Impact of anti-HDV reflex testing at HBs antigen positive discovery in a single center France: Support for primary HDV screening in France.

BACKGROUND: Hepatitis Delta virus (HDV) infection is a major cause of liver-related morbidity and mortality in patients infected with HBV, with a global HDV prevalence uncertain. In France, 2 to 5 % of HBs antigen (HBsAg) carriers present anti-HDV antibodies (anti-HDV). The EASL recommends testing for anti-HDV in all HBsAg-positive patients. Since January 2022, we have systematically carried out anti-HDV serology when a positive HBsAg is discovered (new HBsAg carriers). OBJECTIVES: We evaluated the benefit of anti-HDV reflex testing after one year of practice by comparing anti-HDV and HBsAg serology data over the last six years, among the new HBsAg carriers and all the HBsAg carriers. STUDY DESIGN: HBsAg and anti-HDV were screened using the Abbott Architect HBsAg quanti kit and the DIA.PRO HDVAb kit. Serological, demographic, virological, and clinical data were analyzed. RESULTS: Implementing anti-HDV reflex testing leads to more than a 2-fold increase in diagnoses of HDV infection among all HBsAg carriers. If the anti-HDV positive rate remains stable among the new HBsAg carriers, a significant increase in the anti-HDV positive rate from 6.8 % to 10.3 % was observed considering all HBsAg carriers. Interestingly, the discovery of anti-HDV carriage increased from 3.9 % to 6.5 % in 2022, allowing earlier identification of HBV-HDV-infected patients and a fast referral to hepatologists for adequate clinical management and, in some cases, the introduction of bulevirtide-based therapy. CONCLUSIONS: Our preliminary results at one year seem promising and evaluating the cost-effectiveness of reflex tests in real life with feedback would be helpful.

Two cases of viral re-suppression after M184V + R263†K selection on DTG/3TC without treatment modification.

DTG/3TC has a high genetic barrier against the development of HIV drug resistance. We report two cases of R263K + M184 V mutations during DTG/3TC failure followed by viral suppression after adherence intervention without treatment change that we attribute to residual drug activity, reduced viral fitness, and robust immune competence.

Comparison of HIV-1 DNA load measurements in blood and in relation to successful proviral sequencing.

OBJECTIVE: HIV DNA sequencing is now routinely used for HIV-infected individuals on antiretroviral therapy (ART) with or without partial genotypic history. Successful amplification of HIV pol gene has yet to be correlated with HIV DNA levels. Here, we assessed the relationship between HIV DNA load and sequencing results. METHODS: We analyzed three different qPCR measurements of total (LTR and LTR-gag) and integrated (Alu-LTR) HIV DNA in blood samples collected from viremic as well as virally suppressed HIV-infected individuals on ART. HIV DNA levels were compared to HIV DNA Sanger sequencing and clinical and therapeutic parameters. RESULTS: Among the 135 individuals analyzed for HIV DNA measurements and sequencing, all three HIV DNA measurements were associated with HIV DNA Sanger sequencing results. A threshold of around 2 and 1.5 log copies/million leukocytes of total HIV DNA was identified for LTR and LTR-gag qPCRs, respectively. Integrated HIV DNA positivity was also associated with successful sequencing. We further compared HIV DNA measurement techniques in an extended cohort of 312 individuals and showed that all measurements correlated between the different techniques, regardless of the HIV-1 subtypes analyzed. However, higher detection rates were observed with LTR (96%) compared to LTR-gag (86%) and Alu-LTR (59%) qPCRs. Duration of virological control on ART and CD4 nadir were the main determinants of HIV reservoir size. CONCLUSIONS: HIV DNA measurement is associated with Sanger sequencing success, regardless of the technique used. In a clinical setting, Application of HIV DNA quantification before sequencing should be further evaluated.

Antigen specificities of HIV-infected cells: A role in infection and persistence?

