Pulmonary Hypertension: Intensification and Personalization of Combination Rx (PHoenix): A phase IV randomized trial for the evaluation of dose-response and clinical efficacy of riociguat and selexipag using implanted technologies.

Approved therapies for the treatment of patients with pulmonary arterial hypertension (PAH) mediate pulmonary vascular vasodilatation by targeting distinct biological pathways. International guidelines recommend that patients with an inadequate response to dual therapy with a phosphodiesterase type-5 inhibitor (PDE5i) and endothelin receptor antagonist (ERA), are recommended to either intensify oral therapy by adding a selective prostacyclin receptor (IP) agonist (selexipag), or switching from PDE5i to a soluble guanylate-cyclase stimulator (sGCS; riociguat). The clinical equipoise between these therapeutic choices provides the opportunity for evaluation of individualized therapeutic effects. Traditionally, invasive/hospital-based investigations are required to comprehensively assess disease severity and demonstrate treatment benefits. Regulatory-approved, minimally invasive monitors enable equivalent measurements to be obtained while patients are at home. In this 2 × 2 randomized crossover trial, patients with PAH established on guideline-recommended dual therapy and implanted with CardioMEMS™ (a wireless pulmonary artery sensor) and ConfirmRx™ (an insertable cardiac rhythm monitor), will receive ERA + sGCS, or PDEi + ERA + IP agonist. The study will evaluate clinical efficacy via established clinical investigations and remote monitoring technologies, with remote data relayed through regulatory-approved online clinical portals. The primary aim will be the change in right ventricular systolic volume measured by magnetic resonance imaging (MRI) from baseline to maximal tolerated dose with each therapy. Using data from MRI and other outcomes, including hemodynamics, physical activity, physiological measurements, quality of life, and side effect reporting, we will determine whether remote technology facilitates early evaluation of clinical efficacy, and investigate intra-patient efficacy of the two treatment approaches.

Relationship between inflammatory status and microbial composition in severe asthma and during exacerbation.

BACKGROUND: In T2-mediated severe asthma, biologic therapies, such as mepolizumab, are increasingly used to control disease. Current biomarkers can indicate adequate suppression of T2 inflammation, but it is unclear whether they provide information about airway microbial composition. We investigated the relationships between current T2 biomarkers and microbial profiles, characteristics associated with a ProteobacteriaHIGH microbial profile and the effects of mepolizumab on airway ecology. METHODS: Microbiota sequencing was performed on sputum samples obtained at stable and exacerbation state from 140 subjects with severe asthma participating in two clinical trials. Inflammatory subgroups were compared on the basis of biomarkers, including FeNO and sputum and blood eosinophils. ProteobacteriaHIGH subjects were identified by Proteobacteria to Firmicutes ratio ≥0.485. Where paired sputum from stable visits was available, we compared microbial composition at baseline and following ≥12 weeks of mepolizumab. RESULTS: Microbial composition was not related to inflammatory subgroup based on sputum or blood eosinophils. FeNO ≥50 ppb when stable and at exacerbation indicated a group with less dispersed microbial profiles characterised by high alpha-diversity and low Proteobacteria. ProteobacteriaHIGH subjects were neutrophilic and had a longer time from asthma diagnosis than ProteobacteriaLOW subjects. In those studied, mepolizumab did not alter airway bacterial load or lead to increased Proteobacteria. CONCLUSION: High FeNO could indicate a subgroup of severe asthma less likely to benefit from antimicrobial strategies at exacerbation or in the context of poor control. Where FeNO is <50 ppb, biomarkers of microbial composition are required to identify those likely to respond to microbiome-directed strategies. We found no evidence that mepolizumab alters airway microbial composition.

Biological heterogeneity in idiopathic pulmonary arterial hypertension identified through unsupervised transcriptomic profiling of whole blood.

