Citations

Abstract Background Immunotherapy has yet to make significant gains in glioblastoma (GBM) treatment, due in part to GBM-mediated immune suppression. Increasing evidence points to critical roles for tumor-derived extracellular vesicles (EVs) and immunosuppressive myeloid cells as key factors in this process. Methods Immunophenotyping of the tumor-immune microenvironment was performed using ultrasonic aspirate collected during GBM resection by high-dimensional flow cytometry. EVs collected from patient-derived GBM cell lines were used to condition myeloid cells collected from healthy donors to generate immunosuppressive myeloid cells. siRNA was used to knockdown TIGIT and/or NLRP3 expression prior to EV conditioning. T cell co-culture studies were performed with donor-matched T cells. Results Immune phenotyping of the tumor microenvironment and EV-conditioned myeloid cells revealed similar immunomodulatory protein expression across myeloid cell populations, with particularly elevated TIGIT expression. Knockdown of TIGIT reduced the immunosuppressive polarization of myeloid cells, resulting in improved T cell function. This finding proceeded in an NLRP3-dependent manner, with substantial co-expression of TIGIT and NLRP3 expression prior to knockdown, and concomitant knockdown of NLRP3 abrogating the effect of TIGIT knockdown. TIGIT expression correlated with increased IL-13 expression, and IL-13 blockade unmasked a pro-inflammatory myeloid cell phenotype. Conclusion TIGIT expression in myeloid cells in the GBM microenvironment is a functional marker of immunosuppressive activity, with TIGIT knockdown reducing IL-13 expression and unmasking the pro-inflammatory activity of NLRP3. This study bolsters our understanding of the immunosuppressive complexities of the GBM microenvironment and supports attenuation of immunosuppressive myeloid cell activity as a strategy to restore immune function in GBM.

Abstract: Urine drug testing (UDT) is an important laboratory tool utilized in various healthcare settings to identify drug or toxic exposures. It has wide clinical applications, including but not limited to detecting substance misuse, monitoring treatment effectiveness and compliance, and identifying substances in affected patients. Depending on the clinical care setting and patient population, the UDT service model and practice are important decisions by the clinical laboratory to meet the needs of the healthcare providers. In addition, clinical laboratories must appreciate the testing process and unique aspects of this toxicology test, from specimen collection and integrity, testing methods, to the result reporting and interpretation. Each phase has specific quality requirements to ensure the accuracy and appropriate interpretation of results. This review aims to summarize the preanalytical, analytical, and postanalytical considerations of clinical laboratories when implementing the test or providing support to clinicians in point-of-care settings. To bring awareness of the limitations inherent to different analytical methodologies, this review discusses important considerations and presents the current gaps, opportunities, and recommendations for quality improvement and standardization. This article may serve as a framework for clinical laboratory directors and other laboratory professionals to review their current provision of UDT and provide recommendations on various important aspects when considering changes to the test service models to meet their local clinical needs, including when introducing new test methods. It may also help physicians and healthcare providers appreciate the complexities of UDT and recognize the challenges in clinical interpretation.

Abstract Glioblastomas exhibit low immunogenicity and a highly immunosuppressive tumor microenvironment (TME) mediated by both tumor cells and tumor associated microglia/macrophages (TAMs). However, biomarkers that allow for specific detection, monitoring and therapy response assessment of the TAM phenotype in glioblastoma are still lacking. To address this gap, we characterized the dynamics of TAM clusters in the TME of experimental SB28 glioblastoma using single-cell RNA sequencing, immunofluorescence, and molecular imaging and identified Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) as a dynamic TAM-specific target. Consequently, we investigated a novel 64 Cu-labeled TREM2 radiotracer with a blood-brain barrier transport vehicle for translational mapping of TAMs in the TME of glioblastoma. We found strong and highly myeloid cell-specific PET signals that followed the trajectory of TREM2 gene expression from early- towards late-stage tumors. Transient myeloid cell depletion via CSF1R inhibition showed a reduction of TREM2 PET signals compared to placebo and prolonged survival in SB28 glioblastoma mice, while TREM2 stimulation led to increased TREM2 PET signals. Translation into a pilot cohort of patients with glioblastoma revealed strong TREM2 PET signals predominantly at lesion edges and high heterogeneity across individuals, matching with immunohistochemistry. In summary, TREM2 PET imaging has strong potential as an immune cell-specific biomarker for personalized assessment of the TAM phenotype in the TME of patients with glioblastoma.

