Proximal and Distal Bronchioles Contribute to the Pathogenesis of Non-Cystic Fibrosis Bronchiectasis

Rationale: Non-cystic fibrosis bronchiectasis (NCFB) may originate in bronchiolar regions of the lung. Accordingly, there is a need to characterize the morphology and molecular characteristics of NCFB bronchioles. Objectives: Test the hypothesis that NCFB exhibits a major component of bronchiolar disease manifest by mucus plugging and ectasia. Methods: Morphologic criteria and region-specific epithelial gene expression, measured histologically and by RNA in situ hybridization and immunohistochemistry, identified proximal and distal bronchioles in excised NCFB lungs. RNA in situ hybridization and immunohistochemistry assessed bronchiolar mucus accumulation and mucin gene expression. CRISPR-Cas9-mediated IL-1R1 knockout in human bronchial epithelial cultures tested IL-1α and IL-1β contributions to mucin production. Spatial transcriptional profiling characterized NCFB distal bronchiolar gene expression. Measurements and Main Results: Bronchiolar perimeters and lumen areas per section area were increased in proximal, but not distal, bronchioles in NCFB versus control lungs, suggesting proximal bronchiolectasis. In NCFB, mucus plugging was observed in ectatic proximal bronchioles and associated nonectatic distal bronchioles in sections with disease. MUC5AC and MUC5B mucins were upregulated in NCFB proximal bronchioles, whereas MUC5B was selectively upregulated in distal bronchioles. Bronchiolar mucus plugs were populated by IL-1β-expressing macrophages. NCFB sterile sputum supernatants induced human bronchial epithelial MUC5B and MUC5AC expression that was >80% blocked by IL-1R1 ablation. Spatial transcriptional profiling identified upregulation of genes associated with secretory cells, hypoxia, interleukin pathways, and IL-1β-producing macrophages in mucus plugs and downregulation of epithelial ciliogenesis genes. Conclusions: NCFB exhibits distinctive proximal and distal bronchiolar disease. Both bronchiolar regions exhibit bronchiolar secretory cell features and mucus plugging but differ in mucin gene regulation and ectasia.

Prevalence and Mechanisms of Mucus Accumulation in COVID-19 Lung Disease

Rationale: The incidence and sites of mucus accumulation and molecular regulation of mucin gene expression in coronavirus (COVID-19) lung disease have not been reported. Objectives: To characterize the incidence of mucus accumulation and the mechanisms mediating mucin hypersecretion in COVID-19 lung disease. Methods: Airway mucus and mucins were evaluated in COVID-19 autopsy lungs by Alcian blue and periodic acid-Schiff staining, immunohistochemical staining, RNA in situ hybridization, and spatial transcriptional profiling. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected human bronchial epithelial (HBE) cultures were used to investigate mechanisms of SARS-CoV-2-induced mucin expression and synthesis and test candidate countermeasures. Measurements and Main Results: MUC5B and variably MUC5AC RNA concentrations were increased throughout all airway regions of COVID-19 autopsy lungs, notably in the subacute/chronic disease phase after SARS-CoV-2 clearance. In the distal lung, MUC5B-dominated mucus plugging was observed in 90% of subjects with COVID-19 in both morphologically identified bronchioles and microcysts, and MUC5B accumulated in damaged alveolar spaces. SARS-CoV-2-infected HBE cultures exhibited peak titers 3 days after inoculation, whereas induction of MUC5B/MUC5AC peaked 7-14 days after inoculation. SARS-CoV-2 infection of HBE cultures induced expression of epidermal growth factor receptor (EGFR) ligands and inflammatory cytokines (e.g., IL-1α/β) associated with mucin gene regulation. Inhibiting EGFR/IL-1R pathways or administration of dexamethasone reduced SARS-CoV-2-induced mucin expression. Conclusions: SARS-CoV-2 infection is associated with a high prevalence of distal airspace mucus accumulation and increased MUC5B expression in COVID-19 autopsy lungs. HBE culture studies identified roles for EGFR and IL-1R signaling in mucin gene regulation after SARS-CoV-2 infection. These data suggest that time-sensitive mucolytic agents, specific pathway inhibitors, or corticosteroid administration may be therapeutic for COVID-19 lung disease.

Size matters - redefining sex differences among patients with transthyretin amyloid cardiomyopathy – have we been wrong all along?

Background

Transthyretin amyloid cardiomyopathy (ATTR-CM) is most often diagnosed in men (1–5). The few available studies suggest affected women have a more favourable cardiac phenotype (5–8), but remain unclear regarding differences in outcomes.

Objectives and methods

To characterise sex differences among consecutive patients with non-hereditary and two prevalent forms of hereditary ATTR-CM diagnosed over a 20-year period at our specialist centre through analysis of deep phenotyping at presentation, changes on serial echocardiography and overall prognosis.

