Transcriptome dynamics of CD4+ T cells during malaria maps gradual transit from effector to memory.

The dynamics of CD4+ T cell memory development remain to be examined at genome scale. In malaria-endemic regions, antimalarial chemoprevention protects long after its cessation and associates with effects on CD4+ T cells. We applied single-cell RNA sequencing and computational modelling to track memory development during Plasmodium infection and treatment. In the absence of central memory precursors, two trajectories developed as T helper 1 (TH1) and follicular helper T (TFH) transcriptomes contracted and partially coalesced over three weeks. Progeny of single clones populated TH1 and TFH trajectories, and fate-mapping suggested that there was minimal lineage plasticity. Relationships between TFH and central memory were revealed, with antimalarials modulating these responses and boosting TH1 recall. Finally, single-cell epigenomics confirmed that heterogeneity among effectors was partially reset in memory. Thus, the effector-to-memory transition in CD4+ T cells is gradual during malaria and is modulated by antiparasitic drugs. Graphical user interfaces are presented for examining gene-expression dynamics and gene-gene correlations ( http://haquelab.mdhs.unimelb.edu.au/cd4_memory/ ).

AKT/FOXO signaling enforces reversible differentiation blockade in myeloid leukemias.

AKT activation is associated with many malignancies, where AKT acts, in part, by inhibiting FOXO tumor suppressors. We show a converse role for AKT/FOXOs in acute myeloid leukemia (AML). Rather than decreased FOXO activity, we observed that FOXOs are active in ∼40% of AML patient samples regardless of genetic subtype. We also observe this activity in human MLL-AF9 leukemia allele-induced AML in mice, where either activation of Akt or compound deletion of FoxO1/3/4 reduced leukemic cell growth, with the latter markedly diminishing leukemia-initiating cell (LIC) function in vivo and improving animal survival. FOXO inhibition resulted in myeloid maturation and subsequent AML cell death. FOXO activation inversely correlated with JNK/c-JUN signaling, and leukemic cells resistant to FOXO inhibition responded to JNK inhibition. These data reveal a molecular role for AKT/FOXO and JNK/c-JUN in maintaining a differentiation blockade that can be targeted to inhibit leukemias with a range of genetic lesions.

Splicing factor YBX1 mediates persistence of JAK2-mutated neoplasms.

Janus kinases (JAKs) mediate responses to cytokines, hormones and growth factors in haematopoietic cells1,2. The JAK gene JAK2 is frequently mutated in the ageing haematopoietic system3,4 and in haematopoietic cancers5. JAK2 mutations constitutively activate downstream signalling and are drivers of myeloproliferative neoplasm (MPN). In clinical use, JAK inhibitors have mixed effects on the overall disease burden of JAK2-mutated clones6,7, prompting us to investigate the mechanism underlying disease persistence. Here, by in-depth phosphoproteome profiling, we identify proteins involved in mRNA processing as targets of mutant JAK2. We found that inactivation of YBX1, a post-translationally modified target of JAK2, sensitizes cells that persist despite treatment with JAK inhibitors to apoptosis and results in RNA mis-splicing, enrichment for retained introns and disruption of the transcriptional control of extracellular signal-regulated kinase (ERK) signalling. In combination with pharmacological JAK inhibition, YBX1 inactivation induces apoptosis in JAK2-dependent mouse and primary human cells, causing regression of the malignant clones in vivo, and inducing molecular remission. This identifies and validates a cell-intrinsic mechanism whereby differential protein phosphorylation causes splicing-dependent alterations of JAK2-ERK signalling and the maintenance of JAK2V617F malignant clones. Therapeutic targeting of YBX1-dependent ERK signalling in combination with JAK2 inhibition could thus eradicate cells harbouring mutations in JAK2.

Genome-wide transcription factor-binding maps reveal cell-specific changes in the regulatory architecture of human HSPCs.

