Temporal changes in erythroid progenitors in critically ill patients: a prospective cohort study.

Not available.

Desmopressin for prevention of bleeding for thrombocytopenic, critically ill patients undergoing invasive procedures: A randomised, double-blind, placebo-controlled feasibility trial.

Thrombocytopenic patients have an increased risk of bleeding when undergoing invasive procedures. In a multicentre, phase II, blinded, randomised, controlled feasibility trial, critically ill patients with platelet count 100 × 109/L or less were randomised 1:1 to intravenous desmopressin (0.3 µg/kg) or placebo before an invasive procedure. Forty-three participants (18.8% of those eligible) were recruited, with 41 eligible for analysis. Post-procedure bleeding occurred in one of 22 (4.5%) in the placebo arm and zero of 19 in the desmopressin arm. Despite liberal inclusion criteria, there were significant feasibility challenges recruiting patients in the critical care setting prior to invasive procedures.

High-throughput mass spectrometry maps the sepsis plasma proteome and differences in patient response.

Sepsis, the dysregulated host response to infection causing life-threatening organ dysfunction, is a global health challenge requiring better understanding of pathophysiology and new therapeutic approaches. Here, we applied high-throughput tandem mass spectrometry to delineate the plasma proteome for sepsis and comparator groups (noninfected critical illness, postoperative inflammation, and healthy volunteers) involving 2612 samples (from 1611 patients) and 4553 liquid chromatography-mass spectrometry analyses acquired through a single batch of continuous measurements, with a throughput of 100 samples per day. We show how this scale of data can delineate proteins, pathways, and coexpression modules in sepsis and be integrated with paired leukocyte transcriptomic data (837 samples from n = 649 patients). We mapped the plasma proteomic landscape of the host response in sepsis, including changes over time, and identified features relating to etiology, clinical phenotypes (including organ failures), and severity. This work reveals subphenotypes informative for sepsis response state, disease processes, and outcome; identifies potential biomarkers; and advances opportunities for a precision medicine approach to sepsis.

eQTLs identify regulatory networks and drivers of variation in the individual response to sepsis.

Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated response to infection, for which disease heterogeneity is a major obstacle to developing targeted treatments. We have previously identified gene-expression-based patient subgroups (sepsis response signatures [SRS]) informative for outcome and underlying pathophysiology. Here, we aimed to investigate the role of genetic variation in determining the host transcriptomic response and to delineate regulatory networks underlying SRS. Using genotyping and RNA-sequencing data on 638 adult sepsis patients, we report 16,049 independent expression (eQTLs) and 32 co-expression module (modQTLs) quantitative trait loci in this disease context. We identified significant interactions between SRS and genotype for 1,578 SNP-gene pairs and combined transcription factor (TF) binding site information (SNP2TFBS) and predicted regulon activity (DoRothEA) to identify candidate upstream regulators. Overall, these approaches identified putative mechanistic links between host genetic variation, cell subtypes, and the individual transcriptomic response to infection.

Patient stratification using plasma cytokines and their regulators in sepsis: relationship to outcomes, treatment effect and leucocyte transcriptomic subphenotypes.

RATIONALE: Heterogeneity of the host response within sepsis, acute respiratory distress syndrome (ARDS) and more widely critical illness, limits discovery and targeting of immunomodulatory therapies. Clustering approaches using clinical and circulating biomarkers have defined hyper-inflammatory and hypo-inflammatory subphenotypes in ARDS associated with differential treatment response. It is unknown if similar subphenotypes exist in sepsis populations where leucocyte transcriptomic-defined subphenotypes have been reported. OBJECTIVES: We investigated whether inflammatory clusters based on cytokine protein abundance were seen in sepsis, and the relationships with previously described transcriptomic subphenotypes. METHODS: Hierarchical cluster and latent class analysis were applied to an observational study (UK Genomic Advances in Sepsis (GAinS)) (n=124 patients) and two clinical trial datasets (VANISH, n=155 and LeoPARDS, n=484) in which the plasma protein abundance of 65, 21, 11 circulating cytokines, cytokine receptors and regulators were quantified. Clinical features, outcomes, response to trial treatments and assignment to transcriptomic subphenotypes were compared between inflammatory clusters. MEASUREMENTS AND MAIN RESULTS: We identified two (UK GAinS, VANISH) or three (LeoPARDS) inflammatory clusters. A group with high levels of pro-inflammatory and anti-inflammatory cytokines was seen that was associated with worse organ dysfunction and survival. No interaction between inflammatory clusters and trial treatment response was found. We found variable overlap of inflammatory clusters and leucocyte transcriptomic subphenotypes. CONCLUSIONS: These findings demonstrate that differences in response at the level of cytokine biology show clustering related to severity, but not treatment response, and may provide complementary information to transcriptomic sepsis subphenotypes. TRIAL REGISTRATION NUMBER: ISRCTN20769191, ISRCTN12776039.

Neutrophils and emergency granulopoiesis drive immune suppression and an extreme response endotype during sepsis.