Results

In total, 1732 patients were studied, comprising: 1095 with wild-type (wt)ATTR-CM; 206 with T60A-hATTR-CM; and 431 with V122I-hATTR-CM. Female prevalence was greater in T60A-hATTR-CM (29.6%) and V122I-hATTR-CM (27.8%) compared to wtATTR-CM (6%). At presentation, females were 3.3 years older than males (81.9 vs 77.8 years for wtATTR-CM; 68.7 vs 65.1 years for T60A-hATTR-CM; 77.1 vs 74.9 years for V122I-hATTR-CM). At diagnosis, non-indexed measures of wall thickness were significantly greater in males (interventricular septum in diastole (IVSd) of 17.13mm in males & 16.15mm in females; p<0.001). When indexed for body surface area (BSA), we observed that the mean indexed IVSd was fairly constant in males throughout the study period, but in females, had a tendency to decrease over the same study period. Furthermore, BSA significantly influenced measures of disease severity. When indexed for BSA, overall structural and functional phenotype was similar between sexes; the few observed significant differences including indexed IVSd (9.62mm/m2 in females & 8.88mm/m2 in males; p<0.001), indexed left ventricular (LV) end-diastolic volume (35.07ml/m2 in females & 41.05ml/m2 in males; p<0.001) and indexed LV end-systolic volume (17.95ml/m2 in females & 21.74ml/m2 in males; p<0.001) suggested a mildly worse phenotype in females. No significant differences were observed in disease progression on serial echocardiography and mortality across the overall population (p=0.459) and when divided by genotype (p=0.730 for wtATTR-CM; p=0.161 for T60A-hATTR-CM; p=0.056 for V122I-hATTR-CM).

Conclusion

This study of a well-characterized large cohort of ATTR-CM patients, contrary to previous dogmas, did not demonstrate overall differences between sexes in either clinical phenotype, when indexed, or with respect to disease progression and prognosis. The analysis highlighted the deficiencies in using non-indexed values which can not only lead to the inaccurate perception of a milder clinical phenotype in women compared to men, but has been shown to result in female patients presenting at an older age and with a worse phenotype compared to men. These findings indicate the need for revision of existing clinical guidelines regarding awareness and diagnosis of ATTR-CM in women, and modification of clinical trials which currently use single non-indexed threshold for wall thickness as key inclusion criterion.

Funding Acknowledgement

Type of funding sources: Foundation.

Cardiac transplantation in transthyretin amyloid cardiomyopathy: outcomes from three decades of tertiary centre experience

Background

Transthyretin cardiac amyloidosis (ATTR-CM) is a progressive and fatal cardiomyopathy. Treatment options in patients with advanced heart failure are limited to cardiac transplantation (CT). Despite small case series demonstrating comparable outcomes with CT between patients with ATTR-CM and non-amyloid cardiomyopathies, ATTR-CM is considered to be an absolute contraindication to CT in some centres. This is in part due to a perceived risk of amyloid recurrence in the cardiac allograft. We report outcomes of patients with ATTR-CM assessed at our centre whom underwent CT over the past thirty years.

Methods

We retrospectively evaluated all ATTR-CM patients assessed at the UK National Amyloidosis Centre between 1990 and 2020 who underwent CT. Pre-transplantation disease and patient characteristics were determined and outcomes were compared with our large cohort of non-transplanted ATTR-CM patients. Censor date was 11th January 2022.

Results

Eleven (9 male, 2 female) patients with ATTR-CM underwent CT including 8 with wild-type ATTR-CM and 3 with variant ATTR-CM (ATTRv). Median age at CT was 60.3 years and median follow up post-CT was 65.7 months. Median (range) NT-proBNP concentration pre-transplant was 4478ng/L (1057–8778ng/L), median (range) left ventricular ejection fraction (LVEF) was 39% (27–56%) and mean (IQR) interventricular septal (IVSD) was 18 mm (15.9–20.1 mm). 8 patients were NYHA functional class III, the 3 remaining patients were class II.

One, three, and five-year survival was 100%, 89% and 86%, respectively and the longest surviving patient was censored >19 years post CT. Survival is at least comparable to UK and US CT outcome registry data for all non-amyloid patients undergoing CT. No patients had recurrence of amyloid in the cardiac allograft as assessed by endomyocardial biopsy and/or Tc-DPD scintigraphy. Two patients were commenced on Patisiran for amyloid polyneuropathy at 211 and 5 months post-CT. Graft rejection requiring treatment was observed in 2 patients, and successfully treated with intravenous steroids. Renal impairment was common, with 6 patients being left with chronic kidney disease.

Three patients died, including one with ATTRv-CM from complications of leptomeningeal amyloidosis. Survival among the cohort of patients who underwent CT was significantly longer than UK patients with ATTR-CM generally (P≤0.006), regardless of NAC ATTR disease stage and including those diagnosed under 65 years of age (P=0.028). (Figure 1) All surviving patients were NYHA functional class I at time of censor.

Conclusion

Our data indicates that cardiac transplantation is well tolerated, restores functional capacity, and prolongs survival in ATTR-CM with little risk of recurrence of amyloid in the cardiac allograft. We believe that our data argues strongly for ATTR-CM to be routinely included in the list of indications for cardiac transplantation.

Funding Acknowledgement

Type of funding sources: None.

