Actualización del abordaje de la hipertensión pulmonar tromboembólica crónica / Update in the management of chronic thrombo-embolic pulmonary hypertension

La hipertensión pulmonar tromboembólica crónica (HPTEC) es una forma potencialmente curable de hipertensión pulmonar (HP) que aparece hasta en 3% de los pacientes tras una embolia pulmonar (EP). En estos pacientes, la EP no se resuelve, dando paso a coágulos fibróticos organizados, con el desarrollo de HP precapilar debido a la obstrucción proximal de las arterias pulmonares. También puede desarrollarse una microvasculopatía distal que contribuye al aumento de la resistencia vascular pulmonar (RVP). La ecocardiografía transtorácica (ETT) es la exploración que permite establecer la sospecha de HP. La gammagrafía pulmonar de ventilación-perfusión (V/Q) es la herramienta fundamental en el estudio de los pacientes con sospecha de HPTEC; si es normal, prácticamente la descarta. El cateterismo cardiaco derecho es obligatorio para el diagnóstico. La HPTEC se define como la existencia de síntomas, defectos de perfusión residuales e HP precapilar tras un periodo mínimo de tres meses de anticoagulación. La angiografía pulmonar ayuda a determinar la extensión y la accesibilidad quirúrgica de las lesiones tromboembólicas. Las personas con HPTEC son candidatas a anticoagulación indefinida. La endarterectomía pulmonar es el tratamiento de elección, resultando en una mejoría clínica y hemodinámica significativa. Aproximadamente un 25% de los pacientes presentan HP residual postendarterectomía. La angioplastia pulmonar con balón (APB) es una técnica endovascular dirigida a lesiones más distales, de utilidad para sujetos con HPTEC inoperable o HP persistente/recidivante postendarterectomía. Ambos tipos de pacientes también se pueden beneficiar de tratamiento farmacológico para la HP. Las tres terapias constituyen los pilares de la terapia, que ha evolucionado hacia un enfoque multimodal.(AU)

Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a potentially curable form of pulmonary hypertension (PH) that develops in up to 3% of patients after pulmonary embolism (PE). In these patients, PE does not resolve, leading to organized fibrotic clots, with the development of precapillary PH as a result of the proximal obstruction of the pulmonary arteries. In addition, a distal microvasculopathy may also develop, contributing to the increase of pulmonary vascular resistance. Transthoracic echocardiography is the diagnostic tool that allows to establish the suspicion of PH. Ventilation-perfusion lung scintigraphy is the fundamental tool in the study of patients with suspected CTEPH; if it is normal, virtually rules out the diagnosis. Right heart catheterization is mandatory for the diagnosis of these patients. CTEPH is defined as the existence of symptoms, residual perfusion defects and precapillary PH after a minimum period of three months of anticoagulation. Pulmonary angiography helps determine the extent and surgical accessibility of thromboembolic lesions. CTEPH patients are candidates for long-term anticoagulation. Pulmonary endarterectomy is the treatment of choice, resulting in significant clinical and hemodynamic improvement. About 25% of patients have residual PH post-endarterectomy. Balloon pulmonary angioplasty is an endovascular technique that targets more distal lesions, being potentially useful for patients with inoperable CTEPH or persistent/recurrent PH post-endarterectomy. Both types of patients may also benefit from pharmacological treatment for PH. These three therapies are the cornerstone of CTEPH treatment, which has evolved towards a multimodal approach.(AU)

The Impact of the Mediterranean Diet and Lifestyle Intervention on Lipoprotein Subclass Profiles among Metabolic Syndrome Patients: Findings of a Randomized Controlled Trial.