Sepsis arises from diverse and incompletely understood dysregulated host response processes following infection that leads to life-threatening organ dysfunction. Here we showed that neutrophils and emergency granulopoiesis drove a maladaptive response during sepsis. We generated a whole-blood single-cell multiomic atlas (272,993 cells, n = 39 individuals) of the sepsis immune response that identified populations of immunosuppressive mature and immature neutrophils. In co-culture, CD66b+ sepsis neutrophils inhibited proliferation and activation of CD4+ T cells. Single-cell multiomic mapping of circulating hematopoietic stem and progenitor cells (HSPCs) (29,366 cells, n = 27) indicated altered granulopoiesis in patients with sepsis. These features were enriched in a patient subset with poor outcome and a specific sepsis response signature that displayed higher frequencies of IL1R2+ immature neutrophils, epigenetic and transcriptomic signatures of emergency granulopoiesis in HSPCs and STAT3-mediated gene regulation across different infectious etiologies and syndromes. Our findings offer potential therapeutic targets and opportunities for stratified medicine in severe infection.

An immune dysfunction score for stratification of patients with acute infection based on whole-blood gene expression.

Dysregulated host responses to infection can lead to organ dysfunction and sepsis, causing millions of global deaths each year. To alleviate this burden, improved prognostication and biomarkers of response are urgently needed. We investigated the use of whole-blood transcriptomics for stratification of patients with severe infection by integrating data from 3149 samples from patients with sepsis due to community-acquired pneumonia or fecal peritonitis admitted to intensive care and healthy individuals into a gene expression reference map. We used this map to derive a quantitative sepsis response signature (SRSq) score reflective of immune dysfunction and predictive of clinical outcomes, which can be estimated using a 7- or 12-gene signature. Last, we built a machine learning framework, SepstratifieR, to deploy SRSq in adult and pediatric bacterial and viral sepsis, H1N1 influenza, and COVID-19, demonstrating clinically relevant stratification across diseases and revealing some of the physiological alterations linking immune dysregulation to mortality. Our method enables early identification of individuals with dysfunctional immune profiles, bringing us closer to precision medicine in infection.

Intravenous iron to treat anaemia following critical care: a multicentre feasibility randomised trial.

BACKGROUND: Anaemia is common and associated with poor outcomes in survivors of critical illness. However, the optimal treatment strategy is unclear. METHODS: We conducted a multicentre, feasibility RCT to compare either a single dose of ferric carboxymaltose 1000 mg i.v. or usual care in patients being discharged from the ICU with moderate or severe anaemia (haemoglobin ≤100 g L-1). We collected data on feasibility (recruitment, randomisation, follow-up), biological efficacy, and clinical outcomes. RESULTS: Ninety-eight participants were randomly allocated (49 in each arm). The overall recruitment rate was 34% with 6.5 participants recruited on average per month. Forty-seven of 49 (96%) participants received the intervention. Patient-reported outcome measures were available for 79/93 (85%) survivors at 90 days. Intravenous iron resulted in a higher mean (standard deviation [sd]) haemoglobin at 28 days (119.8 [13.3] vs 106.7 [14.9] g L-1) and 90 days (130.5 [15.1] vs 122.7 [17.3] g L-1), adjusted mean difference (10.98 g L-1; 95% confidence interval [CI], 4.96-17.01; P<0.001) over 90 days after randomisation. Infection rates were similar in both groups. Hospital readmissions at 90 days post-ICU discharge were lower in the i.v. iron group (7/40 vs 15/39; risk ratio=0.46; 95% CI, 0.21-0.99; P=0.037). The median (inter-quartile range) post-ICU hospital stay was shorter in the i.v. iron group but did not reach statistical significance (5.0 [3.0-13.0] vs 9.0 [5.0-16.0] days, P=0.15). CONCLUSION: A large, multicentre RCT of i.v. iron to treat anaemia in survivors of critical illness appears feasible and is necessary to determine the effects on patient-centred outcomes. CLINICAL TRIAL REGISTRATION: ISRCTN13721808 (www.isrctn.com).

Musculoskeletal complications following critical illness: A scoping review.

PURPOSE: To explore the extent to which musculoskeletal (MSK) complications have been reported following critical illness, identifying evidence gaps and providing recommendations for future research. MATERIALS AND METHODS: We searched five databases from January 1st 2000 to March 31st 2021. We included published original research reporting MSK complications in patients discharged from hospital following an admission to an intensive care unit (ICU). Two reviewers independently screened English language articles for eligibility. Data extracted included the MSK area of investigation and MSK outcome measures. The overall quality of study was evaluated against standardised reporting guidelines. RESULTS: 4512 titles were screened, and 32 met the inclusion criteria. Only one study included was interventional, with the majority being prospective cohort studies (n = 22). MSK complications identified included: muscle weakness or atrophy, chronic pain, neuromuscular dysfunction, peripheral joint impairment and fracture risk. The quality of the overall reporting in the studies was deemed adequate. CONCLUSIONS: We identified a heterogenous body of literature reporting a high prevalence of a variety of MSK complications extending beyond muscle weakness, therefore future investigation should include evaluations of more than one MSK area. Further investigation of MSK complications could inform the development of future post critical illness rehabilitation programs.