Implementation Insights Vancouver General Hospital, BC. Challenges we faced. Work-flow integration 11/14/2016

Transcription

1 Implementation Insights Vancouver General Hospital, BC Challenges we faced Will vary depending on what your starting point is (SBT vs Serology) Space Training - Bench and analysis Computerization Integration into LIMS Work-flow integration How much change do you need to take the lab from molecular to NGS? still need pre- and post-pcr areas, so not much change from current set up tissue or sample collection will probably stay the same as current methods (ACD blood, BMT with multiple transfusions?) DNA extractions will also probably stay the same (note the use of EDTA in elution buffer) computerization might be an issue 1

2 Challenges with space Currently we are still running SSO/SSP, our sequencing core has moved into the old serology lab Bench height and width is different Benches dimension need to be able to take equipment (size and weight a MiSeq weighs more than Terasaki typing plates)! Freezer/fridge space Do you keep individual loci amplicon? Or only pooled samples? How long are libraries good for? Challenges with Training Staff training involves; bench/hands on training analysis resulting training Also, disseminating information to clinics and physicians. Challenges with training Bench work; Remarkably similar to current molecular techniques. Micro-volumes require additional experience to achieve consistency Multiplex of high number of samples can be confusing and will require more care awareness during processing Many more steps involved in library preparation (compared to SSO/SSP), time-management is more relevant 2

3 Bench Training Walk through protocol and technology 3 test runs (non-valuable samples; with smaller batch sizes initially), 3 real runs (with standard batch size, concordance with SSO/SSP) All QC tests passed for all 6 runs Training schedule ~5 months Actions to overcome bench challenges Practice good micro-pipetting technique on nonvaluable samples Develop monitoring procedures, and good practice, to ensure no sample mix up when handling many samples Protocols and workflows which are more flexible will permit technicians to develop a time management plan that works for them Challenges with training Analysis; Previous experience with SBT data and the associated software makes the learning curve less steep level of competence comes with analysis of a POOR run not a good run! Simplified workflow of analysis is essential to maintain consistency across calls 3

4 Actions to overcome challenges with analysis training Familiarization with software Lab meetings to show how the software looks, how to navigate through analysis pipeline, examples of results, examples of reports, integration into current reporting procedure Clear SOP (even better, cheat sheets!) Practise datasets (good and bad data). Compare analysis with trainee and trainer, work through challenging calls together Challenges with equipment Due to the significantly higher throughput capabilities of the technology, even simple things will need to be re-assessed; ordering reagents and supplies will be more frequent. Plan accordingly Multichannel pipettes will have to be maintained regularly and calibrated (which is an ASHI standard) CONNECTIVITY Computer specification for software will vary depending on software used; Most can be run on a stand alone desktop, either as individual licenses or as client servers Some will require a dedicated server to run software 4

5 Challenges with connectivity Standard hospital computers are not 64-bit. Data storage requirements for an Immunology lab for the last 40 years ~ 500mb/month, current data storage requirements for an Immunology lab ~100gb/month Data storage security concerns Optimal multiplexing strategy Optimal multiplexing strategy; expected sample throughput, frequency of testing, the assay TAT, the degree of batching (for regions of high genomic complexity, higher read depth can be used to compensate to improve accuracy) for batching samples, there must exist guidelines for standard multiplexing and read depth to ensure equivalence of test results. Validation of barcodes DATA REPORTING Clinical interpretation: Seamless, unambiguous, clinically relevant interpretation for end user Clinical report generation; What to include and what not to include intronic differences, variants of unknown significance 5

6 Integration with LIMS Automatic transfer of fastq files to data analysis software Direct import from analysis software to Histotrac (or equivalent) Update of Tie- breakers All methods tested were excellent and easily implementable in the lab Customer support is critical Although cost is of course important, should not be the deciding factor Tech feedback Top 5 reasons to go NGS The learning curve might be steep, depending on where you start from (serology, SBT), but easily streamlined for a medium-large throughput lab One pass testing; no need to go back and order additional tests (careful with those class 2 s!) Maintain autonomy from other sequencing labs, business model Creating a pre-to-post transplant continuum Cos all your friends are doing it! 6

