Extreme elevations of donor-derived cell-free DNA increases the risk of chronic lung allograft dysfunction and death, even without clinical manifestations of disease

BACKGROUND

Lung transplant recipients are traditionally monitored with pulmonary function testing (PFT) and lung biopsy to detect post-transplant complications and guide treatment. Plasma donor-derived cell free DNA (dd-cfDNA) is a novel molecular approach of assessing allograft injury, including subclinical allograft dysfunction. The aim of this study was to determine if episodes of extreme molecular injury (EMI) in lung transplant recipients increases the risk of CLAD or death.

METHODS

This multicenter prospective cohort study included 238 lung transplant recipients. Serial plasma samples were collected for dd-cfDNA measurement by shotgun sequencing. EMI was defined as a dd-cfDNA above the third quartile of levels observed for acute rejection (dd-cfDNA level of ≥ 5% occurring after 45 days post-transplant). EMI was categorized as Secondary if associated with co-existing acute rejection, infection or PFT decline; or Primary if not associated to these conditions.

RESULTS

EMI developed in 16% of patients at a median 343.5 (IQR: 177.3-535.5) days post-transplant. Over 50% of EMI episodes were classified as Primary. EMI was associated with an increased risk of severe CLAD or death (HR: 2.52, 95% CI: 1.10 - 3.82, p= 0.024). The risk remained consistent for Primary EMI (HR: 2.34, 95% CI 1.18-4.85, p=0.015). Time to first EMI episode was a significant predictor of the likelihood of developing CLAD or death (AUC=0.856, 95% CI =.805-908, p<.001).

CONCLUSIONS

Episodes of EMI in lung transplant recipients are often isolated and not detectable with traditional clinical monitoring approaches. EMI is associated with an increased risk of severe CLAD or death, independent of concomitant transplant complications.

Impact of recipient age on mortality among Cytomegalovirus (CMV)-seronegative lung transplant recipients with CMV-seropositive donors

BACKGROUND

Cytomegalovirus (CMV)-seronegative lung transplant recipients (LTRs) with seropositive donors (CMV D+/R-) have the highest mortality of all CMV serostatuses. Due to immunosenescence and other factors, we hypothesized CMV D+/R- status might disproportionately impact older LTRs. Thus, we investigated whether recipient age modified the relationship between donor CMV status and mortality among CMV-seronegative LTRs.

METHODS

Adult, CMV-seronegative first-time lung-only recipients were identified through the Scientific Registry of Transplant Recipients between May 2005 and December 2019. We used adjusted multivariable Cox regression to assess the relationship of donor CMV status and death. Interaction between recipient age and donor CMV was assessed via likelihood ratio testing of nested Cox models and by the relative excess risk due to interaction (RERI) and attributable proportion (AP) of joint effects.

RESULTS

We identified 11,136 CMV-seronegative LTRs. The median age was 59 years; 65.2% were male, with leading transplant indication of idiopathic pulmonary fibrosis (35.6%); and 60.8% were CMV D+/R-. In multivariable modeling, CMV D+/R- status was associated with 27% increased hazard of death (adjusted hazard ratio: 1.27, 95% confidence interval: 1.21-1.34) compared to CMV D-/R-. Recipient age ≥60 years significantly modified the relationship between donor CMV-seropositive status and mortality on the additive scale, including RERI 0.24 and AP 11.4% (p = 0.001), that is, the interaction increased hazard of death by 0.24 and explained 11.4% of mortality in older CMV D+ recipients.

CONCLUSIONS

Among CMV-seronegative LTRs, donor CMV-seropositive status confers higher risk of posttransplant mortality, which is amplified in older recipients. Future studies should define optimal strategies for CMV prevention and management in older D+/R- LTRs.

Cell-Free DNA Maps Tissue Injury and Correlates with Disease Severity in Lung Transplant Candidates

Rationale: Plasma cell-free DNA levels correlate with disease severity in many conditions. Pretransplant cell-free DNA may risk stratify lung transplant candidates for post-transplant complications. Objectives: To evaluate if pretransplant cell-free DNA levels and tissue sources identify patients at high risk of primary graft dysfunction and other pre- and post-transplant outcomes. Methods: This multicenter, prospective cohort study recruited 186 lung transplant candidates. Pretransplant plasma samples were collected to measure cell-free DNA. Bisulfite sequencing was performed to identify the tissue sources of cell-free DNA. Multivariable regression models determined the association between cell-free DNA levels and the primary outcome of primary graft dysfunction and other transplant outcomes, including Lung Allocation Score, chronic lung allograft dysfunction, and death. Measurements and Main Results: Transplant candidates had twofold greater cell-free DNA levels than healthy control patients (median [interquartile range], 23.7 ng/ml [15.1-35.6] vs. 12.9 ng/ml [9.9-18.4]; P < 0.0001), primarily originating from inflammatory innate immune cells. Cell-free DNA levels and tissue sources differed by native lung disease category and correlated with the Lung Allocation Score (P < 0.001). High pretransplant cell-free DNA increased the risk of primary graft dysfunction (odds ratio, 1.60; 95% confidence interval [CI], 1.09-2.46; P = 0.0220), and death (hazard ratio, 1.43; 95% CI, 1.07-1.92; P = 0.0171) but not chronic lung allograft dysfunction (hazard ratio, 1.37; 95% CI, 0.97-1.94; P = 0.0767). Conclusions: Lung transplant candidates demonstrate a heightened degree of tissue injury with elevated cell-free DNA, primarily originating from innate immune cells. Pretransplant plasma cell-free DNA levels predict post-transplant complications.