Background and Objectives: Cervical artery dissection (CeAD) is a leading cause of ischemic stroke in younger adults, yet sex-specific variations in its clinical presentation, imaging characteristics, and outcomes remain underexplored. We aimed to evaluate these differences using data from a large, multicenter registry. Methods: We analyzed data from the STOP-CAD registry, which includes patients with radiologically confirmed non-traumatic CeAD enrolled between 2015 and 2021 across multiple centers. Clinical and imaging characteristics were compared between men and women using multivariable logistic regression. Outcomes assessed included ischemic stroke recurrence at 180 days, excellent functional outcome (modified Rankin Scale [mRS] 0–1) at 90 days, symptomatic intracerebral hemorrhage (sICH), and mortality. Results: Among 4,023 patients with CeAD, 1,783 (44.6%) were women. Compared to men, women were younger (median age: 42 vs 50 years), more likely to have a history of migraine (26.9% vs 8.3%) and connective tissue disorders (14.3% vs 5.8%), and presented more frequently with non-ischemic symptoms such as headache, neck pain, or tinnitus (adjusted OR [aOR] 2.0; 95% CI, 1.8–2.3; p<0.001). Women had significantly higher odds of vertebral artery dissection (OR, 1.3; 95% CI, 1.2-1.5; p<0.001), multivessel involvement (OR, 2.1; 95% CI, 1.7-2.5; p<0.001), and pseudoaneurysm formation (OR, 1.3; 95% CI, 1.1-1.6; p=0.003). Despite these differences, there was no significant sex-based difference in key clinical outcomes: excellent functional recovery at 90 days (OR 0.94; 95% CI 0.76-1.15 p=0.542), ischemic stroke recurrence at 180 days (OR 0.56 CI 0.23-1.3 p=0.213), or mortality (OR 0.83; 95% CI 0.47-1.48, p=0.529). Conclusion: In this large international cohort, we observed women with CeAD were younger, more likely to present with non-ischemic symptoms with distinct imaging features. These underscore the need for heightened clinical suspicion of CeAD in women presenting with atypical symptoms, even in the absence of ischemic deficits or conventional vascular risk factors, and suggest that sex-specific phenotyping may enhance diagnostic accuracy and early management.

Background: Patients with cervical artery dissection (CAD) have a higher prevalence of cerebral aneurysms, likely due to underlying vasculopathies. Understanding risk factors and outcomes in this population may inform screening and management strategies. Methods: We conducted a post-hoc analysis of the STOP-CAD study, a multicenter international registry of patients with non-major trauma-related CAD across 63 centers. Cerebral aneurysms were identified based on medical history and intracranial vascular imaging obtained for dissection diagnosis. We compared demographic, clinical, laboratory, and imaging characteristics between patients with and without aneurysms. Variables with p<0.05 in univariate analysis were entered into a multivariable binary logistic regression to identify independent predictors. Clinical outcomes including ischemic stroke and symptomatic intracranial hemorrhage at follow-up were compared between both groups. Results: Out of 4023 patients included in the STOP-CAD study, 116 (2.9%) had at least one incidental cerebral aneurysm. In adjusted binary logistic regression, patients with cerebral aneurysm were more likely to have a history of migraine (aOR 1.78 95% CI 1.15-2.75, p=0.009), history of hypertension (aOR 1.65 95% CI 1.12-2.43, p = 0.010), known connective tissue disorder (aOR 3.47 95% CI 1.71-7.03), history of dissection (aOR 2.63 95% CI 1.31-5.28, p = 0.007), and a dissecting aneurysm at the site of the dissection (aOR 1.94 95% CI 1.25-3.01, p = 0.003). At follow-up, the presence of a cerebral aneurysm was not associated with ischemic stroke (7.8% vs. 5.6% p>0.1), but with a trend towards increased odds of symptomatic intracranial hemorrhage (3.4% vs. 1.2%, p = 0.062). Conclusions: Patients with CAD and concurrent incidental cerebral aneurysm were more likely to have a history of migraine headaches and markers of underlying vasculopathy and had a non-significantly increased risk of intracranial hemorrhage at follow-up. Further studies are needed to identify best practices for surveillance and risk stratification in this subgroup.