Metabolic syndrome (MetS) is associated with alterations of lipoprotein structure and function that can be characterized with advanced lipoprotein testing (ADLT). The effect of the Mediterranean diet (MedDiet) and weight loss on the lipoprotein subclass profile has been scarcely studied. Within the PREDIMED-Plus randomized controlled trial, a sub-study conducted at Bellvitge Hospital recruiting center evaluated the effects of a weight loss program based on an energy-reduced MedDiet (er-MedDiet) and physical activity (PA) promotion (intervention group) compared with energy-unrestricted MedDiet recommendations (control group) on ADLT-assessed lipoprotein subclasses. 202 patients with MetS (n = 107, intervention; n = 95, control) were included. Lipid profiles were determined, and ADLT was performed at baseline, 6, and 12 months. Linear mixed models were used to assess the effects of intervention on lipoprotein profiles. Compared to the control diet, at 12 months, the er-MedDiet+PA resulted in a significant additional 4.2 kg of body weight loss, a decrease in body mass index by 1.4 kg/m2, reduction in waist circumference by 2.2 cm, decreased triglycerides, LDL-cholesterol and non-HDL-cholesterol, and increased HDL-cholesterol. In er-MedDiet+PA participants, ADLT revealed a decrease in small dense-LDL-cholesterol (sd-LDL-C), intermediate-density lipoproteins, VLDL-triglyceride, and HDL-Triglyceride, and an increase in large LDL and large VLDL particles. In conclusion, compared to an ad libitum MedDiet (control group), er-MedDiet+PA decreased plasma triglycerides and the triglyceride content in HDL and VLDL particles, decreased sd-LDL-C, and increased large LDL particles, indicating beneficial changes against cardiovascular disease.

Update in the management of chronic thrombo-embolic pulmonary hypertension. / Actualización del abordaje de la hipertensión pulmonar tromboembólica crónica.

Chronic thrombo-embolic pulmonary hypertension (CTEPH) is a potentially curable form of pulmonary hypertension (PH) that develops in up to 3% of patients after pulmonary embolism (PE). In these patients, PE does not resolve, leading to organized fibrotic clots, with the development of precapillary PH as a result of the proximal obstruction of the pulmonary arteries. In addition, a distal microvasculopathy may also develop, contributing to the increase of pulmonary vascular resistance. Transthoracic echocardiography is the diagnostic tool that allows to establish the suspicion of PH. Ventilation-perfusion lung scintigraphy is the fundamental tool in the study of patients with suspected CTEPH; if it is normal, virtually rules out the diagnosis. Right heart catheterization is mandatory for the diagnosis of these patients. CTEPH is defined as the existence of symptoms, residual perfusion defects and precapillary PH after a minimum period of three months of anticoagulation. Pulmonary angiography helps determine the extent and surgical accessibility of thromboembolic lesions. CTEPH patients are candidates for long-term anticoagulation. Pulmonary endarterectomy is the treatment of choice, resulting in significant clinical and hemodynamic improvement. About 25% of patients have residual PH post-endarterectomy. Balloon pulmonary angioplasty is an endovascular technique that targets more distal lesions, being potentially useful for patients with inoperable CTEPH or persistent/recurrent PH post-endarterectomy. Both types of patients may also benefit from pharmacological treatment for PH. These three therapies are the cornerstone of CTEPH treatment, which has evolved towards a multimodal approach.

Symptom-related screening programme for early detection of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: the SYSPPE study.

BACKGROUND: Chronic thromboembolic pulmonary hypertension (CTEPH) is the most severe long-term complication of acute pulmonary embolism (PE). We aimed to evaluate the impact of a symptom screening programme to detect CTEPH in PE survivors. METHODS: This was a multicentre cohort study of patients diagnosed with acute symptomatic PE between January 2017 and December 2018 in 16 centres in Spain. Patients were contacted by phone 2 years after the index PE diagnosis. Those with dyspnoea corresponding to a New York Heart Association (NYHA)/WHO scale≥II, visited the outpatient clinic for echocardiography and further diagnostic tests including right heart catheterisation (RHC). The primary outcome was the new diagnosis of CTEPH confirmed by RHC. RESULTS: Out of 1077 patients with acute PE, 646 were included in the symptom screening. At 2 years, 21.8% (n=141) reported dyspnoea NYHA/WHO scale≥II. Before symptom screening protocol, five patients were diagnosed with CTEPH following routine care. In patients with NYHA/WHO scale≥II, after symptom screening protocol, the echocardiographic probability of pulmonary hypertension (PH) was low, intermediate and high in 76.6% (n=95), 21.8% (n=27) and 1.6% (n=2), respectively. After performing additional diagnostic test in the latter 2 groups, 12 additional CTEPH cases were confirmed. CONCLUSIONS: The implementation of this simple strategy based on symptom evaluation by phone diagnosed more than doubled the number of CTEPH cases. Dedicated follow-up algorithms for PE survivors help diagnosing CTEPH earlier. TRIAL REGISTRATION NUMBER: NCT03953560.