Progression, regression and redefining the treatment response – cardiac magnetic resonance with T1 and extracellular volume mapping in cardiac light-chain amyloidosis

Background

The presence and severity of cardiac involvement in AL amyloidosis is the main driver of prognosis [1]; patients with symptomatic heart failure frequently die within 6 months [1] but median survival has nearly doubled over the past decade, mainly due to significant improvements in chemotherapy. The haematological response to chemotherapy is principally evaluated with serial measurements of serum-free light-chains (FLC) [2]. The cardiac response to chemotherapy is assessed through changes in serum concentrations of brain natriuretic peptides (including NT-proBNP) and echocardiographic parameters [3–5]. Neither are able to directly measure cardiac amyloid burden. Cardiovascular magnetic resonance (CMR) with extra-cellular volume (ECV) mapping can measure the extent cardiac amyloid infiltration [6].

Aims

We investigated the ability of CMR to: 1) measure changes in response to chemotherapy; 2) assess the correlation between haematological response (HMR) and changes in cardiac amyloid; 3) assess the association between changes in cardiac amyloid and prognosis over and above existing predictors.

Methods

In total, 176 patients with cardiac light-chain amyloidosis treated with chemotherapy were assessed with FLC, NT-proBNP and CMR with ECV mapping at baseline (before chemotherapy), 6-months, 12-months & 24-months after commencing chemotherapy. Haematological response was categorized by reductions in FLC as: complete response (CR), very good partial response (VGPR), partial response (PR) or no response (NR). CMR response was categorized by changes in ECV as: progression (≥0.05 increase), stable (<0.05 change) or regression (≥0.05 decrease).

Results

A progressive increase in patients achieving either CR or VGPR was observed at each time point (61% of patients at 6-months, 71% at 12-months and 80% at 24-months). At 6-months, CMR regression was observed in 3% (all had either CR or VGPR) and progression in 32% (61% had either PR or NR; 39% had either CR or VGPR). At 1-year, CMR regression was observed in 22% (all had either CR or VGPR); progression in 22% (63% had either PR or NR; 37% had either CR or VGPR). At 2-years, CMR regression was observed in 38% (all had CR/VGPR); progression in 14% (80% had either PR or NR; 20% had either CR or VGPR). During follow-up (40±15 months), 36 (25%) patients died. CMR response at 6-months predicted death (progression HR 3.821; 95% CI 1.950–7.487; p<0.001) and remained independently associated with prognosis after adjusting for haematological response, NT-proBNP and longitudinal strain on echocardiography (p<0.01).

Conclusions

CMR demonstrates that cardiac amyloid deposits frequently regress following chemotherapy, but only in patients who achieve CR or VGPR, highlighting the need for deep haematological response. Changes in amyloid burden (ECV) predict outcomes after adjusting for known predictors, showing the crucial role of CMR in redefining treatment response.

Funding Acknowledgement

Type of funding sources: Foundation.

SARS-CoV-2 infection produces chronic pulmonary epithelial and immune cell dysfunction with fibrosis in mice

A subset of individuals who recover from coronavirus disease 2019 (COVID-19) develop post-acute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal tissue samples. The mouse-adapted SARS-CoV-2 strain MA10 produces an acute respiratory distress syndrome in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute to clinical recovery phases. At 15 to 120 days after virus clearance, pulmonary histologic findings included subpleural lesions composed of collagen, proliferative fibroblasts, and chronic inflammation, including tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal up-regulation of profibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early antifibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

A model of persistent post SARS-CoV-2 induced lung disease for target identification and testing of therapeutic strategies

COVID-19 survivors develop post-acute sequelae of SARS-CoV-2 (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal samples. Mouse-adapted SARS-CoV-2 MA10 produces an acute respiratory distress syndrome (ARDS) in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute disease through clinical recovery. At 15-120 days post-virus clearance, histologic evaluation identified subpleural lesions containing collagen, proliferative fibroblasts, and chronic inflammation with tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal upregulation of pro-fibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early anti-fibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

In vitro and in vivo modulation of NADPH oxidase activity and reactive oxygen species production in human neutrophils by α1-antitrypsin

Oxidative stress from innate immune cells is a driving mechanism that underlies COPD pathogenesis. Individuals with α-1 antitrypsin (AAT) deficiency (AATD) have a dramatically increased risk of developing COPD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil NADPH oxidase activation, due to the specific lack of plasma AAT.

Experiments were performed using circulating neutrophils isolated from healthy controls and individuals with AATD. Superoxide anion (O₂⁻) production was determined from the rate of reduction of cytochrome c. Quantification of membrane NADPH oxidase subunits was performed by mass spectrometry and Western blot analysis. The clinical significance of our in vitro findings was assessed in patients with AATD and severe COPD receiving intravenous AAT replacement therapy.

In vitro, AAT significantly inhibited O₂⁻ production by stimulated neutrophils and suppressed receptor stimulation of cyclic adenosine monophosphate and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. In addition, AAT reduced plasma membrane translocation of cytosolic phox components of the NADPH oxidase. Ex vivo, AATD neutrophils demonstrated increased plasma membrane-associated p67^phox and p47^phox and significantly increased O₂⁻ production. The described variance in phox protein membrane assembly was resolved post-AAT augmentation therapy in vivo, the effects of which significantly reduced AATD neutrophil O₂⁻ production to that of healthy control cells.

These results expand our knowledge on the mechanism of neutrophil-driven airways disease associated with AATD. Therapeutic AAT augmentation modified neutrophil NADPH oxidase assembly and reactive oxygen species production, with implications for clinical use in conditions in which oxidative stress plays a pathogenic role.

Circulating neutrophils in COPD due to α₁-antitrypsin deficiency illustrate increased NADPH oxidase assembly and reactive oxygen species production, a defect corrected by α₁-antitrypsin augmentation therapyhttps://bit.ly/38NNTzM

Alpha-1 Antitrypsin Augmentation Inhibits Proteolysis of Neutrophil Membrane Voltage-Gated Proton Channel-1 in Alpha-1 Deficient Individuals

Background and Objectives: Alpha-1 antitrypsin is a serine protease inhibitor that demonstrates an array of immunomodulatory functions. Individuals with the genetic condition of alpha-1 antitrypsin deficiency (AATD) are at increased risk of early onset emphysematous lung disease. This lung disease is partly driven by neutrophil mediated lung destruction in an environment of low AAT. As peripheral neutrophil hyper-responsiveness in AATD leads to excessive degranulation and increased migration to the airways, we examined the expression of the membrane voltage-gated proton channel-1 (HVCN1), which is integrally linked to neutrophil function. The objectives of this study were to evaluate altered HVCN1 in AATD neutrophils, serine protease-dependent degradation of HVCN1, and to investigate the ability of serum AAT to control HVCN1 expression. Materials and Methods: Circulating neutrophils were purified from AATD patients (n = 20), AATD patients receiving AAT augmentation therapy (n = 3) and healthy controls (n = 20). HVCN1 neutrophil expression was assessed by flow cytometry and Western blot analysis. Neutrophil membrane bound elastase was measured by fluorescence resonance energy transfer. Results: In this study we demonstrated that HVCN1 protein is under-expressed in AATD neutrophils (p = 0.02), suggesting a link between reduced HVCN1 expression and AAT deficiency. We have demonstrated that HVCN1 undergoes significant proteolytic degradation in activated neutrophils (p < 0.0001), primarily due to neutrophil elastase activity (p = 0.0004). In addition, the treatment of AATD individuals with AAT augmentation therapy increased neutrophil plasma membrane HVCN1 expression (p = 0.01). Conclusions: Our results demonstrate reduced levels of HVCN1 in peripheral blood neutrophils that may influence the neutrophil-dominated immune response in the AATD airways and highlights the role of antiprotease treatment and specifically AAT augmentation therapy in protecting neutrophil membrane expression of HVCN1.

A 33-Year-Old Man With Dyspnea, Chest Pain, and a Massive Pleural Effusion

CASE PRESENTATION

A 33-year-old white man presented to the ED with 1-month history of worsening dyspnea. He experienced gradual onset of right-sided scapular pain and shortness of breath on exertion that progressively worsened over the course of 1 month. He had a mild nonproductive cough and intermittent subjective fevers and reported weight loss of approximately 2 kg over 1 month. He had a history of two episodes of acute pancreatitis that was thought to be autoimmune in origin. He was a never smoker; he denied illicit drug use or recent alcohol consumption. He had no known TB exposure, but his mother had a history of sarcoidosis.

Clinical importance of left atrial infiltration in cardiac transthyretin amyloidosis

Funding Acknowledgements

Type of funding sources: None.

INTRODUCTION

 The clinical significance of left atrial (LA) involvement in ATTR amyloidosis cardiomyopathy (ATTR-CM) has not been characterized. The aims of this study were to characterize: (1)LA pathology in explanted ATTR-CM hearts; (2)LA mechanics using echocardiographic speckle-tracking in a large cohort of ATTR-CM patients; (3)to study the association with mortality.

METHODS AND RESULTS

Congo red staining and immunohistochemistry was performed to assess the presence, type and extent of amyloid and associated changes in 5 explanted ATTR-CM atria. Echo speckle-tracking was used to assess LA reservoir, conduit, contractile function and stiffness in 906 ATTR-CM patients (551 wt-ATTR-CM;93 T60A-ATTR-CM;241 V122I-ATTR-CM;21 other).

There was extensive ATTR amyloid infiltration in the 5 atria with loss of normal architecture, vessels remodelling, capillary disruption and subendocardial fibrosis. Echo speckle-tracking in 906 ATTR-CM patients demonstrated increased atrial stiffness [median(25th-75th quartile) 1.83(1.15-2.92)] that remained independently associated with prognosis, after adjusting for known predictors (lnLA stiff:HR = 1.26,CI 1.07-1.57;p = 0.009). There was substantial impairment of the three phasic functional atrial components [reservoir 8.86(5.94-12.97)%; conduit 6.5(4.53-9.28)%; contraction function 4.0(2.29-6.56)%]. Atrial contraction was absent in 21.6% of patients whose ECG showed sinus rhythm (SR)-"atrial electro-mechanical dissociation"(AEMD). AEMD was associated with poorer prognosis compared to SR patients with effective mechanical contraction (p &lt; 0.0001). AEMD conferred a similar prognosis to patients in AF.