Hematopoietic stem and progenitor cells (HSPCs) rely on a complex interplay among transcription factors (TFs) to regulate differentiation into mature blood cells. A heptad of TFs (FLI1, ERG, GATA2, RUNX1, TAL1, LYL1, LMO2) bind regulatory elements in bulk CD34+ HSPCs. However, whether specific heptad-TF combinations have distinct roles in regulating hematopoietic differentiation remains unknown. We mapped genome-wide chromatin contacts (HiC, H3K27ac, HiChIP), chromatin modifications (H3K4me3, H3K27ac, H3K27me3) and 10 TF binding profiles (heptad, PU.1, CTCF, STAG2) in HSPC subsets (stem/multipotent progenitors plus common myeloid, granulocyte macrophage, and megakaryocyte erythrocyte progenitors) and found TF occupancy and enhancer-promoter interactions varied significantly across cell types and were associated with cell-type-specific gene expression. Distinct regulatory elements were enriched with specific heptad-TF combinations, including stem-cell-specific elements with ERG, and myeloid- and erythroid-specific elements with combinations of FLI1, RUNX1, GATA2, TAL1, LYL1, and LMO2. Furthermore, heptad-occupied regions in HSPCs were subsequently bound by lineage-defining TFs, including PU.1 and GATA1, suggesting that heptad factors may prime regulatory elements for use in mature cell types. We also found that enhancers with cell-type-specific heptad occupancy shared a common grammar with respect to TF binding motifs, suggesting that combinatorial binding of TF complexes was at least partially regulated by features encoded in DNA sequence motifs. Taken together, this study comprehensively characterizes the gene regulatory landscape in rare subpopulations of human HSPCs. The accompanying data sets should serve as a valuable resource for understanding adult hematopoiesis and a framework for analyzing aberrant regulatory networks in leukemic cells.

PLCG1 is required for AML1-ETO leukemia stem cell self-renewal.

In an effort to identify novel drugs targeting fusion-oncogene-induced acute myeloid leukemia (AML), we performed high-resolution proteomic analysis. In AML1-ETO (AE)-driven AML, we uncovered a deregulation of phospholipase C (PLC) signaling. We identified PLCgamma 1 (PLCG1) as a specific target of the AE fusion protein that is induced after AE binding to intergenic regulatory DNA elements. Genetic inactivation of PLCG1 in murine and human AML inhibited AML1-ETO dependent self-renewal programs, leukemic proliferation, and leukemia maintenance in vivo. In contrast, PLCG1 was dispensable for normal hematopoietic stem and progenitor cell function. These findings are extended to and confirmed by pharmacologic perturbation of Ca++-signaling in AML1-ETO AML cells, indicating that the PLCG1 pathway poses an important therapeutic target for AML1-ETO+ leukemic stem cells.

A randomised double-blind placebo-controlled trial of minocycline and/or omega-3 fatty acids added to treatment as usual for at risk Mental States: The NAYAB study.

BACKGROUND: Inflammatory mechanisms are thought to contribute to the onset of psychosis in persons with an at-risk mental state (ARMS). We investigated whether the anti-inflammatory properties of minocycline and omega-3 polyunsaturated fatty acids (omega-3), alone or synergistically, would prevent transition to psychosis in ARMS in a randomised, double-blind, placebo-controlled trial in Pakistan. METHODS: 10,173 help-seeking individuals aged 16-35 years were screened using the Prodromal Questionaire-16. Individuals scoring 6 and over were interviewed using the Comprehensive Assessment of At-Risk Mental States (CAARMS) to confirm ARMS. Participants (n = 326) were randomised to minocycline, omega-3, combined minocycline and omega-3 or to double placebo for 6 months. The primary outcome was transition to psychosis at 12 months. FINDINGS: Forty-five (13.8 %) participants transitioned to psychosis. The risk of transition was greater in those randomised to omega-3 alone or in combination with minocycline (17.3.%), compared to 10.4 % in those not exposed to omega-3; a risk-ratio (RR) of 1.67, 95 % CI [0.95, 2.92] p = 0.07. The RR for transitions on minocycline vs. no minocycline was 0.86, 95 % CI [0.50, 1.49] p > 0.10. In participants who did not become psychotic, CAARMS and depression symptom scores were reduced at six and twelve months (mean CAARMS difference = 1.43; 95 % CI [0.33, 1.76] p < 0.01 in those exposed to omega-3. Minocycline did not affect CAARMS or depression scores. INTERPRETATION: In keeping with other studies, omega-3 appears to have beneficial effects on ARMS and mood symptom severity but it increased transition to psychosis, which may reflect metabolic or developmental consequences of chronic poor nutrition in the population. Transition to psychosis was too rare to reveal a preventative effect of minocycline but minocycline did not improve symptom severity. ARMS symptom severity and transition to psychosis appear to have distinct pathogeneses which are differentially modulated by omega-3 supplementation. FUNDING: The study was funded by the Stanley Research Medical Institute.

