Mucosal associated invariant T cells are altered in patients with Hidradenitis Suppurativa and contribute to the inflammatory milieu

Mucosal Associated Invariant T cells are a population of “innate” T cells, which express the invariant T cell receptor (TCR) a chain Va7.2-Ja33 and are capable of robust rapid cytokine secretion, producing a milieu of cytokines including IFN-g and IL-17. MAIT cells have been reported in multiple human tissues including the gut, periphery and skin. On-going research has highlighted their involvement in numerous inflammatory diseases ranging from rheumatoid arthritis and obesity to psoriasis. Hidradenitis Suppurativa (H.S) is a chronic inflammatory disease of the hair follicles, resulting in painful lesions of apocrine-bearing skin. Several inflammatory cytokines have been implicated in the pathogenesis of H.S including IL-17. The role of MAIT cells in H.S is currently unknown. In this study we show for the first time, that MAIT cells are altered in the peripheral blood of patients with H.S, with reduced frequencies and an IL-17 cytokine bias. We show that CCL20 expression is elevated in lesions of patients with H.S, and MAIT cells can actively traffic towards lesions via CCL20. We show that MAIT cells can accumulate in the lesionsfrom patients with H.S. when compared to adjacent skin, with an IL-17 bias. We show that elevated IL-17, can be linked to the activation of dermal fibroblasts, promoting the expression of chemotactic signals including CCL20 and CXCL1. Finally, we show that targeting the IL-17A transcription factor RORyt robustly reduces IL-17 production by MAIT cells from patients with H.S. Collectively our data detailsIL-17 producing MAIT cells as a novel player in the pathogenesis of H.S and highlights the potential of RORyt inhibition as a novel therapeutic strategy

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Cytokine-induced natural killer cell training is dependent on cellular metabolism and is defective in obesity

Natural killer (NK) cells are a population of innate immune cells that can rapidly kill cancer cells and produce cytokines such as interferon-γ. A key feature of NK cells is their ability to respond without prior sensitization; however, it is now well established that NK cells can possess memory-like features. After activation with cytokines, NK cells demonstrate enhanced effector functions upon restimulation days or weeks later. This demonstrates that NK cells may be trained to be more effective killers and harnessed as more potent cancer immunotherapy agents. We have previously demonstrated that cellular metabolism is essential for NK cell responses, with NK cells upregulating both glycolysis and oxidative phosphorylation upon cytokine stimulation. Limiting NK cell metabolism results in reduced cytotoxicity and cytokine production. We have also demonstrated that defective NK cell responses in obesity are linked to defective cellular metabolism. In the current study, we investigated if cellular metabolism is required during the initial period of NK cell cytokine training and if NK cells from people with obesity (PWO) can be effectively trained. We show that increased flux through glycolysis and oxidative phosphorylation during the initial cytokine activation period is essential for NK cell training, as is the metabolic signaling factor Srebp. We show that NK cells from PWO, which are metabolically defective, display impaired NK cell training, which may have implications for immunotherapy in this particularly vulnerable group

Iron Is Critical for Mucosal-Associated Invariant T Cell Metabolism and Effector Functions

Mucosal-Associated Invariant T (MAIT) cells are a population of innate T cells that play a critical role in host protection against bacterial and viral pathogens. Upon activation, MAIT cells can rapidly respond via both TCR-dependent and -independent mechanisms, resulting in robust cytokine production. The metabolic and nutritional requirements for optimal MAIT cell effector responses are still emerging. Iron is an important micronutrient and is essential for cellular fitness, in particular cellular metabolism. Iron is also critical for many pathogenic microbes, including those that activate MAIT cells. However, iron has not been investigated with respect to MAIT cell metabolic or functional responses. In this study, we show that human MAIT cells require exogenous iron, transported via CD71 for optimal metabolic activity in MAIT cells, including their production of ATP. We demonstrate that restricting iron availability by either chelating environmental iron or blocking CD71 on MAIT cells results in impaired cytokine production and proliferation. These data collectively highlight the importance of a CD71-iron axis for human MAIT cell metabolism and functionality, an axis that may have implications in conditions where iron availability is limited.</p

Identification of distinct long COVID clinical phenotypes through cluster analysis of self-reported symptoms

Background: We aimed to describe the clinical presentation of individuals presenting with prolonged recovery from coronavirus disease 2019 (COVID-19), known as long COVID.Methods: This was an analysis within a multicenter, prospective cohort study of individuals with a confirmed diagnosis of COVID-19 and persistent symptoms >4 weeks from onset of acute symptoms. We performed a multiple correspondence analysis (MCA) on the most common self-reported symptoms and hierarchical clustering on the results of the MCA to identify symptom clusters.Results: Two hundred thirty-three individuals were included in the analysis; the median age of the cohort was 43 (interquartile range [IQR], 36-54) years, 74% were women, and 77.3% reported a mild initial illness. MCA and hierarchical clustering revealed 3 clusters. Cluster 1 had predominantly pain symptoms with a higher proportion of joint pain, myalgia, and headache; cluster 2 had a preponderance of cardiovascular symptoms with prominent chest pain, shortness of breath, and palpitations; and cluster 3 had significantly fewer symptoms than the other clusters (2 [IQR, 2-3] symptoms per individual in cluster 3 vs 6 [IQR, 5-7] and 4 [IQR, 3-5] in clusters 1 and 2, respectively; P Conclusions: Clusters of symptoms are evident in long COVID patients that are associated with functional impairments and may point to distinct underlying pathophysiologic mechanisms of disease.</div

Elective cancer surgery in COVID-19-free surgical pathways during the SARS-CoV-2 pandemic : an international, multicenter, comparative cohort study

PURPOSE As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway. PATIENTS AND METHODS This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation). RESULTS Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% v 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% v 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76). CONCLUSION Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks

Delaying surgery for patients with a previous SARS-CoV-2 infection

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