SARS-CoV-2 infection triggers more potent antibody-dependent cellular cytotoxicity (ADCC) responses than mRNA-, vector-, and inactivated virus-based COVID-19 vaccines.

Neutralizing antibodies (NAbs) are elicited after infection and vaccination and have been well studied. However, their antibody-dependent cellular cytotoxicity (ADCC) functionality is still poorly characterized. Here, we investigated ADCC activity in convalescent sera from infected patients with wild-type (WT) severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) or omicron variant compared with three coronavirus disease 2019 (COVID-19) vaccine platforms and postvaccination breakthrough infection (BTI). We analyzed ADCC activity targeting SARS-CoV-2 spike (S) and nucleocapsid (N) proteins in convalescent sera following WT SARS-CoV-2-infection (n = 91), including symptomatic and asymptomatic infections, omicron-infection (n = 8), COVID-19 vaccination with messenger RNA- (mRNA)- (BNT162b2 or mRNA-1273, n = 77), adenovirus vector- (n = 41), and inactivated virus- (n = 46) based vaccines, as well as post-mRNA vaccination BTI caused by omicron (n = 28). Correlations between ADCC, binding, and NAb titers were reported. ADCC was elicited within the first month postinfection and -vaccination and remained detectable for ≥3 months. WT-infected symptomatic patients had higher S-specific ADCC levels than asymptomatic and vaccinated individuals. Also, no difference in N-specific ADCC activity was seen between symptomatic and asymptomatic patients, but the levels were higher than the inactivated vaccine. Notably, omicron infection showed reduced overall ADCC activity compared to WT SARS-CoV-2 infection. Although post-mRNA vaccination BTI elicited high levels of binding and NAbs, ADCC activity was significantly reduced. Also, there was no difference in ADCC levels across the four vaccines, although NAbs and binding antibody titers were significantly higher in mRNA-vaccinated individuals. All evaluated vaccine platforms are inferior in inducing ADCC compared to natural infection with WT SARS-CoV-2. The inactivated virus-based vaccine can induce N-specific ADCC activity, but its relevance to clinical outcomes requires further investigation. Our data suggest that ADCC could be used to estimate the extra-neutralization level against COVID-19 and provides evidence that vaccination should focus on other Fc-effector functions besides NAbs. Also, the decreased susceptibility of the omicron variant to ADCC offers valuable guidance for forthcoming efforts to identify the specific targets of antibodies facilitating ADCC.

Predicted deleterious variants in the human genome relevant to gene therapy with adeno-associated virus vectors.

Based on the observation that humans have variable responses of gene expression with the same dose of an adeno-associated vector, we hypothesized that there are deleterious variants in genes coding for processes required for adeno-associated virus (AAV)-mediated gene transfer/expression that may hamper or enhance the effectiveness of AAV-mediated gene therapy. To assess this hypothesis, we evaluated 69,442 whole genome sequences from three populations (European, African/African American, and Qatari) for predicted deleterious variants in 62 genes known to play a role in AAV-mediated gene transfer/expression. The analysis identified 5,564 potentially deleterious mutations of which 27 were classified as common based on an allele frequency ≥1% in at least one population studied. Many of these deleterious variants are predicated to prevent while others enhance effective AAV gene transfer/expression, and several are linked to known hereditary disorders. The data support the hypothesis that, like other drugs, human genetic variability contributes to the person-to-person effectiveness of AAV gene therapy and the screening for genetic variability should be considered as part of future clinical trials.

Persistence of spike-specific immune responses in BNT162b2-vaccinated donors and generation of rapid ex-vivo T cells expansion protocol for adoptive immunotherapy: A pilot study.

Introduction: The BNT162b2 mRNA-based vaccine has shown high efficacy in preventing COVID-19 infection but there are limited data on the types and persistence of the humoral and T cell responses to such a vaccine. Methods: Here, we dissect the vaccine-induced humoral and cellular responses in a cohort of six healthy recipients of two doses of this vaccine. Results and discussion: Overall, there was heterogeneity in the spike-specific humoral and cellular responses among vaccinated individuals. Interestingly, we demonstrated that anti-spike antibody levels detected by a novel simple automated assay (Jess) were strongly correlated (r=0.863, P<0.0001) with neutralizing activity; thus, providing a potential surrogate for neutralizing cell-based assays. The spike-specific T cell response was measured with a newly modified T-spot assay in which the high-homology peptide-sequences cross-reactive with other coronaviruses were removed. This response was induced in 4/6 participants after the first dose, and all six participants after the second dose, and remained detectable in 4/6 participants five months post-vaccination. We have also shown for the first time, that BNT162b2 vaccine enhanced T cell responses also against known human common viruses. In addition, we demonstrated the efficacy of a rapid ex-vivo T cell expansion protocol for spike-specific T cell expansion to be potentially used for adoptive-cell therapy in severe COVID-19, immunocompromised individuals, and other high-risk groups. There was a 9 to 13.7-fold increase in the number of expanded T cells with a significant increase of anti-spike specific response showing higher frequencies of both activation and cytotoxic markers. Interestingly, effector memory T cells were dominant in all four participants' CD8+ expanded memory T cells; CD4+ T cells were dominated by effector memory in 2/4 participants and by central memory in the remaining two participants. Moreover, we found that high frequencies of CD4+ terminally differentiated memory T cells were associated with a greater reduction of spike-specific activated CD4+ T cells. Finally, we showed that participants who had a CD4+ central memory T cell dominance expressed a high CD69 activation marker in the CD4+ activated T cells.