The use of breast milk iodine concentration in the first week of lactation as a biomarker of iodine status in breast-feeding women.

Breast milk iodine concentration (BMIC) is a promising indicator of iodine status in lactating women. However, there are limited data on its usefulness to reflect maternal iodine deficiency. Therefore, the aim of our study was to assess iodine concentration in breast milk and urine samples in exclusively breast-feeding women. Eligible pregnant women undergoing routine antenatal care in a large hospital in Shaanxi Province, China, were followed up from the third trimester of pregnancy until the first week of lactation. Urine samples (20 ml) were collected during pregnancy and lactation. Iodine concentration in samples was measured based on Sandell-Kolthoff reaction. Breast milk samples (5 ml) were provided during lactation. A receiver operating curve (ROC) was constructed to determine the diagnostic performance of BMIC. An iodine-specific FFQ was completed twice during pregnancy and lactation. A total of 200 women completed the study. The overall median BMIC was 89 µg/l, indicating iodine sufficiency (i.e. BMIC reference range between 60 and 465 µg/l). Women reported similar median urinary iodine concentration (UIC) during pregnancy and lactation (112 and 113 µg/l, respectively), but their iodine status differed - mild-to-moderate iodine deficiency during pregnancy and iodine sufficiency during lactation. The ROC for BMIC using UIC as a reference standard was 0·755 (95 % CI: 0·644, 0·866). In conclusion, this study demonstrated that women were iodine sufficient in the first week of lactation as assessed by UIC, which was consistent with BMIC. These findings suggested that BMIC is a useful biomarker to assess iodine status in lactating women.

Australia and New Zealand consensus position statement: use of COVID-19 therapeutics in patients with haematological malignancies.

Despite widespread vaccination rates, we are living with high transmission rates of SARS-CoV-2. Although overall hospitalisation rates are falling, the risk of serious infection remains high for patients who are immunocompromised because of haematological malignancies. In light of the ongoing pandemic and the development of multiple agents for treatment, representatives from the Haematology Society of Australia and New Zealand and infectious diseases specialists have collaborated on this consensus position statement regarding COVID-19 management in patients with haematological disorders. It is our recommendation that both patients with haematological malignancies and treating specialists be educated regarding the preventive and treatment options available and that patients continue to receive adequate vaccinations, keeping in mind the suboptimal vaccine responses that occur in haematology patients, in particular, those with B-cell malignancies and on B-cell-targeting or depleting therapy. Patients with haematological malignancies should receive treatment for COVID-19 in accordance with the severity of their symptoms, but even mild infections should prompt early treatment with antiviral agents. The issue of de-isolation following COVID-19 infection and optimal time to treatment for haematological malignancies is discussed but remains an area with evolving data. This position statement is to be used in conjunction with advice from infectious disease, respiratory and intensive care specialists, and current guidelines from the National COVID-19 Clinical Evidence Taskforce and the New Zealand Ministry of Health and Cancer Agency Te Aho o Te Kahu COVID-19 Guidelines.