Racial Disparities in Waiting List Outcomes of Patients Listed for Lung Transplantation

BACKGROUND

The Lung Allocation Score, implemented in 2005, prioritized lung transplant candidates by medical urgency rather than waiting list time and was expected to improve racial disparities in transplant allocation. We evaluated whether racial disparities in lung transplant persisted after 2005.

METHODS

We identified all wait-listed adult lung transplant candidates in the United States from 2005 through 2021 using the Scientific Registry of Transplant Recipients. We evaluated the association between race and receipt of a transplant by using a multivariable competing risk regression model adjusted for demographics, socioeconomic status, Lung Allocation Score, clinical measures, and time. We evaluated interactions between race and age, sex, socioeconomic status, and Lung Allocation Score.

RESULTS

We identified 33,158 candidates on the lung transplant waiting list between 2005 and 2021: 27,074 White (82%), 3350 African American (10%), and 2734 Hispanic (8%). White candidates were older, had higher education levels, and had lower Lung Allocation Scores (P < .001). After multivariable adjustment, African American and Hispanic candidates were less likely to receive lung transplants than White candidates (African American: adjusted subhazard ratio, 0.86; 95% CI, 0.82-0.91; Hispanic: adjusted subhazard ratio, 0.82; 95% CI, 0.78-0.87). Lung transplant was significantly less common among Hispanic candidates aged >65 years (P = .003) and non-White candidates from higher-poverty communities (African-American: P = .013; Hispanic: P =.0036).

CONCLUSIONS

Despite implementation of the Lung Allocation Score, racial disparities persisted for wait-listed African American and Hispanic lung transplant candidates and differed by age and poverty status. Targeted interventions are needed to ensure equitable access to this life-saving intervention.

Healthcare-associated fungal infections and emerging pathogens during the COVID-19 pandemic

Historically, fungi were mainly identified as plant and insect pathogens since they grow at 28°C. At the same time, bacteria are known to be the most common human pathogens as they are compatible with the host body temperature of 37°C. Because of immunocompromised hosts, cancer therapy, and malnutrition, fungi are rapidly gaining attention as human pathogens. Over 150 million people have severe fungal infections, which lead to approximately more than one million deaths per year. Moreover, diseases like cancer involving long-term therapy and prophylactic use of antifungal drugs in high-risk patients have increased the emergence of drug-resistant fungi, including highly virulent strains such as Candida auris. This clinical spectrum of fungal diseases ranges from superficial mucocutaneous lesions to more severe and life-threatening infections. This review article summarizes the effect of hospital environments, especially during the COVID-19 pandemic, on fungal infections and emerging pathogens. The review also provides insights into the various antifungal drugs and their existing challenges, thereby driving the need to search for novel antifungal agents.

Cecal volvulus following appendectomy in a teenage patient: A case report

Patients mimicking appendicitis symptoms in a rural setting or those post-appendectomy, indicating cecal volvulus, should always be considered. Swift action can prevent catastrophic consequences.

Abstract

We present a case of a 14-year-old female who initially underwent open appendectomy for acute appendicitis and subsequently experienced symptoms of abdominal distention, vomiting, and fever. Her condition deteriorated following the appendectomy, despite a prior appendectomy for similar symptoms at a different facility. A computed tomography (CT) scan identified cecal volvulus as the underlying issue. This led to the performance of a laparotomy, cecopexy, and decompressive ileostomy. After six weeks, ileostomy closure was successfully carried out, and the patient currently enjoys good health. This case highlights the significance of considering uncommon factors as potential contributors to postoperative complications in young patients.

Higher Molecular Injury at Diagnosis of Acute Cellular Rejection Increases the Risk of Lung Allograft Failure

RATIONALE

The association of acute cellular rejection (ACR) with chronic lung allograft dysfunction (CLAD) in lung transplant recipients has primarily been described prior to consensus recommendations incorporating restrictive phenotypes. Further, the association of the degree of molecular allograft injury during ACR with CLAD or death remains undefined.

OBJECTIVES

To investigate the association of ACR with the risk of CLAD or death. To further investigate if this risk depends on the degree of molecular allograft injury.

METHODS

This multicenter, prospective cohort study included 188 lung transplant recipients. Subjects underwent serial plasma collections for donor-derived cell-free DNA (dd-cfDNA) at prespecified time points and bronchoscopy. Multivariable Cox proportional hazards analysis analyzed the association of ACR with subsequent CLAD or death as well as the association of dd-cfDNA during ACR with risk of CLAD or death. Additional outcomes analyses were performed with episodes of ACR categorized as "high risk" (dd-cfDNA≥1%) and "low risk" (dd-cfDNA<1%).

