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Review of Candidate Technologies for Rapid Diagnostic Tests Rosanna W Peeling Professor and Chair, Diagnostic Research London School of Hygiene & Tropical Medicine Technologies Needs for POC Settings Technologies for screening and for syndromes, e.g. Screening: HIV and syphilis Syndromes Fever: acute and persistent Sepsis Pneumonia Neurological presentations Consider how diagnostics can support clinical i l algorithms Bacterial vs viral (vs fungal) infections Gram + vs Gram Platform technology with a menu of tests to support Platform technology with a menu of tests to support differential diagnosis in a variety of geographic regions Need for Diagnostics for Syndromes: Antibiotic prescriptions in Dar es Salaam Proportion of febrile patients receiving: Antibiotics Before RDT implementation After RDT implementation 49% 73% Antimalarials 81% 24% Which complaints motivate clinicians to prescribe antibiotics? ear problem (OR = 11.0) skin problem (OR = 4.1) cough (OR = 3.9) D Acremont et al, 2010 Diagnostic Technology Development: What is the test for? Who is the patient? What is the setting? Who will do the test? Courtesy Dr. Ray Waters KSenior K. Lancet ID 9: Diagnostics Methods Confidence DIRECT METHODS INDIRECT METHODS (Microscopy) Genome Antigen Serology Serology Culture detection detection IgM IgG Ease of use Time to Result: Days Hours Hours/Minutes Adapted with permission from J. Cardosa Immunochromatographic Tests (ICTs) or Lateral Flow Devices Procedure: 1. Use dropper provided, dispense 1 drop of serum/whole blood to sample well S 2. Add 2 drops of diluent buffer to sample well S 3. Read results after 15 minutes C T S Negative C T S Positive C T S Invalid Rapid Simultaneous Detection of Reagin and Treponemal Antibodies Using the Signal Trepolipin Flow through Test NON REACTIVE TESTS ONLY THE NON SPECIFIC CARDIOLIPIN TEST REACTIVE CONFIRMED REACTIVE TEST ONLY THE TREPONEMAL TEST REACTIVE Dual Path Technology: HCV/HIV/Syphilis Assay C 1 HCV 2 Syphilis 3 HIV C Control HCV, HIV and Syphilis Positive Rapid Test for Diabetes Using Oral Exudate Source: Antigen Detection: Clearview Chlamydia Test STD clinic and re education centres in China N = 1,497 women; 13% cervical swab vaginal swab sensitivity* specificity* PPV 50% 98% 78% 33% 99% 86% * Performance vs. PCR (Yin et al STI 2006; 82 Suppl V: v33 7) Rapid Tests for Chlamydia Require 7-14 steps The mchip: The Credit Card that can tell you if you have HIV within minutes and costs just $1 Works well with blood Challenges: Specimen processing Getting enough target molecules into the detection zones Chin et al Nature Med 31 July 2011;doi: /nm.2408 POC Technologies Target Amplification Methods Transcription Mediated Amplification Advantages: quantitative, best studied Advantages: isothermal Disadvantages: sample prep, temp. cycling Disadvantages: not quantitative Companies: Roche, Cepheid, Abbott, etc Companies: GenProbe, other isothermal techs. 14 A Sampling of Nucleic Acid Systems Company Platform Commercial Status Technology Applications Attributes Time to Result MPX mol dx, but not 15 min IA and 3 Akonni Biosystems TruDiagnosis System Under development PCR MDR TB, respiratory, ID, HIA integrated hr molecular BD (Handylab) BD Max (Jaguar) On market RT PCR, magnetic beads Also have SDA isothermal tech GeneOhm assays for HIA, ID, Up to 24 assays per run in microwell plate, sample in, result out, incl SP, 2 hour, some 45 min STAT tests may be avail BioHelix Corp IsoAMP, BEST Cassette In Development PCR Isothermal DNA or RNA amplification ( Helicase dependent amplification) 1, 4, 16 module formats; On Market multiple sample in, result out, incl SP; Cepheid GeneXpert tests RT PCR ID, HAI, Respiratory, TB+RIF low MPX min Eiken LAMP GenMark (Osmetech) esensor XT 8 On market end point PCR, not RT PCR Respiratory, drug sens Single test cartridge, up to 8 bays per module, up to 3 modules per sys; high plex capability Sample in, result out; 260 First result in 3.5 Gen Probe Panther Near mkt in EU RT PCR, chemiluminescent read Virology, STD samples in 8 hrs hrs Gentura Dx (Progentech Ltd) IDBox In Development RT PCR Epoch Multiplex technology Does not appear to incl sample prep or NA extraction Great