New genetic drivers in hemorrhagic hereditary telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in around 90% of the patients; also 2% of patients harbor pathogenic variants at SMAD4 and GDF2. Importantly, the genetic cause of 8% of patients with clinical HHT remains unknown. Here, we present new putative genetic drivers of HHT. METHODS: To identify new HHT genetic drivers, we performed exome sequencing of 19 HHT patients and relatives with unknown HHT genetic etiology. We applied a multistep filtration strategy to catalog deleterious variants and prioritize gene candidates based on their known relevance in endothelial cell biology. Additionally, we performed in vitro validation of one of the identified variants. RESULTS: We identified variants in the INHA, HIF1A, JAK2, DNM2, POSTN, ANGPTL4, FOXO1 and SMAD6 genes as putative drivers in HHT. We have identified the SMAD6 p.(Glu407Lys) variant in one of the families; this is a loss-of-function variant leading to the activation of the BMP/TGFß signaling in endothelial cells. CONCLUSIONS: Variants in these genes should be considered for genetic testing in patients with HHT phenotype and negative for ACVRL1/ENG mutations.

Induced Endothelial Cell Cycle Arrest Prevents Arteriovenous Malformations in Hereditary Hemorrhagic Telangiectasia.

BACKGROUND: Distinct endothelial cell cycle states (early G1 versus late G1) provide different "windows of opportunity" to enable the differential expression of genes that regulate venous versus arterial specification, respectively. Endothelial cell cycle control and arteriovenous identities are disrupted in vascular malformations including arteriovenous shunts, the hallmark of hereditary hemorrhagic telangiectasia (HHT). To date, the mechanistic link between endothelial cell cycle regulation and the development of arteriovenous malformations (AVMs) in HHT is not known. METHODS: We used BMP (bone morphogenetic protein) 9/10 blocking antibodies and endothelial-specific deletion of activin A receptor like type 1 (Alk1) to induce HHT in Fucci (fluorescent ubiquitination-based cell cycle indicator) 2 mice to assess endothelial cell cycle states in AVMs. We also assessed the therapeutic potential of inducing endothelial cell cycle G1 state in HHT to prevent AVMs by repurposing the Food and Drug Administration-approved CDK (cyclin-dependent kinase) 4/6 inhibitor (CDK4/6i) palbociclib. RESULTS: We found that endothelial cell cycle state and associated gene expressions are dysregulated during the pathogenesis of vascular malformations in HHT. We also showed that palbociclib treatment prevented AVM development induced by BMP9/10 inhibition and Alk1 genetic deletion. Mechanistically, endothelial cell late G1 state induced by palbociclib modulates the expression of genes regulating arteriovenous identity, endothelial cell migration, metabolism, and VEGF-A (vascular endothelial growth factor A) and BMP9 signaling that collectively contribute to the prevention of vascular malformations. CONCLUSIONS: This study provides new insights into molecular mechanisms leading to HHT by defining how endothelial cell cycle is dysregulated in AVMs because of BMP9/10 and Alk1 signaling deficiencies, and how restoration of endothelial cell cycle control may be used to treat AVMs in patients with HHT.

Enoxaparin for Long-Term Therapy of Venous Thromboembolism in Patients with Cancer and Renal Insufficiency.

BACKGROUND: The optimal therapy of venous thromboembolism (VTE) in cancer patients with renal insufficiency (RI) is unknown. Current guidelines recommend to use low-molecular-weight heparin over direct oral anticoagulants to treat VTE in cancer patients at high risk of bleeding. METHODS: We used the Registro Informatizado Enfermedad Tromboemb00F3lica (RIETE) registry to compare the 6-month incidence rates of (1) VTE recurrences versus major bleeding and (2) fatal pulmonary embolism (PE) versus fatal bleeding in three subgroups (those with mild, moderate, or severe RI) of cancer patients receiving enoxaparin monotherapy. RESULTS: From January 2009 through June 2022, 2,844 patients with RI received enoxaparin for ≥6 months: 1,432 (50%) had mild RI, 1,168 (41%) moderate RI, and 244 (8.6%) had severe RI. Overall, 68, 62, and 12%, respectively, received the recommended doses. Among patients with mild RI, the rates of VTE recurrences versus major bleeding (4.6 vs. 5.4%) and fatal PE versus fatal bleeding (1.3 vs. 1.2%) were similar. Among patients with moderate RI, VTE recurrences were half as common as major bleeding (3.1 vs. 6.3%), but fatal PE and fatal bleeding were close (1.8 vs. 1.2%). Among patients with severe RI, VTE recurrences were threefold less common than major bleeding (4.1 vs. 13%), but fatal PE was threefold more frequent than fatal bleeding (2.5 vs. 0.8%). During the first 10 days, fatal PE was fivefold more common than fatal bleeding (2.1 vs. 0.4%). CONCLUSION: Among cancer patients with severe RI, fatal PE was fivefold more common than fatal bleeding. The recommended doses of enoxaparin in these patients should be revisited.