MEASUREMENTS AND MAIN RESULTS

In multivariable analysis, ACR was associated with the composite outcome of CLAD or death (HR=2.07, 95% CI, 1.05-4.10, p=0.036). Elevated dd-cfDNA ≥1% at ACR diagnosis was independently associated with increased risk of CLAD or death (HR 3.32, 95% CI: 1.31 - 8.40, p=0.012). Patients with high risk ACR were at increased risk of CLAD or death (HR 3.13, 95% CI: 1.41 - 6.93, p=0.005) while patients with low-risk status ACR were not.

CONCLUSION

Patients with ACR are at higher risk of CLAD or death, however, this may depend on the degree of underlying allograft injury on the molecular level.

Multiorgan MRI findings after hospitalisation with COVID-19 in the UK (C-MORE): a prospective, multicentre, observational cohort study

INTRODUCTION

The multiorgan impact of moderate to severe coronavirus infections in the post-acute phase is still poorly understood. We aimed to evaluate the excess burden of multiorgan abnormalities after hospitalisation with COVID-19, evaluate their determinants, and explore associations with patient-related outcome measures.

METHODS

In a prospective, UK-wide, multicentre MRI follow-up study (C-MORE), adults (aged ≥18 years) discharged from hospital following COVID-19 who were included in Tier 2 of the Post-hospitalisation COVID-19 study (PHOSP-COVID) and contemporary controls with no evidence of previous COVID-19 (SARS-CoV-2 nucleocapsid antibody negative) underwent multiorgan MRI (lungs, heart, brain, liver, and kidneys) with quantitative and qualitative assessment of images and clinical adjudication when relevant. Individuals with end-stage renal failure or contraindications to MRI were excluded. Participants also underwent detailed recording of symptoms, and physiological and biochemical tests. The primary outcome was the excess burden of multiorgan abnormalities (two or more organs) relative to controls, with further adjustments for potential confounders. The C-MORE study is ongoing and is registered with ClinicalTrials.gov, NCT04510025.

FINDINGS

Of 2710 participants in Tier 2 of PHOSP-COVID, 531 were recruited across 13 UK-wide C-MORE sites. After exclusions, 259 C-MORE patients (mean age 57 years [SD 12]; 158 [61%] male and 101 [39%] female) who were discharged from hospital with PCR-confirmed or clinically diagnosed COVID-19 between March 1, 2020, and Nov 1, 2021, and 52 non-COVID-19 controls from the community (mean age 49 years [SD 14]; 30 [58%] male and 22 [42%] female) were included in the analysis. Patients were assessed at a median of 5·0 months (IQR 4·2-6·3) after hospital discharge. Compared with non-COVID-19 controls, patients were older, living with more obesity, and had more comorbidities. Multiorgan abnormalities on MRI were more frequent in patients than in controls (157 [61%] of 259 vs 14 [27%] of 52; p<0·0001) and independently associated with COVID-19 status (odds ratio [OR] 2·9 [95% CI 1·5-5·8]; padjusted=0·0023) after adjusting for relevant confounders. Compared with controls, patients were more likely to have MRI evidence of lung abnormalities (p=0·0001; parenchymal abnormalities), brain abnormalities (p<0·0001; more white matter hyperintensities and regional brain volume reduction), and kidney abnormalities (p=0·014; lower medullary T1 and loss of corticomedullary differentiation), whereas cardiac and liver MRI abnormalities were similar between patients and controls. Patients with multiorgan abnormalities were older (difference in mean age 7 years [95% CI 4-10]; mean age of 59·8 years [SD 11·7] with multiorgan abnormalities vs mean age of 52·8 years [11·9] without multiorgan abnormalities; p<0·0001), more likely to have three or more comorbidities (OR 2·47 [1·32-4·82]; padjusted=0·0059), and more likely to have a more severe acute infection (acute CRP >5mg/L, OR 3·55 [1·23-11·88]; padjusted=0·025) than those without multiorgan abnormalities. Presence of lung MRI abnormalities was associated with a two-fold higher risk of chest tightness, and multiorgan MRI abnormalities were associated with severe and very severe persistent physical and mental health impairment (PHOSP-COVID symptom clusters) after hospitalisation.