CONCLUSION

The phenotype of ATTR-CM includes significant infiltration of the atrial walls with progressive loss of atrial function and increased stiffness, which is a strong independent predictor of mortality. AEMD emerged as a distinctive phenotype identifying patients in SR with poor prognosis.

Abstract Figure.

Altered Degranulation and pH of Neutrophil Phagosomes Impacts Antimicrobial Efficiency in Cystic Fibrosis

Studies have endeavored to understand the cause for impaired antimicrobial killing by neutrophils of people with cystic fibrosis (PWCF). The aim of this study was to focus on the bacterial phagosome. Possible alterations in degranulation of cytoplasmic granules and changes in pH were assessed. Circulating neutrophils were purified from PWCF (n = 28), PWCF receiving ivacaftor therapy (n = 10), and healthy controls (n = 28). Degranulation was assessed by Western blot analysis and flow cytometry. The pH of phagosomes was determined by use of BCECF-AM-labelled Staphylococcus aureus or SNARF labelled Candida albicans. The antibacterial effect of all treatments tested was determined by colony forming units enumeration. Bacterial killing by CF and healthy control neutrophils were found to differ (p = 0.0006). By use of flow cytometry and subcellular fractionation the kinetics of intraphagosomal degranulation were found to be significantly altered in CF phagosomes, as demonstrated by increased primary granule CD63 (p = 0.0001) and myeloperoxidase (MPO) content (p = 0.03). In contrast, decreased secondary and tertiary granule CD66b (p = 0.002) and decreased hCAP-18 and MMP-9 (p = 0.02), were observed. After 8 min phagocytosis the pH in phagosomes of neutrophils of PWCF was significantly elevated (p = 0.0001), and the percentage of viable bacteria was significantly increased compared to HC (p = 0.002). Results demonstrate that the recorded alterations in phagosomal pH generate suboptimal conditions for MPO related peroxidase, and α-defensin and azurocidine enzymatic killing of Staphylococcus aureus and Pseudomonas aeruginosa. The pattern of dysregulated MPO degranulation (p = 0.02) and prolonged phagosomal alkalinization in CF neutrophils were normalized in vivo following treatment with the ion channel potentiator ivacaftor (p = 0.04). Our results confirm that alterations of circulating neutrophils from PWCF are corrected by CFTR modulator therapy, and raise a question related to possible delayed proton channel activity in CF.

Regression of cardiac amyloid deposits with novel therapeutics: reaching new frontiers in cardiac ATTR amyloidosis

Background

Cardiac involvement is the main driver of outcome in ATTR amyloidosis. Advances in therapeutics hold potential in transforming the course of the disease but the impact on cardiac amyloid load is unknown. The aim of this study was to evaluate the impact of patisiran, a new double stranded RNA based gene silencing therapy and a stabilizer, diflunisal, on cardiac amyloid load as measured by CMR and T1 mapping, in patients with ATTR amyloidosis.

Methods and results

Thirty-two patients with hereditary cardiac amyloidosis were studied. Sixteen patients received treatment with patisiran, and sixteen control subjects did not receive any disease modifying treatment. Patients were assessed with echocardiogram, CMR, NT-proBNP and six-minute walk time measurements at baseline and at 1 year (Mean interval 11.45±3.08 months in treatment group, mean interval 12.82±5.06 months in the control group). CMR analysis comprised LV volumes, T1 mapping to measure the extracellular volume (ECV) occupied by amyloid, T2 mapping and late gadolinium enhancement imaging. At 1-year follow-up, there was a substantial reduction in cardiac amyloid burden, in keeping with cardiac amyloid regression in 45% of patients on treatment. Overall the treatment group showed a reduction in ECV at 1 year follow up compared to an increase in ECV at 1 year in the control group (−1.37%, 95% CI: −3.43 to 0.68% versus 5.02%, 95% CI: 2.86% to 7.18% respectively, p&lt;0.001). The treatment group also showed an improvement in change in 6MWT at 1 year follow up compared to 6MWT at 1 year in the control group (−8.12 meters, 95% CI: −50.8 to 34.6 meters in the treatment group versus −132.27 meters, 95% CI: −216 to −48.6 meters in the control group, p=0.002). The treatment group showed a reduction in BNP at 1 year follow up compared to an increase in the control group (−567.87, 95% CI: −1288.90 to 153.15 in the treatment group versus 2004, 95% CI: 12.82 to 3995.45 in the control group, p&lt;0.001). There was no significant difference from baseline and 1-year data between the control and treatment groups for the difference in echocardiographic parameters, native T1, T2. There was a significant reduction in the percentage of injected dose by 99Tc-DPD scintigraphy in treated patients at 1 year compared to baseline.

Conclusions

These findings provide the first compelling evidence of substantial cardiac amyloid regression in ATTR amyloidosis, as well as the potential for CMR to be used to track response in treated patients with ATTR cardiac amyloidosis. Combination therapy with transthyretin knock down and stabilizing agents may well be synergistic given enhanced stoichiometry of stabilizers in the face of much reduced plasma transthyretin concentration.

