The COVID-19 pandemic caused by SARS-CoV-2 is a continuous challenge worldwide, and there is an urgent need to map the landscape of immunogenic and immunodominant epitopes recognized by CD8
T cells. ...Here, we analyze samples from 31 patients with COVID-19 for CD8
T cell recognition of 500 peptide-HLA class I complexes, restricted by 10 common HLA alleles. We identify 18 CD8
T cell recognized SARS-CoV-2 epitopes, including an epitope with immunodominant features derived from ORF1ab and restricted by HLA-A*01:01. In-depth characterization of SARS-CoV-2-specific CD8
T cell responses of patients with acute critical and severe disease reveals high expression of NKG2A, lack of cytokine production and a gene expression profile inhibiting T cell re-activation and migration while sustaining survival. SARS-CoV-2-specific CD8
T cell responses are detectable up to 5 months after recovery from critical and severe disease, and these responses convert from dysfunctional effector to functional memory CD8
T cells during convalescence.
Gram-negative bacteremia is a major cause of morbidity and mortality in hospitalized patients. Data to guide the duration of antibiotic therapy are limited.
This was a randomized, multicenter, ...open-label, noninferiority trial. Inpatients with gram-negative bacteremia, who were afebrile and hemodynamically stable for at least 48 hours, were randomized to receive 7 days (intervention) or 14 days (control) of covering antibiotic therapy. Patients with uncontrolled focus of infection were excluded. The primary outcome at 90 days was a composite of all-cause mortality; relapse, suppurative, or distant complications; and readmission or extended hospitalization (>14 days). The noninferiority margin was set at 10%.
We included 604 patients (306 intervention, 298 control) between January 2013 and August 2017 in 3 centers in Israel and Italy. The source of the infection was urinary in 411 of 604 patients (68%); causative pathogens were mainly Enterobacteriaceae (543/604 90%). A 7-day difference in the median duration of covering antibiotics was achieved. The primary outcome occurred in 140 of 306 patients (45.8%) in the 7-day group vs 144 of 298 (48.3%) in the 14-day group (risk difference, -2.6% 95% confidence interval, -10.5% to 5.3%). No significant differences were observed in all other outcomes and adverse events, except for a shorter time to return to baseline functional status in the short-course therapy arm.
In patients hospitalized with gram-negative bacteremia achieving clinical stability before day 7, an antibiotic course of 7 days was noninferior to 14 days. Reducing antibiotic treatment for uncomplicated gram-negative bacteremia to 7 days is an important antibiotic stewardship intervention.
NCT01737320.
Monocyte Distribution Width (MDW), a new cytometric parameter correlating with cytomorphologic changes occurring upon massive monocyte activation, has recently emerged as promising early biomarker of ...sepsis. Similar to sepsis, monocyte/macrophage subsets are considered key mediators of the life-threatening hyper-inflammatory disorder characterizing severe COVID-19. In this study, we longitudinally analyzed MDW values in a cohort of 87 COVID-19 patients consecutively admitted to our hospital, showing significant correlations between MDW and common inflammatory markers, namely CRP (p < 0.001), fibrinogen (p < 0.001) and ferritin (p < 0.01). Moreover, high MDW values resulted to be prognostically associated with fatal outcome in COVID-19 patients (AUC = 0.76, 95% CI: 0.66-0.87, sensitivity 0.75, specificity 0.70, MDW threshold 26.4; RR = 4.91, 95% CI: 1.73-13.96; OR = 7.14, 95% CI: 2.06-24.71). This pilot study shows that MDW can be useful in the monitoring of COVID-19 patients, as this innovative hematologic biomarker is: (1) easy to obtain, (2) directly related to the activation state of a fundamental inflammatory cell subset (i.e. monocytes, pivotal in both cytokine storm and sepsis immunopathogenesis), (3) well correlated with clinical severity of COVID-19-associated inflammatory disorder, and, in turn, (4) endowed with relevant prognostic significance. Additional studies are needed to define further the clinical impact of MDW testing in the management of COVID-19 patients.