INTERPRETATION

After hospitalisation for COVID-19, people are at risk of multiorgan abnormalities in the medium term. Our findings emphasise the need for proactive multidisciplinary care pathways, with the potential for imaging to guide surveillance frequency and therapeutic stratification.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Race-Specific Interpretation of Spirometry: Impact on the Lung Allocation Score

Rationale: Interpretation of spirometry using race-specific reference equations may contribute to health disparities via underestimation of the degree of lung function impairment in Black patients. The use of race-specific equations may differentially affect patients with severe respiratory disease via the use of percentage predicted forced vital capacity (FVCpp) when included in the lung allocation score (LAS), the primary determinant of priority for lung transplantation. Objectives: To determine the impact of a race-specific versus a race-neutral approach to spirometry interpretation on the LAS among adults listed for lung transplantation in the United States. Methods: We developed a cohort from the United Network for Organ Sharing database including all White and Black adults listed for lung transplantation between January 7, 2009, and February 18, 2015. The LAS at listing was calculated for each patient under race-specific and race-neutral approaches, using the FVCpp generated from the Global Lung Function Initiative equation corresponding to each patient's race (race-specific) or from the Global Lung Function Initiative "other" (race-neutral) equation. Differences in LAS between approaches were compared by race, with positive values indicating a higher LAS under the race-neutral approach. Results: In this cohort of 8,982 patients, 90.3% were White and 9.7% were Black. The mean FVCpp was 4.4% higher versus 3.8% lower among White versus Black patients (P < 0.001) under a race-neutral compared with a race-specific approach. Compared with White patients, Black patients had a higher mean LAS under both a race-specific (41.9 vs. 43.9; P < 0.001) and a race-neutral (41.3 vs. 44.3; P < 0.001) approach. However, the mean difference in LAS under a race-neutral approach was -0.6 versus +0.6 for White versus Black patients (P < 0.001). Differences in LAS under a race-neutral approach were most pronounced for those in group B (pulmonary vascular disease) (-0.71 vs. +0.70; P < 0.001) and group D (restrictive lung disease) (-0.78 vs. +0.68; P < 0.001). Conclusions: A race-specific approach to spirometry interpretation has potential to adversely affect the care of Black patients with advanced respiratory disease. Compared with a race-neutral approach, a race-specific approach resulted in lower LASs for Black patients and higher LASs for White patients, which may have contributed to racially biased allocation of lung transplantation. The future use of race-specific equations must be carefully considered.

Pseudomonas-dominant microbiome elicits sustained IL-1β upregulation in alveolar macrophages from lung transplant recipients

BACKGROUND

Isolation of Pseudomonas aeruginosa (PsA) is associated with increased BAL (bronchoalveolar lavage) inflammation and lung allograft injury in lung transplant recipients (LTR). However, the effect of PsA on macrophage responses in this population is incompletely understood. We examined human alveolar macrophage (AMΦ) responses to PsA and Pseudomonas dominant microbiome in healthy LTR.

METHODS

We stimulated THP-1 derived macrophages (THP-1MΦ) and human AMΦ from LTR with different bacteria and LTR BAL derived microbiome characterized as Pseudomonas-dominant. Macrophage responses were assessed by high dimensional flow cytometry, including their intracellular production of cytokines (TNF-α, IL-6, IL-8, IL-1β, IL-10, IL-1RA, and TGF-β). Pharmacological inhibitors were utilized to evaluate the role of the inflammasome in PsA-macrophage interaction.

RESULTS

We observed upregulation of pro-inflammatory cytokines (TNF-α, IL-6, IL-8, IL-1β) following stimulation by PsA compared to other bacteria (Staphylococcus aureus (S.Aur), Prevotella melaninogenica, Streptococcus pneumoniae) in both THP-1MΦ and LTR AMΦ, predominated by IL-1β. IL-1β production from THP-1MΦ was sustained after PsA stimulation for up to 96 hours and 48 hours in LTR AMΦ. Treatment with the inflammasome inhibitor BAY11-7082 abrogated THP-1MΦ IL-1β production after PsA exposure. BAL Pseudomonas-dominant microbiota elicited an increased IL-1β, similar to PsA, an effect abrogated by the addition of antibiotics.

CONCLUSION

PsA and PsA-dominant lung microbiota induce sustained IL-1β production in LTR AMΦ. Pharmacological targeting of the inflammasome reduces PsA-macrophage-IL-1β responses, underscoring their use in lung transplant recipients.

Characterization and translational development of IOA-289, a novel autotaxin inhibitor for the treatment of solid tumors

Background

Autotaxin-lysophosphatidic acid (ATX-LPA) signaling has a predominant role in immunological and fibrotic processes, including cancer. Several ATX inhibitors and LPA receptor antagonists have been clinically evaluated, but none in patients with solid tumors. Many cancers are burdened with a high degree of fibrosis and an immune desert phenotype (so-called 'cold' tumors). In these cold tumors, the fibrotic stroma provides an intrinsic cancer-supporting mechanism. Furthermore, the stroma prevents penetration and limits the effectiveness of existing therapies. IOA-289 is a novel ATX inhibitor with a unique chemical structure, excellent potency and an attractive safety profile.

Materials and methods

In vitro and in vivo pharmacology studies have been carried out to elucidate the pharmaceutical properties and mechanism of action of IOA-289. A phase I clinical study in healthy volunteers was carried out to determine the pharmacokinetics and pharmacodynamics of IOA-289 following a single oral dose.

