Neutrophil activation in patients treated with endovascular therapy is associated with unfavorable outcomes and mitigated by intravenous thrombolysis.

BACKGROUND: Accumulating evidence indicates that neutrophil activation (NA) contributes to microvascular thromboinflammation in acute ischemic stroke (AIS) due to a large vessel occlusion. Preclinical data have suggested that intravenous thrombolysis (IVT) before endovascular therapy (EVT) could dampen microvascular thromboinflammation. In this study we investigated the association between NA dynamics and stroke outcome, and the impact of IVT on NA in patients with AIS treated with EVT. METHODS: A single-center prospective study was carried out, including patients treated with EVT for whom three blood samples (before, within 1 hour, 24 hours post-EVT) were drawn to measure plasma myeloperoxidase (MPO) concentration as a marker of NA. Unfavorable outcome was defined as a modified Rankin score of 3-6 at 3 months. RESULTS: Between 2016 and 2020, 179 patients were included. The plasma MPO concentration peaked significantly 1 hour post-EVT (median increase 21.0 ng/mL (IQR -2.1-150)) and returned to pre-EVT baseline values 24 hours after EVT (median change from baseline -0.8 ng/mL (IQR -7.6-6.7)). This peak was strongly associated with unfavorable outcomes at 3 months (aOR 0.53 (95% CI 0.34 to 0.84), P=0.007). IVT before EVT abolished this 1 hour post-EVT MPO peak. Changes in plasma MPO concentration (baseline to 1 hour post-EVT) were associated with unfavorable outcomes only in patients not treated with IVT before EVT (aOR 0.54 (95% CI 0.33 to 0.88, P=0.013). However, we found no significant heterogeneity in the associations between changes in plasma MPO concentration and outcomes. CONCLUSIONS: A peak in plasma MPO concentration occurs early after EVT and is associated with unfavorable outcomes. IVT abolished the post-EVT MPO peak and may modulate the association between NA and outcomes.

Deficiency of the minor spliceosome component U4atac snRNA secondarily results in ciliary defects in human and zebrafish.

In the human genome, about 750 genes contain one intron excised by the minor spliceosome. This spliceosome comprises its own set of snRNAs, among which U4atac. Its noncoding gene, RNU4ATAC, has been found mutated in Taybi-Linder (TALS/microcephalic osteodysplastic primordial dwarfism type 1), Roifman (RFMN), and Lowry-Wood (LWS) syndromes. These rare developmental disorders, whose physiopathological mechanisms remain unsolved, associate ante- and post-natal growth retardation, microcephaly, skeletal dysplasia, intellectual disability, retinal dystrophy, and immunodeficiency. Here, we report bi-allelic RNU4ATAC mutations in five patients presenting with traits suggestive of the Joubert syndrome (JBTS), a well-characterized ciliopathy. These patients also present with traits typical of TALS/RFMN/LWS, thus widening the clinical spectrum of RNU4ATAC-associated disorders and indicating ciliary dysfunction as a mechanism downstream of minor splicing defects. Intriguingly, all five patients carry the n.16G>A mutation, in the Stem II domain, either at the homozygous or compound heterozygous state. A gene ontology term enrichment analysis on minor intron-containing genes reveals that the cilium assembly process is over-represented, with no less than 86 cilium-related genes containing at least one minor intron, among which there are 23 ciliopathy-related genes. The link between RNU4ATAC mutations and ciliopathy traits is supported by alterations of primary cilium function in TALS and JBTS-like patient fibroblasts, as well as by u4atac zebrafish model, which exhibits ciliopathy-related phenotypes and ciliary defects. These phenotypes could be rescued by WT but not by pathogenic variants-carrying human U4atac. Altogether, our data indicate that alteration of cilium biogenesis is part of the physiopathological mechanisms of TALS/RFMN/LWS, secondarily to defects of minor intron splicing.

Cerebrovascular complications and outcomes of critically ill adult patients with infective endocarditis.

BACKGROUND: Neurological complications are associated with poor outcome in patients with infective endocarditis (IE). Although guidelines recommend systematic brain imaging in the evaluation of IE patients, the association between early brain imaging findings and outcomes has never been evaluated in critically ill patients. We aimed to assess the association of CT-defined neurological complications with functional outcomes of critically ill IE patients. METHODS: This retrospective cohort study included consecutive patients with severe, left-sided IE hospitalized in the medical ICU of a tertiary care hospital. Patients with no baseline brain CT were excluded. Baseline CT-scans were classified in five mutually exclusive categories (normal, moderate-to-severe ischemic stroke, minor ischemic stroke, intracranial hemorrhage, other abnormal CT). The primary endpoint was 1-year favorable outcome, defined by a modified Rankin Scale score of 0-3. RESULTS: Between 06/01/2011 and 07/31/2018, 156 patients were included. Among them, 87/156 (56%) had a CT-defined neurological complication, including moderate-to-severe ischemic stroke (n = 33/156, 21%), intracranial hemorrhage (n = 24/156, 15%), minor ischemic stroke (n = 29/156, 19%), other (n = 3/156, 2%). At one year, 69 (45%) patients had a favorable outcome. Factors negatively associated with favorable outcome in multivariable analysis were moderate-to-severe ischemic stroke (OR 0.37, 95%CI 0.14 - 0.95) and age (OR 0.94, 95%CI 0.91-0.97). By contrast, the score on the Glasgow Coma Scale was positively associated with favorable outcome (per 1-point increment, OR 1.23, 95%CI 1.08-1.42). Sensitivity analyses conducted in operated patients revealed similar findings. Compared to normal CT, only moderate-to-severe ischemic stroke was associated with more frequent post-operative neurological complications (n = 8/23 (35%) vs n = 1/46 (2%), p < 0.01). CONCLUSION: Moderate-to-severe ischemic stroke had an independent negative impact on 1-year functional outcome in critically ill IE patients; whereas other complications, including intracranial hemorrhage, had no such impact.