Immunological fingerprint in coronavirus disease-19 convalescents with and without post-COVID syndrome.

Background: Symptoms lasting longer than 12 weeks after severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection are called post-coronavirus disease (COVID) syndrome (PCS). The identification of new biomarkers that predict the occurrence or course of PCS in terms of a post-viral syndrome is vital. T-cell dysfunction, cytokine imbalance, and impaired autoimmunity have been reported in PCS. Nevertheless, there is still a lack of conclusive information on the underlying mechanisms due to, among other things, a lack of controlled study designs. Methods: Here, we conducted a prospective, controlled study to characterize the humoral and cellular immune response in unvaccinated patients with and without PCS following SARS-CoV-2 infection over 7 months and unexposed donors. Results: Patients with PCS showed as early as 6 weeks and 7 months after symptom onset significantly increased frequencies of SARS-CoV-2-specific CD4+ and CD8+ T-cells secreting IFNγ, TNF, and expressing CD40L, as well as plasmacytoid dendritic cells (pDC) with an activated phenotype. Remarkably, the immunosuppressive counterparts type 1 regulatory T-cells (TR1: CD49b/LAG-3+) and IL-4 were more abundant in PCS+. Conclusion: This work describes immunological alterations between inflammation and immunosuppression in COVID-19 convalescents with and without PCS, which may provide potential directions for future epidemiological investigations and targeted treatments.

Immune response to mRNA-based COVID-19 booster vaccination in people living with HIV.

OBJECTIVES: Our objective was to assess immune responses and their influencing factors in people living with HIV after messenger RNA (mRNA)-based COVID-19 booster vaccination (third dose). METHODS: This was a retrospective cohort study of people living with HIV who received booster vaccination with BNT-162b2 or mRNA-1273 between October 2021 and January 2022. We assessed anti-spike receptor-binding domain (RBD) immunoglobulin G (IgG), virus neutralizing activity (VNA) titres reported as 100% inhibitory dilution (ID100 ), and T-cell response (using interferon-gamma-release-assay [IGRA]) at baseline and quarterly follow-up visits. Patients with reported COVID-19 during follow-up were excluded. Predictors of serological immune response were analyzed using multivariate regression models. RESULTS: Of 84 people living with HIV who received an mRNA-based booster vaccination, 76 were eligible for analysis. Participants were on effective antiretroviral therapy (ART) and had a median of 670 CD4+ cells/µL (interquartile range [IQR] 540-850). Following booster vaccination, median anti-spike RBD IgG increased by 705.2 binding antibody units per millilitre (BAU/mL) and median VNA titres increased by 1000 ID100 at the follow-up assessment (median 13 weeks later). Multivariate regression revealed that time since second vaccination was a predictor of stronger serological responses (p < 0.0001). No association was found for other factors, including CD4+ status, choice of mRNA vaccine, or concomitant influenza vaccination. In total, 45 patients (59%) had a reactive baseline IGRA, of whom two lost reactivity during follow-up. Of 31 patients (41%) with non-reactive baseline IGRA, 17 (55%) converted to reactive and seven (23%) remained unchanged following booster vaccination. CONCLUSIONS: People living with HIV with ≥500 CD4+ cells/µL showed favourable immune responses to mRNA-based COVID-19 booster vaccination. A longer time (up to 29 weeks) since second vaccination was associated with higher serological responses, whereas choice of mRNA vaccine or concomitant influenza vaccination had no impact.

Implementing the Lolli-Method and pooled RT-qPCR testing for SARS-CoV-2 surveillance in schools: a pilot project.

PURPOSE: School closures have been used as part of lockdown strategies to contain the spread of SARS-CoV-2, adversely affecting children's health and education. To ensure the accessibility of educational institutions without exposing society to the risk of increased transmissions, it is essential to establish SARS-CoV-2 testing strategies that are child-friendly, scalable and implementable in a daily school routine. Self-sampling using non-invasive saliva swabs combined with pooled RT-qPCR testing (Lolli-Method) has been proven to be a sensitive method for the detection of SARS-CoV-2. METHODS: We conducted a pilot project in Cologne, Germany, designed to determine the feasibility of a large-scale rollout of the Lolli-Method for testing without any additional on-site medical staff in schools. Over a period of three weeks, students from 22 schools were sampled using the Lolli-Method. At the end of the project, teachers were asked to evaluate the overall acceptance of the project. RESULTS: We analyzed a total of 757 pooled RT-qPCRs obtained from 8,287 individual swabs and detected 7 SARS-CoV-2 infected individuals. The Lolli-Method was shown to be a feasible and accepted testing strategy whose application is only slightly disruptive to the daily school routine. CONCLUSION: Our observations suggest that the Lolli-Method in combination with pooled RT-qPCR can be implemented for SARS-CoV-2 surveillance in daily school routine, applicable on a large scale.

