Role of gender in short- and long-term outcomes after surgery for type A aortic dissection: analysis of a multicentre European registry.

OBJECTIVES: Gender difference in the outcome after type A aortic dissection (TAAD) surgery remains an issue of ongoing debate. In this study, we aimed to evaluate the impact of gender on the short- and long-term outcome after surgery for TAAD. METHODS: A multicentre European registry retrospectively included all consecutive TAAD surgery patients between 2005 and 2021 from 18 hospitals across 8 European countries. Early and late mortality, and cumulative incidence of aortic reoperation were compared between genders. RESULTS: A total of 3902 patients underwent TAAD surgery, with 1185 (30.4%) being females. After propensity score matching, 766 pairs of males and females were compared. No statistical differences were detected in the early postoperative outcome between genders. Ten-year survival was comparable between genders (47.8% vs 47.1%; log-rank test, P = 0.679), as well as cumulative incidences of distal or proximal aortic reoperations. Ten-year relative survival compared to country-, year-, age- and sex-matched general population was higher among males (0.65) compared to females (0.58). The time-period subanalysis revealed advancements in surgical techniques in both genders over the years. However, an increase in stroke was observed over time for both populations, particularly among females. CONCLUSIONS: The past 16 years have witnessed marked advancements in surgical techniques for TAAD in both males and females, achieving comparable early and late mortality rates. Despite these findings, late relative survival was still in favour of males.

Aortic arch surgery for DeBakey type 1 aortic dissection in patients aged 60 years or younger.

BACKGROUND: Extended aortic repair is considered a key issue for the long-term durability of surgery for DeBakey type 1 aortic dissection. The risk of aortic degeneration may be higher in young patients due to their long life expectancy. The early outcome and durability of aortic surgery in these patients were investigated in the present study. METHODS: The subjects of the present analysis were patients under 60 years old who underwent surgical repair for acute DeBakey type 1 aortic dissection at 18 cardiac surgery centres across Europe between 2005 and 2021. Patients underwent ascending aortic repair or total aortic arch repair using the conventional technique or the frozen elephant trunk technique. The primary outcome was 5-year cumulative incidence of reoperation on the distal aorta. RESULTS: Overall, 915 patients underwent surgical ascending aortic repair and 284 patients underwent surgical total aortic arch repair. The frozen elephant trunk procedure was performed in 128 patients. Among 245 propensity score-matched pairs, total aortic arch repair did not decrease the rate of distal aortic reoperation compared to ascending aortic repair (5-year cumulative incidence, 6.7% versus 6.7%, subdistributional hazard ratio 1.127, 95% c.i. 0.523 to 2.427). Total aortic arch repair increased the incidence of postoperative stroke/global brain ischaemia (25.7% versus 18.4%, P = 0.050) and dialysis (19.6% versus 12.7%, P = 0.003). Five-year mortality was comparable after ascending aortic repair and total aortic arch repair (22.8% versus 27.3%, P = 0.172). CONCLUSIONS: In patients under 60 years old with DeBakey type 1 aortic dissection, total aortic arch replacement compared with ascending aortic repair did not reduce the incidence of distal aortic operations at 5 years. When feasible, ascending aortic repair for DeBakey type 1 aortic dissection is associated with satisfactory early and mid-term outcomes. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.

Efficient Strategy to Synthesize Tunable pH-Responsive Hybrid Micelles Based on Iron Oxide and Gold Nanoparticles.

The preparation of multifunctional nanomaterials based on inorganic nanoparticles with organic materials has emerged as a promising strategy for the development of new nanomedicines for in vitro and in vivo biomedical applications. Here, we synthesized pH-responsive hybrid inorganic micelles by combining a novel pH-responsive amphiphilic molecule with hydrophobic payloads. This amphiphile was synthesized in a one-pot reaction and self-assembled readily into micelles under acidic pH conditions. In the presence of hydrophobic NP payloads such as AuNPs or IONPs, the amphiphile self-organized around them through hydrophobic interactions, resulting in the formation of colloidally stable hybrid micelles. The size of the hydrophobic NPs determined the pH-response of the inorganic hybrid micelles, which is tuned from pH 7 to 11 for our pH-responsive amphiphilic molecule. This achievement represents a novel approach for the synthesis of tunable pH-responsive hybrid micelles based on inorganic NPs for biomedical imaging, hyperthermia treatment, and also drug delivery nanosystems.