Idiopathic pulmonary arterial hypertension (IPAH) is a rare but fatal disease diagnosed by right heart catheterisation and the exclusion of other forms of pulmonary arterial hypertension, producing a heterogeneous population with varied treatment response. Here we show unsupervised machine learning identification of three major patient subgroups that account for 92% of the cohort, each with unique whole blood transcriptomic and clinical feature signatures. These subgroups are associated with poor, moderate, and good prognosis. The poor prognosis subgroup is associated with upregulation of the ALAS2 and downregulation of several immunoglobulin genes, while the good prognosis subgroup is defined by upregulation of the bone morphogenetic protein signalling regulator NOG, and the C/C variant of HLA-DPA1/DPB1 (independently associated with survival). These findings independently validated provide evidence for the existence of 3 major subgroups (endophenotypes) within the IPAH classification, could improve risk stratification and provide molecular insights into the pathogenesis of IPAH.

Positioning imatinib for pulmonary arterial hypertension: A phase I/II design comprising dose finding and single-arm efficacy.

Pulmonary arterial hypertension is an unmet clinical need. Imatinib, a tyrosine kinase inhibitor, 200 to 400 mg daily reduces pulmonary artery pressure and increases functional capacity in this patient group, but is generally poorly tolerated at the higher dose. We have designed an open-label, single-arm clinical study to investigate whether there is a tolerated dose of imatinib that can be better targeted to patients who will benefit. The study consists of two parts. Part 1 seeks to identify the best tolerated dose of Imatinib in the range from 100 and up to 400 mg using a Bayesian Continuous Reassessment Method. Part 2 will measure efficacy after 24 weeks treatment with the best tolerated dose using a Simon's two-stage design. The primary efficacy endpoint is a binary variable. For patients with a baseline pulmonary vascular resistance (PVR) >1000 dynes · s · cm-5, success is defined by an absolute reduction in PVR of ≥300 dynes · s · cm-5 at 24 weeks. For patients with a baseline PVR ≤1000 dynes · s · cm-5, success is a 30% reduction in PVR at 24 weeks. PVR will also be evaluated as a continuous variable by genotype as an exploratory analysis. Evaluating the response to that dose by genotype may inform a prospective biomarker-driven study.

Perioperative Management of Pulmonary Hypertension. a Review.

Pulmonary hypertension is a rare and progressive pathology defined by abnormally high pulmonary artery pressure mediated by a diverse range of aetiologies. It affects up to twenty-six individuals per one million patients currently living in the United Kingdom (UK), with a median life expectancy of 2.8 years in idiopathic pulmonary hypertension. The diagnosis of pulmonary hypertension is often delayed due to the presentation of non-specific symptoms, leading to a delay in referral to specialists services. The complexity of treatment necessitates a multidisciplinary approach, underpinned by a diverse disease aetiology from managing the underlying disease process to novel specialist treatments. This has led to the formation of dedicated specialist treatment centres within centralised UK cities. The article aimed to provide a concise overview of pulmonary hypertension's clinical perioperative management, including key definitions, epidemiology, pathophysiology, and risk stratification.

Establishing expert consensus for the optimal approach to holistic risk-management in pulmonary arterial hypertension: a Delphi process and narrative review.

Background: Pulmonary arterial hypertension (PAH) is associated with significant morbidity and reduced life expectancy. Various medical therapies, together with non-medical therapies such as exercise training, have been shown to improve outcomes for patients. We performed a Delphi consensus process to establish optimal approaches to optimizing patient care.Methods: A steering group of PAH experts formulated 38 statements grouped into 6 themes: burden of PAH, risk-stratification, the role of clinical phenotyping in the management of PAH, assessing clinical response to treatment, maximizing the medical treatment pathway and the role of other management options. An online survey was sent to PAH health-care professionals throughout the UK to assess consensus with these statements. Consensus was defined as high if ≥70% and very high if ≥90% of the respondents agreed with a statement. A narrative review for each theme was then performedResults: Consensus was very high in 27 (71%) statements, high in 7 (18%) statements and was not achieved in 4 (11%) statements.Conclusions: Based on the consensus scores, the steering group derived 13 recommendations which, if implemented, should result in improved holistic care of patients with PAH.