Results

In vitro and in vivo studies showed that IOA-289 is a potent inhibitor of ATX and, as a monotherapy, is able to slow progression of lung fibrosis and tumor growth in mouse models. In a clinical study, IOA-289 showed a dose-dependent increase in plasma exposure levels and a corresponding decrease in circulating LPA.

Conclusions

Our data show that IOA-289 is a novel ATX inhibitor with a unique chemical structure, excellent potency and an attractive safety profile. Our data support the further development of IOA-289 as a novel therapeutic approach for the treatment of cancer, particularly those with a high fibrotic and immunologically cold phenotype.

Are non-invasive estimations of plasma volume an accurate measure of congestion in patients with chronic heart failure?

AIMS

We report associations between different formulae for estimating plasma volume status (PVS) and clinical and ultrasound markers of congestion in patients with chronic heart failure (CHF) enrolled in the Hull Lifelab registry.

METHODS AND RESULTS

Cohort 1 comprised patients with data on signs and symptoms at initial evaluation (n = 3505). Cohort 2 included patients with ultrasound assessment of congestion [lung B-line count, inferior vena cava (IVC) diameter, jugular vein distensibility (JVD) ratio] (N = 341). Two formulae for PVS were used: (a) Hakim (HPVS) and (b) Duarte (DPVS). Results were compared with clinical and ultrasound markers of congestion. Outcomes assessed were mortality and the composite of heart failure (HF) hospitalisation and all-cause mortality. In cohort 1, HPVS was associated with mortality [hazard ratio (HR) per unitary increase = 1.02 (1.01-1.03); P < 0.001]. In cohort 2, HPVS was associated with B-line count (HR) = 1.05 [95% confidence interval (CI) (1.01-1.08); P = 0.02] and DPVS with the composite outcome [HR = 1.26 (1.01-1.58); P = 0.04]. HPVS and DPVS were strongly related to haemoglobin concentration and HPVS to weight. After multivariable analysis, there were no strong or consistent associations between PVS and measures of congestion, severity of symptoms, or outcome. By contrast, log[NTproBNP] was strongly associated with all three.

CONCLUSION

Amongst patients with CHF, HPVS and DPVS are not strongly or consistently associated with clinical or ultrasound evidence of congestion, nor clinical outcomes after multivariable adjustment. They appear only to be surrogates of the variables from which they are calculated with no intrinsic clinical utility.

Preemptive treatment of de novo donor-specific antibodies in lung transplant patients reduces subsequent risk of chronic lung allograft dysfunction or death

The development of donor-specific antibodies after lung transplantation is associated with downstream acute cellular rejection, antibody-mediated rejection (AMR), chronic lung allograft dysfunction (CLAD), or death. It is unknown whether preemptive (early) treatment of de novo donor-specific antibodies (dnDSAs), in the absence of clinical signs and symptoms of allograft dysfunction, reduces the risk of subsequent CLAD or death. We performed a multicenter, retrospective cohort study to determine if early treatment of dnDSAs in lung transplant patients reduces the risk of the composite endpoint of CLAD or death. In the cohort of 445 patients, 145 patients developed dnDSAs posttransplant. Thirty patients received early targeted treatment for dnDSAs in the absence of clinical signs and symptoms of AMR. Early treatment of dnDSAs was associated with a decreased risk of CLAD or death (hazard ratio, 0.36; 95% confidence interval, 0.17-0.76; P < .01). Deferring treatment until the development of clinical AMR was associated with an increased risk of CLAD or death (hazard ratio, 3.00; 95% confidence interval, 1.46-6.18; P < .01). This study suggests that early, preemptive treatment of donor-specific antibodies in lung transplant patients may reduce the subsequent risk of CLAD or death.

Willingness to vaccinate children against COVID-19 declined during the pandemic

OBJECTIVES

To document the level of vaccine hesitancy in caregivers' of children younger than 12 years of age over the course of the pandemic in Pediatric Emergency Departments (ED). Study design Ongoing multicenter, cross-sectional survey of caregivers presenting to 19 pediatric EDs in the USA, Canada, Israel, and Switzerland during first months of the pandemic (phase1), when vaccines were approved for adults (phase2) and most recently when vaccines were approved for children (phase3).

RESULTS

Willingness to vaccinate rate declined over the study period (59.7%, 56.1% and 52.1% in the three phases). Caregivers who are fully vaccinated, who have higher education, and those worried their child had COVID-19 upon arrival to the ED, were more likely to plan to vaccinate in all three phases. Mothers were less likely to vaccinate early in the pandemic, but this hesitancy attenuated in later phases. Older caregivers were more willing to vaccinate, and caregivers of older children were less likely to vaccinate their children in phase 3. During the last phase, willingness to vaccinate was lowest in those who had a primary care provider but did not rely on their advice for medical decisions (34%). Those with no primary care provider and those who do and rely on their medical advice, had similar rates of willingness to vaccinate (55.1% and 52.1%, respectively).

CONCLUSIONS

COVID-19 vaccine hesitancy is widespread and growing over time, and public health measures should further try to leverage identified factors associated with hesitancy in order to enhance vaccination rates among children.

