e-mail [email protected] Laboratory Diagnostics ... · always a drop ahead. Introduction...
Transcript of e-mail [email protected] Laboratory Diagnostics ... · always a drop ahead. Introduction...
altona Diagnostics GmbH Mörkenstr. 12 22767 Hamburg Germany phone +49 40 548 06 76 - 0 fax +49 40 548 06 76 - 10 e-mail [email protected]
February 25th 2015
Laboratory Diagnostics of Filovirus Infections
always a drop ahead.
Introduction
Stephan Ölschläger altona Diagnostics GmbH, Hamburg, Germany (since April 2013) Emerging and tropical diseases (MERS-CoV, Filovirus, RVFV, Dengue
Type, Zika virus, …) At altona we currently only work with real-time PCR technology!
always a drop ahead.
What is your role in your institution?
Who is responsible for laboratory diagnostics? Who is responsible for treatment? Who will advice public health measures?
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How does the ideal diagnostic tool look like? Sensitivity high Specificity 100% Easy-to-use Fast < 30 min. Cheap Internal control Quantitative No cool chain required No power supply needed
RELIABLE!
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Basic Considerations on the Workflow
1) Biosafety Protect yourself and others!
2) Reliability
Use the correct method! Prevent contamination and wrong results!
3) Efficiency
Deliver results quickly!
Importance
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Equipment and Methods
Nucleic acid extraction: Manual extraction
More “hands-on” time The reference methods are usually very good! Flexible up to a certain extend (input and output volumes, sample
material) Validate in combination with PCR assay!
Automation
Good and bad systems out there! Closed systems
Is it possible to include internal controls? Expensive Laboratory footprint Needs to be validated for every assay!
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Sample Inactivation
Trizol LS Agent AVL
Buffer : Sample 4 : 1
3:1 Buffer : sample
AT LEAST!
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Equipment and Methods
First-pick real-time Cycler:
Mx 3005P™ QPCR System (Stratagene) VERSANT™ kPCR Molecular System AD (Siemens)
ABI Prism® 7500 SDS and 7500 Fast SDS (Lifetechnologies)
LightCycler® 480 Instrument II (Roche)
Rotor-Gene™ 3000/6000 (Corbett) Rotor-Gene™ Q 5/6 plex Platform (QIAGEN)
CFX96™/Dx Real-Time System (BioRad) CFX96 Deep Well™ Real-Time System (BioRad)
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Equipment and Methods
2nd choice real-time Cycler:
PikoReal Real-Time PCR System StepOne™
SmartCycler® II
LightCycler® 2.0 Instrument
Inter-module variation - Glass capillaries
- Discontinued
Optical systems / multiplexing
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Organisation of the Laboratories
Kitchen Office Office Office
Sample Prep
PCR Set-up II
PCR Set-up I Amplification
Negative Room
Oligo production
Oligo production
Storage
Entrance Color code: Red: infectious AND/OR highly positive Green: no DNA/RNA Orange: low positive
Example – altona Diagnostics Access
restricted
Prevention of contamination!
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Diagnostic Scenarios
Preparedness for imported cases (initial testing) Unknown agent, broad differential diagnostics (several VHF, Malaria,
Leptospira spp., sepsis, ?) Well equipped Laboratory Few samples Not routinely performed
Old reagents (?) Reliability do you trust unfrequently used methods?
Constant training required workshops (ENIVD), participation in EQAs
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Diagnostic Scenarios
Epidemic (follow-up testing) Known etiology Specialized assays Differential diagnostics less important Bad Infrastructure High throughput Logistics
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Diagnostic Scenarios
Screening Contact screening Screening of healthy individuals (e.g. point of entry: airports, boarders)
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Diagnostic Scenarios
Preparedness Outbreak
Aetiology Unknown known
Differential diagnosis
Broad Less important
Infrastructure Good Bad/difficult
Situation Sudden Timed
Routine Method used unfrequently – reliable?
Method used more often – confident
Work load Low Throughput High Throughput (?)