Monocyte-crosstalk drives interferon-mediated signaling following SARS-CoV-2 exposure.

Cells of the innate immune system represent the first line of defense against SARS-CoV-2 and play an essential role in activating adaptive immunity, which mediates long-term protection. In addition, the same cells are key drivers of tissue damage by causing the hyperinflammatory state and cytokine storm that makes COVID-19 a deadly disease. Thus, careful dissection of the host-pathogen interaction on a cellular level is essential to understanding SARS-CoV-2 pathogenesis and developing new treatment modalities against COVID-19. In their recent work, Goffinet and colleagues (Kazmierski et al, 2022) investigate the cell-intrinsic responses of human primary peripheral blood mononuclear cells (PBMCs) exposed to SARS coronaviruses.

Spleen tyrosine kinase mediates innate and adaptive immune crosstalk in SARS-CoV-2 mRNA vaccination.

Durable cell-mediated immune responses require efficient innate immune signaling and the release of pro-inflammatory cytokines. How precisely mRNA vaccines trigger innate immune cells for shaping antigen specific adaptive immunity remains unknown. Here, we show that SARS-CoV-2 mRNA vaccination primes human monocyte-derived macrophages for activation of the NLRP3 inflammasome. Spike protein exposed macrophages undergo NLRP3-driven pyroptotic cell death and subsequently secrete mature interleukin-1ß. These effects depend on activation of spleen tyrosine kinase (SYK) coupled to C-type lectin receptors. Using autologous cocultures, we show that SYK and NLRP3 orchestrate macrophage-driven activation of effector memory T cells. Furthermore, vaccination-induced macrophage priming can be enhanced with repetitive antigen exposure providing a rationale for prime-boost concepts to augment innate immune signaling in SARS-CoV-2 vaccination. Collectively, these findings identify SYK as a regulatory node capable of differentiating between primed and unprimed macrophages, which modulate spike protein-specific T cell responses.

Case Report: Clinical Management of a Patient With Metastatic Non-Small Cell Lung Cancer Newly Receiving Immune Checkpoint Inhibition During Symptomatic COVID-19.

Effects of initiation of programmed-death-protein 1 (PD1) blockade during active SARS-CoV-2 infection on antiviral immunity, COVID-19 course, and underlying malignancy are unclear. We report on the management of a male in his early 40s presenting with highly symptomatic metastatic lung cancer and active COVID-19 pneumonia. After treatment initiation with pembrolizumab, carboplatin, and pemetrexed, the respiratory situation initially worsened and high-dose corticosteroids were initiated due to suspected pneumonitis. After improvement and SARS-CoV-2 clearance, anti-cancer treatment was resumed without pembrolizumab. Immunological analyses with comparison to otherwise healthy SARS-CoV-2-infected ambulatory patients revealed a strong humoral immune response with higher levels of SARS-CoV-2-reactive IgG and neutralizing serum activity. Additionally, sustained increase of Tfh as well as activated CD4+ and CD8+ T cells was observed. Sequential CT scans showed regression of tumor lesions and marked improvement of the pulmonary situation, with no signs of pneumonitis after pembrolizumab re-challenge as maintenance. At the latest follow-up, the patient is ambulatory and in ongoing partial remission on pembrolizumab. In conclusion, anti-PD1 initiation during active COVID-19 pneumonia was feasible and cellular and humoral immune responses to SARS-CoV-2 appeared enhanced in our hospitalized patient. However, distinguishing COVID-19-associated changes from anti-PD1-associated immune-related pneumonitis posed a considerable clinical, radiographic, and immunologic challenge.

Viral Glycoproteins Induce NLRP3 Inflammasome Activation and Pyroptosis in Macrophages.