Background: Cervical artery dissection (CeAD) accounts for nearly 25% of all ischemic strokes in young adults. CeAD can lead to the development of dissecting aneurysms (DA). However, the incidence, risk factors and outcomes of CeAD patients with DA is not well established. This study aims to identify risk factors for developing DA, subsequent growth, and impact on patient outcomes. Methods: This is a secondary analysis of the Antithrombotics for Stroke Prevention in Cervical Artery Dissection (STOP-CAD), a multicenter cross-sectional international retrospective study. CeAD patients were stratified for the presence of DA. We used multivariable regression to identify factors associated with DA. Patients with DA were further analyzed for DA growth. The primary outcome was ischemic stroke after CeAD+DA diagnosis. Secondary outcomes included ischemic stroke after CeAD+DA with DA growth. Multivariable logistic regression analysis was used to assess the association between DA and risk factors. We also performed univariate Cox regression and generated Kaplan-Meier survival curves comparing study outcomes based on presence of DA and subsequent growth. Results: Of the 4023 patients included in the STOP-CAD study, 4008 were included in this analysis and 767 (19%) patients had DA (546 with DA on initial presentation). Patients with DA had a mean age of 46 [IQR 37-55] years and 50% (383) were women. In combined adjusted analyses, DA patients were more often non-Hispanic (aOR 0.63, 95% CI 0.41-0.94, p<0.02), more commonly had a history of migraine (aOR 1.27, 95% CI 1.01-1.59, p=0.037), connective tissue disorder (aOR 2.02, 95% CI 1.22-3.36, p=0.007), minor neck trauma (aOR 1.70, 95% CI 1.29-2.26, p<0.001) and were more likely to present with ischemic stroke (aOR 1.73, 95% CI 1.05-2.87, p=0.031). DA growth was noted in 55 out of 546 (10%) patients with DA on presentation. There was no significant difference in the risk of ischemic stroke by day 180 in patients with DA (hazard ratio [HR] 0.92 [95% CI, 0.65-1.30]; P =0.63) or DA growth (HR 2.40, [95% CI, 0.79-7.24]; P =0.12). Conclusion: In this subanalysis of STOP-CAD, nearly one in five patients with CeAD developed a DA. Factors associated with a higher likelihood of DA included non-Hispanic ethnicity, history of migraine, connective tissue disorder, minor neck trauma, and ischemic stroke at presentation. DA diagnosis and DA growth did not impact the risk of subsequent ischemic stroke at 6 months.