Immunoproteasome function maintains oncogenic gene expression in KMT2A-complex driven leukemia.

Pharmacologic targeting of chromatin-associated protein complexes has shown significant responses in KMT2A-rearranged (KMT2A-r) acute myeloid leukemia (AML) but resistance frequently develops to single agents. This points to a need for therapeutic combinations that target multiple mechanisms. To enhance our understanding of functional dependencies in KMT2A-r AML, we have used a proteomic approach to identify the catalytic immunoproteasome subunit PSMB8 as a specific vulnerability. Genetic and pharmacologic inactivation of PSMB8 results in impaired proliferation of murine and human leukemic cells while normal hematopoietic cells remain unaffected. Disruption of immunoproteasome function drives an increase in transcription factor BASP1 which in turn represses KMT2A-fusion protein target genes. Pharmacologic targeting of PSMB8 improves efficacy of Menin-inhibitors, synergistically reduces leukemia in human xenografts and shows preserved activity against Menin-inhibitor resistance mutations. This identifies and validates a cell-intrinsic mechanism whereby selective disruption of proteostasis results in altered transcription factor abundance and repression of oncogene-specific transcriptional networks. These data demonstrate that the immunoproteasome is a relevant therapeutic target in AML and that targeting the immunoproteasome in combination with Menin-inhibition could be a novel approach for treatment of KMT2A-r AML.

IFN-λ therapy prevents severe gastrointestinal graft-versus-host disease.

Immunopathology and intestinal stem cell (ISC) loss in the gastrointestinal (GI) tract is the prima facie manifestation of graft-versus-host disease (GVHD) and is responsible for significant mortality after allogeneic bone marrow transplantation (BMT). Approaches to prevent GVHD to date focus on immune suppression. Here, we identify interferon-λ (IFN-λ; interleukin-28 [IL-28]/IL-29) as a key protector of GI GVHD immunopathology, notably within the ISC compartment. Ifnlr1-/- mice displayed exaggerated GI GVHD and mortality independent of Paneth cells and alterations to the microbiome. Ifnlr1-/- intestinal organoid growth was significantly impaired, and targeted Ifnlr1 deficiency exhibited effects intrinsic to recipient Lgr5+ ISCs and natural killer cells. PEGylated recombinant IL-29 (PEG-rIL-29) treatment of naive mice enhanced Lgr5+ ISC numbers and organoid growth independent of both IL-22 and type I IFN and modulated proliferative and apoptosis gene sets in Lgr5+ ISCs. PEG-rIL-29 treatment improved survival, reduced GVHD severity, and enhanced epithelial proliferation and ISC-derived organoid growth after BMT. The preservation of ISC numbers in response to PEG-rIL-29 after BMT occurred both in the presence and absence of IFN-λ-signaling in recipient natural killer cells. IFN-λ is therefore an attractive and rapidly testable approach to prevent ISC loss and immunopathology during GVHD.

Real-world experience with caplacizumab in the management of acute TTP.

The cornerstone of life-saving therapy in immune-mediated thrombotic thrombocytopenic purpura (iTTP) has been plasma exchange (PEX) combined with immunomodulatory strategies. Caplacizumab, a novel anti-von Willebrand factor nanobody trialed in 2 multicenter randomized controlled trials (RCTs) leading to European Union and US Food and Drug Administration approval, has been available in the United Kingdom (UK) through a patient access scheme. Data were collected retrospectively from 2018 to 2020 for 85 patients (4 children) receiving caplacizumab from 22 UK hospitals. Patient characteristics and outcomes in the real-world clinical setting were compared with caplacizumab trial end points and historical outcomes in the precaplacizumab era. Eighty-four of 85 patients received steroid and rituximab alongside PEX; 26% required intubation. Median time to platelet count normalization (3 days), duration of PEX (7 days), and hospital stay (12 days) were comparable with RCT data. Median duration of PEX and time from PEX initiation to platelet count normalization were favorable compared with historical outcomes (P < .05). Thrombotic thrombocytopenic purpura (TTP) recurred in 5 of 85 patients; all had persistent ADAMTS13 activity < 5 IU/dL. Of 31 adverse events in 26 patients, 17 of 31 (55%) were bleeding episodes, and 5 of 31 (16%) were thrombotic events (2 unrelated to caplacizumab); mortality was 6% (5/85), with no deaths attributed to caplacizumab. In 4 of 5 deaths, caplacizumab was introduced >48 hours after PEX initiation (3-21 days). This real-world evidence represents the first and largest series of TTP patients, including pediatric patients, receiving caplacizumab outside of clinical trials. Representative of true clinical practice, the findings provide valuable information for clinicians treating TTP globally.

