1
|
Fowler VL, Armson B, Gonzales JL, Wise EL, Howson ELA, Vincent-Mistiaen Z, Fouch S, Maltby CJ, Grippon S, Munro S, Jones L, Holmes T, Tillyer C, Elwell J, Sowood A, de Peyer O, Dixon S, Hatcher T, Patrick H, Laxman S, Walsh C, Andreou M, Morant N, Clark D, Moore N, Houghton R, Cortes NJ, Kidd SP. A highly effective reverse-transcription loop-mediated isothermal amplification (RT-LAMP) assay for the rapid detection of SARS-CoV-2 infection. J Infect 2021; 82:117-125. [PMID: 33271166 PMCID: PMC7703389 DOI: 10.1016/j.jinf.2020.10.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 10/04/2020] [Accepted: 10/07/2020] [Indexed: 12/23/2022]
Abstract
The COVID-19 pandemic has illustrated the importance of simple, rapid and accurate diagnostic testing. This study describes the validation of a new rapid SARS-CoV-2 RT-LAMP assay for use on extracted RNA or directly from swab offering an alternative diagnostic pathway that does not rely on traditional reagents that are often in short supply during a pandemic. Analytical specificity (ASp) of this new RT-LAMP assay was 100% and analytical sensitivity (ASe) was between 1 × 101 and 1 × 102 copies per reaction when using a synthetic DNA target. The overall diagnostic sensitivity (DSe) and specificity (DSp) of RNA RT-LAMP was 97% and 99% respectively, relative to the standard of care rRT-PCR. When a CT cut-off of 33 was employed, above which increasingly evidence suggests there is a low risk of patients shedding infectious virus, the diagnostic sensitivity was 100%. The DSe and DSp of Direct RT-LAMP (that does not require RNA extraction) was 67% and 97%, respectively. When setting CT cut-offs of ≤33 and ≤25, the DSe increased to 75% and 100%, respectively, time from swab-to-result, CT < 25, was < 15 min. We propose that RNA RT-LAMP could replace rRT-PCR where there is a need for increased sample throughput and Direct RT-LAMP as a near-patient screening tool to rapidly identify highly contagious individuals within emergency departments and care homes during times of increased disease prevalence ensuring negative results still get laboratory confirmation.
Collapse
Affiliation(s)
- Veronica L Fowler
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; Eco Animal Health, The Grange, 100 The High Street, London, UK
| | - Bryony Armson
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; School of Veterinary Medicine, University of Surrey, Guildford, UK
| | - Jose L Gonzales
- Wageningen Bioveterinary Research (WBVR), PO Box 65, 8200 AB Lelystad, the Netherlands
| | - Emma L Wise
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; School of Biosciences and Medicine, University of Surrey, Guildford, UK
| | - Emma L A Howson
- GeneSys Biotech Limited, Camberley, Surrey, UK; The Pirbright Institute, Ash Road, Pirbright, Woking, UK
| | - Zoe Vincent-Mistiaen
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; Gibraltar Health Authority, Gibraltar, UK
| | - Sarah Fouch
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; School of Pharmacy and Biomedical Sciences, University of Portsmouth, UK
| | - Connor J Maltby
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Seden Grippon
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Simon Munro
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Lisa Jones
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Tom Holmes
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Claire Tillyer
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Joanne Elwell
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Amy Sowood
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Oliver de Peyer
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Sophie Dixon
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Thomas Hatcher
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Helen Patrick
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | | | | | | | - Nick Morant
- GeneSys Biotech Limited, Camberley, Surrey, UK
| | | | - Nathan Moore
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Rebecca Houghton
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK
| | - Nicholas J Cortes
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK; Gibraltar Health Authority, Gibraltar, UK
| | - Stephen P Kidd
- Hampshire Hospitals NHS Foundation Trust, Basingstoke & North Hampshire Hospital, Department of Microbiology, Basingstoke, UK.