7 THANK YOU Introduction For clinical purposes, NGS has all but replaced it s methodological predecessor, Sanger sequencing. It s faster, cheaper but ALONE, is it sensitive and specific enough to catch every variant while avoiding false-positives? Is cost a barrier to introduction of NGS in HLA labs? Pro s Pushing Transplant diagnostics into the 21st century Con s High set up costs Comparable to current molecular testing costs Fewer supplementary assays More complex training than current molecular testing techniques Minor pipetting error could result in loss of amplicon and consequently no data Limits repeated testing (especially hi-res repeats when Ab detected) Steep learning curve for data analysis 7

8 Interesting article The Scientist Q&A: Confirming NGS results with Sanger (Ambry Genetics CEO, Aaron Elliot) e/q-a--confirming-next-gen-sequencing- Results-with-Sanger/ Is cost a barrier to introduction of NGS in HLA labs? multi-plexing is a double edged sword; if it works, drastically lowers cost, but if theres an error, lose a lot in terms of reagent and time higher start-up costs cost of positive/negative controls (for each library preparation as well as for each sequencing instrument run) 8

9 Costs Evaluation costs Validation/accreditation costs Capital equipment costs Tech costs training costs Capital Equipment Instrument Cost* Investment Illumina MiSeq $100,000 Illumina MiSeq Support (Years 2 & 3) $34,000 Size selection equipment (Optional) $10,000 Plate fluorometer (Optional) $20,000 qpcr machine (Optional) $30,000 5x PCR machine $35, bit computer with 16+ GB RAM $3, x Liquid handler (Optional, pre & post PCR) $50,000+ (each) m four US Labs, rounded to $1,000 workflow integration Upstream integration Sample collection and DNA extractions Library preparation workflows Sample batching Liquid handling automation Data processing and analysis workflows Data transfer automation Analysis automation Long term data storage Approval workflow and tracking LIMS integration Export to NMDP standard Import directly into LIMS 9

10 Work-flow integration multiple QC steps; initially time-consuming but in the long run, will save bench time. Eventually QC steps can be pared down to minimum. to confirm or not to confirm with different assay typing takes longer than antibodies consequence on activation of patient labs not previously engaged in HLA typing could become involved in testing, as the workflow is fairly simple and indeed not drastically different for a wide range of diagnostic tests (cancer panel vs hla panel) however interpretation is KEY Automation 10

11 Work-flow integration WHAT IS OUR CURRENT TAT FOR NGS? Currently not suitable for deceased donor typing Challenges in data interpretation Can be summarised in 3 words; TIME, WORKLOAD, AMBIGUITIES Average time spent analysing and interpreting NGS data time allotment data analysis is still a bottle-neck partly because batches can be so large very few ambiguities gone are the days of chains Challenges in data interpretation determining QC characteristics associations 11

12 Challenges in data interpretation loss of 2nd allele in homozygous! determining true homozygousity drop outs amplicon coverage- accurate pooling required Challenges in data interpretation Submission of new alleles to CTR dictionary getting used to no chains! G group problem is now the reverse of the problem before (cant match too specific vs cant match not specific enough) NGS Data Analysis Approaches Reference- bases alignment, followed by HLA call based on the variants detected during alignment call is only as good at the alignment, coverage often insufficient Database based approach against known alleles novel allele detection and homozygous alleles are difficult to detect 12

13 Complex genetics Duplications High level of segmental duplications Lots of similar genes and lots of similar pseudogenes Duplicated segments can be more similar within an individual than they are to the corresponding segments of a reference genome Complex genetics Particularly DRB Tandem repeats can still be problematic (however no other technique has overcome this issue fully) However Many alleles are already known (even partially), both in terms of sequence and frequencies within a population HLA regions is relatively small, with a high degree of linkage disequilibrim, therefore many haplotypes have been described 13

14 Validation requirements 50 samples (plus 20 blind), over 3 runs Set up as you would routine testing (run size, sample type) Evaluation of; Run to run variability Tech to tech variability Quality Testing Must evaluate potential allele dropouts Documentation for; Sample preparation Monitor fidelity of barcoding methods rotate control samples with different barcode sequences Instrument performance measures internal control sample for instrument run performance Quality Testing Analytic performance criteria Incorporating vendor specifications Base quality, read length, average coverage, uniformity of coverage Independently validate software program Ensure genotyping algorithms are appropriate for sequencing strategy and sequencing error modalities 14