Intact TP-53 function is essential for sustaining durable responses to BH3-mimetic drugs in leukemias.

Selective targeting of BCL-2 with the BH3-mimetic venetoclax has been a transformative treatment for patients with various leukemias. TP-53 controls apoptosis upstream of where BCL-2 and its prosurvival relatives, such as MCL-1, act. Therefore, targeting these prosurvival proteins could trigger apoptosis across diverse blood cancers, irrespective of TP53 mutation status. Indeed, targeting BCL-2 has produced clinically relevant responses in blood cancers with aberrant TP-53. However, in our study, TP53-mutated or -deficient myeloid and lymphoid leukemias outcompeted isogenic controls with intact TP-53, unless sufficient concentrations of BH3-mimetics targeting BCL-2 or MCL-1 were applied. Strikingly, tumor cells with TP-53 dysfunction escaped and thrived over time if inhibition of BCL-2 or MCL-1 was sublethal, in part because of an increased threshold for BAX/BAK activation in these cells. Our study revealed the key role of TP-53 in shaping long-term responses to BH3-mimetic drugs and reconciled the disparate pattern of initial clinical response to venetoclax, followed by subsequent treatment failure among patients with TP53-mutant chronic lymphocytic leukemia or acute myeloid leukemia. In contrast to BH3-mimetics targeting just BCL-2 or MCL-1 at doses that are individually sublethal, a combined BH3-mimetic approach targeting both prosurvival proteins enhanced lethality and durably suppressed the leukemia burden, regardless of TP53 mutation status. Our findings highlight the importance of using sufficiently lethal treatment strategies to maximize outcomes of patients with TP53-mutant disease. In addition, our findings caution against use of sublethal BH3-mimetic drug regimens that may enhance the risk of disease progression driven by emergent TP53-mutant clones.

Follow up of women after obstetric anal sphincter injuries (OASI)-What is the role of anorectal testing?

AIMS: To evaluate the benefit of performing anorectal studies on all women following primary obstetric anal sphincter injury (OASI) repair over performing them on symptomatic women only. METHODS: Women who attended perineal clinic between 2007 and 2020 underwent symptom assessment and anorectal studies at 6 weeks and 6 months postpartum. Anorectal studies including endo anal ultrasound (EAUS) and anal manometry (AM) were performed. The anorectal studies of symptomatic women who were the case group, were compared with asymptomatic women who were the control group. RESULTS: A total of 1348 women were seen in the perineal clinic over 13 years. A total of 454 (33.7%) women were symptomatic. A total of 894 (66.3%) women were asymptomatic. A total of 313 (35%) asymptomatic women had two abnormal anorectal studies, 274 (31%) had abnormal AM alone, and 86 (9.6%) had abnormal EAUS alone. A total of 221 (24.7%) asymptomatic women had normal anorectal studies. CONCLUSION: Almost 70% of women were asymptomatic 6 months following primary OASI repair. Most had at least one abnormal anorectal study result. Selectively performing anorectal tests on symptomatic women would not identify asymptomatic women at risk of future faecal incontinence following further vaginal birth. Without anorectal study results, women would not receive accurate counseling about the risks of vaginal birth. Anorectal studies should be offered to all women following OASI where resources allow.