Antigen-experienced memory CD4+ T cells are the major target of HIV infection and support both productive and latent infections, thus playing a key role in HIV dissemination and persistence, respectively. Here, we reviewed studies that have shown direct association between HIV infection and antigen specificity. During untreated infection, some HIV-specific cells host productive infection, while other pathogen-specific cells such as cytomegalovirus (CMV) and Mycobacterium tuberculosis also contribute to viral persistence on antiretroviral therapy (ART). These patterns could be explained by phenotypic features differing between these pathogen-specific cells. Mechanisms involved in these preferential infection and selection processes include HIV entry and restriction, cell exhaustion, survival, self-renewal and immune escape. For instance, MIP-1ß expressing cells such as CMV-specific memory cells were shown to resist infection by HIV CCR5 coreceptor downregulation/inhibition. Conversely, HIV-infected CMV-specific cells undergo clonal expansion during ART. We have identified several research areas that need further focus such as the role of other pathogens, viral genome intactness, inducibility and phenotypic features. However, given the sheer diversity of both the CD4+ T cell repertoire and antigenic history of each individual, studying HIV-infected, antigen-experienced cells still imposes numerous challenges.

Torque teno virus viral load predicts SARS-CoV-2 vaccine response in kidney transplant recipients.

Transplant recipients display poor responses to SARS-CoV-2 mRNA vaccines. In this retrospective study, we investigate torque teno virus (TTV) viral load (VL), a ubiquitous virus reflecting global immune response levels, as a predictive factor of vaccine response in kidney transplant recipients (KTR). Four hundred and fifty-nine KTR having received two SARS-CoV-2 mRNA vaccine doses were enrolled, and 241 of them subsequently received a third vaccine dose. Antireceptor-binding domain (RBD) IgG response was assessed after each vaccine dose and TTV VL was measured in pre-vaccine samples. Prevaccine TTV VL > 6.2 log10 copies (cp)/mL was independently associated with nonresponse to two doses (odds ratio (OR) = 6.17, 95% confidence interval (CI95) = 2.42-15.78) as well as to three doses (OR = 3.62, 95% CI95 = 1.55-8.49). In nonresponders to the second dose, high TTV VL in prevaccine samples or measured before the third dose were equally predictive of lower seroconversion rates and antibody titers. High TTV VL before and during SARS-CoV-2 vaccination schedules are predictive of poor vaccine response in KTR. This biomarker should be further evaluated regarding other vaccine responses.

Tick-Borne Encephalitis in Pregnant Woman and Long-Term Sequelae.

We report a case of severe tick-borne encephalitis in a pregnant woman, leading to a prolonged stay in the intensive care unit. She showed minor clinical improvement >6 months after her presumed infection. The patient was not vaccinated, although an effective vaccine is available and not contraindicated during pregnancy.

Cerebral perfusion using ASL in patients with COVID-19 and neurological manifestations: A retrospective multicenter observational study.

BACKGROUND AND PURPOSE: Cerebral hypoperfusion has been reported in patients with COVID-19 and neurological manifestations in small cohorts. We aimed to systematically assess changes in cerebral perfusion in a cohort of 59 of these patients, with or without abnormalities on morphological MRI sequences. METHODS: Patients with biologically-confirmed COVID-19 and neurological manifestations undergoing a brain MRI with technically adequate arterial spin labeling (ASL) perfusion were included in this retrospective multicenter study. ASL maps were jointly reviewed by two readers blinded to clinical data. They assessed abnormal perfusion in four regions of interest in each brain hemisphere: frontal lobe, parietal lobe, posterior temporal lobe, and temporal pole extended to the amygdalo-hippocampal complex. RESULTS: Fifty-nine patients (44 men (75%), mean age 61.2 years) were included. Most patients had a severe COVID-19, 57 (97%) needed oxygen therapy and 43 (73%) were hospitalized in intensive care unit at the time of MRI. Morphological brain MRI was abnormal in 44 (75%) patients. ASL perfusion was abnormal in 53 (90%) patients, and particularly in all patients with normal morphological MRI. Hypoperfusion occurred in 48 (81%) patients, mostly in temporal poles (52 (44%)) and frontal lobes (40 (34%)). Hyperperfusion occurred in 9 (15%) patients and was closely associated with post-contrast FLAIR leptomeningeal enhancement (100% [66.4%-100%] of hyperperfusion with enhancement versus 28.6% [16.6%-43.2%] without, p = 0.002). Studied clinical parameters (especially sedation) and other morphological MRI anomalies had no significant impact on perfusion anomalies. CONCLUSION: Brain ASL perfusion showed hypoperfusion in more than 80% of patients with severe COVID-19, with or without visible lesion on conventional MRI abnormalities.

