Citations

Abstract Background Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) uses angiotensin-converting enzyme 2 (ACE2) receptor as a means to enter the host. High density of ACE2 receptor in vascular endothelial cells may explain why vascular complications related to endothelial dysfunction occur in COVID-19. However, in vivo assessment of vascular endothelial function during COVID-19 has not been reported. Objective To investigate the vascular endothelial function and its temporal changes in COVID-19 patients. Methods In this prospective blinded study, systemic endothelial function was assessed using plethysmography-derived peripheral arterial tonometry (PAT). The reactive hyperemia index (LnRHI), a measure of endothelium-mediated hyperaemia, and the augmentation index, a measure of arterial vascular stiffness, were measured in 102 individuals across three study groups using PAT: group 1 (active infection), constituted by 20 patients hospitalised due to acute COVID-19; group 2 (past infection), constituted by 52 patients who had recovered from COVID-19; and group 3 (controls), constituted by 30 healthcare workers not infected by SARS-CoV-2. Additionally, among group 1, PAT assessment was repeated in 14 patients several weeks after recovery from acute COVID-19. PAT studies were analysed at a blinded fashion with respect to the assigned study group. Results Lower resting PAT amplitude was found in acute COVID-19 patients compared to the other groups (ratio of arterial tone signal between hyperemia to resting condition was 1.5 [interquartile range, 1.1] in group 1, 1.3 [0.3] in group 2 and 1.2 [0.3] in group 3, p=0.041). On the contrary, no significant differences between groups were found with respect to the hyperemic PAT amplitude (867.9 [486.1] in group 1, 944.7 [748.1] in group 2 and 819.3 [639.6] in group 3, p=0.444). Due to the lower resting PAT amplitude, there was a paradoxically significantly increased LnRHI during acute COVID-19 compared to past infection and controls (0.73 [0.32] vs. 0.53 [0.31] vs. 0.44 [0.23], respectively; p=0.013) (Figure A). Furthermore, among group 1 patients, LnRHI normalised markedly from acute COVID-19 to past infection stage (0.73 [0.32] vs. 0.49 [0.28], respectively; p=0.005) (Figure B). Augmentation index was significantly higher during acute COVID-19 compared to past COVID-19 and controls (9.6 [19.1] in group 1, 6.97 [18.6] in group 2 and −0.35 [20.53] in group 3; p=0.045 for COVID groups vs. controls). Conclusions Non-invasive assessment of systemic vascular endothelial function with PAT revealed significant differences between subjects with acute COVID-19, past COVID-19 and controls. Lower baseline PAT amplitude and high augmentation index suggest vasoconstriction at rest during the acute phase of COVID-19. These findings open new research opportunities to investigate the prognostic value of PAT in COVID-19 patients. Funding Acknowledgement Type of funding sources: None.

Objective/background: Despite the success of chimeric antigen receptor (CAR) T-cell therapy in patients with aggressive non-Hodgkin lymphoma (aNHL), some patients still fail treatment, and their prognosis is dismal. Methods: We performed a retrospective study of aNHL patients treated with axicabtagene ciloleucel (axi-cel) at two Mayo Clinic centers between 2018 and 2020. We evaluated predictive factors, toxicities, and responses to salvage regimens after CAR T-cell therapy. Results: Thirty-four patients received axi-cel with a median length of hospitalization of 14 days. Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome of any grade occurred in 91% and 41% of patients, respectively. Furthermore, 71% of patients responded to therapy, with 53% achieving a complete response (CR). The CRS grade and absolute lymphocyte count at leukapheresis (ALC Leuk ) correlated with CR and overall survival (OS), respectively. After a median follow-up of 6.8 months (interquartile range [IQR] 4.6–14.9), 15 patients (44%) showed progressive disease (PD). Most patients (60%) progressed during the first 3 months and had persistent CD19 tumor expression. Elevated C-reactive protein at baseline increased the risk of PD, whereas elevated ferritin increased PD and mortality risk. Twelve patients received salvage therapy, but only three responded. Median OS of relapsed/refractory patients to axi-cel was 3 months (IQR 1.3–5.1). Conclusion: The grade of CRS and ALC Leuk correlated with better outcomes to axi-cel therapy. In addition, elevated inflammatory markers at baseline were associated with PD and shorter survival. Relapses after treatment frequently occur within months after axi-cel infusion; they confer a poor prognosis and create an urgent need for novel and effective treatment options in this patient population.