Background: The clinical characteristics and complications associated with de novo pseudoaneurysm formation beyond the acute phase of cervical artery dissection remain poorly defined. In this study, we examined the incidence, risk factors, and related ischemic and hemorrhagic events of post-acute de novo pseudoaneurysm formation. Methods: We analyzed data from the STOP-CAD study (Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection). A de novo pseudoaneurysm was defined as a new (not present on initial imaging) focal enlargement in the diameter of the artery, greater than the native lumen. The incidence of de novo pseudoaneurysm was assessed at 90 days, 180 days, and beyond 180 days of follow-up. Univariate and multivariate regression analyses were conducted to identify risk factors for post-acute de novo pseudoaneurysm formation. Kaplan-Meier survival estimates were used to compare ischemic and hemorrhagic events between patients with and without de novo pseudoaneurysms. Results: Among 4008 patients, 546 were excluded as they had dissecting pseudoaneursyms on initial presentation. Therefore, 3,462 patients were included in this analysis of whom 220 patients (6.35%) developed a de novo pseudoaneurysm over a maximum follow-up of 4.4 years. Of these, 127 (57.72%) were detected within the first 90 days, and 172 (78.18%) within the first 180 days. In multivariate regression analyses, in addition to hypertension, active smoking and Hispanic ethnicity, fibromuscular dysplasia (FMD) was an independent risk factor for post-acute de novo pseudoaneurysm formation (adjusted OR: 2.160; 95% CI: 1.408–3.315; p < 0.001). Notably, the presence of a de novo pseudoaneurysm was not associated with a significant increase in ischemic (hazard ratio [HR] 1.43 [95% CI, 0.89–2.30]; P=0.14) or hemorrhagic events (hazard ratio [HR] 1.42 [95% CI, 0.43–4.69]; P=0.57). Conclusion: De novo pseudoaneurysm formation following a diagnosis of a cervical artery dissection is not uncommon and most frequently occurs within the first 180 days. FMD was independently associated with this complication. The development of a de novo pseudoaneurysm did not significantly increase the risk of subsequent ischemic or hemorrhagic events.

Background and Objectives: Pregnancy and the postpartum period increase the risk of cervical artery dissection (CEAD), a notable cause of stroke in young women. We aimed to describe the clinical presentation, imaging findings, and outcomes of CEAD occurring during pregnancy or shortly after delivery. Methods: We analyzed data from the STOP-CAD registry, a large international multicenter study of patients treated with antithrombotic therapy for non-traumatic CEAD between 2015 and 2021. This sub-study focused on women who were pregnant or within 12 weeks postpartum at the time of symptom onset. We assessed baseline clinical features, imaging results, acute stroke treatments, and functional outcomes. Results: Among 1,783 women in the registry, 62 (3.5%) had pregnancy-associated CEAD, with a median age of 34 years (IQR, 30-38). One-third had a history of migraine (33.9%), one-fifth had hypertension (21.0%), while other vascular risk factors were rare. Recent minor neck trauma was reported in 17.7%. Ischemic stroke symptoms occurred in 25 (40.3%) patients, and 23 (37.1%) had acute infarcts on imaging. However, most (59.7%) presented with non-ischemic symptoms. Vertebral artery dissections were more common than carotid dissections (62.9% vs. 48.4%), and 33.9% had multivessel involvement. Among patients presenting with ischemic stroke symptoms, 4 received thrombolysis and 7 underwent thrombectomy. Remarkably, 92% had excellent functional recovery (modified Rankin Score 0–1) at 90 days, and there were no stroke recurrences at 180 days. Conclusion: Pregnancy- and postpartum-associated CEAD is uncommon and associated with ischemic stroke in nearly half of patients. A history of migraine and hypertension may be potential risk factors. Despite the severity of presentation, most patients had favorable outcomes with timely treatment.