Bayesian Inference Associates Rare KDR Variants with Specific Phenotypes in Pulmonary Arterial Hypertension.

Background - Approximately 25% of patients with pulmonary arterial hypertension (PAH) have been found to harbor rare mutations in disease-causing genes. To identify missing heritability in PAH we integrated deep phenotyping with whole-genome sequencing data using Bayesian statistics. Methods - We analyzed 13,037 participants enrolled in the NIHR BioResource - Rare Diseases (NBR) study, of which 1,148 were recruited to the PAH domain. To test for genetic associations between genes and selected phenotypes of pulmonary hypertension (PH), we used the Bayesian rare-variant association method BeviMed. Results - Heterozygous, high impact, likely loss-of-function variants in the Kinase Insert Domain Receptor (KDR) gene were strongly associated with significantly reduced transfer coefficient for carbon monoxide (KCO, posterior probability (PP)=0.989) and older age at diagnosis (PP=0.912). We also provide evidence for familial segregation of a rare nonsense KDR variant with these phenotypes. On computed tomographic imaging of the lungs, a range of parenchymal abnormalities were observed in the five patients harboring these predicted deleterious variants in KDR. Four additional PAH cases with rare likely loss-of-function variants in KDR were independently identified in the US PAH Biobank cohort with similar phenotypic characteristics. Conclusions - The Bayesian inference approach allowed us to independently validate KDR, which encodes for the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2), as a novel PAH candidate gene. Furthermore, this approach specifically associated high impact likely loss-of-function variants in the genetically constrained gene with distinct phenotypes. These findings provide evidence for KDR being a clinically actionable PAH gene and further support the central role of the vascular endothelium in the pathobiology of PAH.

Successful outcome following pneumonectomy in a teenage boy with cystic fibrosis: a case report.

BACKGROUND: Cystic fibrosis lung disease is generally a diffuse process however rarely one lung may become particularly damaged through chronic collapse and consolidation resulting in end-stage bronchiectasis with relative sparing of the contralateral lung. This clinical situation is sometimes referred to as "destroyed lung". Lung resection surgery is seldom indicated in cystic fibrosis and the associated medical literature is relatively sparse. CASE PRESENTATION: A 14 year old boy was referred to our centre for lung transplantation assessment. He had a chronic history of complete collapse and consolidation of his entire right lung. This was causing severe morbidity in terms of a continuous requirement for intravenous antibiotics over the last year, poor exercise tolerance with forced expiratory volume in 1 s of 35-40% predicted and need for home tuition. He also had significant nutritional problems and gastrointestinal symptoms following a Nissen's fundoplication operation a year earlier. His nutritional status was firstly improved by the institution of jejunal feeding, which also greatly improved his distressing symptoms of nausea and wretching. After thorough multidisciplinary assessment the therapeutic option of performing a right pneumonectomy was considered due to relative sparing of the left lung, which demonstrated only mild bronchiectasis on computed tomography scan. This was performed uneventfully with a smooth peri-operative course. Targeted antimicrobials were used to treat the multiresistant organisms colonising his airways. Subsequently his quality of life, nutritional status and lung function all improved significantly and requirement for lung transplantation has been delayed. CONCLUSIONS: We report a successful outcome following pneumonectomy in a teenage boy with cystic fibrosis referred to our centre for lung transplantation assessment with chronic unilateral collapse and consolidation of his right lung. We believe that improvement of nutritional status pre-operatively and targeted antimicrobial therapy, all contributed to the smooth peri-operative course. Pneumonectomy can be a feasible option in this clinical situation in cystic fibrosis but the associated risks must be considered carefully on a case-by-case basis.

A combination of two novel alpha globin variants Hb Bridlington (HBA1) and Hb Taybe (HBA2) resulting in severe hemolysis, pulmonary hypertension, and death.