Abstract Ibrutinib-based therapies are costly and require continuous administration. We hypothesized combining BTK inhibition with anti-CD20 monoclonal antibodies would yield deep remissions allowing discontinuation. We enrolled 32 therapy-naïve CLL patients to receive ibrutinib plus obinutuzumab, followed by single-agent ibrutinib. Patients could discontinue ibrutinib after 36 months with sustained complete response (CR). We evaluated treatment safety, efficacy, and outcomes after ibrutinib discontinuation. The overall response rate was 100%, 28% achieved a CR, and 12.5% achieved bone marrow undetectable minimal residual disease. At a three-year median follow-up, 91% remain in remission with 100% overall survival. Five patients in sustained CR stopped ibrutinib and have not progressed. Eight non-CR patients discontinued for other reasons, with only two progressing. The treatment was safe, with a lower IRR rate. All patients responded to treatment with longer time-to-progression after discontinuation of ibrutinib. Our data support the evaluation of ibrutinib discontinuation strategies in more extensive clinical trials.

Abstract Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations of PKD1 or PKD2 genes, is characterized by development and growth of cysts causing progressive kidney enlargement. Reduced resting cytosolic calcium and increased cAMP levels associated with the tonic action of vasopressin are two central biochemical defects in ADPKD. Here we show that co‐targeting two GPCRs, the vasopressin V2 receptor (V2R) and the calcium sensing receptor, using the novel V2R antagonist lixivaptan in combination with the calcimimetic R‐568, reduced cyst progression in two animal models of human PKD. Lixivaptan is expected to have a safer liver profile compared to tolvaptan, the only drug approved to delay PKD progression, based on computational model results and initial clinical evidence. PCK rat and Pkd1 RC/RC mouse littermates were fed without or with lixivaptan (0.5%) and R‐568 (0.025% for rats and 0.04% for mice), alone or in combination, for 7 (rats) or 13 (mice) weeks. In PCK rats, the combined treatment strongly decreased kidney weight, cyst and fibrosis volumes by 20%, 49%, and 73%, respectively, compared to untreated animals. In Pkd1 RC/RC mice, the same parameters were reduced by 20%, 56%, and 69%, respectively. In both cases the combined treatment appeared nominally more effective than the individual drugs used alone. These data point to an intriguing new application for two existing drugs in PKD treatment. The potential for synergy between these two compounds suggested in these animal studies, if confirmed in appropriate clinical investigations, would represent a welcome advancement in the treatment of ADPKD.

With stress echo (SE) 2020 study, a new standard of practice in stress imaging was developed and disseminated: the ABCDE protocol for functional testing within and beyond CAD. ABCDE protocol was the fruit of SE 2020, and is the seed of SE 2030, which is articulated in 12 projects: 1-SE in coronary artery disease (SECAD); 2-SE in diastolic heart failure (SEDIA); 3-SE in hypertrophic cardiomyopathy (SEHCA); 4-SE post-chest radiotherapy and chemotherapy (SERA); 5-Artificial intelligence SE evaluation (AI-SEE); 6-Environmental stress echocardiography and air pollution (ESTER); 7-SE in repaired Tetralogy of Fallot (SETOF); 8-SE in post-COVID-19 (SECOV); 9: Recovery by stress echo of conventionally unfit donor good hearts (RESURGE); 10-SE for mitral ischemic regurgitation (SEMIR); 11-SE in valvular heart disease (SEVA); 12-SE for coronary vasospasm (SESPASM). The study aims to recruit in the next 5 years (2021–2025) ≥10,000 patients followed for ≥5 years (up to 2030) from ≥20 quality-controlled laboratories from ≥10 countries. In this COVID-19 era of sustainable health care delivery, SE2030 will provide the evidence to finally recommend SE as the optimal and versatile imaging modality for functional testing anywhere, any time, and in any patient.

