Background-Treatment with bone-marrow-derived mesenchymal stromal cells (MSCs) has shown benefits in preclinical models of acute respiratory distress syndrome (ARDS). Safety has not been established for administration of MSCs in critically ill patients with ARDS. We did a phase 2a trial to assess safety after administration of MSCs to patients with moderate to severe ARDS.Methods-We did a prospective, double-blind, multicentre, randomised trial to assess treatment with one intravenous dose of MSCs compared with placebo. We recruited ventilated patients with

The simultaneous measurement of multiple modalities, known as multimodal analysis, represents an exciting frontier for single-cell genomics and necessitates new computational methods that can define cellular states based on multiple data types. Here, we introduce "weighted-nearest neighbor analysis", an unsupervised framework to learn the relative utility of each data type in each cell, enabling an integrative analysis of multiple modalities. We apply our procedure to a CITE-seq dataset of hundreds of thousands of human white blood cells alongside a panel of 228 antibodies to construct a multimodal reference atlas of the circulating immune system. We demonstrate that integrative analysis substantially improves our ability to resolve cell states and validate the presence of previously unreported lymphoid subpopulations. Moreover, we demonstrate how to leverage this reference to rapidly map new datasets, and to interpret immune responses to vaccination and COVID-19. Our approach represents a broadly applicable strategy to analyze single-cell multimodal datasets, including paired measurements of RNA and chromatin state, and to look beyond the transcriptome towards a unified and multimodal definition of cellular identity. Availability: Installation instructions, documentation, tutorials, and CITE-seq datasets are available at http://www.satijalab.org/seurat

The clinical utility of serum OPG and sRANKL measurements as markers of disease activity requires additional investigation. In particular, rigorous testing of assays and identification of the sources of measurement variability are required.

Osteoprotegerin (OPG) is a recently identified cytokine that acts as a decoy receptor for the receptor activator of NF kappa B ligand. OPG has been shown to be an important inhibitor of osteoclast differentiation and activation in rodent models. Estrogen is known to suppress bone resorption, and the action of estrogen on bone may be mediated by OPG. The relationship between endogenous estrogen and circulating OPG levels and bone status in human populations is unclear. Thus, the aim of this study was to investigate the relationship between biochemical markers of bone turnover and bone density and circulating OPG and endogenous estradiol levels in a population-based cohort of postmenopausal women. Subjects were 180 women ages 55-91 yr (mean age, 67 yr). Serum estradiol was measured using an auto-analyzer. Serum concentrations of OPG were determined by ELISA. Markers of bone formation and resorption were measured by standard methods. Bone mineral density at total body, total hip, femoral neck, and lumbar spine was measured by dual energy x-ray absorptiometry. There was a significant inverse relationship between estradiol and all bone turnover markers (r-values from -0.46 to -0.23; P < 0.05). Serum estradiol was positively related to absolute bone density at all sites and to change in bone density at the hip and femoral neck by univariate analysis (r-values from 0.15-0.29; P < 0.05). We observed a weak inverse association between OPG and serum-based bone turnover markers (r-values -0.18 and -0.16; P < 0.05). There was a significant positive relationship between OPG and bone mineral density at total body, total hip, and femoral neck (r-values from 0.17-0.2; P < 0.05) by univariate analysis, which was lost after adjustment for age and body mass index. There was a significant weak positive relationship between circulating OPG and serum estradiol (r = 0.18; P < 0.02). We observed no significant relationships between OPG and bone turnover markers measured in urine. We conclude that the variation in circulating endogenous estradiol levels is an important factor contributing to levels of bone turnover and bone density at the menopause. Our observations also suggest that circulating levels of OPG may reflect OPG activity in bone and are related to circulating endogenous levels of estradiol. We have previously reported high levels of variability in urine markers of bone resorption, and we suggest that this could account for the absence of a significant association between these markers and circulating OPG.

Our understanding of protective versus pathological immune responses to SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), is limited by inadequate profiling of patients at the extremes of the disease severity spectrum. Here, we performed multi-omic single-cell immune profiling of 64 COVID-19 patients across the full range of disease severity, from outpatients with mild disease to fatal cases. Our transcriptomic, epigenomic, and proteomic analyses revealed widespread dysfunction of peripheral innate immunity in severe and fatal COVID-19, including prominent hyperactivation signatures in neutrophils and NK cells. We also identified chromatin accessibility changes at NF-κB binding sites within cytokine gene loci as a potential mechanism for the striking lack of pro-inflammatory cytokine production observed in monocytes in severe and fatal COVID-19. We further demonstrated that emergency myelopoiesis is a prominent feature of fatal COVID-19. Collectively, our results reveal disease severity–associated immune phenotypes in COVID-19 and identify pathogenesis-associated pathways that are potential targets for therapeutic intervention.

No abstract

Our understanding of protective vs. pathologic immune responses to SARS-CoV-2, the virus that causes Coronavirus disease 2019 (COVID-19), is limited by inadequate profiling of patients at the extremes of the disease severity spectrum. Here, we performed multi-omic single-cell immune profiling of 64 COVID-19 patients across the full range of disease severity, from outpatients with mild disease to fatal cases. Our transcriptomic, epigenomic, and proteomic analyses reveal widespread dysfunction of peripheral innate immunity in severe and fatal COVID-19, with the most profound disturbances including a prominent neutrophil hyperactivation signature and monocytes with anti-inflammatory features. We further demonstrate that emergency myelopoiesis is a prominent feature of fatal COVID-19. Collectively, our results reveal disease severity-associated immune phenotypes in COVID-19 and identify pathogenesis-associated pathways that are potential targets for therapeutic intervention.One Sentence SummarySingle-cell profiling demonstrates multifarious dysregulation of innate immune phenotype associated with COVID-19 severity.

The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6 f 4.3 (mean f SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant ( n = 17) compared to those ( n = 32) with fixed femoral implants ( P < 0.05 all comparisons). This BMD difference was greatest (-3l'%, P = 0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N-telopeptides of type-I collagen ( P = 0.02) than those with a fixed femoral implant. N o diferences in pelvic BMD or bone turnover markers were found between subjects with loose ( n = 18) versus fixed (17 = 31) pelvic implants. This study suggests that failure of femoral components after cemented THA is associated with region-specific decreases in BMD and an increase in urinary excretion of N-telopeptide cross-links of type-I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological.