Cardiac transplant rejection assessment with 18F-FDG PET-CT: initial single-centre experience for diagnosis and management

BACKGROUND

Rejection is a major cause of mortality and morbidity in heart transplant (HTx) recipients. Current methods for diagnosing rejection have limitations. Imaging methods to map the entire left ventricle and reliably identify potential sites of rejection is lacking. Animal studies suggest FDG PET-CT (FDG PET) could have potential application in human HTx recipients.

METHODS

Between December 2020 and February 2022, all HTx recipients at Harefield Hospital, London, with definite or suspected rejection underwent FDG PET in addition to routine work-up.

RESULTS

Thirty HTx recipients (12 with definite and 18 with suspected rejection) underwent FDG PET scans. Overall, 12 of the 30 patients had FDG PET with increased myocardial avidity, of whom 2 died (17%). Eighteen patients of the 30 patients had FDG PET with no myocardial avidity and all are alive (100%, p = 0.15). All patients with definite rejection, scanned within 2 weeks of starting anti-rejection treatment, showed increased myocardial avidity. In 5 cases, FDG PET showed myocardial avidity beyond 6 weeks despite pulsed steroid treatment, suggesting unresolved myocardial rejection.

CONCLUSION

Preliminary findings suggest FDG PET may have a role in diagnosing cardiac transplant rejection. Future blinded studies are needed to help further validate this.

Assessing the role of phosphorylated S6 ribosomal protein in the pathological diagnosis of pulmonary antibody-mediated rejection

BACKGROUND

Pulmonary antibody-mediated rejection is still a challenging diagnosis as C4d immunostaining has poor sensitivity. Previous studies have indicated that the phosphorylated S6 ribosomal protein, a component of the mammalian target of rapamycin (mTOR) pathway, is correlated with de novo donor-specific antibodies in lung transplantation. The objective of this study was to evaluate the phosphorylation of S6 ribosomal protein as a surrogate for antibody-mediated rejection diagnosis in lung transplant patients.

METHODS

This multicentre retrospective study analyzed transbronchial biopsies from 216 lung transplanted patients, 114 with antibody-mediated rejection and 102 without (19 with acute cellular rejection, 17 with ischemia/reperfusion injury, 18 with infection, and 48 without post-transplant complications). Immunohistochemistry was used to quantify phosphorylated S6 ribosomal protein expression in macrophages, endothelium, epithelium, and inter-pathologist agreement was assessed.

RESULTS

Median phosphorylated S6 ribosomal protein expression values were higher in antibody-mediated rejection cases than in controls for all cell components, with the highest sensitivity in macrophages (0.9) and the highest specificity in endothelial expression (0.8). The difference was mainly significant in macrophages compared to other post-lung transplantation complications. Inter-pathologist agreement was moderate for macrophages and endothelium, with higher agreement when phosphorylated S6 ribosomal protein expression was dichotomized into positive/negative. The inclusion of phosphorylated S6 ribosomal protein in the diagnostic algorithm could have increased antibody-mediated rejection certainty levels by 25%.

CONCLUSIONS

The study supports the role of the mTOR pathway in antibody-mediated rejection-related graft injury and suggests that tissue phosphorylation of S6 ribosomal protein could be a useful surrogate for a more accurate pathological diagnosis of lung antibody-mediated rejection.

Lung extracellular matrix modulates KRT5+ basal cell activity in pulmonary fibrosis

Aberrant expansion of KRT5+ basal cells in the distal lung accompanies progressive alveolar epithelial cell loss and tissue remodelling during fibrogenesis in idiopathic pulmonary fibrosis (IPF). The mechanisms determining activity of KRT5+ cells in IPF have not been delineated. Here, we reveal a potential mechanism by which KRT5+ cells migrate within the fibrotic lung, navigating regional differences in collagen topography. In vitro, KRT5+ cell migratory characteristics and expression of remodelling genes are modulated by extracellular matrix (ECM) composition and organisation. Mass spectrometry- based proteomics revealed compositional differences in ECM components secreted by primary human lung fibroblasts (HLF) from IPF patients compared to controls. Over-expression of ECM glycoprotein, Secreted Protein Acidic and Cysteine Rich (SPARC) in the IPF HLF matrix restricts KRT5+ cell migration in vitro. Together, our findings demonstrate how changes to the ECM in IPF directly influence KRT5+ cell behaviour and function contributing to remodelling events in the fibrotic niche.

The Global Task Force for Chronic Pain in People with HIV (PWH): Developing a research agenda in an emerging field

Chronic pain is a common comorbidity in people with HIV (PWH), with prevalence estimates of 25-85%. Research in this area is growing, but significant gaps remain. A Global Task Force of HIV experts was organized to brainstorm a scientific agenda and identify measurement domains critical to advancing research in this field. Experts were identified through literature searches and snowball sampling. Two online questionnaires were developed by Task Force members. Questionnaire 1 asked participants to identify knowledge gaps in the field of HIV and chronic pain and identify measurement domains in studies of chronic pain in PWH. Responses were ranked in order of importance in Questionnaire 2, which was followed by a group discussion. 29 experts completed Questionnaire 1, 25 completed Questionnaire 2, and 21 participated in the group. Many important clinical and research priorities emerged, including the need to examine etiologies of chronic pain in PWH. Pain-related measurement domains were discussed, with a primary focus on domains that could be assessed in a standardized manner across various cohorts that include PWH in different countries. We collaboratively identified clinical and research priorities, as well as gaps in standardization of measurement domains, that can be used to move the field forward.

Wheeze in the time of COVID-19: overcoming obstacles to an unusual diagnosis

This case is an example of a rare cause of a common clinical presentation (persistent lobar collapse with wheeze). We describe patient management from primary care through to a national thoracic referral centre. We highlight the importance of objective testing to support an asthma diagnosis and the need to consider alternative or additional diagnoses if a patient does not respond to treatment or the clinical course is unexpected. We highlight the importance of follow-up X-ray to determine whether atelectasis has resolved, which was significantly delayed in this case due to COVID-19 restrictions. Though rare, an endobronchial tumour should be considered if atelectasis persists and when planning endoscopy for a presumed foreign body, especially if the clinical history and patient factors make a foreign body less likely. Greater awareness of this as a differential may expedite diagnoses for patients in future. We show how virtual, multicentre, multidisciplinary meetings can aid rapid diagnosis, surgical planning and coordination of follow-up across centres.

Post-thymectomy myasthenia gravis: a case report and systematic review of literature

Myasthenia gravis (MG) is an autoimmune condition affecting the neuromuscular junction characterised by weakness and fatiguability, carrying a high morbidity if treatment is delayed. A clear association with thymoma has led to management with thymectomy as a common practice, but MG presenting post-thymectomy has rarely been reported. We present a case of an 82- year-old woman developing fatigue, ptosis and dysarthria 3 months after thymectomy. After a clinical diagnosis of MG was made, she responded well to prompt treatment with prednisolone and pyridostigmine. Her anti-acetylcholine receptor antibody (anti-AChR) subsequently came back positive. Our systematic review reveals that post-thymectomy MG can be categorised as early-onset or late-onset form with differing aetiology, and demonstrated correlation between preoperative anti-AChR titres and post-thymectomy MG. The postulated mechanisms for post-thymectomy MG centre around long-lasting peripheral autoantibodies. Clinicians should actively look for MG symptoms in thymoma patients and measure anti-AChR preoperatively to aid prognostication.

Responsibility for Structural Racism in Medicine: Reflections and Recommendations from One Institution

In this article, we draw upon recent ethical arguments by Zheng and Young to explain our experience applying the social connection model of responsibility to structural racism in medicine. We propose that taking responsibility for structural racism must begin with acknowledging, studying, and learning from localized, particular instances of racism. Such practices raise personal and institutional consciousness about racism and injustice, creating a knowledge base from which effective action is possible. We describe our experiences engaging with responsibility for structural racism as a small group of scholars dedicated to learning more about our institution's history and our own agency in altering its future trajectory. Our learning and introspection were developed over multiple sessions in the 2019-2020 academic year when the authors participated in a Medical Ethics Forum Fellowship.The Medical Ethics Forum Fellowship (the Forum) of the Medical University of South Carolina (MUSC) is composed of a diverse group of interdisciplinary faculty members, students, and practicing health professionals. The precise membership of the group changes every year, with a number of members continuing for multiple years. Each academic year the Forum focuses on a specific bioethical issue of current interest. Our focus for the academic year 2019-2020 was race and ethnicity in 21st century health care. This paper is the result of our year-long deliberations based on study of the relevant literature, monthly discussions, as well as personal presentations and discussions with nationally known scholars in this field.

The Respiratory Microbiome in Chronic Hypersensitivity Pneumonitis Is Distinct from That of Idiopathic Pulmonary Fibrosis

Rationale: Chronic hypersensitivity pneumonitis (CHP) is a condition that arises after repeated exposure and sensitization to inhaled antigens. The lung microbiome is increasingly implicated in respiratory disease, but, to date, no study has investigated the composition of microbial communities in the lower airways in CHP.

Objectives: To characterize and compare the airway microbiome in subjects with CHP, subjects with idiopathic pulmonary fibrosis (IPF), and control subjects.

Methods: We prospectively recruited individuals with a CHP diagnosis (n = 110), individuals with an IPF diagnosis (n = 45), and control subjects (n = 28). Subjects underwent BAL and bacterial DNA was isolated, quantified by quantitative PCR and the 16S ribosomal RNA gene was sequenced to characterize the bacterial communities in the lower airways.

Measurements and Main Results: Distinct differences in the microbial profiles were evident in the lower airways of subjects with CHP and IPF. At the phylum level, the prevailing microbiota of both subjects with IPF and subjects with CHP included Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. However, in IPF, Firmicutes dominated, whereas the percentage of reads assigned to Proteobacteria in the same group was significantly lower than the percentage found in subjects with CHP. At the genus level, the Staphylococcus burden was increased in CHP, and Actinomyces and Veillonella burdens were increased in IPF. The lower airway bacterial burden in subjects with CHP was higher than that in control subjects but lower than that of those with IPF. In contrast to IPF, there was no association between bacterial burden and survival in CHP.

Conclusions: The microbial profile of the lower airways in subjects with CHP is distinct from that of IPF, and, notably, the bacterial burden in individuals with CHP fails to predict survival.

Interleukin-31 promotes pathogenic mechanisms underlying skin and lung fibrosis in scleroderma

OBJECTIVES

Cytokines released by infiltrating T cells may promote mechanisms leading to fibrosis in scleroderma. The aim of this study was to investigate the role of the Th2 cytokine IL-31, and its receptor IL-31RA, in scleroderma skin and lung fibrosis.

METHODS

IL-31 was measured by ELISA of plasma, and by immunochemistry of fibrotic skin and lung tissue of scleroderma patients. The receptor, IL-31RA, was assayed by qPCR of tissue resident cells. Next-generation sequencing was used to profile the responses of normal skin fibroblasts to IL-31. In wild-type Balb/c mice, IL-31 was administered by subcutaneous mini pump, with or without additional TGFβ, and the fibrotic reaction measured by histology and ELISA of plasma.

RESULTS

IL-31 was present at high levels in plasma and fibrotic skin and lung lesions in a subset of scleroderma patients, and the receptor overexpressed by downstream cells relevant to the disease process, including skin and lung fibroblasts, through loss of epigenetic regulation by miR326. In skin fibroblasts, IL-31 induced next generation sequencing profiles associated with cellular growth and proliferation, anaerobic metabolism and mineralization, and negatively associated with angiogenesis and vascular repair, as well as promoting phenotype changes including migration and collagen protein release via pSTAT3, resembling the activation state in the disease. In mice, IL-31 induced skin and lung fibrosis. No synergy was seen with TGFβ, which supressed IL-31RA.

CONCLUSION

IL-31/IL-31RA is confirmed as a candidate pro-fibrotic pathway, which may contribute to skin and lung fibrosis in a subset of scleroderma patients.

Mucinous adenocarcinoma arising in congenital pulmonary airway malformation: clinicopathological analysis of 37 cases

AIMS

Mucinous adenocarcinoma arising in congenital pulmonary airway malformation (CPAM) is a rare complication, with little being known about its natural course. The aims of this article are to describe a series of mucinous adenocarcinomas arising from CPAMs, and present their clinicopathological features, genetics, and clinical outcome.

METHODS AND RESULTS

Thirty-seven cases were collected within a 34-year period, and the subtype of adenocarcinoma and CPAM, tumour location, stage, growth patterns, molecular data and follow-up were recorded. The cohort comprised CPAM type 1 (n = 33) and CPAM type 2 (n = 4). Morphologically, 34 cases were mucinous adenocarcinomas (21 in situ; 13 invasive), and three were mixed mucinous and non-mucinous adenocarcinoma. Seventeen cases showed purely extracystic (intra-alveolar) adenocarcinoma, 15 were mixed intracystic and extracystic, and five showed purely intracystic proliferation. Genetically, nine of 10 cases tested positive for KRAS mutations, four with exon 2 G12V mutation and five with exon 2 G12D mutation. Residual disease on completion lobectomy was observed in two cases, and three cases recurred 7, 15 and 32 years after the original diagnosis. Two patients died of metastatic invasive mucinous adenocarcinoma.

CONCLUSIONS

Most adenocarcinoma that arise in type 1 CPAMs, are purely mucinous, and are early-stage disease. Intracystic proliferation is associated with lepidic growth, an absence of invasion, and indolent behaviour, whereas extracystic proliferation may be associated with more aggressive behaviour and advanced stage. Most cases are cured by lobectomy, and recurrence/residual disease seems to be associated with limited surgery. Long-term follow-up is needed, as recurrence can occur decades later.

Radiological-pathological correlation of negative CT biopsy results enables high negative predictive value for thoracic malignancy

AIM

To evaluate multidisciplinary team (MDT) practice of radiological-pathological correlation of non-malignant biopsy results to examine the additive effect on the predictive values of computed tomography (CT) biopsy for malignancy and their subsequent management and outcomes.

MATERIALS AND METHODS

A service evaluation of the MDT management of non-malignant lung biopsy results (May 2014- May 2017) was undertaken.

RESULTS

Sixty patients had a non-malignant diagnosis on initial CT biopsy. Five patients were lost to follow-up leaving 55 in the final cohort. Forty-eight of the 55 patients had biopsy results classified as potentially non-specific, of which 26 were classified as concordant with radiology (e.g., organising pneumonia with compatible CT features), and 22 were classified as discordant (e.g., non-specific inflammation and yet sufficiently suspicious CT features). Patients with concordant negative pathology showed resolution (n=19) or stability (n=6) on imaging follow-up. One lesion demonstrated growth and was proven malignant on surgical resection. Discordant lesions were managed with repeat biopsy (n=8) or surgical resection (n=13), with 12 final benign diagnoses and nine malignancies. The negative predictive value of CT biopsy alone was 44/55 (80%), following repeat biopsy was 44/50 (88%), and following radiological-pathological assessment was 32/33 (97%). No patients underwent a shift in stage from time of biopsy to resection.

CONCLUSION

Combining radiological-pathological interpretation of negative biopsy results offers superior negative predictive value for lung malignancy without delayed diagnosis of lung cancer.

Interaction between the promoter MUC5B polymorphism and mucin expression: is there a difference according to ILD subtype?

The MUC5B promoter variant rs35705950 is associated with idiopathic pulmonary fibrosis (IPF). MUC5B glycoprotein is overexpressed in IPF lungs. We examined immunohistochemical expression of MUC5B in different interstitial lung disease patterns according to rs35705950 T-allele carriage. We observed increased expression of MUC5B in T-allele carriers in both distal airways and honeycomb cysts in patients with IPF (n=23), but no difference in MUC5B expression according to T-carrier status in the distal airways of patients with idiopathic non-specific interstitial pneumonitis (n=17), in scleroderma-associated non-specific interstitial pneumonitis (n=15) or in control lungs (n=20), suggesting that tissue overexpression in MUC5B rs35705950 T-carriers is specific to IPF.

Mechanism of lung development in the aetiology of adult congenital pulmonary airway malformations

Congenital pulmonary airway malformations (CPAMs) are rare lung abnormalities that result in cyst formation and are associated with respiratory distress in infants and malignant potential in adults. The pathogenesis of CPAMs remains unknown but data suggest disruption of the normal proximo-distal programme of airway branching and differentiation. Here, we demonstrate that adult human CPAM are lined with epithelium that retains SOX-2 and thyroid transcription factor-1 immunohistochemical markers, characteristic of the developing lung. However, RALDH-1, another key marker, is absent. This suggests a more complex aetiology for CPAM than complete focal arrest of lung development and may provide insight to the associated risk of malignancy.

Investigation of the safety and feasibility of AAV1/SERCA2a gene transfer in patients with chronic heart failure supported with a left ventricular assist device - the SERCA-LVAD TRIAL

The SERCA-LVAD trial was a phase 2a trial assessing the safety and feasibility of delivering an adeno-associated vector 1 carrying the cardiac isoform of the sarcoplasmic reticulum calcium ATPase (AAV1/SERCA2a) to adult chronic heart failure patients implanted with a left ventricular assist device. The SERCA-LVAD trial was one of a program of AAV1/SERCA2a cardiac gene therapy trials including CUPID1, CUPID 2 and AGENT trials. Enroled subjects were randomised to receive a single intracoronary infusion of 1 × 10¹³ DNase-resistant AAV1/SERCA2a particles or a placebo solution in a double-blinded design, stratified by presence of neutralising antibodies to AAV. Elective endomyocardial biopsy was performed at 6 months unless the subject had undergone cardiac transplantation, with myocardial samples assessed for the presence of exogenous viral DNA from the treatment vector. Safety assessments including ELISPOT were serially performed. Although designed as a 24 subject trial, recruitment was stopped after five subjects had been randomised and received infusion due to the neutral result from the CUPID 2 trial. Here we describe the results from the 5 patients at 3 years follow up, which confirmed that viral DNA was delivered to the failing human heart in 2 patients receiving gene therapy with vector detectable at follow up endomyocardial biopsy or cardiac transplantation. Absolute levels of detectable transgene DNA were low, and no functional benefit was observed. There were no safety concerns in this small cohort. This trial identified some of the challenges of performing gene therapy trials in this LVAD patient cohort which may help guide future trial design.

Presence of pleomorphic features but not growth patterns improves prognostic stratification of epithelioid malignant pleural mesothelioma by 2-tier nuclear grade

AIMS

Nuclear grade has been recently validated as a powerful prognostic tool in epithelioid malignant pleural mesothelioma (E-MPM). In other studies histological parameters including pleomorphic features and growth patterns were also shown to exert prognostic impact. The primary aims of our study are (i) externally validate the prognostic role of pleomorphic features in E-MPM and (ii) investigate if evaluating growth pattern in addition to 2-tier nuclear grade improves prognostication.

METHODS AND RESULTS

614 consecutive cases of E-MPM from our institution over a period of 15 years were retrospectively reviewed, of which 51 showed pleomorphic features. E-MPM with pleomorphic features showed significantly worse overall survival compared to those without (5.4 versus 14.7 months). Tumours with predominantly micropapillary pattern showed the worst survival (6.2 months) followed by solid (10.5 months), microcystic (15.3 months), discohesive (16.1 months), trabecular (17.6 months) and tubulo-papillary (18.6 months). Sub-classification of growth patterns into high grade (solid, micropapillary) and low grade (all others) led to good separation of overall survival (10.5 versus 18.0 months) but did not predict survival independent of 2-tier nuclear grade. A composite score comprised of growth pattern and 2-tier nuclear grade did not improve prognostication compared with nuclear grade alone. Intra-tumoural heterogeneity in growth patterns is ubiquitous.

CONCLUSIONS

Our findings support the incorporation of E-MPM with pleomorphic features in the epithelioid subtype as a highly aggressive variant distinct from 2-tier nuclear grade. E-MPM demonstrates extensive heterogeneity in growth pattern but its evaluation does not offer additional prognostic utility to 2-tier nuclear grade.

Bacterial burden in the lower airways predicts disease progression in idiopathic pulmonary fibrosis and is independent of radiological disease extent

Increasing bacterial burden in the lower airways of patients with idiopathic pulmonary fibrosis confers an increased risk of disease progression and mortality. However, it remains unclear whether this increased bacterial burden directly influences progression of fibrosis or simply reflects the magnitude of the underlying disease extent or severity.We prospectively recruited 193 patients who underwent bronchoscopy and received a multidisciplinary diagnosis of idiopathic pulmonary fibrosis. Quantification of the total bacterial burden in bronchoalveolar lavage fluid was performed by 16S rRNA gene qPCR. Imaging was independently evaluated by two readers assigning quantitative scores for extent, severity and topography of radiographic changes and relationship of these features with bacterial burden was assessed.Increased bacterial burden significantly associated with disease progression (HR 2.1; 95% CI 1.287-3.474; p=0.0028). Multivariate stepwise regression demonstrated no relationship between bacterial burden and radiological features or extent of disease. When specifically considering patients with definite or probable usual interstitial pneumonia there was no difference in bacterial burden between these two groups. Despite a postulated association between pleuroparenchymal fibroelastosis and clinical infection, there was no relationship between either the presence or extent of pleuroparenchymal fibroelastosis and bacterial burden.We demonstrate that bacterial burden in the lower airways is not simply secondary to the extent of the underlying architectural destruction of the lung parenchyma seen in idiopathic pulmonary fibrosis. The independent nature of this association supports a relationship with the underlying pathogenic mechanisms and highlights the urgent need for functional studies.

Cryotherapy Ablation in Immunoglobulin G4-Related Disease of the Trachea

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated condition comprising a group of disorders with shared clinicopathologic features. Manifestations of IgG4-RD are increasingly recognized in multiple organs, but tracheal involvement remains rare. Patients may present with a mass in the affected organ and most will respond to glucocorticoids, particularly in early stages of disease; however, between 15% and 60% of patients will experience relapse. We consider cryotherapy effective and safe for tumor debulking and symptomatic relief in IgG4-RD. We report on a case of a patient with upper tracheal stenosis exhibiting marked reduction in tumor size and symptom burden, after cryotherapy ablation.

Pleuroparenchymal Fibroelastosis. A Review of Clinical, Radiological, and Pathological Characteristics

Pleuroparenchymal fibroelastosis (PPFE) is an unusual pulmonary disease with unique clinical, radiological, and pathological characteristics. Designated a rare idiopathic interstitial pneumonia in 2013, its name refers to a combination of fibrosis involving the visceral pleura and fibroelastotic changes predominating in the subpleural lung parenchyma. Although a number of disease associations have been described, no single cause of PPFE has been unequivocally identified. A diagnosis of PPFE is most commonly achieved by identifying characteristic abnormalities on computed tomographic scans. The earliest changes are consistently located in the upper lobes close to the lung apices, the same locations where subsequent disease progression is also most conspicuous. When sufficiently severe, the disease leads to progressive volume loss of the upper lobes, which, in combination with decreased body mass, produces platythorax. Once regarded as a slowly progressing entity, it is now acknowledged that some patients with PPFE follow an inexorably progressive course that culminates in irreversible respiratory failure and early death. In the absence of effective medical drug treatment, lung transplant remains the only therapeutic option for this disorder. This review focuses on improving early disease recognition and evaluating its pathophysiological impact and discusses working approaches for its management.

Evaluation of inter-observer variation for computed tomography identification of childhood interstitial lung disease

Interstitial lung diseases (ILDs) that present in childhood (chILD) are seen far less frequently than ILDs presenting in adults which themselves constitute rare disorders [1]. Histopathological [2, 3] and imaging [4] characterisation of chILD disease subtypes therefore lags behind adult ILDs. The field has also been constrained by comparisons with disease morphology in adults, despite the developmental differences in terms of growth and healing in the paediatric lung, which may alter disease patterns and distributions. The American Thoracic Society [5] and European [1] chILD management guidelines both specify a pivotal role for computed tomography (CT) imaging in the work-up of chILD patients to: 1) determine whether a chILD is present or not; and 2) where possible, to make a specific diagnosis of the underlying cause. For the second aim to be achieved, diagnostic reviews need to be reproducible between experts. Our study uniquely examined agreement between observers of varying experience in the CT evaluation of chILD to inform whether the current status of CT imaging and knowledge can be diagnostic of specific chILDs. We hypothesised that observer agreement for chILD groups and diagnoses would be limited. The study was not designed to relate CT agreement to final diagnosis. As a secondary analysis, we examined how CT interpretation differed between observers in children under and over 2 years of age.

Making chILD diagnoses on CT is poorly reproducible, even amongst sub-specialists. CT might best improve diagnostic confidence in a multidisciplinary team setting when augmented with clinical, functional and haematological results.http://bit.ly/327jRCw

The impacted foetal head at caesarean section: incidence and techniques used in a single UK institution

An impaction of the foetal head at caesarean section is a topical concern in modern obstetric practice. The management options for this problem are well described but the incidence or even definition of impaction, is unknown. The primary aim of this study was to ascertain the incidence of impacted foetal head at CS in labour. This prospective study used data from all women undergoing CS during a 12-month period in a single unit. Following completion of all CS, the surgeon completed a questionnaire covering: cervical dilation at time of CS; if the surgeon felt there was a difficulty in delivering the foetal head as an indicator of impaction, as well as the other techniques utilised. Of 440 EMCS in labour, 18% (n = 81) reported a difficulty delivering the head, which was most common at cervical dilation ≥8 cm (n = 124, 48%). A difficulty with the delivery of the foetal head was associated with 36% increased measured blood loss. Impact statement What is already known on this subject? Impaction of the foetal head at a caesarean section is a recognised complication of CS in late labour but there are no reliable data on the incidence of the problem. It is poorly defined and yet many techniques and devices have been described to overcome this problem, however, optimal management remains uncertain. What do the results of this study add? The primary aim of this study was to determine the incidence of the impacted foetal head during CS in labour as determined by whether the surgeon experienced difficulty with delivery of the head. We report that at least some difficulty in delivering the foetal head at CS is common, and most often encountered when cervical dilation is ≥8 cm. When additional manoeuvres were required, the 'push' technique was exclusively adopted with implications for training. A difficulty in delivering the foetal head was associated with a 36% increase in the measured maternal blood loss. What are the implications of these findings for clinical practice and/or further research? Further multi-centre investigation is required to ascertain incidence of this obstetric problem with predicting factors determined. This work will inform decisions about the optimal management.

Histology of Pulmonary and Bronchiolar Disorders in Connective Tissue Diseases

Connective tissue diseases (CTDs) are a heterogeneous group of disorders, acquired or hereditary, involving an autoimmune-mediated inflammation of connective tissues in the whole body. Lung involvement is common with CTDs, and associated with significant morbidity and mortality. Each compartment of the lung may be affected, often simultaneously, depending on the type of CTD. In addition, the lung may show pathological changes related to treatment, such as infection, drug reaction, and neoplasia. A multidisciplinary approach to diagnose these patients is essential and incorporates radiological and clinical as well as pathological data. In this review we describe the patterns of lung disease associated with common CTDs, lung disease in pediatric CTD patients, and newly recognized conditions.

Restrictive lung defects: parenchymal, chest wall and neuromuscular

Sarcoidosis is a multisystem condition which may affect a number of organs and, within the cardiopulmonary system, most commonly manifests as parenchymal, airway-centred, nodal, vascular or cardiac disease. Pleural involvement is rare, but well described, and often presents as pleural effusions or pleural thickening. Here, we present the first case of active sarcoidosis manifesting as bilateral pleural calcification. We highlight the importance of a nuanced understanding of pulmonary physiology when dissecting coexistent extrathoracic and intrathoracic pulmonary restriction. We demonstrate the value of positron emission tomography scanning for identification of sites of sarcoid activity, in this case the pleura, to ensure tissue confirmation of this rare but functionally important manifestation of disease. Sarcoidosis should be considered within the differential diagnosis for patients with pleural calcification, not explained by more common causes.

Distribution and frequency of mitochondrial DNA polymorphisms in blue mussel (Mytilus edulis) populations of southwestern Nova Scotia (Canada)

The Atlantic blue mussel (Mytilus edulis Linnaeus, 1758) exhibits doubly uniparental inheritance of mitochondrial (mt) DNA. Females are usually homoplasmic for a female-transmitted mt genome (the F type) and males are heteroplasmic for an F type and a male-transmitted mt genome (the M type). F types can undergo “role-reversal” events, resulting in new male-transmitted mtDNA genomes known as recently masculinized (RM) types that co-occur in populations with evolutionarily older standard-male (SM) types. Phylogenetic analyses have shown that RM types periodically replace SM types. It has also been shown that sperm with RM mtDNA have greater swimming velocity and more efficient components of the electron transport chain compared to sperm with SM mtDNA, thus leading to the hypothesis that RM sperm may have a selective advantage over SM sperm. The present study examines the distribution of RM and SM mitotypes in male M. edulis (n = 225) from 13 localities in southwestern Nova Scotia (Canada). The SM type was more common in all populations, with the proportion of RM types ranging from 0% to 24.1%. The highest proportion of RM types was observed in an aquaculture operation. Analyses of additional populations are required to evaluate the selective pressures affecting the geographic distribution of RM and SM mitotypes in M. edulis.

Expression of PD-L1 correlates with pleomorphic morphology and histological patterns of non-small-cell lung carcinomas

AIMS

As immunomodulatory therapy is being integrated into treatment regimens for non-small-cell lung carcinoma, we aimed to prospectively collect data on the immunohistochemical profile of tumours assessed in our institution and to correlate this with morphological tumour features.

METHODS AND RESULTS

Immunohistochemistry for programmed death-ligand 1 (PD-L1) was considered to be adequate when >100 tumour cells were seen microscopically. When adequate, PD-L1 staining was scored as <1%, ≥1-49% or ≥50% positive membrane staining within tumour cells only. There were 197 assessable cases, of which 87% of those with pleomorphic features (n = 39) showed ≥50% positivity for PD-L1 expression, as compared with only 33% of cases without pleomorphic features (P < 0.05) (90% versus 25% in resected cases). Further correlation of PD-L1 expression with architectural patterns within the tumours was performed in 74 adenocarcinoma resections. All invasive mucinous adenocarcinomas scored <1%. All lepidic components in non-mucinous adenocarcinoma resections scored <1%. Thirty-five per cent of the acinar/papillary components and 53% of the solid/micropapillary components were positive for PD-L1 expression.

CONCLUSIONS

There are significant differences in PD-L1 expression in relation to histological patterns, with particularly high levels in those with pleomorphic features and low/undetectable levels in invasive mucinous adenocarcinomas and the lepidic components of non-mucinous adenocarcinomas. Assessment of PD-L1 expression in a resected adenocarcinoma with a lepidic component may therefore not be reliable when immumodulatory therapy for recurrent disease is being considered, and either re-biopsy or limiting assessment to the invasive component may be more appropriate.

Reverse Takotsubo Cardiomyopathy and Cardiogenic Shock Associated With Methamphetamine Consumption

BACKGROUND

Reverse Takotsubo cardiomyopathy is characterized by transient myocardial hypokinesia affecting predominantly the basal myocardial wall. It is a rare variant of Takotsubo cardiomyopathy affecting younger patients.

CASE REPORT

We report a case of a young man who having consumed methamphetamines presented with cardiogenic shock and severe left ventricular systolic dysfunction, affecting predominantly the basal segments with sparing of the apex. After inotropic support, the left ventricular ejection fraction improved. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: It is important that emergency physicians are aware of the danger of methamphetamine consumption, and how it can lead to potentially fatal acute cardiac syndromes, including reverse Takotsubo cardiomyopathy and cardiogenic shock.

Perioperative detection of circulating tumour cells in patients with lung cancer

Lung cancer is a leading cause of mortality and despite surgical resection a proportion of patients may develop metastatic spread. The detection of circulating tumour cells (CTCs) may allow for improved prediction of metastatic spread and survival. The current study evaluates the efficacy of the ScreenCell® filtration device, to capture, isolate and propagate CTCs in patients with primary lung cancer. Prior to assessment of CTCs, the present study detected cancer cells in a proof-of-principle- experiment using A549 human lung carcinoma cells as a model. Ten patients (five males and five females) with pathologically diagnosed primary non-small cell lung cancer undergoing surgical resection, had their blood tested for CTCs. Samples were taken from a peripheral vessel at the baseline, from the pulmonary vein draining the lobe containing the tumour immediately prior to division, a further central sample was taken following completion of the resection, and a final peripheral sample was taken three days post-resection. A significant increase in CTCs was observed from baseline levels following lung manipulation. No association was able to be made between increased levels of circulating tumour cells and survival or the development of metastatic deposits. Manipulation of the lung during surgical resection for non-small cell lung carcinoma results in a temporarily increased level of CTCs; however, no clinical impact for this increase was observed. Overall, the study suggests the ScreenCell® device has the potential to be used as a CTC isolation tool, following further work, adaptations and improvements to the technology and validation of results.

Probing the disparate effects of arginine and lysine residues on antimicrobial peptide/bilayer association

Antimicrobial peptides (AMPs) are key components of the innate immune response and represent promising templates for the development of broad-spectrum alternatives to conventional antibiotics. Most AMPs are short, cationic peptides that interact more strongly with negatively charged prokaryotic membranes than net neutral eukaryotic ones. Both AMPs and synthetic analogues with arginine-like side chains are more active against bacteria than those with lysine-like amine groups, though the atomistic mechanism for this increase in potency remains unclear. To examine this, we conducted comparative molecular dynamics simulations of a model negatively-charged membrane system interacting with two mutants of the AMP KR-12: one with lysine residues mutated to arginines (R-KR12) and one with arginine residues mutated to lysine (K-KR12). Simulations show that both partition analogously to the bilayer and display similar preferences for hydrogen bonding with the anionic POPGs. However, R-KR12 binds stronger to the bilayer than K-KR12 and forms significantly more hydrogen bonds, leading to considerably longer interaction times. Additional simulations with methylated R-KR12 and charge-modified K-KR12 mutants show that the extensive interaction seen in the R-KR12 system is partly due to arginine's strong atomic charge distribution, rather than being purely an effect of the greater number of hydrogen bond donors. Finally, free energy simulations reveal that both peptides are disordered in solution but form an amphipathic α-helix when inserted into the bilayer headgroup region. Overall, these results highlight the role of charge and hydrogen bond strength in peptide bilayer insertion, and offer potential insights for designing more potent analogues in the future.

Detection of Circulating Tumour Cells and Survival of Patients with Non-small Cell Lung Cancer

BACKGROUND

Detection of circulating tumour cells (CTCs) in the peripheral blood of lung cancer patients may predict survival. Various platforms exist that allow capture of these cells for further analysis; little work however, has been done with the ScreenCell device, an antibody-independent CTC platform. The aim of our study was to evaluate the ScreenCell device for detection of CTCs in lung cancer patients and to establish correlations of these findings with survival.

MATERIALS AND METHODS

Twenty-three patients, nine males, and fourteen females, underwent surgical treatment from February to May 2014 for non-small cell lung cancer. Thirteen patients had adenocarcinoma and ten squamous cell carcinoma, while eight were at an early stage (I-II) and five at a later stage (III-IV). Blood samples were obtained prior to surgery and following filtration through the ScreenCell device, were independently reviewed by 2 consultant pathologists.

RESULTS

The pathologists were able to independently identify CTCs in 78.3% (N=18) and 73.9% (N=17) of the cases examined, with overall 80.6% in early stages compared to 60.0% in late stages. The median survival times of positive vs. negative for CTC patients were 1011 and 711 days respectively, with a survival percentage rate of 77.8% and 60% in positive and negative CTC cohorts respectively.

CONCLUSION

The results of this study suggest that the presence of CTCs analyzed by ScreenCell did not necessarily lead to a poorer prognosis in patients with lung cancer after curative surgery.

Inertia based microfluidic capture and characterisation of circulating tumour cells for the diagnosis of lung cancer

BACKGROUND

Routine clinical application of circulating tumour cells (CTCs) for blood based diagnostics is yet to be established. Despite growing evidence of their clinical utility for diagnosis, prognosis and treatment monitoring, the efficacy of a robust platform and universally accepted diagnostic criteria remain uncertain. We evaluate the diagnostic performance of a microfluidic CTC isolation platform using cytomorphologic criteria in patients undergoing lung cancer surgery.

METHODS

Blood was processed from 51 patients undergoing surgery for known or suspected lung cancer using the ClearBridge ClearCell FX system^TM (ClearBridge Biomedics, Singapore). Captured cells were stained on slides with haematoxylin and eosin (H&E) and independently assessed by two pathologist teams. Diagnostic performance was evaluated against the pathologists reported diagnosis of cancer from surgically obtained specimens.

RESULTS

Cancer was diagnosed in 43.1% and 54.9% of all cases. In early stage primary lung cancer, between the two reporting teams, a positive diagnosis of CTCs was made for 50% and 66.7% of patients. The agreement between the reporting teams was 80.4%, corresponding to a kappa-statistic of 0.61±0.11 (P<0.001), indicating substantial agreement. Sensitivity levels for the two teams were calculated as 59% (95% CI, 41-76%) and 41% (95% CI, 24-59%), with a specificity of 53% for both.

CONCLUSIONS

The performance of the tested microfluidic antibody independent device to capture CTCs using standard cytomorphological criteria provides the potential of a diagnostic blood test for lung cancer.