Evaluation of a novel university-based testing platform to increase access to SARS-CoV-2 testing during the COVID-19 pandemic in a cohort study

OBJECTIVE

We aimed to evaluate the feasibility and utility of an unsupervised testing mechanism, in which participants pick up a swab kit, self-test (unsupervised) and return the kit to an on-campus drop box, as compared with supervised self-testing at staffed locations.

DESIGN

University SARS-CoV-2 testing cohort.

SETTING

Husky Coronavirus Testing provided voluntary SARS-CoV-2 testing at a university in Seattle, USA.

OUTCOME MEASURES

We computed descriptive statistics to describe the characteristics of the study sample. Adjusted logistic regression implemented via generalised estimating equations was used to estimate the odds of a self-swab being conducted through unsupervised versus supervised testing mechanisms by participant characteristics, including year of study enrolment, pre-Omicron versus post-Omicron time period, age, sex, race, ethnicity, affiliation and symptom status.

RESULTS

From September 2021 to July 2022, we received 92 499 supervised and 26 800 unsupervised self-swabs. Among swabs received by the laboratory, the overall error rate for supervised versus unsupervised swabs was 0.3% vs 4%, although this declined to 2% for unsupervised swabs by the spring of the academic year. Results were returned for 92 407 supervised (5% positive) and 25 836 unsupervised (4%) swabs from 26 359 participants. The majority were students (79%), 61% were female and most identified as white (49%) or Asian (34%). The use of unsupervised testing increased during the Omicron wave when testing demand was high and stayed constant in spring 2022 even when testing demand fell. We estimated the odds of using unsupervised versus supervised testing to be significantly greater among those <25 years of age (p<0.001), for Hispanic versus non-Hispanic individuals (OR 1.2, 95% CI 1.0 to 1.3, p=0.01) and lower among individuals symptomatic versus asymptomatic or presymptomatic (0.9, 95% CI 0.8 to 0.9, p<0.001).

CONCLUSIONS

Unsupervised swab collection permitted increased testing when demand was high, allowed for access to a broader proportion of the university community and was not associated with a substantial increase in testing errors.

Utilizing a university testing program to estimate relative effectiveness of monovalent COVID-19 mRNA booster vaccine versus two-dose primary series against symptomatic SARS-CoV-2 infection

Vaccine effectiveness (VE) studies utilizing the test-negative design are typically conducted in clinical settings, rather than community populations, leading to bias in VE estimates against mild disease and limited information on VE in healthy young adults. In a community-based university population, we utilized data from a large SARS-CoV-2 testing program to estimate relative VE of COVID-19 mRNA vaccine primary series and monovalent booster dose versus primary series only against symptomatic SARS-CoV-2 infection from September 2021 to July 2022. We used the test-negative design and logistic regression implemented via generalized estimating equations adjusted for age, calendar time, prior SARS-CoV-2 infection, and testing frequency (proxy for test-seeking behavior) to estimate relative VE. Analyses included 2,218 test-positive cases (59 % received monovalent booster dose) and 9,615 test-negative controls (62 %) from 9,066 individuals, with median age of 21 years, mostly students (71 %), White (56 %) or Asian (28 %), and with few comorbidities (3 %). More cases (23 %) than controls (6 %) had COVID-19-like illness. Estimated adjusted relative VE of primary series and monovalent booster dose versus primary series only against symptomatic SARS-CoV-2 infection was 40 % (95 % CI: 33-47 %) during the overall analysis period and 46 % (39-52 %) during the period of Omicron circulation. Relative VE was greater for those without versus those with prior SARS-CoV-2 infection (41 %, 34-48 % versus 33 %, 9 %-52 %, P < 0.001). Relative VE was also greater in the six months after receiving a booster dose (41 %, 33-47 %) compared to more than six months (27 %, 8-42 %), but this difference was not statistically significant (P = 0.06). In this relatively young and healthy adult population, an mRNA monovalent booster dose provided increased protection against symptomatic SARS-CoV-2 infection, overall and with the Omicron variant. University testing programs may be utilized for estimating VE in healthy young adults, a population that is not well-represented by routine VE studies.

1916. Evaluation of nasal swab collection methods on a university campus during the SARS-CoV-2 pandemic

Background

Characterizing SARS-CoV-2 outbreaks on university campuses is critical for informed public health measures and understanding transmission dynamics. Figure 1.Dropbox and Kiosk Samples Collected September 10, 2021 to April 23, 2022.