Aflibercept for Gastrointestinal Bleeding in Hereditary Hemorrhagic Telangiectasia: A Case Report.

Herein, we present the first described hereditary hemorrhagic telangiectasia (HHT) patient treated with aflibercept for severe GI involvement after tachyphylaxis to bevacizumab, with promising results. HHT is a rare genetic disease characterized by systemic vascular malformations. Gastrointestinal telangiectasia is one of the major involvements that can produce chronic severe iron-deficiency anemia. Nowadays, support treatment with iron replacement therapy, red blood cell transfusions, and antiangiogenic drugs-mainly bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF)-are the main therapeutic options for this complication. The evidence of alternative drugs in patients with failure to this approach, such as tachyphylaxis to bevacizumab, is scarce. Aflibercept is a VEGF inhibitor with antiangiogenic properties approved for the treatment of different types of cancer and ocular neovascularization diseases.

Identification of Low-risk Patients With Acute Symptomatic Pulmonary Embolism

Background: Identification of patients with acute symptomatic pulmonary embolism (PE) who are at low-risk for short-term complications to warrant outpatient care lacks clarity. Method: In order to identify patients at low-risk for 30-day all-cause and PE-related mortality, we used a cohort of haemodynamically stable patients from the RIETE registry to compare the false-negative rate of four strategies: the simplified Pulmonary Embolism Severity Index (sPESI); a modified (i.e., heart rate cutoff of 100beats/min) sPESI; and a combination of the original and the modified sPESI with computed tomography (CT)-assessed right ventricle (RV)/left ventricle (LV) ratio. Results: Overall, 137 of 3117 patients with acute PE (4.4%) died during the first month. Of these, 41 (1.3%) died from PE, and 96 (3.1%) died from other causes. The proportion of patients categorized as having low-risk was highest with the sPESI and lowest with the combination of a modified sPESI and CT-assessed RV/LV ratio (32.5% versus 16.5%; P<0.001). However, among patients identified as low-risk, the 30-day mortality rate was lowest with the combination of a modified sPESI and CT-assessed RV/LV ratio and highest with the sPESI (0.4% versus 1.0%; P=0.03). The 30-day PE-related mortality rates for patients designated as low-risk by the sPESI, the modified sPESI, and the combination of the original and modified sPESI with CT-assessed RV/LV ratio were 0.7%, 0.4%, 0.7%, and 0.2%, respectively. Conclusions: The combination of a negative modified sPESI with CT-assessed RV/LV ratio ≤1 identifies patients with acute PE who are at very low-risk for short-term mortality. (AU)

Identification of Low-risk Patients With Acute Symptomatic Pulmonary Embolism.

BACKGROUND: Identification of patients with acute symptomatic pulmonary embolism (PE) who are at low-risk for short-term complications to warrant outpatient care lacks clarity. METHOD: In order to identify patients at low-risk for 30-day all-cause and PE-related mortality, we used a cohort of haemodynamically stable patients from the RIETE registry to compare the false-negative rate of four strategies: the simplified Pulmonary Embolism Severity Index (sPESI); a modified (i.e., heart rate cutoff of 100beats/min) sPESI; and a combination of the original and the modified sPESI with computed tomography (CT)-assessed right ventricle (RV)/left ventricle (LV) ratio. RESULTS: Overall, 137 of 3117 patients with acute PE (4.4%) died during the first month. Of these, 41 (1.3%) died from PE, and 96 (3.1%) died from other causes. The proportion of patients categorized as having low-risk was highest with the sPESI and lowest with the combination of a modified sPESI and CT-assessed RV/LV ratio (32.5% versus 16.5%; P<0.001). However, among patients identified as low-risk, the 30-day mortality rate was lowest with the combination of a modified sPESI and CT-assessed RV/LV ratio and highest with the sPESI (0.4% versus 1.0%; P=0.03). The 30-day PE-related mortality rates for patients designated as low-risk by the sPESI, the modified sPESI, and the combination of the original and modified sPESI with CT-assessed RV/LV ratio were 0.7%, 0.4%, 0.7%, and 0.2%, respectively. CONCLUSIONS: The combination of a negative modified sPESI with CT-assessed RV/LV ratio ≤1 identifies patients with acute PE who are at very low-risk for short-term mortality.