Clinical features and allograft failure rates of pulmonary antibody-mediated rejection categories

BACKGROUND

Pulmonary antibody-mediated rejection (AMR) consensus criteria categorize AMR by diagnostic certainty. This study aims to define the clinical features and associated outcomes of these recently defined AMR categories.

METHODS

Adjudication committees reviewed clinical data of 335 lung transplant recipients to define clinical or subclinical AMR based on the presence of allograft dysfunction, and the primary endpoints, time from transplant to allograft failure, a composite endpoint of chronic lung allograft dysfunction and/or death. Clinical AMR was subcategorized based on diagnostic certainty as definite, probable or possible AMR if 4, 3, or 2 characteristic features were present, respectively. Allograft injury was assessed via plasma donor-derived cell-free DNA (ddcfDNA). Risk of allograft failure and allograft injury was compared for AMR categories using regression models.

RESULTS

Over the 38.5 months follow-up, 28.7% of subjects developed clinical AMR (n = 96), 18.5% developed subclinical AMR (n = 62) or 58.3% were no AMR (n = 177). Clinical AMR showed higher risk of allograft failure and ddcfDNA levels compared to subclinical or no AMR. Clinical AMR included definite/probable (n = 21) or possible AMR (n = 75). These subcategories showed similar clinical characteristics, ddcfDNA levels, and risk of allograft failure. However, definite/probable AMR showed greater measures of AMR severity, including degree of allograft dysfunction and risk of death compared to possible AMR.

CONCLUSIONS

Clinical AMR showed greater risk of allograft failure than subclinical AMR or no AMR. Subcategorization of clinical AMR based on diagnostic certainty correlated with AMR severity and risk of death, but not with the risk of allograft failure.

Optimization with photonic wave-based annealers

Many NP-hard combinatorial optimization (CO) problems can be cast as a quadratic unconstrained binary optimization model, which maps naturally to an Ising model. The final spin configuration in the Ising model can adiabatically arrive at a solution to a Hamiltonian, given a known set of interactions between spins. We enhance two photonic Ising machines (PIMs) and compare their performance against classical (Gurobi) and quantum (D-Wave) solvers. The temporal multiplexed coherent Ising machine (TMCIM) uses the bistable response of an electro-optic modulator to mimic the spin up and down states. We compare TMCIM performance on Max-cut problems. A spatial photonic Ising machine (SPIM) convolves the wavefront of a coherent laser beam with the pixel distribution of a spatial light modulator to adiabatically achieve a minimum energy configuration, and solve a number partitioning problem (NPP). Our computational results on Max-cut indicate that classical solvers are still a better choice, while our NPP results show that SPIM is better as the problem size increases. In both cases, connectivity in Ising hardware is crucial for performance. Our results also highlight the importance of better understanding which CO problems are most likely to benefit from which type of PIM. This article is part of the theme issue 'Quantum annealing and computation: challenges and perspectives'.

Evaluation of Latex Agglutination Test for Rapid Identification of Staphylococcus aureus Isolated from Pyogenic Wound Infections at a Tertiary Care Hospital

Background Staphylococcus aureus infections are increasingly reported worldwide. It is a major clinical problem and imposes significant morbidity and mortality due to widespread emergence of multidrug resistant pathogens like methicillin resistant Staphylococcus aureus. Thus, rapid and reliable identification of Staphylococcus aureus is essential for timely and effective management of patient. Objective The performance of Latex agglutination test (Staphaurex Plus) was compared to conventional method tube coagulase test which is gold standard too for the identification of Staphylococcus aureus. Method This study was conducted at B.P. Koirala Institute of Health Sciences. Following standard microbiological methods, isolation and identification was done in the Department of Microbiology. MRSA detection was performed following Clinical and Laboratory Standard Institute. All the isolates of Staphylococci were subjected for Latex agglutination test and was performed according to manufacturer's instructions using Staphaurex Plus kit. Result Out of 377 (methicillin sensitive Staphylococcus aureus - 142; methicillin resistant Staphylococcus aureus - 233; Coagulase Negative Staphylococci -2) isolates of Staphylococci, Latex agglutination test was found to be positive in 138 (97.1%) of methicillin sensitive Staphylococcus aureus (MSSA) and 220 (94.4%) of methicillin resistant Staphylococcus aureus (MRSA). Overall sensitivity, specificity, positive predictive value and negative predictive value of Latex agglutination test was found to be 95.46%, 100%, 100%, 10.52% respectively. Conclusion In conclusion, Latex agglutination test is a rapid and reliable test for the identification of Staphylococcus aureus.