Tick-borne encephalitis in pediatrics: An often overlooked diagnosis.

Tick-borne encephalitis (TBE) is a vector-borne disease caused by a flavivirus, the tick-borne encephalitis virus (TBEV), and transmitted by the bite of infected Ixodes ricinus ticks. The European subtype (TBEV-Eu) is endemic in 27 European countries. During the last decade, increased TBE incidence was observed in many countries, including some of those believed to be of low endemicity/devoid of TBEV circulation. However, data dealing with TBE in children are far less profuse than with adults. Historically, children are known to have mild TBEV infection with favorable outcomes. That said, recent case reports and observational studies on pediatric cohorts have challenged this point of view. Like adults, children may present severe forms and fail to completely recover following TBE infection, at times leading to long-term cognitive impairment. In this review, we comprehensively describe the incidence, exposure factors, and transmission routes of TBEV in children, as well as the clinical and biological manifestations of TBE and imaging findings in this population. We also harness new data on long-term outcomes and sequelae in pediatric cohorts. Finally, we provide an overview of vaccination recommendations for children in European countries.

HIV Productively Infects Highly Differentiated and Exhausted CD4+ T Cells During AIDS.

Background: Throughout HIV infection, productively infected cells generate billions of viral particles and are thus responsible for body-wide HIV dissemination, but their phenotype during AIDS is unknown. As AIDS is associated with immunological changes, analyzing the phenotype of productively infected cells can help understand HIV production during this terminal stage. Methods: Blood samples from 15 untreated viremic participants (recent infection, n=5; long-term infection, n=5; active opportunistic AIDS-defining disease, n=5) and 5 participants virologically controlled on antiretroviral therapy (ART) enrolled in the Analysis of the Persistence, Reservoir and HIV Latency (APRIL) study (NCT05752318) were analyzed. Cells expressing the capsid protein p24 (p24+ cells) after 18 hours of resting or 24 hours of stimulation (HIV-Flow) revealed productively infected cells from viremic participants or translation-competent reservoir cells from treated participants, respectively. Results: The frequency of productively infected cells tended to be higher during AIDS in comparison with recent and long-term infections (median, 340, 72, and 32/million CD4+ T cells, respectively) and correlated with the plasma viral load at all stages of infection. Altogether, these cells were more frequently CD4low, HLA-ABClow, CD45RA-, Ki67+, PD-1+, with a non-negligible contribution from pTfh (CXCR5+PD-1+) cells, and were not significantly enriched in HIV coreceptors CCR5 nor CXCR4 expression. The comparison markers expression between stages showed that productively infected cells during AIDS were enriched in memory and exhausted cells. In contrast, the frequencies of infected pTfh were lower during AIDS compared to non-AIDS stages. A UMAP analysis revealed that total CD4+ T cells were grouped in 7 clusters and that productive p24+ cells were skewed to given clusters throughout the course of infection. Overall, the preferential targets of HIV during the latest stages seemed to be more frequently highly differentiated (memory, TTD-like) and exhausted cells and less frequently pTfh-like cells. In contrast, translation-competent reservoir cells were less frequent (5/million CD4+ T cells) and expressed more frequently HLA-ABC and less frequently PD-1. Conclusions: In long-term infection and AIDS, productively infected cells were differentiated and exhausted. This could indicate that cells with these given features are responsible for HIV production and dissemination in an immune dysfunction environment occurring during the last stages of infection.