Long-term use of somatostatin analogs for chronic gastrointestinal bleeding in hereditary hemorrhagic telangiectasia.

Background: Chronic bleeding due to gastrointestinal (GI) involvement in patients with hemorrhagic hereditary telangiectasia (HHT) can provoke severe anemia with high red blood cells (RBC) transfusion requirements. However, the evidence about how to deal with these patients is scarce. We aimed to assess the long-term efficacy and safety of somatostatin analogs (SA) for anemia management in HHT patients with GI involvement. Methods: This is a prospective observational study including patients with HHT and GI involvement attended at a referral center. SA were considered for those patients with chronic anemia. Anemia-related variables were compared in patients receiving SA before and during treatment. Patients receiving SA were divided into responders (patients with minimal hemoglobin levels improvement >10 g/L and maintaining hemoglobin levels ≥80 g/L during treatment), and non-responders. Adverse effects during follow-up were collected. Results: Among 119 HHT patients with GI involvement, 67 (56.3%) received SA. These patients showed lower minimal hemoglobin levels (73 [60-87] vs. 99 [70.2-122.5], p < 0.001), and more RBC transfusion requirements (61.2% vs. 38.5%, p = 0.014) than patients without SA therapy. Median treatment period was 20.9 ± 15.2 months. During treatment, there was a statistically significant improvement in minimum hemoglobin levels (94.7 ± 29.8 g/L vs. 74.7 ± 19.7, p < 0.001) and a reduction of patients with minimal hemoglobin levels <80 g/L (39 vs. 61%, p = 0.007) and RBC transfusions requirement (33.9% vs. 59.3%, p < 0.001). Sixteen (23.9%) patients showed mild adverse effects, mostly diarrhea or abdominal pain, leading to treatment discontinuation in 12 (17.9%) patients. Fifty-nine patients were eligible for efficacy assessment and 32 (54.2%) of them were considered responders. Age was associated with non-responder patients, OR 95% CI; 1.070 (1.014-1.130), p = 0.015. Conclusion: SA can be considered a long-term effective and safe option for anemia management in HHT patients with GI bleeding. Older age is associated with poorer response.

Improving Hereditary Hemorrhagic Telangiectasia Molecular Diagnosis: A Referral Center Experience.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in more than 90% of the patients undergoing molecular testing. The identification of variants of unknown significance is often seen as a challenge in clinical practice that makes family screening and genetic counseling difficult. Here, we show that the implementation of cDNA analysis to assess the effect of splice site variants on mRNA splicing is a powerful tool. METHODS: Gene panel sequencing of genes associated with HHT and other arteriovenous malformation-related syndromes was performed. To evaluate the effect of the splice site variants, cDNA analysis of ENG and ACVRL1 genes was carried out. RESULTS: three novel splice site variants were identified in ENG (c.68-2A > T and c.1311+4_1311+8del) and ACVLR1 (c.526-6C > G) genes correspondingly in three individuals with HHT that met ≥ 3 Curaçao criteria. All three variants led to an aberrant splicing inducing exon skipping (ENG:c.68-2A > T and ACVRL1:c.526-6C > G) or intron retention (ENG:c.1311+4_1311+8del) allowing the confirmation of the predicted effect on splicing and the reclassification from unknown significance to pathogenic/likely pathogenic of two of them. CONCLUSIONS: RNA analysis should be performed to assess and/or confirm the impact of variants on splicing. The molecular diagnosis of HHT patients is crucial to allow family screening and accurate genetic counseling. A multidisciplinary approach including clinicians and geneticists is crucial when dealing with patients with rare diseases.

Deep vein thrombosis symptoms and 30-day mortality in acute pulmonary embolism.