Two adenovirus-based vaccines, ChAdOx1 nCoV-19 and Ad26.COV2.S, and two mRNA-based vaccines, BNT162b2 and mRNA.1273, have been approved by the European Medicines Agency (EMA), and are invaluable in preventing and reducing the incidence of coronavirus disease-2019 (COVID-19). Recent reports have pointed to thrombosis with associated thrombocytopenia as an adverse effect occurring at a low frequency in some individuals after vaccination. The causes of such events may be related to SARS-CoV-2 spike protein interactions with different C-type lectin receptors, heparan sulfate proteoglycans (HSPGs) and the CD147 receptor, or to different soluble splice variants of the spike protein, adenovirus vector interactions with the CD46 receptor or platelet factor 4 antibodies. Similar findings have been reported for several viral diseases after vaccine administration. In addition, immunological mechanisms elicited by viral vectors related to cellular delivery could play a relevant role in individuals with certain genetic backgrounds. Although rare, the potential COVID-19 vaccine-induced immune thrombotic thrombocytopenia (VITT) requires immediate validation, especially in risk groups, such as the elderly, chronic smokers, and individuals with pre-existing incidences of thrombocytopenia; and if necessary, a reformulation of existing vaccines.

Background: Two-dimensional volumetric exercise stress echocardiography (ESE) provides an integrated view of left ventricular (LV) preload reserve through end-diastolic volume (EDV) and LV contractile reserve (LVCR) through end-systolic volume (ESV) changes. Purpose: To assess the dependence of cardiac reserve upon LVCR, EDV, and heart rate (HR) during ESE. Methods: We prospectively performed semi-supine bicycle or treadmill ESE in 1344 patients (age 59.8 ± 11.4 years; ejection fraction = 63 ± 8%) referred for known or suspected coronary artery disease. All patients had negative ESE by wall motion criteria. EDV and ESV were measured by biplane Simpson rule with 2-dimensional echocardiography. Cardiac index reserve was identified by peak-rest value. LVCR was the stress-rest ratio of force (systolic blood pressure by cuff sphygmomanometer/ESV, abnormal values ≤2.0). Preload reserve was defined by an increase in EDV. Cardiac index was calculated as stroke volume index * HR (by EKG). HR reserve (stress/rest ratio) <1.85 identified chronotropic incompetence. Results: Of the 1344 patients, 448 were in the lowest tertile of cardiac index reserve with stress. Of them, 303 (67.6%) achieved HR reserve <1.85; 252 (56.3%) had an abnormal LVCR and 341 (76.1%) a reduction of preload reserve, with 446 patients (99.6%) showing ≥1 abnormality. At binary logistic regression analysis, reduced preload reserve (odds ratio [OR]: 5.610; 95% confidence intervals [CI]: 4.025 to 7.821), chronotropic incompetence (OR: 3.923, 95% CI: 2.915 to 5.279), and abnormal LVCR (OR: 1.579; 95% CI: 1.105 to 2.259) were independently associated with lowest tertile of cardiac index reserve at peak stress. Conclusions: Heart rate assessment and volumetric echocardiography during ESE identify the heterogeneity of hemodynamic phenotypes of impaired chronotropic, preload or LVCR underlying a reduced cardiac reserve.