Funding Acknowledgement

Type of funding source: None

Global longitudinal strain predicts survival and response in patients with systemic AL amyloidosis. analysis of 915 patients from the ALchemy prospective trial

Background

Cardiac involvement determines prognosis in systemic AL amyloidosis. The extent is assessed by biomarker-based staging systems. This a prospective report of a large cohort of patients assessing the utility of changes in longitudinal function by 2D strain (GLS%), impairment - a hallmark of amyloidosis.

Purpose

To evaluate the prognostic role of GLS% and other echocardiographic parameters in systemic AL amyloidosis.

Methods

915 newly diagnosed patients seen at the UK National Amyloidosis Centre (February 2010–August 2017) were included. All patients underwent 6-monthly comprehensive assessments inclusive of echocardiogram. The European modification of the Mayo 2004 staging was used with Mayo stage III patients stratified into IIIa (NT-proBNP &lt;8500ng/L) and IIIb (NT-proBNP ≥8500ng/L).

Results

653/915 (71.4%) patients had cardiac involvement. Mayo stage 1, 2, 3a and 3b in 144 (15.7%), 302 (33.0%) 344 (37.6%) and 125 (13.7%) respectively. The median NT-proBNP was 2228ng/L and TNT was 0.54ng/ml. The GLS% significantly worsened with increasing Mayo stage (p&lt;0.0001 between GLS% for each Mayo stage). Poorer baseline GLS% associated with significantly worse OS and stratified patients into three groups: GLS% &lt;−12.8%: OS 69.1 months; GLS% −12.8% to −9%: OS 54.5 months; GLS% &gt;−9%: OS 45.3 months (p&lt;0.0001). On univariate analysis, 11/14 parameters predicted survival (LV wall thickness, LV ejection fraction, systolic velocities of the septal (s'sep) and lateral mitral annulus (s' lat), mitral annulus movement at the lateral corner (e' lat), transmitral early peak flow velocity (E) divided by tissue Doppler mitral annular motion velocity (e') – E/e' and mitral annular plane systolic excursion (MAPSE)). Baseline GLS% &gt;−17% was independent of Mayo stage in predicting survival [Mayo II: Hazard ratio (HR) 2.10 (95% CI: 1.12–3.92) p=0.02, Mayo III: HR 3.94 (95% CI: 2.13–7.32) p&lt;0.0001, Mayo IV: HR 7.49 (95% CI: 3.94–14.21) p&lt;0.0001, GLS &lt;17%: HR 2.14 (95% CI: 1.59–2.88) p&lt;0.0001]. At 12 months, only patients in a haematological complete response (CR) had significant improvement in overall GLS% (p=0.02) as well as baso-lateral (p=0.0004) and baso-septal (p=0.0001) GLS% and MAPSE (p=0.002). The OS was significantly better in patients who achieved a minimum absolute improvement in GLS% of 1.5% improvement (not reached in those with improved GLS% vs. 72 mo in those without) (p=0.034)).

Conclusion

These data show that baseline GLS% is an independent predictor of survival in AL amyloidosis. GLS% is the first functional marker that is independent of the Mayo staging in predicting outcomes and should be incorporated in prognostic staging for patients with AL amyloidosis. GLS% shows improvement in patients who achieve a complete haematologic response to treatment and improvement in GLS% of 1.5% is associated with improved outcomes. An absolute improvement in GLS% should be considered as a criterion for cardiac response in AL amyloidosis.

Funding Acknowledgement

Type of funding source: None

α1 Antitrypsin therapy modulates the neutrophil membrane proteome and secretome

Obstructive pulmonary disease in patients with α₁ antitrypsin (AAT) deficiency (AATD) occurs earlier in life compared with patients without AATD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil characteristics, due to the specific lack of plasma AAT, compared with non-AATD COPD.This study focussed on the neutrophil plasma membrane and, by use of label-free tandem mass spectrometry, the proteome of the neutrophil membrane was compared in forced expiratory volume in 1 s (FEV₁)-matched AATD, non-AATD COPD and in AATD patients receiving weekly AAT augmentation therapy (n=6 patients per cohort). Altered protein expression in AATD was confirmed by Western blot, ELISA and fluorescence resonance energy transfer analysis.The neutrophil membrane proteome in AATD differed significantly from that of COPD as demonstrated by increased abundance and activity of primary granule proteins including neutrophil elastase on the cell surface in AATD. The signalling mechanism underlying increased degranulation involved Rac2 activation, subsequently resulting in proteinase-activated receptor 2 activation by serine proteinases and enhanced reactive oxygen species production. In vitro and ex vivo, AAT reduced primary granule release and the described plasma membrane variance was resolved post-AAT augmentation therapy in vivo, the effects of which significantly altered the AATD neutrophil membrane proteome to that of a non-AATD COPD cell.These results provide strong insight into the mechanism of neutrophil driven airways disease associated with AATD. Therapeutic AAT augmentation modified the membrane proteome to that of a typical COPD cell, with implications for clinical practice.

1171Myocardial perfusion mapping in cardiac amyloidosis - exploring the spectrum from infiltration to ischaemia

Background

Cardiac involvement is the main driver of outcome in systemic amyloidosis, but the relationship between amyloid deposits and outcomes is not well understood. The simple explanation of physical, mechanical replacement of the interstitium by amyloid seems insufficient. Preliminary studies support the hypothesis that myocardial ischaemia could contribute to cell damage.