Variability in Skeletal Muscle Protein Synthesis Rates in Critically Ill Patients.

(1) Background: Muscle protein synthesis in critically ill patients is, on average, normal despite dramatic muscle loss, but the variation is much larger than in controls. Here, we evaluate if this variation is due to 1) heterogeneity in synthesis rates, 2) morphological variation or infiltrating cells, or 3) heterogeneity in the synthesis of different protein fractions. (2) Methods: Muscle biopsies were taken from both legs of critically ill patients (n = 17). Mixed and mitochondrial protein synthesis rates and morphologies were evaluated in both legs. Synthesis rates of myosin and actin were determined in combined biopsies and compared with controls. (3) Results: Muscle protein synthesis rates had a large variability in the patients (1.4-10.8%/day). No differences in mixed and mitochondrial protein synthesis rates between both legs were observed. A microscopic examination revealed no morphological differences between the two legs or any infiltrating inflammatory cells. The synthesis rates for myosin were lower and for actin they were higher in the muscles of critically ill patients, compared with the controls. (4) Conclusions: The large variation in muscle protein synthesis rates in critically ill patients is not the result of heterogeneity in synthesis rates, nor due to infiltrating cells. There are differences in the synthesis rates of different proteins, but these do not explain the larger variations.

Characteristics and predictors of burnout among healthcare professionals: a cross-sectional study in two tertiary hospitals.

BACKGROUND: The pattern and impact of burnout among the medical staff are not yet well defined. However, the consequences of burnout are not limited to the healthcare providers but also may affect their family, colleagues and patients in a negative manner. We aimed to assess the characteristics and predictors of burnout among health professionals at two large tertiary hospitals. METHODS: We conducted a cross-sectional study during the period from July 2018 to 31 December 2018. Data, via Maslach Burnout Inventory survey, were collected from physicians and other healthcare workers in two hospitals. RESULTS: A total of 624 responses to questionnaires were analysed. Half of the respondents were physicians, and men constituted the majority. About 10% (95% CI, 7.8 to 12.5) of the respondents satisfied the criteria of burnout. Emotional exhaustion (EE) was observed in 45.7%, depersonalisation (DP) in 26.9% and personal accomplishment (PA) in 41.2% of the respondents. There was a positive correlation between EE and DP (r=0.627, p=0.001), and a weak negative correlation between DP and PA (r=-0.195, p=0.001). Young age, less experience, trauma surgery, lack of habits and getting depressed ≥1 time/week were predictors of burnout. CONCLUSIONS: Burnout affects one-tenth of the health professionals in the tertiary hospitals in Qatar. Physicians are more likely to have higher DP and lower PA, whereas nurses prone to have higher EE. In this study, no gender discrepancy is appreciated and the junior medical staff is at a higher risk of burnout.

Indications and outcomes of extracorporeal life support in trauma patients.