Methods

Faculty, staff, and students at a major public university in Seattle, WA, USA were enrolled in a COVID-19 testing study. Individuals could test using observed self-swabs at on-campus kiosks or unobserved self-swabs using a kit and returning it to a dropbox on campus. Sample collection volume for observed self-swabs was limited by staffing and space. All samples were returned to the laboratory and tested for SARS-CoV-2 by qRT-PCR.

Results

From September 10, 2021 to April 23, 2022, 38,400 individuals were enrolled in the study. Of these individuals, 5,089 used dropboxes only, 14,421 used kiosks only, and 5,820 used both. A total of 21,653 dropbox swabs and 75,493 observed self-swabs were collected. Median age was similar between individuals using dropboxes and observed self-swabs (20 vs. 22 years). A greater proportion of dropbox users were students compared to faculty and staff (students made up 83% of dropbox only population, 75% of kiosk only, and 86% of both, χ² p-value&lt; 0.0001). Symptom data was reported for 65,349 swabs. Dropbox users were less likely to have symptoms compared to observed self-swab users (24% of swabs vs. 54%, χ² p-value&lt; 0.0001). SARS-CoV-2 positivity was slightly lower for dropboxes compared to kiosks (4% vs. 5%; p=0.001). Dropboxes were highly utilized during periods of increased testing demand, including after academic breaks and variant emergence (Figure 1). Of the total tests distributed for use, a greater proportion of dropbox kits were unable to be resulted (6%) compared to observed self-swab kits (0.02%).

Conclusion

Dropboxes provided a flexible, high-volume collection method at times of increased testing demand. Individuals who used dropboxes were less likely to report symptoms and slightly less likely to test positive, suggesting a role for dropbox utilization in high-risk asymptomatic individuals during periods of high community transmission on a university campus.

Disclosures

Geoffrey S. Gottlieb, MD, PhD, Abbott Molecular Diagnostics: Grant/Research Support|Alere Technologies: Grant/Research Support|BMGF: Grant/Research Support|BMS: Grant/Research Support|Cerus Corp.: Grant/Research Support|Gilead Sciences: Grant/Research Support|Janssen Pharmaceutica: Grant/Research Support|Merck & Co: Grant/Research Support|Roche Molecular Systems: Grant/Research Support|THERA Technologies/TaiMed Biologics: Grant/Research Support|ViiV Healthcare: Grant/Research Support Helen Y. Chu, MD, MPH, Cepheid: Reagents|Ellume: Advisor/Consultant|Gates Ventures: Grant/Research Support|Merck: Advisor/Consultant|Pfizer: Advisor/Consultant.

OP0074 DISTINCT CIRCULATING LYMPHOCYTE SUBSETS DISTINGUISH FLARE FROM DRUG-FREE REMISSION IN RHEUMATOID ARTHRITIS

Background

Rheumatoid arthritis (RA) is characterised by relapsing joint and systemic inflammation, yet the immunopathological basis of these disease flares and their clinical prediction remain uncertain.

Objectives

Using mass cytometry and single cell RNA sequencing, we aimed to identify circulating lymphocyte subsets associated with RA flare, and identify potential cellular biomarkers to predict flare versus drug-free remission (DFR).

Methods

We analysed peripheral blood mononuclear cells (PBMCs) from patients recruited to the BioRRA study (Figure 1), a prospective clinical trial of conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) cessation.[1] Patients with RA in clinical (DAS28-CRP < 2.4) and ultrasound (absence of power Doppler signal in 7 joints) remission stopped csDMARDs, with flare defined as DAS28-CRP ≥ 2.4 during 6 month follow-up. A 44-marker mass cytometry panel was used to profile PBMCs from 36 patients (20 flare, 16 DFR) at two time points each (baseline, and flare onset / month 6 DFR). In a subset of patients (n = 12: 8 flare, 4 DFR), fluorescence-activated cell sorting of T and B cells was followed by single cell sequencing (n = 81,923 cells) incorporating 320 immune genes, 34 oligo-tagged surface protein antibodies, and TCR/BCR CDR3 sequence. Clones were defined as ≥2 cells with identical CDR3 nucleotide sequence, and clonal expansion as a significant increase in proportion from baseline to final study visit. Statistical significance was assessed after Benjamini-Hochberg multiple test correction (adj p < 0.05).

Figure 1.

Results

Mass cytometry revealed 31 distinct cell clusters: notably, greater proportions of memory (CD45RO+/PD1hi) CD4+ and CD8+ T cells, and memory (CD27+/CD21-) B cells, were observed at onset of flare versus baseline (Table 1).