Polycystic kidney disease (PKD) is the most common monogenic kidney disorder and an important cause of end stage renal disease. Vascular abnormalities are the most important non‐cystic complication and contribute to renal disease progression. Homocysteine (Hcy)‐mediated endothelial dysfunction (ED) and oxidative stress are evident early on, but the underlying mechanisms remain unknown. We hypothesized that abnormalities in Hcy metabolism are responsible for the increased levels, leading to Hcy‐induced ED from early stages of PKD. Methods We investigated the Hcy metabolic pathway (transulfuration/remethylation fig. 1) and downstream effects ‐main sources of renal tubular (RT) and endothelial cell (EC) reactive oxygen species (ROS), NADPH oxidase 4, (NOX4) and mitochondria‐ in 4‐week‐old PCK and Sprague‐Dawley (SD) control rats (n=12 each). Kidneys were harvested, frozen in liquid nitrogen, or preserved in formalin for metabolomics and ex‐vivo studies. Twenty‐four‐hour urine and terminal blood samples were collected for metabolite analysis and chemistries. Plasma folic acid, vitamin B12, and Hcy were determined by ELISA. Hcy pathway metabolites (betaine, dimethylglycine) were determined by 1 HNMR. Endothelial NO (eNOS) and oxidative stress were assessed by double immunofluorescence staining for CD31/eNOS and CD31/NOX4, respectively. RT and EC mitochondrial structure was assessed by electron microscopy. Results Serum creatinine and BUN remained unchanged, yet kidney weight/body weight ratio were increased in PCK. eNOS immunoreactivity was lower in PCK vs SD. Plasma Hcy and urine excretion of methyl donor betaine were elevated in PCK, and Hcy positively correlated with urine betaine. Plasma betaine was similar between the groups, but its tissue concentration was lower in PCK, which may lead to betaine insufficiency, impaired betaine dependent remethylation, and hyperhomocysteinemia. Contrarily, tissue glutathione concentration was higher in PCK vs SD, and plasma folate and vitamin B12 were similar, arguing against a defect in the transsulfuration or folate‐dependent remethylation pathways. RT NOX4 expression and immunoreactivity were increased in PCK compared to SD, in association with renal oxidative stress. PCK had increased number of CD31/NOX4 positive cells in peritubular capillaries, indicating increased EC ROS production. Collecting duct and EC mitochondria were swollen and showed cristae remodeling. Conclusion In PKD, early elevation in Hcy is likely related to betaine insufficiency and impaired betaine‐dependent remethylation may be responsible for the early elevation of Hcy. NOX4 and mitochondria abnormalities may be important contributors to oxidative stress and disease severity. Our data suggests these may not only be early vascular disease markers, but also play an important pathogenic role in vascular complications associated with PKD, and contribute to renal disease progression. Support or Funding Information R25‐DK101405, NIDDK P30 DK090728, NIDDK P30 DK 106912 This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Disruption of intracellular calcium likely underlies the upregulation of cyclic AMP (cAMP) signaling and the proliferative and secretory phenotype of the cystic epithelium in ADPKD. However, the mechanisms by which polycystins reduce cytoplasmic calcium remain elusive. Impaired flow‐induced calcium entry through ciliary polycystin complex has been previously proposed as a pathogenic mechanism, but newer evidence suggests the involvement of polycystins in modulation of other mechanosensitive ion channels such as Piezo1, the newly‐identified stretch‐activated non‐selective cation channel. We hypothesized that polycystins, through their physical and functional interaction with Piezo1, modulate various cellular responses to mechanical stimulation. Piezo1 was expressed in both wild type mouse inner medullary collecting duct cells (mIMCD3) cells and PKD2 null cells (~3 fold higher than wild type). Wild type mIMCD3 cells were stably transfected with genetically encoded biosensors, jRGeco1a and Flamindo2, to study spatiotemporal dynamics of calcium and cAMP during live cell imaging, respectively. Piezo1 activation by Yoda1 increased cytoplasmic calcium and simultaneously lowered forskolin‐induced cAMP (Figure 1A). Additionally, exerting physiological fluid shear stress (FSS) (ibidi pump system) led to reduction in cAMP (Figure 1B). Both Yoda1 and FSS lead to an increase in ATP release in mIMCD3 cells (Figure 1C). Furthermore, Yoda1 significantly reduced forskolin‐induced in vitro cystogenesis by 68% in WT and by 48% in PKD2 null mIMCD3 cells (Figure 1D). These results suggest that Piezo1 is involved in renal cystogenesis by controlling FSS‐induced calcium entry. Further studies are required to determine in vivo effect of Piezo1 on renal cystogenesis. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .

Substantial evidence indicates the importance of elevated cAMP in polycystic kidney disease (PKD). Preclinical and clinical trials have shown the feasibility of therapies (vasopressin V2 receptor antagonists and somatostatin analogs) acting on G protein coupled receptors to inhibit adenylyl cyclase activity and production of cAMP. An additional or alternative approach could be to increase phosphodiesterase (PDE) mediated hydrolysis of cAMP. Of the large PDE superfamily, PDE1 is the only family activated by calcium, which is reduced in PKD cells. To assess the contribution of PDE1A to renal cyst formation, we depleted PDE1A levels using antisense morpholinos in zebrafish. We identified two splice isoforms with alternative starts corresponding to human PDE1A1 and PDE1A5. Two splice‐blocking morpholinos targeting the common hydrolase domain of both isoforms induced renal cysts. Two additional morpholinos, targeting each start, also induced renal cysts with dose dependence and additive effects. Co‐injection of the start 1 morpholino with pkd2 morpholino increased the severity of hydrocephalus, renal cysts, and body curvature, demonstrating functional interaction of PDE1A and PC2. Overall, data implicate PDE1A in PKD pathogenesis and validate further investigation of PDE1A as a therapeutic target in PKD.