15 KNOW YOUR ASSAY S LIMITATIONS! Issues to consider inclusion of positive control sample, library QC use of phix for cross lot QC, run QC Top 5 reasons to go NGS The learning curve might be steep, depending on where you start from (serology, SBT), but easily streamlined for a medium-large throughput lab one pass testing; no need to go back and order additional tests (careful with those class 2 s!), auto-antibody issue Cos all your friends are doing it potential for epitope etc, rejection assay that detects donor-derived cellfree DNA in recipient plasma (Journal of Molecular Diagnostics) Circulating cell-free DNA enables noninvasive diagnosis of heart transplant rejection. De Vlaminck et al. Sci Transl Med Jun 18;6(241)?maintain autonomy from (cancer) other sequencing labs, business model Creating a pre-to-post transplant continuum? 15

16 11/14/2016 Single Molecule, Real-Time (SMRT ) Sequencing Unique capability to reveal the unknown Very Long 1 Read lengths Single Molecule Real Time Sequencing is capable of generating long reads to enable resolution of variation 2 High Accuracy Achieves >99.999% consensus accuracy Lack of systematic sequencing errors Coverage 4 3 High Uniformity Lack of GC content or sequence complexity bias Sequence native DNA No DNA amplification Epigenome characterization Roche s Single Molecule Real-Time Sequencer Accessible Benefits of Single Molecule Real-Time Sequencing Long read lengths High accuracy Sensitivity to detect minor variants at low frequencies Designed To Deliver: Simultaneous base-modification detection High coverage uniformity Short run times (minutes to few hours) Analytically validated workflows and analysis algorithms An optional, simplified supplied and supported compute pipeline Products in development and not available for global distribution. For Research Use Only. Not for use in diagnostic procedures. SMRT is a trademark of Pacific Biosciences 16

17 LOCATION SPACE ASHI Standards require (wipe tests for both); Pre-PCR and Thermocyclers, vortexer, centrifuge (no change from current molecular requirements) Post-PCR areas DNA quantitation equipment, thermocyclers, vortexer, centrifuge, library preparation auxiliary equipment, sequencer DNA extraction area EQUIPMENT (specific) Auxiliary equipment (not just the sequencer) is required for any HLA kit on the market DNA quantitation (and qualitation) equipment (fluorometers, spectrophotometers, gel equipment, RT-PCR etc) Library preparation equipment (magnetic stands for beads (remarkably expensive!), Pippin prep), thermocyclers) 17

18 Challenges with space Currently we are still running SSO/SSP, our sequencing core has moved into the old serology lab Bench height is different Benches dimension need to be able to take equipment (size and weight a MiSeq weighs more than Terisaki plates)! Freezer/fridge space Do you keep individual loci amplicon? Or only pooled samples? How long are libraries good for? DNA quantitation equipment Equipment (standard) Vortexers (plate and tube) Centrifuges (plate and tube) Amplification thermocyclers Multichannel pipette 18

19 Other equipment Challenges with equipment Due to the significantly higher throughput capabilities of the technology, even simple things will need to be re-assessed; ordering reagents and supplies will be more frequent. Plan accordingly Multichannel pipettes will have to be maintained regularly and calibrated (which is an ASHI standard), but when pipetting for heavy loads and with microvolumes, any tiny variability will cause samples to fail Equipment (general) Liquid handlers are highly recommended for both Pre- and Post-PCR steps Budget allowing (otherwise, get the 1 for Pre- PCR) Are programmable for other uses within the laboratory 19

20 Challenges with equipment Sequencers and liquid handlers have relatively large footprints, and can be very heavy and sensitive Must be on weight bearing bench No located on the same bench as a centrifuge or hightraffic area as vibrations can affect both the sequencer and the liquid handler Highly recommended NOT to move sequencers (alignment of internal optics) or liquid handlers (alignment and very heavy) unless absolute need..pick a permanent place Equipment (specific) Staff training involves; TRAINING bench/hands on training analysis resulting training Also, disseminating information to clinics and physician. Whilst the reported typings (if remaining at 4 digits) will look the same, the loss of chains and the ambiguities (no more XX) will need to be clarified with the programs 20