Diameter and dissection of the abdominal aorta and the risk of distal aortic reoperation after surgery for type A aortic dissection.

BACKGROUND: Surgery for Stanford type A aortic dissection (TAAD) is associated with an increased risk of late aortic reoperations due to degeneration of the dissected aorta. METHODS: The subjects of this analysis were 990 TAAD patients who survived surgery for acute TAAD and had complete data on the diameter and dissection status of all aortic segments. RESULTS: After a mean follow-up of 4.2 ± 3.6 years, 60 patients underwent 85 distal aortic reoperations. Ten-year cumulative incidence of distal aortic reoperation was 9.6%. Multivariable competing risk analysis showed that the maximum preoperative diameter of the abdominal aorta (SHR 1.041, 95%CI 1.008-1.075), abdominal aorta dissection (SHR 2.133, 95%CI 1.156-3.937) and genetic syndromes (SHR 2.840, 95%CI 1.001-8.060) were independent predictors of distal aortic reoperation. Patients with a maximum diameter of the abdominal aorta >30 mm and/or abdominal aortic dissection had a cumulative incidence of 10-year distal aortic reoperation of 12.0% compared to 5.7% in those without these risk factors (adjusted SHR 2.076, 95%CI 1.062-4.060). CONCLUSION: TAAD patients with genetic syndromes, and increased size and dissection of the abdominal aorta have an increased the risk of distal aortic reoperations. A policy of extensive surgical or hybrid primary aortic repair, completion endovascular procedures for aortic remodeling and tight surveillance may be justified in these patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.

Nature of Neurological Complications and Outcome After Surgery for Type A Aortic Dissection.

Surgery for type A aortic dissection (TAAD) is frequently complicated by neurologic complications. The prognostic impact of neurologic complications of different nature has been investigated in this study. The subjects of this analysis were 3,902 patients who underwent surgery for acute TAAD from the multicenter European Registry of Type A Aortic Dissection (ERTAAD). During the index hospitalization, 722 patients (18.5%) experienced stroke/global brain ischemia. Ischemic stroke was detected in 539 patients (13.8%), hemorrhagic stroke in 76 patients (1.9%) and global brain ischemia in 177 patients (4.5%), with a few patients having had findings of more than 1 of these conditions. In-hospital mortality was increased significantly in patients with postoperative ischemic stroke (25.6%, adjusted odds ratio [OR] 2.422, 95% confidence interval [CI] 1.825 to 3.216), hemorrhagic stroke (48.7%, adjusted OR 4.641, 95% CI 2.524 to 8.533), and global brain ischemia (74.0%, adjusted OR 22.275, 95% CI 14.537 to 35.524) compared with patients without neurologic complications (13.5%). Similarly, patients who experienced ischemic stroke (46.3%, adjusted hazard ratio [HR] 1.719, 95% CI 1.434 to 2.059), hemorrhagic stroke (62.8%, adjusted HR 3.236, 95% CI 2.314 to 4.525), and global brain ischemia (83.9%, adjusted HR 12.777, 95% CI 10.325 to 15.810) had significantly higher 5-year mortality than patients without postoperative neurologic complications (27.5%). The negative prognostic effect of neurologic complications on survival vanished about 1 year after surgery. In conclusion, postoperative ischemic stroke, hemorrhagic stroke, and global cerebral ischemia increased early and midterm mortality after surgery for acute TAAD. The magnitude of risk of mortality increased with the severity of the neurologic complications, with postoperative hemorrhagic stroke and global brain ischemia being highly lethal complications.