Protocol for Clinical GLP-1 Receptor PET/CT Imaging with [68Ga]Ga-NODAGA-Exendin-4

Imaging with radiolabeled exendin enables detection and characterization of glucagon-like peptide 1 receptors (GLP-1Rs) in vivo with high specificity. The novel radiotracer [⁶⁸Ga]Ga-NODAGA-exendin-4 forms a stable complex after a simple and fast labeling procedure. Beta-cell mass in the islets of Langerhans can be visualized using [⁶⁸Ga]Ga-NODAGA-exendin-4, which is promising for research into diabetes mellitus (DM) pathophysiology. Furthermore, this radiotracer enables very sensitive detection of insulinomas, resulting from vast overexpression of GLP-1Rs, and seems promising for the detection of focal lesions in congenital hyperinsulinism (CHI). Here, we describe the procedures involved in [⁶⁸Ga]Ga-NODAGA-exendin-4 positron emission tomography (PET)/computed tomography (CT) imaging including the radiolabeling of the NODAGA-exendin conjugate with ⁶⁸Ga, quality controls, and PET/CT.

Contemporary trends in PGD incidence, outcomes, and therapies

BACKGROUND

We sought to describe trends in extracorporeal membrane oxygenation (ECMO) use, and define the impact on PGD incidence and early mortality in lung transplantation.

METHODS

Patients were enrolled from August 2011 to June 2018 at 10 transplant centers in the multi-center Lung Transplant Outcomes Group prospective cohort study. PGD was defined as Grade 3 at 48 or 72 hours, based on the 2016 PGD ISHLT guidelines. Logistic regression and survival models were used to contrast between group effects for event (i.e., PGD and Death) and time-to-event (i.e., death, extubation, discharge) outcomes respectively. Both modeling frameworks accommodate the inclusion of potential confounders.

RESULTS

A total of 1,528 subjects were enrolled with a 25.7% incidence of PGD. Annual PGD incidence (14.3%-38.2%, p = .0002), median LAS (38.0-47.7 p = .009) and the use of ECMO salvage for PGD (5.7%-20.9%, p = .007) increased over the course of the study. PGD was associated with increased 1 year mortality (OR 1.7 [95% C.I. 1.2, 2.3], p = .0001). Bridging strategies were not associated with increased mortality compared to non-bridged patients (p = .66); however, salvage ECMO for PGD was significantly associated with increased mortality (OR 1.9 [1.3, 2.7], p = .0007). Restricted mean survival time comparison at 1-year demonstrated 84.1 days lost in venoarterial salvaged recipients with PGD when compared to those without PGD (ratio 1.3 [1.1, 1.5]) and 27.2 days for venovenous with PGD (ratio 1.1 [1.0, 1.4]).

CONCLUSIONS

PGD incidence continues to rise in modern transplant practice paralleled by significant increases in recipient severity of illness. Bridging strategies have increased but did not affect PGD incidence or mortality. PGD remains highly associated with mortality and is increasingly treated with salvage ECMO.

An audit of high oral broad-spectrum antibiotic prescribing within a Bristol-based general practice

Introduction

Oral broad-spectrum antibiotics (OBSAs), defined here as cephalosporins, fluoroquinolones and co-amoxiclav, are associated with AMR and adverse events in the elderly (ie. over 60s). Despite stringent national and local system-wide approaches aimed at reducing their inappropriate prescribing, the regional care commissioning group (CCG) alerted that OBSA prescribing within this practice between February and August 2021 at up to 14% of antibiotics prescriptions, has exceeded both the national and CCG limit which is 10%.1,2 This necessitates minimising OBSA prescribing among the over 60s in this practice.

Aim

To identify the percentage of inappropriate prescribing of OBSAs at Downend Health Group and investigate factors leading to their high prescribing rates using the following standard: 0% of OBSAs were prescribed inappropriately within a 7-month period, which includes prescribing outside of regional guidance without specialist input or evidence of infection.

Methods

The study design, data collection and analysis were conducted by the foundation trainee, supervised by the lead pharmacist. A retrospective population reporting search was run on our prescribing system (EMIS) to identify active patients over 60 years prescribed OBSAs between February and August 2021. To produce our IT data collection tool, the inclusion criteria were ages over 60 years, name of antibiotic, location of consultation, authorising user and prescribing indication. The search was piloted with 235 patients and narrowed down to 208 patients by adding acute (ie. one-off) prescription type as another inclusion criteria. Inactive and deceased patients at the time of the search were excluded. Data from the search was then compared against the regional guidance and further analysed. Ethics approval was not required for this audit.

Results

The results did not meet the set standard. Out of 208 active patients over 60 years prescribed OBSAs on acute during the defined period, 107 (51%) prescriptions were inappropriate. 63 (30%) prescriptions had the wrong antibiotic choice whereas 44 (21%) prescriptions had no evidence of infection. The top conditions with inappropriate OBSA prescriptions include UTI (22%), diverticulitis without pyrexia (15%) and cellulitis (11%). Furthermore, remote consultations had higher inappropriate prescribing as the error bar comparison between face-to-face vs remote consultations on influencing inappropriate OBSA prescribing showed statistical significance (p &lt; 0.05). Although GPs authorised 188 (90%) of OBSA prescriptions, 15 out of the 20 (75%) OBSA prescriptions authorised by non-GPs were inappropriate. Despite the similar rates of appropriate (51%) and inappropriate (49%) OBSA prescribing among the GPs, four GPs had disproportionately high inappropriate OBSA prescribing.