BACKGROUND: In patients with acute symptomatic pulmonary embolism (PE), the presence of concomitant lower-limb deep vein thrombosis (DVT) has been associated with a higher mortality rate. The prognostic significance of DVT symptoms among these patients remains uncertain. METHODS: We used the RIETE (Registro Informatizado de Enfermedad TromboEmbólica) registry to compare the 30-day mortality rate in patients with PE and concomitant lower-limb DVT, according to the presence or absence of DVT symptoms. Primary outcomes were all-cause death and PE-related death within the first 30 days. RESULTS: Since March 2001 to June 2021, there were 17,742 patients with acute symptomatic PE and objectively proven concomitant lower-limb DVT. Of these, 11,984 (68%) had DVT symptoms. Most patients with or without DVT symptoms (82% vs. 81%) received low-molecular-weight heparin initially. Then, most (61% vs. 58%) switched to vitamin K antagonists. During the first 30 days of therapy, 497 patients with DVT symptoms (4.1%) and 164 (2.8%) with no DVT symptoms died (rate ratio [RR]: 1.48; 95%CI: 1.23-1.77). The rates of PE-related death were: 1.0% vs. 0.7%, respectively (RR: 1.50; 95%CI: 1.04-2.16). On multivariable analysis, patients with DVT symptoms were at increased risk for all-cause death (adjusted hazard ratio [aHR]: 1.49; 95%CI: 1.24-1.78), and PE-related death (aHR: 1.52; 95%CI: 1.05-2.20). CONCLUSION: Among patients with acute symptomatic PE and concomitant lower-limb DVT, those with DVT symptoms had an increased all-cause and PE-related mortality within 30 days. Assessment of DVT symptoms would assist with risk stratification of these patients.

Perioperative Complications and Long-Term Follow-Up of Liver Transplantation in Hemorrhagic Hereditary Telangiectasia: Report of Three Cases and Systematic Review.

The aim was to describe three patients with hemorrhagic hereditary telangiectasia (HHT) requiring liver transplantation (LT) and to perform a systematic review focusing on surgical complications and long-term follow-up. Unrestricted searches of the Medline and Embase databases were performed through February 2022. Forty-five studies were selected including 80 patients plus the three new reported patients, 68 (81.9%) were female and mean age was 50 (27-72) years. Main indications for LT were high-output cardiac failure (n = 40; 48.2%), ischemic cholangitis (n = 19; 22.9%), and a combination of both conditions (n = 13;15.6%). Mean cold ischemic time and red blood cell units transfused during LT were 554 (300-941) minutes and 11.4 (0-88) units, respectively. Complications within 30 days were described in 28 (33.7%) patients, mainly bleeding complications in 13 patients, hepatic artery (HA) thrombosis in four and hepatic vein thrombosis in one. Mean follow-up was 76.4 (1-288) months, and during it, four new patients developed thrombotic complications in HA, HA aneurysm, celiac artery, and the portal-splenic-mesenteric vein. HHT relapse in the transplant allograft was detected in 13 (17.1%) patients after 1-19 years (including two fatal recurrences). Overall mortality was 12%. In conclusion, previous assessment of HA anatomy and hyperdynamic circulatory state could reduce LT complications. The risk of relapse in the hepatic graft supports a multidisciplinary follow-up for HHT patients with LT.

Potential of FX06 to prevent disease progression in hospitalized non-intubated COVID-19 patients - the randomized, EU-wide, placebo-controlled, phase II study design of IXION.