Infections with viral pathogens are widespread and can cause a variety of different diseases. In-depth knowledge about viral triggers initiating an immune response is necessary to decipher viral pathogenesis. Inflammasomes, as part of the innate immune system, can be activated by viral pathogens. However, viral structural components responsible for inflammasome activation remain largely unknown. Here we analyzed glycoproteins derived from SARS-CoV-1/2, HCMV and HCV, required for viral entry and fusion, as potential triggers of NLRP3 inflammasome activation and pyroptosis in THP-1 macrophages. All tested glycoproteins were able to potently induce NLRP3 inflammasome activation, indicated by ASC-SPECK formation and secretion of cleaved IL-1ß. Lytic cell death via gasdermin D (GSDMD), pore formation, and pyroptosis are required for IL-1ß release. As a hallmark of pyroptosis, we were able to detect cleavage of GSDMD and, correspondingly, cell death in THP-1 macrophages. CRISPR-Cas9 knockout of NLRP3 and GSDMD in THP-1 macrophages confirmed and strongly support the evidence that viral glycoproteins can act as innate immunity triggers. With our study, we decipher key mechanisms of viral pathogenesis by showing that viral glycoproteins potently induce innate immune responses. These insights could be beneficial in vaccine development and provide new impulses for the investigation of vaccine-induced innate immunity.

Providing care in isolation while awaiting SARS-CoV-2 test results: Considering differential diagnoses and avoiding anchoring bias.

ABSTRACT: Isolation of confirmed or suspected coronavirus disease 2019 (COVID-19) cases is essential but, as symptoms of COVID-19 are non-specific and test results not immediately available, case identification at admission remains challenging. To inform optimization of triage algorithms, patient flow and patient care, we analyzed characteristics of patients admitted to an isolation ward, both severe acute respiratory syndrome coronavirus 2019 (SARS-CoV-2) positive patients and patients in which initial suspicion was not confirmed after appropriate testing.Data from patients with confirmed or suspected COVID-19 treated in an isolation unit were analyzed retrospectively. Symptoms, comorbidities and clinical findings were analyzed descriptively and associations between patient characteristics and final SARS-CoV-2 status were assessed using univariate regression.Eighty three patients (49 SARS-CoV-2 negative and 34 positive) were included in the final analysis. Of initially suspected COVID-19 cases, 59% proved to be SARS-CoV-2-negative. These patients had more comorbidities (Charlson Comorbidity Index median 5(interquartile range [IQR] 2.5, 7) vs 2.7(IQR 1, 4)), and higher proportion of active malignancy than patients with confirmed COVID-19 (47% vs 15%; P = .004), while immunosuppression was frequent in both patient groups (20% vs 21%; P = .984). Of SARS-CoV-2 negative patients, 31% were diagnosed with non-infectious diseases.A high proportion of patients (59%) triaged to the isolation unit were tested negative for SARS-CoV-2. Of these, many suffered from active malignancy (47%) and were immunosuppressed (20%). Non-infectious diseases were diagnosed in 31%, highlighting the need for appropriate patient flow, timely expert medical care including evaluation for differential diagnostics while providing isolation and ruling out of COVID-19 in these patients with complex underlying diseases.

Pooled RT-qPCR testing for SARS-CoV-2 surveillance in schools - a cluster randomised trial.

BACKGROUND: The extent to which children and adolescents contribute to SARS-CoV-2 transmission remains not fully understood. Novel high-capacity testing methods may provide real-time epidemiological data in educational settings helping to establish a rational approach to prevent and minimize SARS-CoV-2 transmission. We investigated whether pooling of samples for SARS-CoV-2 detection by RT-qPCR is a sensitive and feasible high-capacity diagnostic strategy for surveillance of SARS-CoV-2 infections in schools. METHODS: In this study, students and school staff of 14 educational facilities in Germany were tested sequentially between November 9 and December 23, 2020, two or three times per week for at least three consecutive weeks. Participants were randomized for evaluation of two different age adjusted swab sampling methods (oropharyngeal swabs or buccal swabs compared to saliva swabs using a 'lolli method'). Swabs were collected and pooled for SARS-CoV-2 RT-qPCR. Individuals of positive pooled tests were retested by RT-qPCR the same or the following day. Positive individuals were quarantined while the SARS-CoV-2 negative individuals remained in class with continued pooled RT-qPCR surveillance. The study is registered with the German Clinical Trials register (registration number: DRKS00023911). FINDINGS: 5,537 individuals were eligible and 3970 participants were enroled and included in the analysis. In students, a total of 21,978 swabs were taken and combined in 2218 pooled RT-qPCR tests. We detected 41 positive pooled tests (1·8%) leading to 36 SARS-CoV-2 cases among students which could be identified by individual re-testing. The cumulative 3-week incidence for primary schools was 564/100,000 (6/1064, additionally 1 infection detected in week 4) and 1249/100,000 (29/2322) for secondary schools. In secondary schools, there was no difference in the number of SARS-CoV-2 positive students identified from pooled oropharyngeal swabs compared to those identified from pooled saliva samples (lolli method) (14 vs. 15 cases; 1·3% vs. 1·3%; OR 1.1; 95%-CI 0·5-2·5). A single secondary school accounted for 17 of 36 cases (47%) indicating a high burden of asymptomatic prevalent SARS-CoV-2 cases in the respective school and community. INTERPRETATION: In educational settings, SARS-CoV-2 screening by RT-qPCR-based pooled testing with easily obtainable saliva samples is a feasible method to detect incident cases and observe transmission dynamics. FUNDING: Federal Ministry of education and research (BMBF; Project B-FAST in "NaFoUniMedCovid19"; registration number: 01KX2021).