Classification of the Urgency of the Procedure and Outcome of Acute Type A Aortic Dissection.

Surgery for type A aortic dissection (TAAD) is associated with a high risk of early mortality. The prognostic impact of a new classification of the urgency of the procedure was evaluated in this multicenter cohort study. Data on consecutive patients who underwent surgery for acute TAAD were retrospectively collected in the multicenter, retrospective European Registry of TAAD (ERTAAD). The rates of in-hospital mortality of 3,902 consecutive patients increased along with the ERTAAD procedure urgency grades: urgent procedure 10.0%, emergency procedure grade 1 13.3%, emergency procedure grade 2 22.1%, salvage procedure grade 1 45.6%, and salvage procedure grade 2 57.1% (p <0.0001). Preoperative arterial lactate correlated with the urgency grades. Inclusion of the ERTAAD procedure urgency classification significantly improved the area under the receiver operating characteristics curves of the regression model and the integrated discrimination indexes and the net reclassification indexes. The risk of postoperative stroke/global brain ischemia, mesenteric ischemia, lower limb ischemia, dialysis, and acute heart failure increased along with the urgency grades. In conclusion, the urgency of surgical repair of acute TAAD, which seems to have a significant impact on the risk of in-hospital mortality, may be useful to improve the stratification of the operative risk of these critically ill patients. This study showed that salvage surgery for TAAD is justified because half of the patients may survive to discharge.

Delineating the dispersal of Y-chromosome sub-haplogroup O2a2b-P164 among Austronesian-speaking populations.

This article reports on an exploration of the Y-chromosome sub-haplogroup O2a2b-P164 in Austronesian-speaking populations. Moderate to high abundance of the P 164 mutation is seen in the West Pacific including the Amis of Formosa (36%) and the Filipinos of Mindanao (50%) as well as in the Kiritimati of Micronesia (70%), and Tonga and Samoa of West Polynesia (54% and 33%, respectively), and it drops to low frequencies in populations of East Polynesia. The communities of Polynesia and Micronesia exhibit considerable inter- and intra-population haplotype sharing suggesting extensive population affinity. The observed affinities, as well as the ages and diversity values within the P 164 sub-haplogroup among Austronesian-speaking populations signal an ancestral migration route and relationships that link the Amis of Taiwan with distant communities in West and East Polynesia, Micronesia, and the Maori of New Zealand. High resolution sequencing of the Austronesian Y chromosome indicate that the P 164 lineage originated about 19,000 ya and then split into three branches separating the Ami aborigines, Southeast Asian and Polynesian/Micronesian populations about 4700 ya, roughly coinciding with the initiation of the Austronesian diaspora. The Y-chromosomes of all the Polynesian and Micronesian population examined belong to the new FT 257096 haplogroup.

Orange surface waveguide laser in Pr:LiYF4 produced by a femtosecond laser writing.

Depressed-cladding surface channel waveguides were inscribed in a 0.5 at.% Pr:LiYF4 crystal by femtosecond Direct Laser Writing. The waveguides consisted of a half-ring cladding (inner diameter: 17 µm) and side structures ("ears") improving the mode confinement. The waveguide propagation loss was as low as 0.14 ± 0.05 dB/cm. The orange waveguide laser operating in the fundamental mode delivered 274 mW at 604.3 nm with 28.4% slope efficiency, a laser threshold of only 29 mW and linear polarization (π), representing record-high performance for orange Pr waveguide lasers.

Preoperative arterial lactate and outcome after surgery for type A aortic dissection: The ERTAAD multicenter study.