The role of anal manometry in the follow-up of women with obstetric anal sphincter injuries (OASI).

INTRODUCTION AND HYPOTHESIS: Mode of birth (MOB) following OASI is determined by choice, symptoms and anorectal study results in asymptomatic women. Endoanal ultrasound (EAUS) is the gold-standard imaging modality. EAUS use in MOB counselling is supported by strong evidence. Less is understood about how anal manometry (AM) influences MOB counselling. METHODS: A retrospective observational study was conducted from 2007 to 2020. Women underwent symptom assessment using validated ePAQ and St Mark's incontinence score (SMIS). Anorectal studies using EAUS and AM were performed. The case group was the normal ultrasound group and the control group was the abnormal ultrasound group. Both groups were compared with normal and abnormal AM result groups. RESULTS: A total of 1348 women were included over 13 years. Among these, 454 women were symptomatic, 894 were asymptomatic; 274 (31%) asymptomatic women had isolated abnormal AM results, 313 (35%) had two abnormal anorectal results and 221 (24.7%) had normal anorectal results. Eighty-six asymptomatic women (10.4%) had isolated abnormal EAUS results, 138 (30.4%) symptomatic women had isolated abnormal AM, 221 (48.7%) had two abnormal anorectal results and 57 (12.6%) had normal anorectal results. Thirty-eight symptomatic women (8.4%) had an isolated abnormal EAUS result. CONCLUSIONS: AM identifies more women with sphincter function impairment than EAUS alone. Without AM, almost one third of asymptomatic women would not have been identified and could have been inadequately counselled. Performing AM and EAUS together captured most women with compromised anal sphincter function. We conclude that AM should be performed in all women with OASI alongside EAUS to enable accurate MOB counselling.

Optimizing DNA hypomethylating therapy in acute myeloid leukemia and myelodysplastic syndromes.

The DNA hypomethylating agents (HMA) azacitidine (AZA) and decitabine (DAC) improve survival and transfusion independence in myelodysplastic syndrome (MDS) and enable a low intensity cytotoxic treatment for aged AML patients unsuitable for intensive chemotherapy, particularly in combination with novel agents. The proposed mechanism of AZA and DAC relies on active DNA replication and therefore patient responses are only observed after multiple cycles of treatment. Although extended dosing may provide the optimal scheduling, the reliance of injectable formulation of the drug limits it to intermittent treatment. Recently, an oral formulation of AZA demonstrated significantly improved patient relapse free survival (RFS) and overall survival (OS) when used as maintenance after chemotherapy for AML. In addition, both DAC and AZA were found to be highly effective to improve survival in elderly patients with AML through combination with other drugs. These recent exciting results have changed the therapeutic paradigm for elderly patients with AML. In light of this, we review current knowledge on HMA mechanism of action, clinical trials exploring dosing and scheduling, and recent HMA combination therapies to enhance efficacy.

Using technology to reduce critical deterioration (the DETECT study): a cost analysis of care costs at a tertiary children's hospital in the United Kingdom.

