Selenium (Se) and zinc (Zn) are essential trace elements needed for appropriate immune system responses, cell signalling and anti-viral defence. A cross-sectional observational study was conducted at two hospitals in Ghent, Belgium, to investigate whether Se and/or Zn deficiency upon hospital admission correlates to disease severity and mortality risk in COVID-19 patients with or without co-morbidities. Trace element concentrations along with additional biomarkers were determined in serum or plasma and associated to disease severity and outcome. An insufficient Se and/or Zn status upon hospital admission was associated with a higher mortality rate and a more severe disease course in the entire study group, especially in the senior population. In comparison to healthy European adults, the patients displayed strongly depressed total Se (mean ± SD: 59.2 ± 20.6 vs. 84.4 ± 23.4 µg L⁻¹) and SELENOP (mean ± SD: 2.2 ± 1.9 vs. 4.3 ± 1.0 mg L⁻¹) concentrations at hospital admission. Particularly strong associations were observed for death risk of cancer, diabetes and chronic cardiac disease patients with low Se status, and of diabetes and obese patients with Zn deficiency. A composite biomarker based on serum or plasma Se, SELENOP and Zn at hospital admission proved to be a reliable tool to predict severe COVID-19 course and death, or mild disease course. We conclude that trace element assessment at hospital admission may contribute to a better stratification of patients with COVID-19 and other similar infectious diseases, support clinical care, therapeutic interventions and adjuvant supplementation needs, and may prove of particular relevance for patients with relevant comorbidities.

In the last decade, there has been increasing scientific and legislative focus on antiretroviral treatment (ART) for all people living with HIV. Especially early ART initiation, preferably during a...

IL-1R integrates signals from IL-1α and IL-1β, and it is widely expressed across tissues and immune cell types. While the expression pattern and function of IL-1R within the innate immune system is well studied, its role in adaptive immunity, particularly within the CD8 T cell compartment, remains underexplored. Here, we show that CD8 T cells dynamically upregulate IL-1R1 levels during priming by APCs, which correlates with their proliferation status and the acquisition of an effector phenotype. Notably, this IL-1 sensitivity persists in memory CD8 T cells of both mice and humans, influencing effector cytokine production upon TCR reactivation. Furthermore, our study highlights that antiviral effector and tissue-resident CD8 T cell responses against influenza A virus infection become impaired in the absence of IL-1 signaling. Altogether, these data support the exploitation of IL-1 activity in the context of T cell vaccination strategies and warrant consideration of the impact of clinical IL-1 inhibition on the rollout of T cell immunity.

Introduction: We present the results of the COVID-19 rule-out protocol at Ghent University Hospital, a step-wise testing approach which included repeat NFS SARS-CoV-2 rRT-PCR, respiratory multiplex RT-PCR, low-dose chest CT and bronchoscopy with BAL to confirm or rule-out SARS-CoV-2 infection in patients admitted with symptoms suggestive of COVID-19. Results: Between 19 March 2020 and 30 April 2020, 455 non-critically ill patients with symptoms suspect for COVID-19 were admitted. The initial NFS for SARS-CoV-2 rRT-PCR yielded 66.9%, the second NFS 25.4% and bronchoscopy with BAL 5.9% of total COVID-19 diagnoses. In the BAL fluid, other respiratory pathogens were detected in 65% (13/20) of the COVID-19 negative patients and only in 1/7 COVID-19 positive patients. Retrospective antibody testing at the time around BAL sampling showed a positive IgA or IgG in 42.9 % of the COVID-19 positive and 10.5% of the COVID-19 negative group. Follow-up serology showed 100% COVID-19 positivity in the COVID-19 positive group and 100% IgG negativity in the COVID-19 negative group. Conclusion: In our experience, bronchoscopy with BAL can have an added value to rule-in or rule-out COVID-19 in patients with clinical and radiographical high-likelihood of COVID-19 and repeated negative NFS testing. Furthermore, culture and respiratory multiplex PCR on BAL fluid can aid to identify alternative microbial etiological agents in this group. Retrospective analysis of antibody development in this selected group of patients suggests that the implementation of serological assays in the routine testing protocol will decrease the need for invasive procedures like bronchoscopy.

The events during acute HIV infection (AHI) set the stage for the subsequent course of the disease. Early initiation of antiretroviral therapy (ART) has been associated with favorable immunovirological outcomes, yet the precise impact of ART timing during AHI remains unclear, particularly on lymphoid tissues. The ACS cohort is a prospective cohort study in Belgium, collecting longitudinal clinical data and human bodily material (HBM) from people diagnosed and treated during AHI. The aim of the cohort is to study the impact of ART initiation during AHI on HIV reservoir and immune dysfunction in peripheral blood and anatomical sanctuary sites, as well as its effect on the gut microbiome. The cohort consists of two HBM sampling trajectories: one limited (blood, stool and leukapheresis) and a more extensive one (blood, stool, leukapheresis, colonoscopy, inguinal lymph node excision and lumbar puncture). Here we describe the baseline characteristics, immunovirological outcomes, safety and tolerability of HBM sampling. Between March 2016 and April 2024, 47 participants were enrolled, predominantly men who have sex with men (MSM), with a median age of 36 years [IQR 30-43.5]. Almost 90 % of participants initiated ART within 72 h after study inclusion, irrespective of HBM sampling trajectory. The timing of ART initiation according to the Fiebig stage did not significantly impact immune recovery (CD4/CD8 ratio ≥1) or the time to viral suppression. Approximately 40 % of participants opted for the extensive HBM sampling trajectory during AHI. However, the participation rate for the extensive trajectory decreased by nearly half at the longitudinal follow-up timepoint. In general, study-related procedures were safe and well-tolerated, with limited procedure-related adverse events (AEs). Inguinal lymph node excision was associated with the highest AE rate, in line with previous reports. Our findings reaffirm the beneficial effect of ART initiation during AHI on long term immunovirological outcomes, regardless of Fiebig stage at treatment initiation. Additionally, we demonstrate that the collection of HBM during and longitudinally after AHI is safe and feasible, without compromising time to ART initiation. Cohorts that integrate comprehensive clinical data with high-quality HBM samples are essential to longitudinally study the impact of early ART on reservoir dynamics and immune responses across various anatomical sites after AHI.