Explore the vast range of titles available.

T-cell responses to SARS-CoV-2 remain largely preserved across variants despite waning neutralizing antibodies. However, T-cell immunity may vary with the host's immune status, and data on T-cell responses in post-vaccine infections (PVI) are limited. We assessed Spike-specific T-cell responses in 32 vaccinated individuals, 16 of whom experienced PVI. Immune responses were evaluated at three time points: 1 month after the second vaccine dose (T1), 1 month after the booster dose (T2), and, in the PVI group, 1-3 months after the first positive nasal swab (T3). Additionally, we evaluated anti-spike antibody levels, T-cell exhaustion markers, and natural killer cell subsets, focusing on memory-like CD57 NKG2C cells. Subjects who developed PVI exhibited significantly reduced Spike-specific CD4 T-cell responses following the booster dose compared to vaccinated individuals who remained uninfected. This was accompanied by increased frequencies of LAG-3 CD4 and CD8 T-cells. A positive correlation was observed between AIM CD4 T-cells and NKG2C NK cells at T2 in PVI subjects. Following natural infection, T-cell responses were enhanced and associated with an expansion of NKG2C NK cells. Individuals experiencing PVI displayed impaired booster-induced CD4 T-cell responses and increased expression of the immune checkpoint LAG-3. Natural infection restored and enhanced cellular immunity, particularly through the expansion of Spike-specific T-cells and memory NK cell populations. This study identifies an immune profile characterized by low spike-specific responses, which are associated with an increased susceptibility to breakthrough infections.

Background: Early treatment with remdesivir (RMD) or monoclonal antibodies (mAbs) could be a valuable tool in patients at risk of severe COVID-19 with unsatisfactory responses to vaccination. We aim to assess the safety and clinical outcomes of these treatments among immunocompromised subjects. Methods: We retrospectively reviewed all nonhospitalized patients who received an early treatment with RMD or mAbs for COVID-19, from 25 November 2021 to 25 January 2022, in a large tertiary hospital. Outcomes included frequency of adverse drug reaction (ADR), duration of symptoms and molecular swab positivity, emergency department access, hospital or intensive care unit admission, and mortality in the 14 days following treatment administration. Results: Early treatments were administered to 143 patients, 106/143 (74.1%) immunocompromised, including 41 solid organ and 6 hematopoietic stem cell transplant recipients. Overall, 23/143 (16.1%) subjects reported ADRs. Median time from treatment start to SARS-CoV-2 nasopharyngeal swab negativity and symptom resolution was 10 (IQR 6–16) and 2.5 days (IQR 1.0–6.0), respectively, without differences between immunocompromised and nonimmunocompromised patients. In the 14 days after treatment administration, 5/143 patients (3.5%) were hospitalized and one died as a result of causes related to COVID-19, all of them were immunocompromised. Conclusions: RMD and mAbs have minimal ADRs and favourable outcomes in immunocompromised patients.

Objectives: Monoclonal antibodies (mAbs) have proven to be a valuable tool against COVID-19, mostly among subjects with risk factors for progression to severe illness. Tixagevimab/cilgavimab (TIX/CIL), a combination of two Fc-modified human monoclonal antibodies, has been recently approved to be employed as early treatment. Methods: Two groups of immunocompromised patients exposed to different early treatments (i.e., TIX/CIL vs. other mAbs [casirivimab/imdevimab, bamlanivimab/etesevimab, sotrovimab]) were compared in terms of clinical outcomes (hospitalisation and mortality within 14 days from administration) and time to the negativity of nasal swabs. We used either Pearson’s chi-square or Fisher’s exact test for categorical variables, whereas the Wilcoxon rank–sum test was employed for continuous ones. Kaplan–Meier curves were produced to compare the time to nasopharyngeal swab negativity. Results: Early treatment with TIX/CIL was administered to 19 immunocompromised patients, while 89 patients received other mAbs. Most of them were solid organ transplant recipients or suffering from hematologic or solid malignancies. Overall, no significant difference was observed between the two groups regarding clinical outcomes. In the TIX/CIL group, one patient (1/19, 5.3%), who was admitted to the emergency room within the first 14 days from treatment and was hospitalised due to COVID-19 progression, died. Regarding the time to nasal swab negativity, no significant difference (p = 0.088) emerged. Conclusions: Early treatment of SARS-CoV-2 infection with TIX/CIL showed favourable outcomes in a small group of immunocompromised patients, reporting no significant difference compared to similar patients treated with other mAbs.