Purpose

(1) To assess myocardial ischaemia in cardiac amyloidosis. (2) To compare patients with cardiac amyloidosis to patients assessed on invasive coronary angiography (ICA) to have normal coronary physiology (NCP), microvascular dysfunction (MVD) and triple vessel coronary disease (3VD). (3) To assess correlation of perfusion mapping to markers of disease severity and prognosis.

Methods

86 patients and 20 healthy volunteers (HV) underwent CMR at 1.5T (Siemens) with standard cine, PSIR-LGE, T1, T2, Extracellular Volume (ECV) mapping and adenosine stress with myocardial blood flow (MBF) mapping. Thirty-eight patients also underwent ICA with 3 vessel assessment of Index of Microcirculatory Resistance and Fractional Flow Reserve: 7 had cardiac amyloidosis, 8 had NCP, 15 had MVD and 8 had 3VD.

Results

Cardiac amyloidosis patients had severe reduction in stress MBF and myocardial perfusion reserve (MPR) (1.22ml/g/min±0.70 and 1.62±0.63) compared to HV (3.21ml/g/min±0.64, p<0.001 and 4.17±0.78, p<0.001), NCP (2.66±0.56, p<0.001 and 2.51±0.43, p=0.036) and MVD (2.10±0.31, p<0.001 and 2.29±0.87, p=0.014) with the degree of reduction being similar only to patients with 3VD (1.44±0.54, p=1.000 and 1.64±0.68, p=1.000) (Figure 1). Rest MBF was also lower in amyloidosis than HV. Cardiac amyloidosis stress MBF and MPR inversely correlated with amyloid burden (ECV, r=−0.715, p<0.001, transmurality of LGE, p<0.01), systolic dysfunction (EF, r=0.405, p<0.01), and blood biomarkers (NT-proBNP (r=−0.678, p<0.001) and Troponin T (r=−0.628, p<0.001)). There was a correlation between stress MBF and native T1 (r=−0.588, p<0.001) but not T2 (p=0.591). Stress MBF and MPR were early disease markers, being elevated in patients with early cardiac amyloid infiltration (raised ECV, no LGE, P<0.01 vs HV).

Conclusion

Myocardial ischaemia is common in cardiac amyloidosis – with stress MBF and MPR similar to that of patients with 3VD. The reduction correlates with the degree of amyloid infiltration and markers of adverse prognosis, highlighting the potential role of myocardial ischaemia as a key mechanism in the pathophysiology of cardiac amyloidosis.

Multicentric Evaluation of a New PT Reagent Based on Recombinant Human Tissue Factor and Synthetic Phospholipids

A new PT reagent based on recombinant human tissue factor and synthetic phospholipids (phosphatidyl choline and phosphatidyl serine) with defined fatty acid side chains was calibrated against BCT/253 and CRM 149R. A small but consistent bias in the International Sensitivity Index (ISI) value was obtained using either the human or rabbit brain reference material. ISI values were around 1.0 or slightly lower depending on the respective instrument. Mixing studies with factor deficient plasmas showed a high factor sensitivity especially for factor VII as compared to commercial rabbit brain or human placenta thromboplastin. In an international field trial the reagent was tested using fully or semi automated Electra™ coagulometers in 4 different laboratories. Results with normal samples were in excellent agreement among the different laboratories. Mean values were 10.9, 10.9, 11.0, 11,7 s with a range of 9.5 to 12.5 s. Results of males and females were not different. In patients with liver disease very similar PT activities were found as compared to sensitive rabbit brain or human placental thromboplastins. In normals and patients with oral anticoagulation INR values correlated very well against BCT (r = 0.98, regression line y =-0.07 + 0.9 x). The distribution of samples was linear over the whole range. In the comparison against sensitive rabbit brain thromboplastin or human placental thromboplastin similar correlations were found. In a few cases higher INR values were observed for the recombinant reagent especially in patients with intensive treatment. Factor assays in those patients showed at least the strong reduction of one vitamin Independent coagulation factor. Over all the linearity was better against the rabbit brain reagent than against the human placental reagent which is slightly less factor VII sensitive as shown in mixing studies with normal and factor VII deficient plasma. Precision studies in the 4 laboratories showed excellent reproducibility of lyophilised controls or local patient plasma pools for all reagents with a better performance of the recombinant reagent. C. V. values from day to day ranged from 1.3% to 5% for normal and abnormal controls.

These results show that the recombinant PT reagent, especially in conjunction with a precise automated instrument, may improve the results of PT testing and thus may lead to better patient care.

Femtosecond Laser Mass Spectrometry and High Harmonic Spectroscopy of Xylene Isomers

Structural isomers, molecules having the same chemical formula but with atoms bonded in different order, are hard to identify using conventional spectroscopy and mass spectrometry. They exhibit virtually indistinguishable mass spectra when ionized by electrons. Laser mass spectrometry based on photoionization of the isomers has emerged as a promising alternative but requires shaped ultrafast laser pulses. Here we use transform limited femtosecond pulses to distinguish the isomers using two methods. First, we probe doubly charged parent ions with circularly polarized light. We show that the yield of doubly charged ortho-xylene decreases while para-xylene increases over a range of laser intensities when the laser polarization is changed from linear to circular. Second, we probe high harmonic generation from randomly oriented isomer molecules subjected to an intense laser field. We show that the yield of high-order harmonics varies with the positioning of the methyl group in xylene isomers (ortho-, para- and meta-) and is due to differences in the strength of tunnel ionization and the overlap between the angular peaks of ionization and photo-recombination.