Discussion/Conclusion

Further to excluding deceased patients from the sample size, another limitation is the lack of investigations to rule out the confounding variables of researcher bias and the potential influence of lockdowns in the high levels of remote consultations. Regardless, the results suggest that the practice can meet the national and CCG OBSA prescribing limit by reducing inappropriate OBSA prescribing from 51% to 0%. Following an internal clinical governance meeting with the authorising users, we will update relevant internal EMIS alerts and antimicrobial stewardship protocols, followed by a reaudit 7-months after implementing the updates.

References

1. Nice.org.uk. 2015. Overview | Antimicrobial stewardship: systems and processes for effective antimicrobial medicine use | Guidance | NICE. [online] Available at: https://www.nice.org.uk/guidance/ng15/ (accessed 14 March 2022).

2. Remedy.bnssgccg.nhs.uk. 2021: REMEDY. Available at: https://remedy.bnssgccg.nhs.uk/media/5026/antimicrobial-rx-guidelines-for-bnssg2019-version-83-including-covid.pdf/ (accessed 14 March 2022).

Elevated cell-free DNA in respiratory viral infection and associated lung allograft dysfunction

Respiratory viral infection (RVI) in lung transplant recipients (LTRs) is a risk for chronic lung allograft dysfunction (CLAD). We hypothesize that donor-derived cell-free DNA (%ddcfDNA), at the time of RVI predicts CLAD progression. We followed 39 LTRs with RVI enrolled in the Genomic Research Alliance for Transplantation for 1 year. Plasma %ddcfDNA was measured by shotgun sequencing, with high %ddcfDNA as ≥1% within 7 days of RVI. We examined %ddcfDNA, spirometry, and a composite (progression/failure) of CLAD stage progression, re-transplant, and death from respiratory failure. Fifty-nine RVI episodes, 38 low and 21 high %ddcfDNA were analyzed. High %ddcfDNA subjects had a greater median %FEV₁ decline at RVI (-13.83 vs. -1.83, p = .007), day 90 (-7.97 vs. 0.91, p = .04), and 365 (-20.05 vs. 1.09, p = .047), compared to those with low %ddcfDNA and experienced greater progression/failure within 365 days (52.4% vs. 21.6%, p = .01). Elevated %ddcfDNA at RVI was associated with an increased risk of progression/failure adjusting for symptoms and days post-transplant (HR = 1.11, p = .04). No difference in %FEV₁ decline was seen at any time point when RVIs were grouped by histopathology result at RVI. %ddcfDNA delineates LTRs with RVI who will recover lung function and who will experience sustained decline, a utility not seen with histopathology.

Targeted discovery proteomics to identify clinical phenotypes in heart failure with preserved ejection fraction: a proteomics substudy of VITALITY-HFpEF

Background

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous syndrome that may emerge from overlapping systemic processes associated with several medical co-morbidities, often within an inflammatory milieu. Identification of unique proteins associated with distinct phenotypes may yield insight into novel therapeutics.

Purpose

Determine if unique clusters of circulating proteins are associated with specific clinical characteristics in patients with HFpEF.

Methods

A targeted discovery proteomics approach with 358 unique proteins associated with cardiovascular disease and inflammation (Olink) was used at baseline in VITALITY-HFpEF among 789 participants with documented left ventricular EF ≥45% and recent decompensation (&lt;6 mos). Proteins were clustered applying the weighted correlation network analysis (WCNA). The associations of the clinical characteristics and frailty and clusters were estimated with linear regression adjusted for age and eGFR. Frailty was characterized as normal, pre-frail, and frail using the Fried criteria. KCCQ was the primary and 6-minute walk distance (6MWD) the secondary endpoint of VITALITY-HFpEF.

Results

Four unique clusters were identified containing 24, 66, 197, and 81 proteins, respectively. Figure 1 shows the adjusted association of the 4 protein clusters, shown with their hub proteins, with the clinical characteristics. The color (red: positive, green: negative relationship) and intensity indicate the magnitude of the standardized difference (relative to the variation [i.e., T-value]); p-value shown in boxes. Cluster 3, with tumor necrosis factor receptor 1 as a hub protein that mediates apoptosis and inflammation, was associated with greater frailty and physical limitation along with shorter 6MWD. In contrast, cluster 4, with protein C as a hub protein that regulates anticoagulation and exerts a protective function on endothelial cells, is associated with less frailty and younger age, and more frequently male sex. Cluster 2 was associated with only younger age and cluster 1 with no clinical characteristics.

Conclusions

Proteomics appear to identify specific clinical phenotypes associated with HFpEF. Further exploration of this approach may provide insight into the diverse pathophysiology characterizing this disorder and a more targeted approach to therapy.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): VITALITY-HFpEF was funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA and Bayer AG, Wuppertal, Germany.

Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).