Background: Acute type A aortic dissection (TAAD) is associated with significant mortality and morbidity. In this study we evaluated the prognostic significance of preoperative arterial lactate concentration on the outcome after surgery for TAAD. Methods: The ERTAAD registry included consecutive patients who underwent surgery for acute type A aortic dissection (TAAD) at 18 European centers of cardiac surgery. Results: Data on arterial lactate concentration immediately before surgery were available in 2798 (71.7 %) patients. Preoperative concentration of arterial lactate was an independent predictor of in-hospital mortality (mean, 3.5 ± 3.2 vs 2.1 ± 1.8 mmol/L, adjusted OR 1.181, 95%CI 1.129-1.235). The best cutoff value preoperative arterial lactate concentration was 1.8 mmol/L (in-hospital mortality, 12.0 %, vs. 26.6 %, p < 0.0001). The rates of in-hospital mortality increased along increasing quintiles of arterial lactate and it was 12.1 % in the lowest quintile and 33.6 % in the highest quintile (p < 0.0001). The difference between multivariable models with and without preoperative arterial lactate was statistically significant (p = 0.0002). The NRI was 0.296 (95%CI 0.200-0.391) (p < 0.0001) with -17 % of events correctly reclassified (p = 0.0002) and 46 % of non-events correctly reclassified (p < 0.0001). The IDI was 0.025 (95%CI 0.016-0.034) (p < 0.0001). Six studies from a systematic review plus the present one provided data for a pooled analysis which showed that the mean difference of preoperative arterial lactate between 30-day/in-hospital deaths and survivors was 1.85 mmol/L (95%CI 1.22-2.47, p < 0.0001, I2 64 %). Conclusions: Hyperlactatemia significantly increased the risk of mortality after surgery for acute TAAD and should be considered in the clinical assessment of these critically ill patients.

Shot Boundary Detection with 3D Depthwise Convolutions and Visual Attention.

Shot boundary detection is the process of identifying and locating the boundaries between individual shots in a video sequence. A shot is a continuous sequence of frames that are captured by a single camera, without any cuts or edits. Recent investigations have shown the effectiveness of the use of 3D convolutional networks to solve this task due to its high capacity to extract spatiotemporal features of the video and determine in which frame a transition or shot change occurs. When this task is used as part of a scene segmentation use case with the aim of improving the experience of viewing content from streaming platforms, the speed of segmentation is very important for live and near-live use cases such as start-over. The problem with models based on 3D convolutions is the large number of parameters that they entail. Standard 3D convolutions impose much higher CPU and memory requirements than do the same 2D operations. In this paper, we rely on depthwise separable convolutions to address the problem but with a scheme that significantly reduces the number of parameters. To compensate for the slight loss of performance, we analyze and propose the use of visual self-attention as a mechanism of improvement.

Circulating bone morphogenetic protein 8A is a novel biomarker to predict advanced liver fibrosis.

BACKGROUND & AIMS: Advanced hepatic fibrosis is the main risk factor of liver-related morbidity and mortality in patients with chronic liver disease. In this study, we assessed the potential role of bone morphogenetic protein 8A (BMP8A) as a novel target involved in liver fibrosis progression. METHODS: Histological assessment and BMP8A expression were determined in different murine models of hepatic fibrosis. Furthermore, serum BMP8A was measured in mice with bile duct ligation (BDL), in 36 subjects with histologically normal liver (NL) and in 85 patients with biopsy-proven non-alcoholic steatohepatitis (NASH): 52 with non- or mild fibrosis (F0-F2) and 33 with advanced fibrosis (F3-F4). BMP8A expression and secretion was also determined in cultured human hepatocyte-derived (Huh7) and human hepatic stellate (LX2) cells stimulated with transforming growth factor ꞵ (TGFꞵ). RESULTS: Bmp8a mRNA levels were significantly upregulated in livers from fibrotic mice compared to control animals. Notably, serum BMP8A levels were also elevated in BDL mice. In addition, in vitro experiments showed increased expression and secretion to the culture supernatant of BMP8A in both Huh7 and LX2 cells treated with TGFꞵ. Noteworthy, we found that serum BMP8A levels were significantly higher in NASH patients with advanced fibrosis than in those with non- or mild fibrosis. In fact, the AUROC of circulating BMP8A concentrations to identify patients with advanced fibrosis (F3-F4) was 0.74 (p˂0.0001). Moreover, we developed an algorithm based on serum BMP8A levels that showed an AUROC of 0.818 (p˂0.0001) to predict advanced fibrosis in NASH patients. CONCLUSION: This study provides experimental and clinical evidence indicating that BMP8A is a novel molecular target linked to liver fibrosis and introduces an efficient algorithm based on serum BMP8A levels to screen patients at risk for advanced hepatic fibrosis.