Table 1.Mass cytometry (n = 20 flare + 16 DFR)ContrastClusterMedian %Adj. p (GLMM)Flare onset vs baseline: Flare patientsCD4+/CD45RO+/PD1+ memory T cells2.14 vs 0.24<0.001CD8+/CD45RO+/PD1+ memory T cells6.64 vs 0.07<0.001CD19+/CD27+/CD21- memory B cells2.39 vs 0.03<0.001Single cell RNAseq (n = 8 flare + 4 DFR)ContrastClusterMedian %Adj. p (Wilcoxon)Flare onset vs baseline: Flare patientsIgA+ plasma cells0.37 vs 0.210.020Flare vs DFR patients: BaselineCD4+/CD25+/Foxp3+ Treg cells0.55 vs 1.270.022

To better characterise these flare-associated subsets, single cell sequencing of CD45RO+/PD1hi CD4+ and CD8+ T cells, and CD19+ B cells, was performed and identified 21 distinct clusters. CDR3 sequencing revealed significant clonal expansion (Fisher exact, adj. p < 0.05) at flare onset within five unique CD8+ clones (4 patients), one CD4+ clone (1 patent), and no B clones. Overall, there was a significantly greater proportion of IgA+ plasma cells at flare onset versus baseline. In contrast, a significantly lower proportion of CD25+/FoxP3+ regulatory T cells were present at csDMARD cessation (baseline) in subsequent flare versus DFR patients (Table 1), suggesting biomarker potential.

To further assess the predictive performance of CD4+ Tregs as a biomarker for flare versus DFR, we analysed PBMCs from an independent cohort of 50 patients (25 flare, 25 DFR) stopping csDMARDs in the ongoing BIO-FLARE study.[2] By flow cytometry, we confirmed a lower proportion of CD4+/CD25hi Tregs at baseline in flare vs DFR (median 4.74 versus 6.37%, Wilcoxon p = 0.037; AUC: 0.67). In this cohort, stopping csDMARDs only in patients with elevated (> 6.11% total CD4) baseline Tregs would have prevented drug cessation in 18/25 (72%) of flare patients; 9/25 (36%) of DFR patients would have continued csDMARDs unnecessarily.

Conclusion

We present a detailed longitudinal characterisation of circulating lymphocyte surface phenotype, gene expression, and clonal expansion in RA flare vs DFR. Furthermore our data, across two independent cohorts, suggests a role for CD4+ Tregs in promoting drug-free remission meriting further investigation, with potential for future clinical biomarker development.

References

[1]Baker et al; J Autoimmunity; 105:102298

[2]Rayner et al; BMC Rheumatology; 5:22

Acknowledgements

This work was funded by research grants from Wellcome Trust [102595/Z/13/A to KFB], Newcastle NIHR Biomedical Research Centre [BH136167/PD0045 to KFB], British Society for Rheumatology [KFB], Academy of Medical Sciences [SGL022\1074 to KFB], Newcastle University Wellcome Trust Translational Partnership [KFB], Newcastle Hospitals Charity [8033 to KFB], and a National Institute for Health Research Clinical Lectureship [CL-2017-01-004 to KFB]. Our work is supported by the Research into Inflammatory Arthritis Centre Versus Arthritis (RACE) (grant number 20298), and Rheuma Tolerance for Cure (European Union Innovative Medicines Initiative 2, grant number 777357). AGP and JDI are named as inventors on a patent application by Newcastle University (“Prediction of Drug-Free Remission in Rheumatoid Arthritis”; International Patent Application Number PCT/GB2019/050902). The views expressed are those of the authors and not necessarily those of the NHS, the NIHR, or the Department of Health and Social Care.

Disclosure of Interests

Kenneth F Baker Consultant of: Modern Biosciences Ltd, Grant/research support from: Pfizer, Genentech, Fiona Rayner: None declared, Henrique Lemos: None declared, David McDonald: None declared, Gillian Hulme: None declared, Rafiqul Hussain: None declared, Jonathan Coxhead Speakers bureau: Tesaro, Arthur Pratt Grant/research support from: Pfizer, Gilead, Amy E. Anderson: None declared, Andrew Filby Grant/research support from: Becton Dickinson, John Isaacs Speakers bureau: Abbvie, Gilead, Roche, UCB, Grant/research support from: GSK, Janssen, Pfizer.