BACKGROUND: Electronic early warning systems have been used in adults for many years to prevent critical deterioration events (CDEs). However, implementation of similar technologies for monitoring children across the entire hospital poses additional challenges. While the concept of such technologies is promising, their cost-effectiveness is not established for use in children. In this study we investigate the potential for direct cost savings arising from the implementation of the DETECT surveillance system. METHODS: Data were collected at a tertiary children's hospital in the United Kingdom. We rely on the comparison between patients in the baseline period (March 2018 to February 2019) and patients in the post-intervention period (March 2020 to July 2021). These provided a matched cohort of 19,562 hospital admissions for each group. From these admissions, 324 and 286 CDEs were observed in the baseline and post-intervention period, respectively. Hospital reported costs and Health Related Group (HRG) National Costs were used to estimate overall expenditure associated with CDEs for both groups of patients. RESULTS: Comparing post-intervention with baseline data we found a reduction in the total number of critical care days, driven by an overall reduction in the number of CDEs, however without statistical significance. Using hospital reported costs adjusted for the Covid-19 impact, we estimate a non-significant reduction of total expenditure from £16.0 million to £14.3 million (corresponding to £1.7 million of savings - 11%). Additionally, using HRG average costs, we estimated a non-significant reduction of total expenditure from £8.2 million to £ 7.2 million (corresponding to £1.1 million of savings - 13%). DISCUSSION AND CONCLUSION: Unplanned critical care admissions for children not only impose a substantial burden on patients and families but are also costly for hospitals. Interventions aimed at reducing emergency critical care admissions can be crucial to contribute to the reduction of these episodes' costs. Even though cost reductions were identified in our sample, our results do not support the hypothesis that reducing CDEs using technology leads to a significant reduction on hospital costs. TRIAL REGISTRATION: Current Controlled Trials ISRCTN61279068, date of registration 07/06/2019, retrospectively registered.

Reduction of NETosis by targeting CXCR1/2 reduces thrombosis, lung injury, and mortality in experimental human and murine sepsis.

BACKGROUND: Neutrophil extracellular traps (NETs) facilitate bacterial clearance but also promote thrombosis and organ injury in sepsis. We quantified ex vivo NET induction in septic humans and murine models of sepsis to identify signalling pathways that may be modulated to improve outcome in human sepsis. METHODS: NET formation in human donor neutrophils was quantified after incubation with plasma obtained from patients with sepsis or systemic inflammation (double-blinded assessment of extracellular DNA using immunofluorescence microscopy). NET formation (% neutrophils forming NETs) was correlated with plasma cytokine levels (MultiPlex assay). Experimental sepsis (caecal ligation and puncture or intraperitoneal injection of Escherichia coli) was assessed in C57/BL6 male mice. The effect of pharmacological inhibition of CXCR1/2 signalling (reparixin) on NET formation, organ injury (hepatic, renal, and cardiac biomarkers), and survival in septic mice was examined. RESULTS: NET formation was higher after incubation with plasma from septic patients (median NETs=25% [10.5-46.5%]), compared with plasma obtained from patients with systemic inflammation (14% [4.0-23.3%]; P=0.02). Similar results were observed after incubation of plasma from mice with neutrophils from septic non-septic mice. Circulating CXCR1/2 ligands correlated with NETosis in patients (interleukin-8; r=0.643) and mice (macrophage inflammatory protein-2; r=0.902). In experimental sepsis, NETs were primarily observed in the lungs, correlating with fibrin deposition (r=0.702) and lung injury (r=0.692). Inhibition of CXCR1/2 using reparixin in septic mice reduced NET formation, multi-organ injury, and mortality, without impairing bacterial clearance. CONCLUSION: CXCR1/2 signalling-induced NET formation is a therapeutic target in sepsis, which may be guided by ex vivo NET assays.

Health professionals' initial experiences and perceptions of the acceptability of a whole-hospital, pro-active electronic paediatric early warning system (the DETECT study): a qualitative interview study.