Complex Left Atrial Appendage Occlusion Using the Novel Amplatzer Steerable Delivery Sheath.

Left atrial appendage (LAA) occlusion has emerged as an al- ternative to oral anticoagulation in non-valvular atrial fibril- lation. The success rate is high, but we are still facing some challenging LAA anatomies that may increase the risk of sub- optimal results. These images show that the Amplatzer steer- able sheath is useful for LAA occlusion, especially in cases with challenging anatomies. Small variations of the distal end angle can improve the success rate and reduce complications.

Porous Cellulose Thin Films as Sustainable and Effective Antimicrobial Surface Coatings.

In the present work, we developed an effective antimicrobial surface film based on sustainable microfibrillated cellulose. The resulting porous cellulose thin film is barely noticeable to human eyes due to its submicrometer thickness, of which the surface coverage, porosity, and microstructure can be modulated by the formulations and the coating process. Using goniometers and a quartz crystal microbalance, we observed a threefold reduction in water contact angles and accelerated water evaporation kinetics on the cellulose film (more than 50% faster than that on a flat glass surface). The porous cellulose film exhibits a rapid inactivation effect against SARS-CoV-2 in 5 min, following deposition of virus-loaded droplets, and an exceptional ability to reduce contact transfer of liquid, e.g., respiratory droplets, to surfaces such as an artificial skin by 90% less than that from a planar glass substrate. It also shows excellent antimicrobial performance in inhibiting the growth of both Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus epidermidis) due to the intrinsic porosity and hydrophilicity. Additionally, the cellulose film shows nearly 100% resistance to scraping in dry conditions due to its strong affinity to the supporting substrate but with good removability once wetted with water, suggesting its practical suitability for daily use. Importantly, the coating can be formed on solid substrates readily by spraying, which requires solely a simple formulation of a plant-based cellulose material with no chemical additives, rendering it a scalable, affordable, and green solution as antimicrobial surface coating. Implementing such cellulose films could thus play a significant role in controlling future pan- and epidemics, particularly during the initial phase when suitable medical intervention needs to be developed and deployed.

Interinstitutional analysis of the outcome after surgery for type A aortic dissection.

PURPOSE: To evaluate the impact of individual institutions on the outcome after surgery for Stanford type A aortic dissection (TAAD). METHODS: This is an observational, multicenter, retrospective cohort study including 3902 patients who underwent surgery for TAAD at 18 university and non-university hospitals. RESULTS: Logistic regression showed that four hospitals had increased risk of in-hospital mortality, while two hospitals were associated with decreased risk of in-hospital mortality. Risk-adjusted in-hospital mortality rates were lower in four hospitals and higher in other four hospitals compared to the overall in-hospital mortality rate (17.7%). Participating hospitals were classified as overperforming or underperforming if their risk-adjusted in-hospital mortality rate was lower or higher than the in-hospital mortality rate of the overall series, respectively. Propensity score matching yielded 1729 pairs of patients operated at over- or underperforming hospitals. Overperforming hospitals had a significantly lower in-hospital mortality (12.8% vs. 22.2%, p < 0.0001) along with decreased rate of stroke and/or global brain ischemia (16.5% vs. 19.9%, p = 0.009) compared to underperforming hospitals. Aggregate data meta-regression of the results of participating hospitals showed that hospital volume was inversely associated with in-hospital mortality (p = 0.043). Hospitals with an annual volume of less than 15 cases had an increased risk of in-hospital mortality (adjusted OR, 1.345, 95% CI 1.126-1.607). CONCLUSION: The present findings indicate that there are significant differences between hospitals in terms of early outcome after surgery for TAAD. Low hospital volume may be a determinant of poor outcome of TAAD. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04831073.