Oral immune dysfunction is associated with the expansion of FOXP3+PD-1+Amphiregulin+ T cells during HIV infection

Residual systemic inflammation and mucosal immune dysfunction persist in people living with HIV, despite treatment with combined anti-retroviral therapy, but the underlying immune mechanisms are poorly understood. Here we report that the altered immune landscape of the oral mucosa of HIV-positive patients on therapy involves increased TLR and inflammasome signaling, localized CD4+ T cell hyperactivation, and, counterintuitively, enrichment of FOXP3+ T cells. HIV infection of oral tonsil cultures in vitro causes an increase in FOXP3+ T cells expressing PD-1, IFN-γ, Amphiregulin and IL-10. These cells persist even in the presence of anti-retroviral drugs, and further expand when stimulated by TLR2 ligands and IL-1β. Mechanistically, IL-1β upregulates PD-1 expression via AKT signaling, and PD-1 stabilizes FOXP3 and Amphiregulin through a mechanism involving asparaginyl endopeptidase, resulting in FOXP3+ cells that are incapable of suppressing CD4+ T cells in vitro. The FOXP3+ T cells that are abundant in HIV-positive patients are phenotypically similar to the in vitro cultured, HIV-responsive FOXP3+ T cells, and their presence strongly correlates with CD4+ T cell hyper-activation. This suggests that FOXP3+ T cell dysregulation might play a role in the mucosal immune dysfunction of HIV patients on therapy.

iChain: Peer-To-Peer Machine Learning Powered by Blockchain Technology

iChain is an application which was created to help meet the growing demand of machine learning. It allows users to pay those with powerful machines to run machine learning tasks for them, bypassing the need for a significant investment in a powerful computer to run it themselves. This is similar to services like a render farm. Our application functions using the Ethereum blockchain which ensures security and decentralization, as well as providing a platform for payment transactions. This article will discuss the background on machine learning and blockchain, the application, how it works, how the data moves through it, and how to use it. We hope our application will enable many without the funds to build or buy a powerful computer to experiment with and utilize complex machine learning tasks.

National survey of occupational advice for lower limb arthroplasty patients

BACKGROUND

Little is known what advice or support patients are given about return to work (RTW) after hip or knee replacement surgery.

AIMS

This study aims to understand the delivery, timing and content of 'RTW' advice currently delivered by surgical teams offering hip and knee replacements across the UK.

METHODS

National online survey exploring five specific areas relating to 'RTW' advice: (i) timings of interactions between hospital orthopaedic teams and patients prior to surgery, (ii) routine delivery of 'RTW' advice, (iii) methods used to deliver 'RTW' advice, (iv) confidence delivering advice and (v) need for an occupational 'RTW' advice intervention.

RESULTS

A total of 152 participants including surgeons, physiotherapists, occupational therapists and nurses from 59 different public and private health providers responded. Only 20% (n = 30) of respondents reported that working patients were identified as a specific subgroup in need of additional support. Overall, 62% (n = 92) stated that they did not routinely offer 'RTW' advice. When given, 'RTW' advice was almost always verbal, generic advice using blanket timescales and based on the respondent's anecdotal experience rather than the patients individualized needs. Overall, 116 (78%) felt an occupational advice intervention was needed.

CONCLUSIONS

This national survey demonstrated wide variation in the timing, content and delivery of information and advice for patients in work and intending to RTW after hip and knee replacement surgery. Current RTW advice provided to hip and knee replacement patients is inadequate.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Relative Serum Antiplasmin Levels in Normal and Hemophilic Dogs Treated with Choline

Peroral administration of choline in relatively high dosage (300 or 600 mg choline dihydrogen citrate per 17-20 lb body weight, 4 times daily) caused no significant change in serum antiplasmin activity of either normal or factor VIII-deficient beagle dogs. Also, no alteration in antiplasmin level was found to be associated with the hemophilic state.

Canine serum antiplasmins are stable at low temperatures. Like human antiplasmins, they appear to have two major components which differ conspicuously in stability at 60° C.

Other data presented in this paper show that crude plasmin readily obtained from human serum euglobulins provides an enzyme preparation suitable for screening antiplasmin levels of sera by the caseinolytic method.

Soft Tissue Metastasis from Carcinoma. A Case Report

The authors report a case of a man who developed soft tissue metastasis to the thigh from pulmonary carcinoma. In the preoperative staging, computerized tomograms and magnetic resonance imaging allowed to identify and characterize the features of soft tissue masses; these studies, however, must be always completed with needle (tru-cut) or incisional biopsy.