Background and Objectives: Cervical artery dissection (CeAD) is a common cause of ischemic stroke in young adults. We aim to identify age-based differences in clinical presentation, imaging findings, and outcomes after CeAD. Methods: This was a sub-study using the STOP-CAD registry, a multicenter cross-sectional international retrospective study of patients diagnosed with CeAD and treated with an antithrombotic from January 1, 2015 to December 31, 2021. Baseline clinical and imaging characteristics were compared between younger and older adults with CeAD (≤45 versus >45 years of age) using multivariable logistic regression. We chose this age cut off due to its frequent usage in stroke in the young literature. Multiple logistic regression models were used to determine association between young age and outcomes after CeAD (ischemic stroke at 180 days, excellent functional outcome with modified Rankin Scale of 0-1 at 90 days, and mortality) after adjusting for sex, vascular risk factors, CeAD characteristics, and NIHSS on presentation. Results: Among 4023 CeAD patients included in the study, 1901 (47.3%) were ≤45 years of age. Patients were followed for a median of 307 days (IQR 102-831). Young adults with CeAD were more likely to be women (Odds Ratio [OR], 2.4; 95% CI, 2.1-2.9; p<0.001), of Hispanic ethnicity (OR, 1.8; 95% CI 1.3-2.5; p<0.001), have a history of migraines (OR, 1.6; 95% CI, 1.3-2.0; p<0.001) and recent neck trauma (OR, 1.6; 95% CI, 1.3-1.9; p<0.001) while having fewer traditional vascular risk factors. Young adults with CeAD had higher odds of a non-ischemic presentation (OR, 1.3; 95% CI, 1.1-1.5; p=0.013), vertebral artery dissection (OR 2.5; 95% CI, 2.2-3.0; p<0.001), and multivessel involvement (OR 1.5; 95% CI, 1.1-1.9; p=0.004). In adjusted analysis, younger age was not associated with an increased risk of recurrent ischemic stroke (adjusted Hazard Ratio [HR], 0.48; 95% CI 0.2-1.2; p=0.119). Younger age was associated with significantly greater odds of excellent functional outcome at 90 days (aOR, 1.48; 1.20-1.84, p<0.001) and lower risk of death at follow up (aHR, 0.37; 95% CI, 0.17-0.81; p=0.012) after CeAD. Conclusion: In a large international cohort, young adults with CeAD had a distinct clinical phenotype with higher odds of non-ischemic presentation, vertebral artery dissection, and multivessel involvement while having fewer traditional vascular risk factors. Young adults had a decreased odds of disability and mortality after CeAD.

BACKGROUND: Cervical artery dissection (CeAD) may result in dissecting aneurysm (DA) formation. We aimed to characterize risk factors and clinical outcomes associated with DA in a large, international CeAD cohort. METHODS: We performed a secondary analysis of STOP-CAD (Antithrombotic Treatment for Stroke Prevention in Cervical Artery Dissection), an international, multicenter, retrospective cohort. Patients with spontaneous CeAD were assessed for DA at baseline and de novo DA formation. Significant covariates in univariable analysis were included in multivariable regression models aiming to identify factors associated with DA formation. Logistic regression and Cox proportional hazards models evaluated the association of DA with ischemic and hemorrhagic outcomes. RESULTS: Among 4008 patients with CeAD, 546 (13.6%) had a DA at baseline, and 221/2938 (7.5%) patients developed a de novo DA during follow-up, of which 172/221 (78.2%) were detected in the first 180 days. Patients with DA had a mean age of 47 years, and 383 (49.9%) were women. Baseline or de novo DA was associated with a history of connective tissue disorder (adjusted odds ratio [aOR], 2.02 [95% CI, 1.22–3.36]), fibromuscular dysplasia (aOR, 1.69 [95% CI, 1.28–2.25]), and multiple vessel dissection (aOR, 1.53 [95% CI, 1.19–1.98]). Lower odds of DA were seen in Hispanic ethnicity (aOR, 0.64 [95% CI, 0.43–0.97]) and ischemic stroke presentation (aOR, 0.41 [95% CI, 0.34–0.49]). Fibromuscular dysplasia was associated with de novo DA formation (aOR, 2.30 [95% CI, 1.52–3.49]). DA was not associated with ischemic stroke (hazard ratio, 0.71 [95% CI, 0.44–1.16]; P =0.173) or intracranial hemorrhage (HR, 1.09 [95% CI, 0.42–2.84]; P =0.86) by day 180. CONCLUSIONS: DAs are relatively common manifestations of CeAD, typically occurring within 6 months of CeAD diagnosis. DA was not associated with an increased risk of subsequent ischemic stroke or intracranial hemorrhage.