On the Y chromosome of Chennai, Tamil Nadu and the Indian subcontinent.

Several migratory waves from various origins along with cultural practices restricting marriages between people of different castes and tribes as well as continued endogamy have led to a complex and diverse society in the Indian subcontinent. Despite being widely represented in genetic studies, several interrogatives remain with regards to India's current genetic constituents and distributions, source populations and population relationships. To identify the forces that may have shaped Indian population's genetic relationships, we undertook a comprehensive comparative study of the Y-chromosomes across India utilizing Y-STR and Y-SNP chromosomal markers using the general population of Chennai in the state of Tamil Nadu as a point of reference. Our analyses identify differences in source populations for different regions within India, unique linguistic characteristics as well as demographic and cultural forces that may have shaped population structure.

Bidirectional dispersals during the peopling of the North American Arctic.

It is thought that Paleo-Inuit were the first people that settled the American Arctic about 5000 BP (before the present) from a migration that crossed Beringia from Northeast Asia. It is theorized that this group initially migrated to the North Slopes of Alaska and subsequently expanded eastward, eventually reaching Greenland. A second circumpolar dispersal of Neo-Inuit from the North Slopes associated with the Thule-Inuk culture has been postulated to have extended eastward around 800 BP, totally replacing the original Paleo-Inuit without admixing. Although generally accepted, this migration scenario is incompatible with previously reported indications of east to west gene flow across the American Arctic. Here we report on the Y-chromosome haplogroup and Y-STR diversity of the four circumpolar populations of the Tuva Republic (N = 24), Northeast Siberia (N = 9), Bethel, Alaska (N = 40), and Barrow, Alaska (N = 31). Four haplogroup lineages (Q-NWT01, Q-M3, Q-M346, and Q-M120) were detected, Q-NWT01 and Q-M3 being the most abundant at 11.11 and 66.67% in Northeast Siberia, 32.50 and 65.00% in Bethel, and 67.74 and 32.26% in Barrow, respectively. The same samples genotyped for Y-chromosome SNPs were typed for 17 Y-STYR loci using the AmpFlSTR Yfiler system. Age estimates and diversity values for the Q-NWT01 and Q-M3 mutations suggest extensive movement of male individuals along the entire longitudinal stretch of the American circumpolar region. Throughout the entire region, Q-M3 exhibits a west to east decreasing gradient in age and diversity while Q-NWT01 indicates the opposite with older TMRCA and higher diversity values running from east to west with the most recent estimates in Canada and Alaska. The high age and diversity values in Greenland are congruent with an origin of the Q-NWT01 mutation in the east of the circumpolar range about 2000-3000 ya. This scenario is incompatible with a complete biological replacement starting about 700 BP of Paleo-Inuit like the Dorset by the Thule-Inuit (Neo-Inuit), as is currently thought, and more parsimonious with gene flow carrying the NWT01 mutation from a pre-Thule population to the ancestors of the present-day Inuit.

Baseline risk factors of in-hospital mortality after surgery for acute type A aortic dissection: an ERTAAD study.