Association of COVID-19 mortality with serum selenium, zinc and copper: Six observational studies across Europe.

Introduction: Certain trace elements are essential for life and affect immune system function, and their intake varies by region and population. Alterations in serum Se, Zn and Cu have been associated with COVID-19 mortality risk. We tested the hypothesis that a disease-specific decline occurs and correlates with mortality risk in different countries in Europe. Methods: Serum samples from 551 COVID-19 patients (including 87 non-survivors) who had participated in observational studies in Europe (Belgium, France, Germany, Ireland, Italy, and Poland) were analyzed for trace elements by total reflection X-ray fluorescence. A subset (n=2069) of the European EPIC study served as reference. Analyses were performed blinded to clinical data in one analytical laboratory. Results: Median levels of Se and Zn were lower than in EPIC, except for Zn in Italy. Non-survivors consistently had lower Se and Zn concentrations than survivors and displayed an elevated Cu/Zn ratio. Restricted cubic spline regression models revealed an inverse nonlinear association between Se or Zn and death, and a positive association between Cu/Zn ratio and death. With respect to patient age and sex, Se showed the highest predictive value for death (AUC=0.816), compared with Zn (0.782) or Cu (0.769). Discussion: The data support the potential relevance of a decrease in serum Se and Zn for survival in COVID-19 across Europe. The observational study design cannot account for residual confounding and reverse causation, but supports the need for intervention trials in COVID-19 patients with severe Se and Zn deficiency to test the potential benefit of correcting their deficits for survival and convalescence.

Clinical phenotypes and outcomes associated with SARS-CoV-2 variant Omicron in critically ill French patients with COVID-19.

Infection with SARS-CoV-2 variant Omicron is considered to be less severe than infection with variant Delta, with rarer occurrence of severe disease requiring intensive care. Little information is available on comorbid factors, clinical conditions and specific viral mutational patterns associated with the severity of variant Omicron infection. In this multicenter prospective cohort study, patients consecutively admitted for severe COVID-19 in 20 intensive care units in France between December 7th 2021 and May 1st 2022 were included. Among 259 patients, we show that the clinical phenotype of patients infected with variant Omicron (n = 148) is different from that in those infected with variant Delta (n = 111). We observe no significant relationship between Delta and Omicron variant lineages/sublineages and 28-day mortality (adjusted odds ratio [95% confidence interval] = 0.68 [0.35-1.32]; p = 0.253). Among Omicron-infected patients, 43.2% are immunocompromised, most of whom have received two doses of vaccine or more (85.9%) but display a poor humoral response to vaccination. The mortality rate of immunocompromised patients infected with variant Omicron is significantly higher than that of non-immunocompromised patients (46.9% vs 26.2%; p = 0.009). In patients infected with variant Omicron, there is no association between specific sublineages (BA.1/BA.1.1 (n = 109) and BA.2 (n = 21)) or any viral genome polymorphisms/mutational profile and 28-day mortality.

Torque teno virus DNA load as a predictive marker of antibody response to a three-dose regimen of COVID-19 mRNA-based vaccine in lung transplant recipients.