Alpha-1-antitrypsin deficiency-related panniculitis: two cases with diverse clinical courses

Alpha-1-antitrypsin deficiency (AATD)-related panniculitis is an extremely rare and underdiagnosed entity, and there is a paucity of data on its treatment. We report two cases of AATD-related panniculitis. The first was a 24-year-old woman with known AATD who presented with painful leg ulcers refractory to treatment with corticosteroids and colchicine. She had a good response to α1-antitrypsin infusions but required dose adjustment due to flares in disease activity. The second case was a 38-year-old woman who presented with painful nodules on the legs refractory to corticosteroid therapy. Laboratory investigations revealed severe AATD. She had an excellent response to colchicine therapy. In both these cases of AATD, panniculitis was the first clinical manifestation of the disease. AATD-related panniculitis may have none of the typical clinical clues for AATD, such as a family history, cirrhosis or emphysema. Early identification may help prevent these complications from developing.

Genome-wide association study of immunoglobulin light chain amyloidosis in three patient cohorts: comparison with myeloma

Immunoglobulin light chain (AL) amyloidosis is characterized by tissue deposition of amyloid fibers derived from immunoglobulin light chain. AL amyloidosis and multiple myeloma (MM) originate from monoclonal gammopathy of undetermined significance. We wanted to characterize germline susceptibility to AL amyloidosis using a genome-wide association study (GWAS) on 1229 AL amyloidosis patients from Germany, UK and Italy, and 7526 healthy local controls. For comparison with MM, recent GWAS data on 3790 cases were used. For AL amyloidosis, single nucleotide polymorphisms (SNPs) at 10 loci showed evidence of an association at P<10^-5 with homogeneity of results from the 3 sample sets; some of these were previously documented to influence MM risk, including the SNP at the IRF4 binding site. In AL amyloidosis, rs9344 at the splice site of cyclin D1, promoting translocation (11;14), reached the highest significance, P=7.80 × 10^-11; the SNP was only marginally significant in MM. SNP rs79419269 close to gene SMARCD3 involved in chromatin remodeling was also significant (P=5.2 × 10^-8). These data provide evidence for common genetic susceptibility to AL amyloidosis and MM. Cyclin D1 is a more prominent driver in AL amyloidosis than in MM, but the links to aggregation of light chains need to be demonstrated.

A novel oxygen and/or carbon dioxide-sensitive optical transducer

A novel oxygen (O(2)) and/or carbon dioxide (CO(2))-sensitive transducer for the measurement of both gaseous O(2) and CO(2) over the concentration ranges of O(2), 0-100% and CO(2), 0-10% has been described employing a solution of 10.6 muM fluorescein (FL) and 190 muM potassium hydroxide in a solvent mixtures of 1:1 (v/v) N,N'-diethylaniline (DEA) and N,N-dimethylformamide. Increasing O(2) concentrations cause the absorbance of the solution at a wavelength of 400 nm to increase owing to a contact charge transfer reaction existing between O(2) and DEA molecules, and increasing CO(2) concentrations produce a non-linear fall in absorbance at 520 nm as the colour of FL changes from its orange dianion form to the colourless neutral, lactonic form. Both processes are independent of each other and reversible. The response to changes in O(2) concentrations is in good agreement with Beer-Lambert's law and the response to changes in CO(2) concentrations in non-linear. A fibre optic sensing system based on this solvent-dye solution has been set up for continuous and reversible determination of both gaseous O(2) and CO(2). Possible applications include environmental and physiological monitoring of O(2) over the ranges of 0-100% and CO(2), 0-10%.

Guidance on the severity classification of scientific procedures involving fish: report of a Working Group appointed by the Norwegian Consensus-Platform for the Replacement, Reduction and Refinement of animal experiments (Norecopa)

The severity classification of procedures using animals is an important tool to help focus the implementation of refinement and to assist in reporting the application of the 3Rs (replacement, reduction and refinement). The recently revised Directive that regulates animal research and testing within the European Union requires Member States to ensure that all procedures are classified as ‘non-recovery’, ‘mild’, ‘moderate’ or ‘severe’, using assignment criteria set out by the European Commission (EC). However, these are focused upon terrestrial species, so are of limited relevance to fish users. A Working Group set up by the Norwegian Consensus-Platform for the 3Rs (Norecopa) has produced guidance on the classification of severity in scientific procedures involving fish, including examples of ‘subthreshold’, ‘mild’, ‘moderate’, ‘severe’ and ‘upper threshold’ procedures. The aims are to complement the EC guidelines and help to ensure that suffering in fish is effectively predicted and minimized. Norecopa has established a website (www.norecopa.no/categories) where more information on severity classification for procedures using fish, including field research, will be made available.