BACKGROUND: More than 2.7 million hospitalizations of COVID-19-infected patients have occurred in Europe alone since the outbreak of the coronavirus in 2020. Interventions against SARS-CoV-2 are still in high need to prevent admissions to ICUs worldwide. FX06, a naturally occurring peptide in humans and other mammals, has the potential to reduce capillary leak by improving endothelial dysfunction and thus preventing the deterioration of patients. With IXION, we want to investigate the potential of FX06 to prevent disease progression in hospitalized, non-intubated COVID-19 patients. METHODS: IXION is an EU-wide, multicentre, placebo-controlled, double-blinded, parallel, randomized (2:1) phase II clinical study. Patient recruitment will start in September 2022 (to Q2/2023) in Germany, Italy, Lithuania, Spain, Romania, Portugal, and France. A total of 306 hospitalized patients (≥ 18 years and < 75 years) with a positive SARS-CoV-2 PCR test and a COVID-19 severity of 4-6 according to the WHO scale will be enrolled. After randomization to FX06 or placebo, patients will be assessed until day 28 (and followed up until day 60). FX06 (2 × 200 mg per day) or placebo will be administered intravenously for 5 consecutive days. The primary endpoint is to demonstrate a difference in the proportion of patients with progressed/worsened disease state in patients receiving FX06 compared to patients receiving placebo. Secondary endpoints are lung function, oxygen saturation and breathing rate, systemic inflammation, survival, capillary refill time, duration of hospital stay, and drug accountability. DISCUSSION: With IXION, the multidisciplinary consortium aims to deliver a new therapy in addition to standard care against SARS-CoV-2 for the clinical management of COVID-19 during mild and moderate stages. Potential limitations might refer to a lack of recruiting and drop-out due to various possible protocol violations. While we controlled for drop-outs in the same size estimation, recruitment problems may be subject to external problems difficult to control for. TRIAL REGISTRATION: EudraCT 2021-005059-35 . Registered on 12 December 2021. Study Code TMP-2204-2021-47.

Evaluation of Humoral and Cellular Immune Responses to the SARS-CoV-2 Vaccine in Patients With Common Variable Immunodeficiency Phenotype and Patient Receiving B-Cell Depletion Therapy.

Introduction: SARS-CoV-2 vaccines' effectiveness is not yet clearly known in immunocompromised patients. This study aims to assess the humoral and cellular specific immune response to SARS-CoV-2 vaccines and the predictors of poor response in patients with common variable immunodeficiency (CVID) phenotype and in patients treated with B-cell depletion therapies (BCDT), as well as the safety of these vaccines. Methods: From March to September 2021, we performed a prospective study of all adult patients who would receive the SARS-CoV-2 vaccination and were previously diagnosed with (i) a CVID syndrome (CVID phenotype group; n=28) or (ii) multiple sclerosis (MS) treated with B-cell depleting therapies three to six months before vaccination (BCD group; n=24). Participants with prior SARS-CoV-2 infection; or prior SARS-CoV-2 vaccine administration; or use of any immunosuppressant (except BCDT in MS group) were excluded. A group of subjects without any medical condition that confers immunosuppression and who met all study criteria was also assessed (control group; n=14). A chemiluminescence immunoassay was used to determine pre- and post-SARS-CoV-2 vaccine anti-S IgG antibodies. T-cell specific response was assessed by analysis of pre- and post-SARS-CoV-2 vaccination blood samples with an interferon-gamma release assay. The baseline blood sample also included several biochemical, haematological and immunological analyses. Results: SARS-CoV-2 vaccines are safe in immunocompromised patients, although their effectiveness was lower than in healthy individuals. CVID phenotype patients showed impaired humoral (29%) and cellular (29%) response, while BCD patients fundamentally presented humoral failure (54%). Low IgA values, low CD19+ peripheral B cells, low switched memory B cells, and a low CD4+/CD8+ ratio were predictors of inadequate specific antibody response in CVID phenotype patients. No factor was found to predict poor cellular response in CVID phenotype patients, nor a defective humoral or cellular response in BCD patients. Conclusion: The effectiveness of SARS-CoV-2 vaccines in CVID phenotype and BCD patients is lower than in healthy individuals. Knowledge of predictive factors of humoral and cellular response failure in immunocompromised patients could be very useful in clinical practice, and thus, studies in this regard are clearly needed.

Rethinking growth factors: the case of BMP9 during vessel maturation.

Angiogenesis is an essential process for correct development and physiology. This mechanism is tightly regulated by many signals that activate several pathways, which are constantly interacting with each other. There is mounting evidence that BMP9/ALK1 pathway is essential for a correct vessel maturation. Alterations in this pathway lead to the development of hereditary haemorrhagic telangiectasias. However, little was known about the BMP9 signalling cascade until the last years. Recent reports have shown that while BMP9 arrests cell cycle, it promotes the activation of anabolic pathways to enhance endothelial maturation. In light of this evidence, a new criterion for the classification of cytokines is proposed here, based on the physiological objective of the activation of anabolic routes. Whether this activation by a growth factor is needed to sustain mitosis or to promote a specific function such as matrix formation is a critical characteristic that needs to be considered to classify growth factors. Hence, the state-of-the-art of BMP9/ALK1 signalling is reviewed here, as well as its implications in normal and pathogenic angiogenesis.