Long-lived macrophage reprogramming drives spike protein-mediated inflammasome activation in COVID-19.

Innate immunity triggers responsible for viral control or hyperinflammation in COVID-19 are largely unknown. Here we show that the SARS-CoV-2 spike protein (S-protein) primes inflammasome formation and release of mature interleukin-1ß (IL-1ß) in macrophages derived from COVID-19 patients but not in macrophages from healthy SARS-CoV-2 naïve individuals. Furthermore, longitudinal analyses reveal robust S-protein-driven inflammasome activation in macrophages isolated from convalescent COVID-19 patients, which correlates with distinct epigenetic and gene expression signatures suggesting innate immune memory after recovery from COVID-19. Importantly, we show that S-protein-driven IL-1ß secretion from patient-derived macrophages requires non-specific monocyte pre-activation in vivo to trigger NLRP3-inflammasome signaling. Our findings reveal that SARS-CoV-2 infection causes profound and long-lived reprogramming of macrophages resulting in augmented immunogenicity of the SARS-CoV-2 S-protein, a major vaccine antigen and potent driver of adaptive and innate immune signaling.

Swarm Learning for decentralized and confidential clinical machine learning.

Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine1,2. Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes3. However, there is an increasing divide between what is technically possible and what is allowed, because of privacy legislation4,5. Here, to facilitate the integration of any medical data from any data owner worldwide without violating privacy laws, we introduce Swarm Learning-a decentralized machine-learning approach that unites edge computing, blockchain-based peer-to-peer networking and coordination while maintaining confidentiality without the need for a central coordinator, thereby going beyond federated learning. To illustrate the feasibility of using Swarm Learning to develop disease classifiers using distributed data, we chose four use cases of heterogeneous diseases (COVID-19, tuberculosis, leukaemia and lung pathologies). With more than 16,400 blood transcriptomes derived from 127 clinical studies with non-uniform distributions of cases and controls and substantial study biases, as well as more than 95,000 chest X-ray images, we show that Swarm Learning classifiers outperform those developed at individual sites. In addition, Swarm Learning completely fulfils local confidentiality regulations by design. We believe that this approach will notably accelerate the introduction of precision medicine.

Low-Avidity CD4+ T Cell Responses to SARS-CoV-2 in Unexposed Individuals and Humans with Severe COVID-19.

CD4+ T cells reactive against SARS-CoV-2 can be found in unexposed individuals, and these are suggested to arise in response to common cold coronavirus (CCCoV) infection. Here, we utilized SARS-CoV-2-reactive CD4+ T cell enrichment to examine the antigen avidity and clonality of these cells, as well as the relative contribution of CCCoV cross-reactivity. SARS-CoV-2-reactive CD4+ memory T cells were present in virtually all unexposed individuals examined, displaying low functional avidity and multiple, highly variable cross-reactivities that were not restricted to CCCoVs. SARS-CoV-2-reactive CD4+ T cells from COVID-19 patients lacked cross-reactivity to CCCoVs, irrespective of strong memory T cell responses against CCCoV in all donors analyzed. In severe but not mild COVID-19, SARS-CoV-2-specific T cells displayed low functional avidity and clonality, despite increased frequencies. Our findings identify low-avidity CD4+ T cell responses as a hallmark of severe COVID-19 and argue against a protective role for CCCoV-reactive T cells in SARS-CoV-2 infection.

Remdesivir against COVID-19 and Other Viral Diseases.