| |
Collapse
|
2
|
Mato A, Svoboda J, Luning Prak E, Schuster S, Tsao P, Dorsey C, Sarmasti L, Becker P, Brander D, Nasta S, Landsburg D, King C, Morrigan B, Elwell J, Kennard K, Roeker L, Zelenetz A, Purdom M, Paskalis D, Sportelli P, Miskin H, Weiss M, Shadman M. PHASE I/II STUDY OF UMBRALISIB (TGR-1202) IN COMBINATION WITH UBLITUXIMAB (TG-1101) AND PEMBROLIZUMAB IN PATIENTS WITH REL/REF CLL AND RICHTER'S TRANSFORMATION. Hematol Oncol 2019. [DOI: 10.1002/hon.79_2629] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- A.R. Mato
- CLL Program; Leukemia Service, Memorial Sloan-Kettering Cancer Center; New York NY United States
| | - J. Svoboda
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - E.T. Luning Prak
- Department of Pathology and Laboratory Medicine; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - S.J. Schuster
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - P.Y. Tsao
- Department of Pathology and Laboratory Medicine; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - C. Dorsey
- CLL Program; Leukemia Service, Memorial Sloan-Kettering Cancer Center; New York NY United States
| | - L.M. Sarmasti
- CLL Program; Leukemia Service, Memorial Sloan-Kettering Cancer Center; New York NY United States
| | - P.S. Becker
- Department of Hematology; Fred Hutchinson Cancer Research Center; Seattle WA United States
| | - D.M. Brander
- Division of Hematologic Malignancies; Duke University Medical Center; Durham NC United States
| | - S. Nasta
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - D.J. Landsburg
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - C.M. King
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - B. Morrigan
- Department of Hematology; Fred Hutchinson Cancer Research Center; Seattle WA United States
| | - J. Elwell
- Department of Hematology; Fred Hutchinson Cancer Research Center; Seattle WA United States
| | - K. Kennard
- Lymphoma Department; University of Pennsylvania, Abramson Cancer Center; Philadelphia PA United States
| | - L. Roeker
- CLL Program; Leukemia Service, Memorial Sloan-Kettering Cancer Center; New York NY United States
| | - A.D. Zelenetz
- Lymphoma Service; Memorial Sloan-Kettering Cancer Center; New York NY United States
| | - M. Purdom
- Clinical Development; TG Therapeutics, Inc.; New York NY United States
| | - D. Paskalis
- Clinical Development; TG Therapeutics, Inc.; New York NY United States
| | - P. Sportelli
- Clinical Development; TG Therapeutics, Inc.; New York NY United States
| | - H.P. Miskin
- Clinical Development; TG Therapeutics, Inc.; New York NY United States
| | - M.S. Weiss
- Clinical Development; TG Therapeutics, Inc.; New York NY United States
| | - M. Shadman
- Department of Hematology; Fred Hutchinson Cancer Research Center; Seattle WA United States
| |
Collapse
|
3
|
Gordon BM, Mohan V, Chapekis AT, Kander NH, Elwell J, Antalis G, Yakubov SJ. An analysis of the safety of performing dobutamine stress echocardiography in an ambulatory setting. J Am Soc Echocardiogr 1995; 8:15-20. [PMID: 7710746 DOI: 10.1016/s0894-7317(05)80353-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Dobutamine echocardiography has become widely used in the past decade in the evaluation of patients with suspected coronary artery disease who are unable to undergo exercise treadmill or bicycle testing. The safety of this procedure has been studied in a hospital-based setting. However, no studies thus far have evaluated the safety of this procedure in an office-based setting, remote from a hospital. We performed dobutamine echocardiography on 127 patients in an office-based setting, remote from a hospital. Throughout the course of this study there were no deaths, myocardial infarctions, sustained episodes of ventricular tachycardia, or syncopal episodes associated with dobutamine infusion. The frequency of noncardiac side effects was 29%, the majority of which were nausea, vomiting, and paresthesias. Three patients had nonsustained ventricular tachycardia, none of whom had symptoms. We conclude that dobutamine echocardiography is safe, well tolerated, and useful in an office-based setting.