BACKGROUND: Previous studies have reported that lung transplant recipients (LTR) develop a poor response to two doses of COVID-19 vaccine, but data regarding the third dose are lacking. We investigated the antibody response after three doses of mRNA vaccine in LTR and its predictive factors. METHODS: A total of 136 LTR, including 10 LTR previously infected and 126 COVID-19-naive LTR, were followed during and after three doses of mRNA vaccine. We retrospectively measured anti-receptor-binding domain (RBD) IgG response and neutralizing antibodies. In a posthoc analysis, we used a multivariate logistic regression model to assess the association between vaccine response and patient characteristics, including viral DNA load (VL) of the ubiquitous Torque teno virus (TTV) (optimal cut-off set by ROC curve analysis), which reflects the overall immunosuppression. RESULTS: After 3 doses, 47/126 (37.3%) COVID-19-naive LTR had positive anti-RBD IgG (responders) and 14/126 (11.1%) had antibody titers above 264 Binding Antibody Units/mL. None neutralized the omicron variant versus 7 of the 10 previously infected LTR. Nonresponse was associated with TTV VL ≥6.2 log10 copies/mL before vaccination (Odds Ratio (OR) = 17.87, 95% confidence interval (CI95) = 3.02-105.72), mycophenolate treatment (OR = 4.73, CI95 = 1.46-15.34) and BNT162b2 (n = 34; vs mRNA-1273, n = 101) vaccine (OR = 6.72, CI95 = 1.75-25.92). In second dose non-responders, TTV VL ≥6.2 or <3.2 log10 copies/mL before the third dose was associated with low (0/19) and high (9/10) rates of seroconversion. CONCLUSION: COVID-19-naive LTR respond poorly to three doses of mRNA vaccine, especially those with high TTV VL. Future studies could further evaluate this biomarker as a guide for vaccine strategies.

Prediction of Vaccine Response and Development of a Personalized Anti-SARS-CoV-2 Vaccination Strategy in Kidney Transplant Recipients: Results from a Large Single-Center Study.

Kidney transplant recipients (KTRs) displays marked inter-individual variations in magnitude of immune responses to anti-SARS-CoV-2 vaccination. The aim of this large single-center study was to identify the predictive factors for serological response to the mRNA-1273 vaccine in KTRs. We also devised a score to optimize prediction with the goal of implementing a personalized vaccination strategy. The study population consisted of 564 KTRs who received at least two doses of the mRNA-1273 vaccine. Anti-RBD IgG titers were quantified one month after each vaccine dose and until six months thereafter. A third dose vaccine was given when the antibody titer after the second dose was <143 BAU/mL. A score to optimize prediction of vaccine response was devised using the independent predictors identified in multivariate analysis. The seropositivity rate after the second dose was 46.6% and 22.2% of participants were classified as good responders (titers ≥ 143 BAU/mL). On analyzing the 477 patients for whom serology testing was available after the second or third dose, the global seropositivity rate was 69% (good responders: 46.3%). Immunosuppressive drugs, graft function, age, interval from transplantation, body mass index, and sex were associated with vaccine response. The devised score was strongly associated with the seropositivity rate (AUC = 0.752, p < 0.0001) and the occurrence of a good antibody response (AUC = 0.785, p < 0.0001). Notably, antibody titers declined over time both after the second and third vaccine doses. In summary, a high burden of comorbidities and immunosuppression was correlated with a weaker antibody response. A fourth vaccine dose and/or pre-exposure prophylaxis with monoclonal antibodies should be considered for KTRs who remain unprotected.

Kinetics of the SARS-CoV-2 Antibody Avidity Response Following Infection and Vaccination.

Serological assays capable of measuring antibody responses induced by previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been critical tools in the response to the COVID-19 pandemic. In this study, we use bead-based multiplex assays to measure IgG and IgA antibodies and IgG avidity to five SARS-CoV-2 antigens (Spike (S), receptor-binding domain (RBD), Nucleocapsid (N), S subunit 2, and Membrane-Envelope fusion (ME)). These assays were performed in several cohorts of healthcare workers and nursing home residents, who were followed for up to eleven months after SARS-CoV-2 infection or up to six months after vaccination. Our results show distinct kinetic patterns of antibody quantity (IgG and IgA) and avidity. While IgG and IgA antibody levels waned over time, with IgA antibody levels waning more rapidly, avidity increased with time after infection or vaccination. These contrasting kinetic patterns allow for the estimation of time since previous SARS-CoV-2 infection. Including avidity measurements in addition to antibody levels in a classification algorithm for estimating time since infection led to a substantial improvement in accuracy, from 62% to 78%. The inclusion of antibody avidity in panels of serological assays can yield valuable information for improving serosurveillance during SARS-CoV-2 epidemics.