In patients infected by SARS‐CoV‐2 who experience an exaggerated inflammation leading to pneumonia, monocytes likely play a major role but have received poor attention. Thus, we analyzed peripheral ...blood monocytes from patients with COVID‐19 pneumonia and found that these cells show signs of altered bioenergetics and mitochondrial dysfunction, had a reduced basal and maximal respiration, reduced spare respiratory capacity, and decreased proton leak. Basal extracellular acidification rate was also diminished, suggesting reduced capability to perform aerobic glycolysis. Although COVID‐19 monocytes had a reduced ability to perform oxidative burst, they were still capable of producing TNF and IFN‐γ in vitro. A significantly high amount of monocytes had depolarized mitochondria and abnormal mitochondrial ultrastructure. A redistribution of monocyte subsets, with a significant expansion of intermediate/pro‐inflammatory cells, and high amounts of immature monocytes were found, along with a concomitant compression of classical monocytes, and an increased expression of inhibitory checkpoints like PD‐1/PD‐L1. High plasma levels of several inflammatory cytokines and chemokines, including GM‐CSF, IL‐18, CCL2, CXCL10, and osteopontin, finally confirm the importance of monocytes in COVID‐19 immunopathogenesis.
SYNOPSIS
Investigation of patients with COVID‐19 pneumonia revealed that SARS‐CoV‐2 infection affects innate immunity by reshaping peripheral blood monocyte subsets and altering their functionality, in terms of bioenergetics, membrane potential and expression of checkpoint inhibitors.
A peripheral blood increase in intermediate monocytes, reduction of classical monocytes, increase of circulating immature monocytes and upregulation of PD‐1 and PD‐L1 on such cells characterize patients with COVID‐19 pneumonia.
Monocytes display reduced oxidative phosphorylation, reduced extracellular acidification rate and altered mitochondrial ultrastructure.
Monocytes had a reduced capability to perform the respiratory burst, although they still remain able to produce inflammatory cytokines.
Several inflammatory cytokines and chemokine, including GM‐CSF, IL‐18, CCL2, IL‐6, CXCL10 and osteopontin are present at high concentration in plasma from COVID‐19 patients.
Investigation of patients with COVID‐19 pneumonia revealed that SARS‐CoV‐2 infection affects innate immunity by reshaping peripheral blood monocyte subsets and altering their functionality, in terms of bioenergetics, membrane potential and expression of checkpoint inhibitors.
SARS-CoV-2 infection can affect all human beings, including pregnant women. Thus, understanding the immunological changes induced by the virus during pregnancy is nowadays of pivotal importance. ...Here, using peripheral blood from 14 pregnant women with asymptomatic or mild SARS-CoV-2 infection, we investigate cell proliferation and cytokine production, measure plasma levels of 62 cytokines, and perform a 38-parameter mass cytometry analysis. Our results show an increase in low density neutrophils but no lymphopenia or gross alterations of white blood cells, which display normal levels of differentiation, activation or exhaustion markers and show well preserved functionality. Meanwhile, the plasma levels of anti-inflammatory cytokines such as interleukin (IL)-1RA, IL-10 and IL-19 are increased, those of IL-17, PD-L1 and D-dimer are decreased, but IL-6 and other inflammatory molecules remain unchanged. Our profiling of antiviral immune responses may thus help develop therapeutic strategies to avoid virus-induced damages during pregnancy.
The purpose of this survey is to explore changes in the management of COVID-19 during the first versus the second wave, with particular emphasis on therapies, antibiotic prescriptions, and elderly ...care. An internet-based questionnaire survey was distributed to European Society of Clinical Microbiology and Infectious Diseases (ESCMID) members. Therapeutic approach to patients with mild-to-moderate (PiO
2
/FiO
2
200–350) and severe (PiO
2
/FiO
2
< 200) COVID-19, antibiotic use, and reasons for excluding patients from the intensive care unit (ICU) were investigated. A total of 463 from 21 countries participated in the study. Most representatives were infectious disease specialists (68.3%). During the second wave of pandemic, physicians abandoned the use of hydroxychloroquine, lopinavir/ritonavir, and azithromycin in favor of dexamethasone, low-molecular weight heparin (LMWH), and remdesivir in mild-to-moderate COVID-19. In critically ill patients, we detected an increased use of high-dose steroids (51%) and a decrease in tocilizumab use. The use of antibiotics at hospital admission decreased but remained high in the second wave. Age was reported to be a main consideration for exclusion of patients from ICU care by 25% of responders; a third reported that elderly were not candidates for ICU admission in their center. The decision to exclude patients from ICU care was based on the individual decision of an intensivist in 59.6% of cases. The approach of physicians to COVID-19 changed over time following evidence accumulation and guidelines. Antibiotic use at hospital admission and decision to exclude patients from ICU care remain critical aspects that should be better investigated and harmonized among clinicians.
Causes of blackwater fever, a complication of malaria treatment, are not completely clear, and immune mechanisms might be involved. Clinical management is not standardized. We describe an episode of ...blackwater fever in a nonimmune 12-year-old girl in Italy who was treated with steroids, resulting in a rapid clinical resolution.