Background: Surgery for type A aortic dissection (TAAD) is associated with high risk of mortality. Current risk scoring methods have a limited predictive accuracy. Methods: Subjects were patients who underwent surgery for acute TAAD at 18 European centers of cardiac surgery from the European Registry of Type A Aortic Dissection (ERTAAD). Results: Out of 3,902 patients included in the ERTAAD, 2,477 fulfilled the inclusion criteria. In the validation dataset (2,229 patients), the rate of in-hospital mortality was 18.4%. The rate of composite outcome (in-hospital death, stroke/global ischemia, dialysis, and/or acute heart failure) was 41.2%, and 10-year mortality rate was 47.0%. Logistic regression identified the following patient-related variables associated with an increased risk of in-hospital mortality [area under the curve (AUC), 0.755, 95% confidence interval (CI), 0.729-0.780; Brier score 0.128]: age; estimated glomerular filtration rate; arterial lactate; iatrogenic dissection; left ventricular ejection fraction ≤50%; invasive mechanical ventilation; cardiopulmonary resuscitation immediately before surgery; and cerebral, mesenteric, and peripheral malperfusion. The estimated risk score was associated with an increased risk of composite outcome (AUC, 0.689, 95% CI, 0.667-0.711) and of late mortality [hazard ratio (HR), 1.035, 95% CI, 1.031-1.038; Harrell's C 0.702; Somer's D 0.403]. In the validation dataset (248 patients), the in-hospital mortality rate was 16.1%, the composite outcome rate was 41.5%, and the 10-year mortality rate was 49.1%. The estimated risk score was predictive of in-hospital mortality (AUC, 0.703, 95% CI, 0.613-0.793; Brier score 0.121; slope 0.905) and of composite outcome (AUC, 0.682, 95% CI, 0.614-0.749). The estimated risk score was predictive of late mortality (HR, 1.035, 95% CI, 1.031-1.038; Harrell's C 0.702; Somer's D 0.403), also when hospital deaths were excluded from the analysis (HR, 1.024, 95% CI, 1.018-1.031; Harrell's C 0.630; Somer's D 0.261). Conclusions: The present analysis identified several baseline clinical risk factors, along with preoperative estimated glomerular filtration rate and arterial lactate, which are predictive of in-hospital mortality and major postoperative adverse events after surgical repair of acute TAAD. These risk factors may be valuable components for risk adjustment in the evaluation of surgical and anesthesiological strategies aiming to improve the results of surgery for TAAD. Clinical Trial Registration: https://clinicaltrials.gov, identifier NCT04831073.

Epigenetic and transcriptomic reprogramming in monocytes of severe COVID-19 patients reflects alterations in myeloid differentiation and the influence of inflammatory cytokines

COVID-19 manifests with a wide spectrum of clinical phenotypes, ranging from asymptomatic and mild to severe and critical. Severe and critical COVID-19 patients are characterized by marked changes in the myeloid compartment, especially monocytes. However, little is known about the epigenetic alterations that occur in these cells during hyperinflammatory responses in severe COVID-19 patients. In this study, we obtained the DNA methylome and transcriptome of peripheral blood monocytes from severe COVID-19 patients. DNA samples extracted from CD14+CD15-monocytes of 48 severe COVID-19 patients and 11 healthy controls were hybridized on MethylationEPIC BeadChip arrays. In parallel, single-cell transcriptomics of 10 severe COVID-19 patients were generated. CellPhoneDB was used to infer changes in the crosstalk between monocytes and other immune cell types. We observed DNA methylation changes in CpG sites associated with interferon-related genes and genes associated with antigen presentation, concordant with gene expression changes. These changes significantly overlapped with those occurring in bacterial sepsis, although specific DNA methylation alterations in genes specific to viral infection were also identified. We also found these alterations to comprise some of the DNA methylation changes occurring during myeloid differentiation and under the influence of inflammatory cytokines. A progression of DNA methylation alterations in relation to the Sequential Organ Failure Assessment (SOFA) score was found to be related to interferon-related genes and T-helper 1 cell cytokine production. CellPhoneDB analysis of the single-cell transcriptomes of other immune cell types suggested the existence of altered crosstalk between monocytes and other cell types like NK cells and regulatory T cells. Our findings show the occurrence of an epigenetic and transcriptional reprogramming of peripheral blood monocytes, which could be associated with the release of aberrant immature monocytes, increased systemic levels of pro-inflammatory cytokines, and changes in immune cell crosstalk in these patients.