OBJECTIVE AND IMPORTANCE: To describe two novel hemoglobin mutations that resulted in an unstable hemoglobin with a severe hemolytic phenotype. CLINICAL PRESENTATION: A patient with an unstable hemoglobin and chronic hemolysis underwent splenectomy at age 15, subsequently developing chronic thrombo-embolic pulmonary hypertension at age 27 that was ultimately fatal. INTERVENTION: DNA sequencing of the alpha globin gene revealed heterozygous inheritance of Hb Taybe, arising from a novel mutation in the HBA2 gene and Hb Bridlington, a novel HBA1 mutation. Greater disease severity is predicted by the position of the Hb Taybe mutation on the HBA2 gene (which transcribes more globin than the HBA1 gene). CONCLUSION: Splenectomy was not clearly beneficial and may have contributed to the development of pulmonary hypertension. The case favors a cautious approach when considering splenectomy for patients with Hb Taybe.

Mechanistic differences between phenotypes of chronic lung allograft dysfunction after lung transplantation.

Distinct phenotypes of chronic lung allograft dysfunction (CLAD) after lung transplantation are emerging with lymphocytic bronchiolitis (LB)/azithromycin reversible allograft dysfunction (ARAD), classical or fibrotic bronchiolitis obliterans syndrome (BOS), and restrictive allograft syndrome (RAS) proposed as separate entities. We have additionally identified lung transplant recipients with prior LB, demonstrating persistent airway neutrophilia (PAN) despite azithromycin treatment. The aim of this study was to evaluate differences in the airway microenvironment in different phenotypes of CLAD. Bronchoalveolar lavage (BAL) from recipients identified as stable (control), LB/ARAD, PAN, BOS, and RAS were evaluated for differential cell counts and concentrations of IL-1α, IL-1ß, IL-6, IL-8, and TNF-α. Primary human bronchial epithelial cells were exposed to BAL supernatants from different phenotypes and their viability measured. BOS and RAS showed increased BAL neutrophilia but no change in cytokine concentrations compared with prediagnosis. In both LB/ARAD and PAN, significant increases in IL-1α, IL-1ß, and IL-8 were present. BAL IL-6 and TNF-α concentrations were increased in PAN and only this phenotype demonstrated decreased epithelial cell viability after exposure to BAL fluid. This study demonstrates clear differences in the airway microenvironment between different CLAD phenotypes. Systematic phenotyping of CLAD may help the development of more personalized approaches to treatment.

Comparison of single lung transplant with and without the use of cardiopulmonary bypass.

OBJECTIVES: Many centres avoid using cardiopulmonary bypass (CPB) for lung transplant due to concerns over aggravated lung reperfusion injury and excessive blood loss. We reviewed our 23-years' experience of single lung transplantation. METHODS: A retrospective review of single lung transplants at our institution (1987-2010), examining differences in allograft function and postoperative complications between CPB and non-bypass (non-CPB) cases. RESULTS: Two hundred and fifty-nine single lung transplants were undertaken. Fifty-three (20.5%) with CPB. There was no difference demographically between the two groups. No difference existed in preoperative PO(2)/FiO(2). At 1 and 24 h, the postoperative PO(2)/FiO(2) ratio was no different (mean 2.95 and 3.24 in non-CPB cases; 3.53 and 3.75 in CPB patients, P = 0.18 and P = 0.34, respectively). Extubation time was not influenced by the use of CPB. Postoperative blood loss was greater in the CPB group. The usage of fresh frozen plasma and platelets was similar (P = 0.64 and 0.41, respectively). More blood was transfused during postoperative care of CPB patients (P = 0.02). CONCLUSIONS: Fears of poor postoperative lung function after CPB appear unfounded. We could detect no difference in function or extubation time. Although the use of CPB increases postoperative bleeding and the need for transfusion, it may be used safely to facilitate lung transplantation.

The human syndrome of dendritic cell, monocyte, B and NK lymphoid deficiency.