Results from clinical trials and observational studies suggest that dolutegravir plus lamivudine could be an effective and well-tolerated option for simplification in HIV-1-positive patients. We ...aimed to assess long-time efficacy and safety in our multicenter cohort.
This was a retrospective study enrolling HIV-1-infected, virologically suppressed patients switching to dolutegravir + lamivudine. We performed survival analysis to evaluate time to virological failure (VF, defined by a single HIV-RNA ≥1000 copies/mL or by 2 consecutive HIV-RNA ≥ 50 copies/mL) and treatment discontinuation (defined as the interruption of either 3TC or dolutegravir), assessing predictors via Cox regression analyses.
Seven-hundred eighty-five patients were considered for the analysis: 554 were men (70.6%), with a median age of 52 years (interquartile range 45-58 years). Estimated probabilities of maintaining virological suppression at weeks 96, 144, and 240 were 97.7% (SD ±0.6), 96.9% (SD ±0.8), and 96.4% (SD ±0.9), respectively. A non-B HIV subtype (P = 0.014) and a previous VF (P = 0.037) resulted predictors of VF. We did not observe differences in probability of VF in people living with HIV with an M184V resistance mutation (P = 0.689); however, in a deeper analysis, M184V mutation was a predictor of VF (P = 0.038) in patients with time of virological suppression <88 months. Estimated probabilities of remaining on study regimen at 96, 144, and 240 weeks were 82.9% (SD ±1.4), 79.7% (SD ±1.6) and 74.3% (SD ±2.2), respectively.
Our findings show the long-term efficacy and tolerability of dolutegravir plus lamivudine in virologically suppressed patients.
To investigate the association between current CD4+ T-cell count and CD4/CD8+ ratio with severity of frailty among people aging with HIV.
Cross-sectional observational study analysing data from all ...study visits in the ongoing prospective Modena HIV Metabolic Clinic Cohort between 2006 and 2015. Frailty severity was assessed using a frailty index (FI). We visualized the relationships between frailty index score and current CD4 cell count and CD4/CD8 ratio on two different curves adjusted for age, sex, and duration of HIV infection.
Frailty index scores exhibited an inverse relationship with current CD4 count, up to 900 cells/μL. The CD4/CD8 ratio was inversely correlated with frailty index both below and above the cut-off of 900 CD4 cells/μL.
Frailty in PLWH is inversely associated with both immune-activation, depicted by CD4/CD8 ratio and immune-deficit depicted by CD4 count. The first association shows a linear shape while the second shows a hook-shape with a turning point at 900 cells. Above this cut off level CD4 do not represent a significant risk factor for frailty.
Resilience is defined as an individual's positive adaptation to stressors. The COVID-19 pandemic represents a generalized stressor which may affect differently people living with HIV (PLWH). The ...objective of this study was to characterize resilience in PLWH with particular regarding the identification of frailty-resilience phenotypes, which may differently affect health-related quality of life (HR-QoL).
This was an observational study of PLWH attending Modena HIV Metabolic Clinic. Frailty was assessed in 2019, before the onset of the COVID-19 pandemic by using 37-Item frailty index ranging from 0 to 1. The frailty index score was categorized as fit (<0.25) or frail (>0.25). In January 2021, PLWH were offered to complete a set of electronic questionnaires including the CD-RISC-25 for resilience and EQ-5D5L and SF-36 for HR-QoL. Resilience was defined as CD-RISC-25 score >75.7 (ranging from 0 to 100).
Of 800 PLWH reached by mail, 575 (72%) completed the questionnaires. The median age and HIV duration were 54.5 and 24.3 years, respectively. Impaired resilience was associated with loneliness odds ratio (OR = 2.39; 1.20 to 4.76, P < 0.001). Predictors for EQ-5D5L <89.7% were the phenotypes "frail/nonresilient" OR = 5.21, 95% confidence interval (CI): 2.62 to 10.33 and "fit/nonresilient" (OR = 5.48, 95% CI: 2.8 to 10.74). Predictors for SF-36 <64.40 were the phenotypes "frail/nonresilient" (OR = 7.43, 95% CI: 2.57 to 21.22) and "fit/nonresilient" (OR = 6.27, 95% CI: 2.17 to 18.16). Both models were corrected for age, sex, HIV duration, and nadir CD4.
Resilience characterizes the well-being of PLWH during the COVID-19 crisis. This construct is complementary to frailty in the identification of clinical phenotypes with different impacts on HR-QoL.
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