Patients and physicians worldwide are facing tremendous health care hazards that are caused by the ongoing severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) pandemic. Remdesivir (GS-5734) is the first approved treatment for severe coronavirus disease 2019 (COVID-19). It is a novel nucleoside analog with a broad antiviral activity spectrum among RNA viruses, including ebolavirus (EBOV) and the respiratory pathogens Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV, and SARS-CoV-2. First described in 2016, the drug was derived from an antiviral library of small molecules intended to target emerging pathogenic RNA viruses. In vivo, remdesivir showed therapeutic and prophylactic effects in animal models of EBOV, MERS-CoV, SARS-CoV, and SARS-CoV-2 infection. However, the substance failed in a clinical trial on ebolavirus disease (EVD), where it was inferior to investigational monoclonal antibodies in an interim analysis. As there was no placebo control in this study, no conclusions on its efficacy in EVD can be made. In contrast, data from a placebo-controlled trial show beneficial effects for patients with COVID-19. Remdesivir reduces the time to recovery of hospitalized patients who require supplemental oxygen and may have a positive impact on mortality outcomes while having a favorable safety profile. Although this is an important milestone in the fight against COVID-19, approval of this drug will not be sufficient to solve the public health issues caused by the ongoing pandemic. Further scientific efforts are needed to evaluate the full potential of nucleoside analogs as treatment or prophylaxis of viral respiratory infections and to develop effective antivirals that are orally bioavailable.

A comparative analysis of remdesivir and other repurposed antivirals against SARS-CoV-2.

The ongoing SARS-CoV-2 pandemic stresses the need for effective antiviral drugs that can quickly be applied in order to reduce morbidity, mortality, and ideally viral transmission. By repurposing of broadly active antiviral drugs and compounds that are known to inhibit viral replication of related viruses, several advances could be made in the development of treatment strategies against COVID-19. The nucleoside analog remdesivir, which is known for its potent in vitro activity against Ebolavirus and other RNA viruses, was recently shown to reduce the time to recovery in patients with severe COVID-19. It is to date the only approved antiviral for treating COVID-19. Here, we provide a mechanism and evidence-based comparative review of remdesivir and other repurposed drugs with proven in vitro activity against SARS-CoV-2.

RNAemia Corresponds to Disease Severity and Antibody Response in Hospitalized COVID-19 Patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a global health emergency. To improve the understanding of the systemic component of SARS-CoV-2, we investigated if viral load dynamics in plasma and respiratory samples are associated with antibody response and severity of coronavirus disease 2019 (COVID-19). SARS-CoV-2 RNA was found in plasma samples from 14 (44%) out of 32 patients. RNAemia was detected in 5 out of 6 fatal cases. Peak IgG values were significantly lower in mild/moderate than in severe (0.6 (interquartile range, IQR, 0.4-3.2) vs. 11.8 (IQR, 9.9-13.0), adjusted p = 0.003) or critical cases (11.29 (IQR, 8.3-12.0), adjusted p = 0.042). IgG titers were significantly associated with virus Ct (Cycle threshold) value in plasma and respiratory specimens ((ß = 0.4, 95% CI (confidence interval, 0.2; 0.5), p < 0.001 and ß = 0.5, 95% CI (0.2; 0.6), p = 0.002). A classification as severe or a critical case was additionally inversely associated with Ct values in plasma in comparison to mild/moderate cases (ß = -3.3, 95% CI (-5.8; 0.8), p = 0.024 and ß = -4.4, 95% CI (-7.2; 1.6), p = 0.007, respectively). Based on the present data, our hypothesis is that the early stage of SARS-CoV-2 infection is characterized by a primary RNAemia, as a potential manifestation of a systemic infection. Additionally, the viral load in plasma seems to be associated with a worse disease outcome.

COVID-19 complicated by parainfluenza co-infection in a patient with chronic lymphocytic leukemia.

The number of people suffering from the new coronavirus SARS-CoV-2 continues to rise. In SARS-CoV-2, superinfection with bacteria or fungi seems to be associated with increased mortality. The role of co-infections with respiratory viral pathogens has not yet been clarified. Here, we report the course of COVID-19 in a CLL patient with secondary immunodeficiency and viral co-infection with parainfluenza.

COVID-19 associated pulmonary aspergillosis.

OBJECTIVES: Patients with acute respiratory distress syndrome (ARDS) due to viral infection are at risk for secondary complications like invasive aspergillosis. Our study evaluates coronavirus disease 19 (COVID-19) associated invasive aspergillosis at a single centre in Cologne, Germany. METHODS: A retrospective chart review of all patients with COVID-19 associated ARDS admitted to the medical or surgical intensive care unit at the University Hospital of Cologne, Cologne, Germany. RESULTS: COVID-19 associated invasive pulmonary aspergillosis was found in five of 19 consecutive critically ill patients with moderate to severe ARDS. CONCLUSION: Clinicians caring for patients with ARDS due to COVID-19 should consider invasive pulmonary aspergillosis and subject respiratory samples to comprehensive analysis to detect co-infection.