Serum Lactate Dehydrogenase (LDH) as a Tumor Marker in Ewing's Sarcoma

The pretreatment serum lactic acid dehydrogenase (LDH) level of 246 patients with Ewing's sarcoma of bone (47 metastatic and 199 localized at presentation) was examined to evaluate the use of LDH as a tumor marker. The percentage of patients with increased serum LDH levels was significantly higher in the metastatic group than in the group of patients with localized disease (83 % vs 41 %; p < 0.01). In the latter group the relapse rate after treatment with combined therapy was significantly higher in patients with an elevated serum LDH at admission than in those with normal serum levels (68.2 % vs 39.3 %; p < 0.01). After local treatment, in 73 out of 82 patients with an elevated serum LDH at admission the enzyme level normalized whereas in 9 it fell but never reached a normal value. The rate of relapse in these two groups was respectively 64 % and 100 %. The value of serum LDH at the time of recurrence, determined in 62 patients, was elevated in 50 (80.7 %). These data demonstrate that in Ewing's sarcoma of bone pretreatment serum LDH levels have a definitive value in establishing the prognosis and could also be used in evaluating the response to therapy. A persistent elevated value of serum LDH, or an increasing value after a transient normalization, is usually followed by relapse.

Neoadjuvant Chemotherapy for Localized Ewing's Sarcoma of the Extremities: Preliminary Results of a Protocol Which uses Surgery (Alone or Followed by Radiotherapy) for Local Control

From June 1983 to December 1985, thirty-eight paients with localized Ewing's sarcoma of the extremities were treated with a protocol that consisted of an initial nine week period of polychemotherapy (vincristine, adriamycin and cyclophosphamide) followed by local therapy and additional chemotherapy (vincristine, adriamycin, cyclophosphamide and dactino-mycln) for one year. As local treatment all patients were offered surgery; thirty-two accepted and six refused. These six patients were locally treated with radiotherapy alone (50 Gy). In the remaining patients an amputation was performed in one case and a resection in thirty-one. In resected patients when a wide margin was achieved (24 cases) no further local treatment was performed; when it was marginal (5 cases) or intralesional (2 cases) radiotherapy at lower doses (40 Gy) followed. At mean follow-up of thirty-seven months the percentage of continuously disease-free patients was 50 % for those treated with radiotherapy, 76 % with surgery, and 85 % with surgery and radiotherapy. Eight patients developed metastatic disease and two patients had local recurrence and metastases. The local recurrences were seen in one patient locally treated with surgery and in one locally treated with radiotherapy. Nine major local complications were observed: three in patients treated with radiotherapy, five in patients treated with surgery, and one in a patient treated with surgery and radiotherapy. These results indicate that after induction chemotherapy conservative surgery is possible in almost all cases of Ewing's sarcoma of the extremities and that such treatment is better than radiotherapy alone as local therapy.

Dijet imbalance measurements in Au+Au and pp collisions at sqrt[s_{NN}]=200 GeV at STAR

We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2  GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature-momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2.

Traumatic pulmonary pseudocyst: An underreported entity

BACKGROUND

Traumatic pulmonary pseudocysts (TPP) are underreported cavitary lesions of the pulmonary parenchyma that can develop following blunt chest trauma. Although the occurrence of traumatic pulmonary pseudocyst is rare, this condition should be considered in the differential diagnosis of any cavitary lesion. Awareness of this injury and its clinical significance is important for successful management in order to avoid medical errors in the course of treatment.

METHODS

A literature search was conducted through Medline using the key phrases "traumatic pulmonary pseudocyst" and "traumatic pneumatocele." Relevant articles, especially those with focus on diagnosis and management of traumatic pneumatocele in adults, were selected. Due to the scarcity of literature and lack of Level I evidence on this subject, studies published in any year were considered.

RESULTS

A search of "traumatic pulmonary pseudocyst" and "traumatic pneumatocele" yielded 114 studies. Most of these were excluded based on inclusion and exclusion criteria. Thirty-five articles were reviewed. The majority of these were individual case studies; only eight articles were considered large case studies (greater than eight patients).

CONCLUSION

Traumatic pulmonary pseudocysts are lesions that occur secondary to blunt chest trauma. Diagnosis is based on a history of trauma and appearance of a cystic lesion on CT. Accurate diagnosis of traumatic pulmonary pseudocyst is imperative to achieve successful outcomes. Failure to do so may lead to unnecessary procedures and complications.

Charge-Dependent Directed Flow in Cu+Au Collisions at sqrt[s_{NN}]=200 GeV

We present the first measurement of charge-dependent directed flow in Cu+Au collisions at sqrt[s_{NN}]=200  GeV. The results are presented as a function of the particle transverse momentum and pseudorapidity for different centralities. A finite difference between the directed flow of positive and negative charged particles is observed that qualitatively agrees with the expectations from the effects of the initial strong electric field between two colliding ions with different nuclear charges. The measured difference in directed flow is much smaller than that obtained from the parton-hadron-string-dynamics model, which suggests that most of the electric charges, i.e., quarks and antiquarks, have not yet been created during the lifetime of the strong electric field, which is of the order of, or less than, 1  fm/c.