Basin Scientific POC MDx, isothermal helicasedependent amplification and chipbased detection, sample in, result out startedwith extracted NA rapid multi pathogen dx Does not appear to incl sample prep or NA extraction min Iquum Liat Analyzer Developed, not on mkt RT PCR ID, flu, STD One sample at a time; low plex; sample in, result out but may accept only blood min Qiagen/Corbett/Rotogene Corbett/Rotogene On market NA amplification and detection ID, flu, resp etc Non, integrated QuantuMDx bio chips used in POC, lab on chip, sample prep, DNA extraction, PCR, RT PCR, biosensors, DNA seq, POC hand held device Disease detection and hand held DNA sequencer, too STMicroelectronics In Check Under development Lab on Chip ID, flu, Integrated Wave80 Eoscape In development bdna based HIV and other ID 15 Courtesy of M. Urdea, Halteres Associates Recombinase Polymerase Amplification, TwistDx, UK Isothermal amplification basedon recombinases, capable of pairing oligonucleotide primers with homologous sequence in duplex DNA DNA amplification reaction results in specific DNA amplification from just a few target copies to detectable levels typically within 5 10 minutes. Piepenburg et al. PLoS Biol 2006;4(7): e204. The entire reaction system is stable as a dried formulation and can be transported safely without refrigeration. Helicase Dependent Amplification (HDA) BioHelixCorp, USA One Tube Isothermal One tube isothermal amplification detect short DNA sequences ( bp) Time to result: 1.8 hours Storage temp: 20 C Cost: USD 6.00/reaction Goldmeyer J et al J Molecular Diagnostics November 2007 (Biohelix Corporation, USA) Isothermal Amplification Assay for Ct and Ng: Ustar, China Need: Waterbath Centrifuge C Micropipette Reaction time: 1.5hours Reagent storage: 20 Cost: USD 12.00 GeneXpert: A multi disease, Random Access Platform based on Real time PCR MTB/RIF CT/Ng HIV Viral Load Xpert MTB/RIF Samples per shift GeneXpert: Assay principles and procedure Neonatal Sepsis Blood culture Antigen detection (latex) Blood neutrophil count & differential C Reactive Protein Molecular identification of pathogens PCR or isothermal amplification DNA or protein microarrays + fluorescent signals (can include resistance targets, virulence markers) Edmond et al 2010 PLoS Med 7:e Microfluidic lab on a chip a devices Pulse oximetry device Mark Ansermino Point of Care of Device System Diagram Boxed in components (modules) constitute front end Sample Acquisition (Collection) Sample Preparation Sample Processing Automation of front end a critical milestone for successful POC devices Transduction (detection) Assay Hybridization Amplification (signal/copy) Data Analysis Algorithms Device Output Connectivity and Database 22 Courtesy of John C. Carrano of Carrano Consulting Our Hypothesis POC Dx Initiative An effective, agreed upon set of standards would have a transformative impact on the performance, health impact and costs of Point of Care Diagnostics These standards might include: technical, interface, product performance, quality, logistics, i business, IP,. These standards would need to be supported by an appropriate regulatory andbusiness regime 23 POC Dx Initiative Goals Develop an open point of care instrument platform capable of delivering optimum performance Establish interoperability standards to encourage menu expansion by competing companies/sources Reduce barriers to entry into the GH markets by eliminating the need for expensive instrument development Achieve a harmonized regulatory environment 24 POC DX Platform Options PCR ISO TB HIV Malaria Fever TB HIV Malaria Fever P1 P3 P2 PCR PCR/ISO ISO 25 25 Diagnostics Development: Fragmented Landscape, Lack of Advocacy and Investment R & D: 2 10 years; $ million Regulatory Approval: 2 5 years Target Product Profile Diagnostic Targets Technology platform Product Prototype Proof of Principle Lab & field evaluations Policy and guidelines for use Test adoption Valley of Death: Policy & Uptake 5 7 years Diagnostic Technology Development: The 3Rs of Partnership Regulatory Harmonization Product Specifications Diagnostic Targets Technology platform Product Prototype Proof of Principle Lab & field evaluations Policy & Guidelines Test adoption Shared Resources Shared Risks Shared Rewards