Training Continuous, low level
Regularly, maneuvers
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Reliability
• Performance Evaluation
• Stability
• Controls
• Quality Control
• Post Market Surveillance
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Reliability
• Performance Evaluation
• Stability
• Controls
• Quality Control
• Post Market Surveillance
Analytical Sensitivity
Analytical Specificity
Cross-Reactivity
Interfering Substances
Total Failture Rate / Robustness
Accuracy of Measurement
Linearity
Equivalence Diagnostic Evaluation Studies
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Reliability
• Performance Evaluation
• Stability
• Controls
• Quality Control
• Post Market Surveillance
in use
Room temperature
+4°C
Freeze & Thaw
Transport
Long term / shelf life
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Reliability
• Performance Evaluation
• Stability
• Controls
• Quality Control
• Post Market Surveillance
Positive Controls
Quantification Standards
Negative Controls
High Positive Controls
Low Positive Controls
Sensitivity Controls
Reference Standards
Calibration Standards
Working Standards
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Reliability
• Performance Evaluation
• Stability
• Controls
• Quality Control
• Post Market Surveillance
Reagents
Kits
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Reliability
Quality Control - Specificity
Pos. Control / QS
NTC Neg. Matrix Eluate
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Reliability
Quality Control – Standard Curve
Pos. Control / QS
NTC Neg. Matrix Eluate
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Reliability
Quality Control – Ct-values
Pos. Control / QS
NTC Neg. Matrix Eluate
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Reliability
Quality Control - Fluorescence
Pos. Control / QS
NTC Neg. Matrix Eluate
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Reliability
Quality Control - Sensitivity
Pos. Control / QS
NTC Neg. Matrix Eluate
Sensitivity Control
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Reliability
Quality Control - Trueness
Pos. Control / QS
NTC Neg. Matrix Eluate
Sensitivity Control High Pos. Control
Low Pos. Control
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Reliability
Quality Control – Internal Control
Pos. Control / QS
NTC Neg. Matrix Eluate
Sensitivity Control High Pos. Control
Low Pos. Control
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Reliability
Quality Control – Reagents / Enzyme
Enzyme lot A: pos. Control - sensitivity control - NTC Enzyme lot B: pos. Control - sensitivity control - NTC
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Isothermal amplification
High and low temperature methods: NASBA, RPA, LAMP, SDA, … Advantages
No cycler needed Fast Cheap
Disadvantages
Unspecific detection and unreliable (LAMP) If used for real-time detection, more sophisticated instrumentation/software
needed. Multiplexing? Internal Control? More complicated assay design – higher conservation of sequences
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RPA for Ebola and Marburg Detection
Sensitivity similar to real-time RT-PCR Target gene for RPA: NP Parallel assays for EBOV, SUDV, MARV 1 and MARV 2 “Lab in a suitcase”
http://www.dpz.eu/de/startseite/einzelansicht/news/labor-im-koffer-zu-ebola-entwickelt.html
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Polymerase Chain Reaction (PCR)
Agarose gel PCR Risk of contamination Integration of Internal control difficult No multiplexing No quantitation …
Real-Time PCR Instrument requirements Less prone to contamination Multiplexing Quantitation …
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Real-Time RT-PCR
Observation of reaction kinetics allows quantification.
Gel detection will show different band intensity
Cycles
96 replicates
real-time PCR-detection
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Roche and TibMolbiol
LightMix® Ebola Zaire rRT-PCR Test Zaire ebolavirus specific Internal control FDA Emergency Use Authorization Inactivated virus used Discussion: PCR indeterminate or negative?
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Roche and TibMolbiol
LightMix® Ebola Zaire rRT-PCR Test Zaire ebolavirus specific Internal control FDA Emergency Use Authorization Inactivated virus used Discussion: PCR indeterminate or negative?
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BioFire
Specific for Zaire ebolavirus Two versions both with FDA EUA FilmArray NGDS BT-E Assay FilmArray Biothreat-E test “The EUA for the FilmArray Biothreat-E test enables hospitals with laboratories that fit these characteristics to conduct a PCR test for Ebola in-house, without having to send the sample to an outside lab” Analytical sensitivity: 10e+4 PFU/ml (inactivated virus) Live virus is at least 10 x better:
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Department of Defense and CDC Assays
DOD: Zaire ebolavirus specific CDC: Zaire ebolavirus specific
100 µl sample in 90 µl eluate ~ 650 TCID50/ml
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Department of Defense and CDC Assays
DOD: Zaire ebolavirus specific CDC: Zaire ebolavirus specific
100 µl sample in 90 µl eluate ~ 650 TCID50/ml
External inhibition controls
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altona Diagnostics
RealStar Ebolavirus RT-PCR Kit 1.0 (derivative of the Filovirus Screen kit) internal control
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EUA Sensitivity Data
Assay PFU/ml (TCID50/ml) Geq/ml
DOD 1,000 ?
CDC NP (6,500)
CDC VP40 (650)
Biofire 1 10,000* 436,000
Biofire 2 600,000* ?
LightMix 4,781* ?
RealStar 1 3,500
* Inactivated gamma irradiated virus
Forget these data and wait for international standard…
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Other PCR Kits
Fast-Track Zaire specific (CE-IVD) No access to validation files
Genesig / Primerdesign Zaire specific (RUO) No validation data available
Bioneer AccuPower® EBOV Real-Time RT-PCR Kit (RUO) Zaire specific ~46 copies/rxn (LoD 95%)
altona Diagnostics GmbH RealStar Filovirus Screen RT-PCR Kit (CE-IVD, WHO prequal.) pan-filovirus sensitivity species dependent (~10-70 copies/rxn)
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Other PCR Kits
Lipsdiag Zaire and Sudan Kits (RUO) No validation data
Liferiver Zaire specific (CE-IVD) LOD 1,000 copies/ml (“depending on extraction”)
Sacace Ebola Zaire (RUO?) No validation data
…
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Rapid Tests
Find and WHO defined a “wish list” for rapid simple tests Clinical sensitivity >95% Clinical specificity >99% Corgenix ReBOV is prequalified by WHO What will you do with a result like this?
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Future Diagnostics
Several systems (pouches, cartridges, chips) are currently under development…