Introduction Evidence from HIV‐negative cohorts suggests a link between osteoporosis and cardiovascular disease. We evaluated the presence and distribution of abdominal aortic calcifications (AAC) and its correlation with bone mineral density (BMD) and vertebral fractures (VF) in a cohort of HIV‐positive patients. Materials and Methods In this cross‐sectional study, 280 asymptomatic HIV‐positive patients from the SPID (“San Paolo” Infectious Diseases) cohort were submitted to lateral spine X‐ray and DXA. AAC was identified using the AAC‐8 score, which estimates the total length of calcification of the anterior and posterior aortic walls in front of vertebrae L1–L4. Low BMD was defined by T‐score or Z‐score <−1 at lumbar spine or femoral neck. VF were identified by morph‐metric analysis of X‐ray and were defined by the “spine deformity index” (SDI) ≥1 according to semiquantitative method by Genant. Associations between AAC, BMD and SDI were evaluated by univariate and multivariate logistic regression models. The relationship between the grade of AAC and SDI was evaluated by Spearman's correlation. Results AAC≥1 was present in 65 patients (23.2%); of these 15 patients showed moderate/severe calcifications (AAC>2). Low BMD was found in 163 patients (58.2%) and VF (SDI≥1) in 47/274 patients (17.1%). By univariate analysis, factors associated with AAC>=1 were: age (for additional 10 years older HR 3.81 [IC95% 2.64–5.51], p<0.0001) lower CD4 nadir (for additional 50 CD4 HR 0.89 [IC95% 0.82–0.97], p=0.01) AIDS‐diagnosis (HR 2.13 [IC95 % 1.11–4.08], p=0.02) and being on HAART (HR 2.75 [IC95% 1.28–5.90], p=0.009). In multivariate analysis, only age (OR 2.62, IC95% 1.72–3.99, p<0.0001) resulted significantly associated with AAC≥1. Patients with AAC≥1 had twofold increase in the risk of low BMD (HR 2.45 [IC95% 1.32–4.45], p=0.004) and VF (SDI>=1: HR 2.17 [IC95% 1.1–4.2], p=0.02) compared to patients without AAC. The grade of AAC was directly correlated with the grade of SDI (rho=0.16; p=0.008): AAC>2 determines a sixfold increase in the risk of VF (HR 6.44 [IC95% 2.21–18.79], p=0.0006). AAC≥1 predict VF independently from BMD, vitamin D status and bone turnover marker (Table 1). Conclusions In our HIV population, AAC resulted a strong predictor of both low BMD and VF, irrespective of factors involved in bone formation. The grade of AAC was directly correlated with the grade of VF.

Akkermansia muciniphila is considered as one of the next-generation beneficial bacteria in the context of obesity and associated metabolic disorders. Although a first proof-of-concept of its beneficial effects has been established in the context of metabolic syndrome in humans, mechanisms are not yet fully understood. This study aimed at deciphering whether the bacterium exerts its beneficial properties through the modulation of the endocannabinoidome (eCBome). Circulating levels of 25 endogenous endocannabinoid-related lipids were quantified by liquid chromatography with tandem mass spectrometry (LC-MS/MS) in the plasma of overweight or obese individuals before and after a 3 months intervention consisting of the daily ingestion of either alive or pasteurized A. muciniphila. Results from multivariate analyses suggested that the beneficial effects of A. muciniphila were not linked to an overall modification of the eCBome. However, subsequent univariate analysis showed that the decrease in 1-Palmitoyl-glycerol (1-PG) and 2-Palmitoyl-glycerol (2-PG), two eCBome lipids, observed in the placebo group was significantly counteracted by the alive bacterium, and to a lower extent by the pasteurized form. We also discovered that 1- and 2-PG are endogenous activators of peroxisome proliferator-activated receptor alpha (PPARα). We hypothesize that PPARα activation by mono-palmitoyl-glycerols may underlie part of the beneficial metabolic effects induced by A. muciniphila in human metabolic syndrome.