Dynamic Light ScatteringDynamic Light Scattering

Measuring Platelet Quality and Measuring Platelet Quality and Bacterial ContaminationBacterial Contamination

Elisabeth Maurer, Ph.D.Elisabeth Maurer, Ph.D.

Canadian Blood Services, R&D VancouverCanadian Blood Services, R&D Vancouver

UBC, Department of Pathology and Laboratory MedicineUBC, Department of Pathology and Laboratory MedicineUBC Centre for Blood ResearchUBC Centre for Blood Research

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The ProblemThe Problem

• Platelet transfusions used to treat and/or prevent bleeding

• Number of platelet transfusions produced per year: Canada: 300,000

United States: 2,000,000

Europe: 2,500,000

• Platelets are sensitive to stress (e.g., cold damage) • Activated platelets do not help patients.

Storage at 22ºC to prevent cold damageIncreased risk for bacterial growth

Shortages - addressed by increasing donor recruitment

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OutlineOutline• The Problem Clinical Situation

• Solving the problem Novel Approach

Data Acquisition

DLS-PM score

• The Invention Technology BackgroundThe DLS-PMAccomplishments

Clinical Results

• Summary Other Technology Accuracy, Sensitivity

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No non-invasive in vitro test available Tested inventory cannot be transfused Platelet quality / bacterial testing cannot be mandated

Good outcome Assumption: good platelets

Bad outcome Assumption: bad platelets

Transfusion outcome serves as retrospective platelet quality indicator.

The Problem: Clinical SituationThe Problem: Clinical Situation

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The Problem: SummaryThe Problem: Summary

• at least 20% discard rate

• Additional 10% discarded after testing (invasive technology)

Unknown quality of transfused platelets

• $1,000 / transfusion

Worldwide loss of at least 1 billion dollars per year

In summary:

Unknown platelet quality is a safety issue

Discarded platelet transfusions are a financial burden

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Multi-dimensional quality

measurement

DLS-PM detects • discoid platelets• activated platelets• microparticles• bacteria at the same time

Solving the Problem: Novel ApproachSolving the Problem: Novel Approach

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88% 88% Platelets1179 +/- 173 nm1179 +/- 173 nm50-100 nm

1200 nm

Solving the Problem: Data AcquisitionSolving the Problem: Data Acquisition

BACTERIA (if present)500 +/- 60 nm500 +/- 60 nm500 nm

10% 10% Microparticles54 +/- 7 nm54 +/- 7 nm

Transfus Med Rev 2007; 21(4):295

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Solving the Problem: DLS-PM ScoreSolving the Problem: DLS-PM Score

High DLS-PM scoreHigh DLS-PM score

Medium Medium DLS-PM scoreDLS-PM score

Low DLS-PM scoreLow DLS-PM score

Most fresh platelet transfusions

Most platelet transfusions until day 7 - 12 of storage

TemperatureResponse

Micr

opar

ticle

s

PlateletSize

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The Invention:The Invention:The Dynamic Light Scattering Platelet Monitor (DLS-PM)The Dynamic Light Scattering Platelet Monitor (DLS-PM)

• Non-invasive• Small sample volume• Fast• Inexpensive

Phys Med Biol 2006; 51:3747

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The Invention: AccomplishmentsThe Invention: Accomplishments

May - Aug 2007

First clinical pilot study

2006

ValidationLatex beads

PlateletsBacteriaProteins

Nanoparticles

Sept 2005

First generation instrument

April 2005

First prototype

Nov 2003

Proof of principle

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CoCorrelation of rrelation of DDLS-PM results with LS-PM results with iin n vvivoivo transfusion transfusion ooutcomeutcome

49 patients enrolled, 160 transfusions49 patients enrolled, 160 transfusions Location: Vancouver General HospitalLocation: Vancouver General Hospital

Data collected:Data collected: DLS-PM scoresDLS-PM scores 1h and 24h patient platelet counts 1h and 24h patient platelet counts

transfusion merittransfusion merit

The Invention: Clinical ResultsThe Invention: Clinical Results

DLS-PM score vs. transfusion merit

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104/160 transfusions

65 %

Transfusion merit

correlates with DLS-PM

score

The Invention: CoDIVO ResultsThe Invention: CoDIVO Results

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• INVASIVE

• No single instrument can determine platelet quality and function in multiple dimensions

• Impedance• Optical• Immunofluorescence

• Hematology analyzers cannot assess bacterial

contamination BacT/Alert required

Sysmex XE-2100 Kobe

Advia 120Siemens

FacsCanto IIBD

Other Technology: Platelet CountingOther Technology: Platelet Counting

BacT/AlertbioMérieux

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Sysmex XE2100Sysmex XE2100 Optical platelet count + 1-micron beads Optical platelet count + 1-micron beads

Other Technology: AccuracyOther Technology: Accuracy

Without beads

With beads

Beads

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Optical methods - Low sensitivity

Especially for platelet counts

< 15,000 / L

Other Technology: SensitivityOther Technology: Sensitivity

Segal et al. BrJ Haematol 2005; 128:520.

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Mandated technology for hospitals / blood banks

10,000 hospitals / blood banks in North America

Extended shelf life - reduced outdate-discard rate

Patient safety

Monitor manufacturing processes

SummarySummary

DLS-PM: The only technology for noninvasive bacterial detection and platelet

quality testing at the same time

Thank You!

Keddie Brown, iCapture

Audrey Labrie, CBS

Dr. Mark Scott, CBS

Dr. Kate Chipperfield, VGH

Cheryl Pittendreigh, CBS

Nobu Kitamura, CBS

CBS Intellectual Property, Intramural and Bridge Funding

KeddieKeddie

AudreyAudrey

NobuNobu

CherylCheryl