atmospheric temperature was rarely a limiting factor in the circulation of viruses., Background Acute respiratory infections are a principal cause of illness and mortality especially in young children worldwide. Objectives To study the epidemiology and seasonality of viral respiratory infections in hospitalized children (under the age of 16) between September 2012 and August 2016. Study design Nasopharyngeal swabs or aspirates were collected from 3199 symptomatic patients and then screened with a routine multiplex PCR assay. Results Respiratory viruses were detected for 1624 (50.8%) of the 3199 children in the study population. Of these, 210 (13.3%) were positive for two viruses, 28 (1.7%) were positive for three, and 3 (0.2%) were positive for four. The viral profile varied with age. Some viruses were significantly more frequent in children under the age of 1 month (such as human respiratory syncytial virus (p

This study compared the performance of 3 automated immunoassays, Architect® (Abbott), Immulite® (Siemens) and Liaison® (Diasorin), for Epstein-Barr virus (EBV) serology. Ninety-one serum samples collected in Amiens University Hospital were analyzed for the presence of Viral Capsid Antigen (VCA) IgG and IgM and Epstein-Barr Nuclear Antigen (EBNA) IgG. The agreement between the 3 assays was calculated for each marker individually and for determination of the EBV profile, based on interpretation of the combination of these 3 EBV markers. Although similar results were obtained with Architect® and Liaison®, several discordant results were observed with Immulite®, particularly for EBNA IgG. A large number of EBNA IgG-positive results were observed, which interfered with interpretation of the EBV profile. In contrast, Immulite® performed similarly to the 2 other assays for detection of VCA IgM.

International audience; Hepatitis C virus (HCV) is a human hepatotropic virus, but many hepatoma cell lines are not permissive to this virus. In a previous study, we observed that SNU‐182, SNU‐398 and SNU‐449 hepatoma cell lines were nonpermissive to HCV. To understand the nonpermissivity, we evaluated the ability of each cell line to support the different steps of HCV life cycle (entry, replication and production of infectious particles). Using retroviral pseudoparticles pseudotyped with HCV envelope proteins and recombinant HCV produced in cell culture, we observed that low level or absence of claudin‐1 (CLDN1) expression limited the viral entry process in SNU‐182 and SNU‐398 cells, respectively. Our results also showed that supplementation of the three cell lines with miR‐122 partly restored the replication of a JFH1 HCV replicon. Finally, we observed that expression of apolipoprotein E (ApoE) was very low or undetectable in the three cell lines and that its ectopic expression permits the production of infectious viral particles in SNU‐182 and SNU‐398 cells but not in SNU‐449 cells. Nevertheless, the supplementation of SNU‐182, SNU‐398 and SNU‐449 cells with CLDN1, miR‐122 and ApoE was not sufficient to render these cells as permissive as HuH‐7 cells. Thus, these cell lines could serve as cell culture models for functional studies on the role of CLDN1, miR‐122 and ApoE in HCV life cycle but also for the identification of new restriction and/or dependency host factors essential for HCV infection.

International audience