Collapse
Affiliation(s)
- B M Gordon
- Department of Internal Medicine, Riverside Methodist Hospitals, Columbus, OH, USA
| | | | | | | | | | | | | |
Collapse
|
4
|
Gipson IK, Spurr-Michaud S, Tisdale A, Elwell J, Stepp MA. Redistribution of the hemidesmosome components alpha 6 beta 4 integrin and bullous pemphigoid antigens during epithelial wound healing. Exp Cell Res 1993; 207:86-98. [PMID: 8319775 DOI: 10.1006/excr.1993.1166] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
As basal cells of stratified squamous epithelia become migratory in response to wounding, they lose their cell-substrate adhesion junctions, the hemidesmosomes. We report here studies to determine the fate of the hemidesmosome components, alpha 6 beta 4 integrin and the bullous pemphigoid antigens (BPAGs), as recognized by bullous pemphigoid autoantisera (BPA), in migrating epithelium. In addition, we report studies to determine whether relative synthesis and amount of alpha 6 beta 4 is altered during migration. Mouse corneas with 1.5- to 2-mm-diameter central epithelial debridements were allowed to heal in vitro or in vivo for 1-18 h. In order to do preembedding immunoelectron microscopic localization of alpha 6 beta 4, sheets of stationary and migrating corneal epithelium were removed from their basal laminae after organ culture. BPA and antibodies to alpha 6 and beta 4 were used for immunofluorescence microscopy on frozen sections of intact corneas healing in vivo 1-18 h. Both alpha 6 and beta 4 were found to redistribute from their clustered location within hemidesmosomes to a more even distribution within the substrate-associated membrane of basal cells of the tip of the leading edge of migrating epithelium. Behind the tip of the leading edge, basal cells bound the integrin antibodies around their entire membrane. BPAGs moved from their location along the basal cell membrane of stationary epithelium to a diffuse location within the cytoplasm of migrating cells at the leading edge of migration. Quantitative immunoprecipitation and immunoblotting of alpha 6 beta 4 as well as beta 1 integrin from stationary and migrating epithelium were done to determine whether the synthesis or total amount of the integrins were altered during migration. The relative syntheses of alpha 6 beta 4 and beta 1 per milligram of protein or per cell do not appear to differ between stationary and migrating epithelium and the total amount of the beta 4 and beta 1 does not change despite increased rates of protein synthesis in migrating epithelium. Taken together, these studies suggest that as hemidesmosomes disassemble, their clustered integrin component distributes more evenly in the basal cell membrane, the components recognized by BPA and associated with intermediate filaments are released from the membrane, and these events occur in the absence of any measurable change in the synthesis or total amount of the alpha 6 beta 4 component.
Collapse
Affiliation(s)
- I K Gipson
- Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114
| | | | | | | | | |
Collapse
|
7
|
Hoffman R, Bruno E, Elwell J, Mazur E, Gewirtz AM, Dekker P, Denes AE. Acquired amegakaryocytic thrombocytopenic purpura: a syndrome of diverse etiologies. Blood 1982; 60:1173-8. [PMID: 6982086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The possible pathogenetic mechanisms responsible for the production of acquired amegakaryocytic thrombocytopenic purpura (AATP) were investigated in a group of patients with this disorder. Absence of megakaryocytes and small platelet glycoprotein-bearing mononuclear cells, as determined by immunochemical staining of patient marrows with an antisera to platelet glycoproteins, suggested that the defect in AATP occurs in an early progenitor cell of the megakaryocytic lineage. Using an in vitro clonal assay system for negakaryocytic progenitor cells or megakaryocyte colony-forming units (CFU-M), the proliferative capacity of AATP marrow cells was then assessed. Bone marrow cells from three of four patients formed virtually no megakaryocyte colonies, suggesting that in these individuals the AATP was due to an intrinsic defect in the CFU-M. Bone marrow cells from an additional patient, however, formed 12% of the normal numbers of colonies, providing evidence for at least partial integrity of the CFU-M compartment in this patient. Serum specimens from all six patients were screened for their capacity to alter in vitro megakaryocyte colony formation. Five of six sera enhanced colony formation in a stepwise fashion, demonstrating appropriately elevated levels of megakaryocyte colony-stimulating activity. The serum of the patient with partial integrity of the CFU-M compartment, however, stimulated colony formation only at low concentrations. At higher concentrations, this patient's serum actually inhibited the number of colonies cloned, suggesting the presence of a humoral inhibitor to CFU-M. Serum samples from all patients were further screened for such humoral inhibitors of megakaryocyte colony formation using a cytotoxicity assay. The patient whose serum was inhibitory to CFU-M at high concentrations was indeed found to have a complement-dependent serum IgG inhibitor that was cytotoxic to allogeneic and autologous marrow CFU-M but did not alter erythroid colony formation. These-studies suggest that AATP can be due to at least two mechanisms: either an intrinsic effect at the level of the CFU-M or a circulating cytotoxic autoantibody directed against the CFU-M.
Collapse
|