BACKGROUND: Paediatric early warning systems (PEWS) alert health professionals to signs of a child's deterioration with the intention of triggering an urgent review and escalating care. They can reduce unplanned critical care transfer, cardiac arrest, and death. Electronic systems may be superior to paper-based systems. The objective of the study was to critically explore the initial experiences and perceptions of health professionals about the acceptability of DETECT e-PEWS, and what factors influence its acceptability. METHODS: A descriptive qualitative study (part of The DETECT study) was undertaken February 2020-2021. Single, semi-structured telephone interviews were used. The setting was a tertiary children's hospital, UK. The participants were health professionals working in study setting and using DETECT e-PEWS. Sampling was undertaken using a mix of convenience and snowballing techniques. Participants represented two user-groups: 'documenting vital signs' (D-VS) and 'responding to vital signs' (R-VS). Perceptions of clinical utility and acceptability of DETECT e-PEWS were derived from thematic analysis of transcripts. RESULTS: Fourteen HPs (12 nurses, 2 doctors) participated; seven in D-VS and seven in the R-VS group. Three main themes were identified: complying with DETECT e-PEWS, circumventing DETECT e-PEWS, and disregarding DETECT e-PEWS. Overall clinical utility and acceptability were deemed good for HPs in the D-VS group but there was diversity in perception in the R-VS group (nurses found it more acceptable than doctors). Compliance was better in the D-VS group where use of DETECT e-PEWS was mandated and used more consistently. Some health professionals circumvented DETECT e-PEWS and fell back into old habits. Doctors (R-VS) did not consistently engage with DETECT e-PEWS, which reduced the acceptability of the system, even in those who thought the system brought benefits. CONCLUSIONS: Speed and accuracy of real-time data, automation of triggering alerts and improved situational awareness were key factors that contributed to the acceptability of DETECT e-PEWS. Mandating use of both recording and responding aspects of DETECT e-PEWS is needed to ensure full implementation.

Cardiac pathology and outcomes vary between Kawasaki disease and PIMS-TS.

Overlapping clinical features promoted the discussion of whether Kawasaki disease (KD) and PIMS-TS share pathophysiological features and disease outcomes. Medical records from English patients with KD (2015-02/20, N = 27) and PIMS-TS (02/2020-21, N = 34) were accessed to extract information. Children with PIMS-TS were older and more frequently of minority ethnicity background. They patients more commonly exhibited cytopenias and hyperferritinemia, which associated with diffuse cardiac involvement and functional impairment. In some PIMS-TS cases, cardiac pathology developed late, but outcomes were more favorable. In both, KD and PIMS-TS, baseline coronary diameter was a predictor of outcomes. PIMS-TS treatment more frequently included respiratory and cardiovascular support, and corticosteroids with IVIG. Cardiac involvement in PIMS-TS may be the result of a cytokine storm. Though more severe and diffuse when compared to KD, cardiac involvement of PIMS-TS has a more favorable prognosis, which may, after recovery, mitigate the need for long-term follow up.

Limited sensitivity and specificity of the ACR/EULAR-2019 classification criteria for SLE in JSLE?-observations from the UK JSLE Cohort Study.

OBJECTIVES: This study aimed to test the performance of the new ACR and EULAR criteria, that include ANA positivity as entry criterion, in JSLE. METHODS: Performance of the ACR/EULAR-2019 criteria were compared with Systemic Lupus International Collaborating Clinics (SLICC-2012), using data from children and young people (CYP) in the UK JSLE Cohort Study (n = 482), with the ACR-1997 criteria used as reference standard. An unselected cohort of CYP positive for ANA (n = 129) was used to calculate positive/negative predictive values of the criteria. RESULTS: At both first and last visits, the number of patients fulfilling the different classification criteria varied significantly (P < 0.001). The sensitivity of the SLICC-2012 criteria was higher when compared with that of the ACR/EULAR-2019 criteria at first and last visits (98% vs 94% for first visit, and 98% vs 96% for last visit; P < 0.001), when all available CYP were considered. The ACR/EULAR-2019 criteria were more specific when compared with the SLICC-2012 criteria (77% vs 67% for first visit, and 81% vs 71% for last visit; P < 0.001). Significant differences between the classification criteria were mainly caused by the variation in ANA positivity across ages. In the unselected cohort of ANA-positive CYP, the ACR/EULAR-2019 criteria produced the highest false-positive classification (6/129, 5%). CONCLUSION: In CYP, the ACR/EULAR-2019 criteria are not superior to those of the SLICC-2012 or ACR-1997 criteria. If classification criteria are designed to include CYP and adult populations, paediatric rheumatologists should be included in the consensus and evaluation process, as seemingly minor changes can significantly affect outcomes.