Congenital or acquired cellular deficiencies in humans have the potential to reveal much about normal hematopoiesis and immune function. We show that a recently described syndrome of monocytopenia, B and NK lymphoid deficiency additionally includes the near absence of dendritic cells. Four subjects showed severe depletion of the peripheral blood HLA-DR(+) lineage(-) compartment, with virtually no CD123(+) or CD11c(+) dendritic cells (DCs) and very few CD14(+) or CD16(+) monocytes. The only remaining HLA-DR(+) lineage(-) cells were circulating CD34(+) progenitor cells. Dermal CD14(+) and CD1a(+) DC were also absent, consistent with their dependence on blood-derived precursors. In contrast, epidermal Langerhans cells and tissue macrophages were largely preserved. Combined loss of peripheral DCs, monocytes, and B and NK lymphocytes was mirrored in the bone marrow by complete absence of multilymphoid progenitors and depletion of granulocyte-macrophage progenitors. Depletion of the HLA-DR(+) peripheral blood compartment was associated with elevated serum fms-like tyrosine kinase ligand and reduced circulating CD4(+)CD25(hi)FoxP3(+) T cells, supporting a role for DC in T reg cell homeostasis.

Pseudomonas aeruginosa colonization of the allograft after lung transplantation and the risk of bronchiolitis obliterans syndrome.

Long-term survival after lung transplantation remains limited by the development of bronchiolitis obliterans syndrome (BOS). Allograft colonization with Pseudomonas aeruginosa is common particularly in recipients with BOS, but a possible etiological relationship remains unexplored. In 155 consecutive lung transplants, the development of allograft colonization with Pseudomonas was strongly associated with the development of BOS within 2 years of transplant (23.4% vs. 7.7% in those colonized and not colonized, respectively, P=0.006). Freedom from BOS was significantly shorter in those patients without any pretransplant bacterial reservoir developing de novo allograft pseudomonal colonization as compared with those remaining free of colonization (Kaplan-Meier log-rank P=0.014). The isolation of Pseudomonas preceded the diagnosis of BOS in 14 of 18 (78%) and by a median of 204 days (95% confidence interval 115-492) in patients developing both these complications. We conclude that de novo colonization of the lung allograft by Pseudomonas is strongly associated with the subsequent development of BOS.

The phosphodiesterase type IV inhibitor cilomilast decreases pro-inflammatory cytokine production from primary bronchial epithelial cells in lung transplantation patients.

BACKGROUND: Bronchiolitis obliterans syndrome (BOS) remains the major cause of long-term morbidity and mortality after lung transplantation, and new therapeutic measures are needed. We speculated that cilomilast might reduce mediators of airway inflammation and angiogenesis from the airway epithelium, supporting a potential value in the treatment of BOS. We used an ex vivo primary bronchial epithelial cell culture (PBEC) model to investigate this hypothesis. Increasing evidence suggests the epithelium is central in stimulating both inflammatory and proliferative responses in the airway. METHODS: Bronchial brushings were taken from 7 stable lung allograft recipients and were used to establish sub-confluent PBECs. The effect of incubation for 48 hours with 0.1 to 10 micromol/liter cilomilast on basal production of interleukin (IL)-8, IL-6, granulocyte macrophage colony-stimulating factor (GMCSF), and vascular endothelial growth factor (VEGF) were assayed by multiplex analyser. RESULTS: There was a dose dependent fall in basal IL-8 and GMCSF levels with cilomilast. Median change for IL-8 was -25% (range, -66% to 5%; p = 0.035) at 1 micromol/liter , and -40% (range, -72% to -20; p = 0.022) at 10 micromol/liter. Median GMSCF change was -34% (range, -70% to 16%; p = 0.05) at 1 micromol/liter, and 37% (range, -80% to -8%; p = 0.04) at 10 micromol/liter. There were no effects on VEGF. CONCLUSION: The phosphodiesterase type IV inhibitor cilomilast reduced IL-8 and GMCSF release from PBECs. These cytokines are associated with the persistence of airway neutrophilic inflammation and airway remodelling seen in obliterative bronchiolitis. These ex vivo results suggest a potential for cilomilast in the treatment of BOS, which would need to be evaluated in appropriate clinical studies.