BACKGROUND: The use of extracorporeal life support (ECLS) in the trauma population remains controversial and has been reported only in small cohort studies. Recent ECLS technical advances have increased its use as an advanced critical care option in trauma. Given the degree of resource utilization, costs, and expertise required to provide ECLS support in trauma patients, we sought to perform a multi-institutional study to assess the indications and outcomes of ECLS in trauma. METHODS: A retrospective review of adult (≥16 years) trauma patients receiving ECLS support in the Extracorporeal Life Support Organization (ELSO) registry (1989-2016) was performed. Standardized data from the contributing ELSO centers includes patient demographics, diagnoses, and ECLS technique and procedures. Additionally, baseline characteristics, precannulation and postcannulation physiologic data, complications, and outcomes were recorded. Survival was categorized both by transition off ECLS support and survival to hospital discharge. RESULTS: Two hundred seventy-nine trauma patients were identified (0.92% of 30,273 adult ECLS patients). Extracorporeal life support increased significantly in the last 5 years (173 in 2011-2016, 62%) compared with 106 in the prior 18 years. Trauma patients were predominantly male (78%), with a mean age of 34.8 ± 15.4 years (range, 16-88 years). Thoracic injury was the most common diagnosis; acute respiratory distress syndrome was the most common indication. Extracorporeal life support was venovenous for respiratory failure (89%), VA for cardiac failure (7%), and VA for ECLS-assisted cardiopulmonary resuscitation (CPR) (E-CPR) (4%). Extracorporeal life support duration was 8.8 ± 9.5 days (longest 83 days), and was longer for respiratory support (9.3 ± 9.3 days) vs. cardiac support (4.1 ± 4.5 days) and E-CPR (6.5 ± 16.8 days). Overall survival from ECLS was 70% and survival to hospital discharge was 61% in the total cohort (63% respiratory, 50% cardiac, 25% E-CPR), similar to survival rates in other ELSO registry cohorts. More than 80% of patients had a reported complication during ECLS support. The most common complication was cardiovascular (51%) followed by a bleeding complication (29%). Multiple organ failure was the most common cause of death (15.4%). CONCLUSION: Data from the largest registry of critically ill trauma patients receiving ECLS support demonstrates reasonable survival. With growing experience and improved safety profile, trauma should not be considered a contraindication for ECLS. Further analysis of the ELSO registry regarding trauma-specific risk factors and ECLS-specific practices may identify best candidates and improve trauma ECLS outcomes. LEVEL OF EVIDENCE: Therapeutic study, level III.

Long-term outcomes and cardiac surgery in critically ill patients with infective endocarditis.

AIMS: To assess long-term outcomes and the management of critical left-sided infective endocarditis (IE) and evaluate the impact of surgery. METHODS AND RESULTS: Among the 198 patients included prospectively for IE across 33 adult intensive care units (ICU) in France from 1 April 2007 to 1 October 2008, 137 (69%) were dead at a median follow-up time of 59.5 months. Characteristics significantly associated with mortality were: Sepsis-related Organ-Failure Assessment (SOFA) score at ICU admission [Hazard ratio (HR), 95% Confidence Interval (CI) of 1.43 (0.79-2.59) for SOFA 5-9; 2.01 (1.05-3.85) for SOFA 10-14; 3.53 (1.75-7.11) for SOFA 15-20; reference category SOFA 0-4; P = 0.003]; prosthetic mechanical valve IE [HR 2.01; 95% CI 1.09-3.69, P = 0.025]; vegetation size ≥15 mm [HR 1.64; 95% CI 1.03-2.63, P = 0.038]; and cardiac surgery [HR (95%CI), 0.33 (0.16-0.67) for surgery ≤1 day after IE diagnosis; 0.61 (0.29-1.26) for surgery 2-7 days after IE diagnosis; 0.42 (0.21-0.83) for surgery >7 days after IE diagnosis; reference category no surgery; P = 0.005]. One hundred and three (52%) patients underwent cardiac surgery after a median time of 6 (16) days. Independent predictors of surgical intervention on multivariate analysis were: age ≤60 years [Odds ratio (OR) 5.30; 95% CI (2.46-11.41), P < 0.01], heart failure [OR 3.27; 95% CI (1.03-10.35), P = 0.04], cardiogenic shock [OR 3.31; 95% CI (1.47-7.46), P = 0.004], septic shock [OR 0.25; 95% CI (0.11-0.59), P = 0.002], immunosuppression [OR 0.15; 95% CI (0.04-0.55), P = 0.004], and diagnosis before or within 24 h of ICU admission [OR 2.81; 95% CI (1.14-6.95), P = 0.025]. SOFA score calculated the day of surgery was the only independently associated factor with long-term mortality [HR (95% CI) 1.59 (0.77-3.28) for SOFA 5-9; 3.56 (1.71-7.38) for SOFA 10-14; 11.58 (4.02-33.35) for SOFA 15-20; reference category SOFA 0-4; P < 0.0001]. Surgical timing was not associated with post-operative outcomes. Of the 158 patients with a theoretical indication for surgery, the 58 deemed not fit had a 95% mortality rate. CONCLUSION: Mortality in patients with critical IE remains unacceptably high. Factors associated with long-term outcomes are the severity of multiorgan failure, prosthetic mechanical valve IE, vegetation size ≥15 mm, and surgical treatment. Up to one-third of potential candidates do not undergo surgery and these patients experience extremely high mortality rates. The strongest independent predictor of post-operative mortality is the pre-operative multiorgan failure score while surgical timing does not seem to impact on outcomes.