21 Challenges with training Bench work; Remarkably similar to current molecular techniques. Micro-volumes require additional experience to achieve consistency Multiplex of high number of samples can be confusing and will require more care awareness during processing Many more steps involved in library preparation (compared to SSO/SSP), time-management is more relevant Actions to overcome bench challenges Practice good micro-pipetting technique on nonvaluable samples Develop monitoring procedures, and good practice, to ensure no sample mix up when handling many samples (do not overwhelm the tech identify a suitable number of multiplex-able sample and use that as a standard) Protocols and workflows which are more flexible will permit technicians to develop a time management plan that works for them Challenges with training Analysis; Previous experience with SBT data and the associated software makes the learning curve less steep level of competence comes with analysis of a POOR run not a good run! Simplified workflow of analysis is essential to maintain consistency across calls 21

22 Actions to overcome challenges with analysis training Familiarization with software Lab meetings to show how the software looks, how to navigate through analysis pipeline, examples of results, examples of reports, integration into current reporting procedure Clear SOP (even better, cheat sheets!) Practise datasets (good and bad data). Compare analysis with trainee and trainer, work through challenging calls together ADDITIONAL During the validation phase of assay development, it is important to test assay performance using reference material Positive control material Must establish what constitutes a fail or a pass positive control Requirement to include a Negative control 22

23 Bench Training Walk through protocol and technology 3 test runs (non-valuable samples; with smaller batch sizes initially), 3 real runs (with standard batch size, concordance with SSO/SSP) All QC tests passed for all 6 runs Equipment Training Monitoring sequencing runs SOP will outline run metrics, positive control for sequencing portion of protocol (cross run variability) Maintenance of sequencers (do not knock bench while machine is running etc, wash maintenance schedule) CONNECTIVITY Computer specification for software will vary depending on software used; Most can be run on a stand alone desktop, either as individual licenses or as client servers Some will require a dedicated server to run software 23

24 Challenges with connectivity Standard hospital computers are not 64-bit. Data storage requirements for an Immunology lab for the last 40 years ~ 500mb/month, current data storage requirements for an Immunology lab ~350gb/month Data storage security concerns (there is a paper published that individuals could be identified from anonymous NGS data; Science : Identifying personal genomes by surname inference) BIOINFORMATICS essential to have a strategy to detect and investigate false Challenges of Bioinformatics 24

25 COST COMPARISON Demonstrating cost effectiveness of clinical NGS is key to payor reimbursement, hospital uptake OTHER CHALLENGES The question is not technological can it be done but rather practical how can NGS technology be developed into a mainstream clinical typing tool? Quality control standardisation lack thereof current NGS technologies have higher error rates and novel error modes compared to traditional sequencing what is an appropriate orthogonal technology? i mean, we assume SSO/SSP is right. What is the true measure of truth 25

26 BMT samples; the way we request samples may need to change what if the patient has had multiple transfusions and we are not detecting patient cells but donor DNA DNA often low, cell count low in certain types malignancies How we overcame challenges FLOW DIAGRAMS OF VENDORS 26

27 Illumina TruSight Life Technologies (Thermo Fisher) NXType 27

28 FLOW DIAGRAMS IN PRACTICE CAP NGS checklist recommends orthogonal analytical confirmation of all encountered mutations from an assay before the mutation is reported as clinically actionable (is this relevant for HLA possibly not) FDA-Cleared instrumentation Optimal multiplexing strategy; includes taking into account the following expected sample throughput, frequency of testing, the assay TAT, the degree of batching (for regions of high genomic complexity, higher read depth can be used to compensate to improve accuracy) for batching samples, there must exist guidelines for standard multiplexing and read depth to ensure equivalence of test results. 28

29 DATA REPORTING Clinical interpretation: Seamless, unabiguous, clinically relevant interpretation for end user Clinical report generation; What to include and what not to include intronic differences, variants of unknown significance Parallel analysis of control samples Raw reads (DAT files, BCL files) Demultiplexing Deconvoluted reads (FASTQ files) Alignment to reference genome Aligned reads (BAM files) Coverage calculations, local alignment On target alignment Variation analysis QC raw and QC passed run yield, read quality, run parameters QC barcoding deconvolution, sample read distribution QC alignment (mapping quality), library complexity QC coverage depth, coverage uniformity, allellelic frequency, strand bias, GC content Filtration Clinical report Truth QC controls 29