Presentation on theme: "Current Status of Pathogen Reduction Methods"— Presentation transcript:
1Current Status of Pathogen Reduction Methods Thank you. It is a pleasure and an honor to be invited to speak before you this evening.I would like to review the potential benefits and drawbacks associated with implementation of pathogen inactivation technologies in order to help clarify exactly what may be gained by their introduction.James P. AuBuchon, MDPresident & Chief Executive OfficerPuget Sound Blood CenterProfessor of Medicine and of Laboratory MedicineUniversity of WashingtonSeattle, Washington
2Transfusion safety is like an onion… HGPNCVITSINGETRANODECUIRVOLUNTEDSAFETYIt has been said that transfusion safety is like an onion. Our current systems provide multiple layers of protection, beginning with the use of volunteer donors who are educated about transmission risks and extending to the use of sensitive testing techniques. Pathogen inactivation would potentially add another layer of safety against viruses and bacteria.
4Pathogen Inactivation Methods Currently Under Investigation or in UseChemicals: Physical disruptionSolvent/detergent technologyPhotoactive compounds: Genomic disruptionPsoralen derivatives (amotosalen)RiboflavinMethylene blueChemicals: Short-term activation Genomic disruptionS-303 (FRALE: Frangible Anchor Linker Extender)Direct radiation effect Genomic disruptionUVC
5Methods: Available or Approaching PlasmaQuarantined plasmaSolvent/detergent treatmentMethylene blue + lightAmotosalen + UVRiboflavin + UVUVC alonePlateletsAmotosalen + UVRiboflavin + UVUVC aloneRed cells/Whole bloodS-303Riboflavin + UV
6PI Plasma: The Similarities Reduction in procoagulant activity: 10-20%Effect of implementation: Clinical utilityRock G. Vox Sang 2011;100;
7PI Plasma: The Differences SD Plasma↓Allergic reactions (1/50,000 units)↓TRALI [0 ?]NAT for non-enveloped viruses (HAV, B19)Reduction in HMW vWF + ADAMTS-13 retentionReduction in anticoagulant proteins thrombosis [?]MB PlasmaSlightly greater fibrinogen + F VIII reduction
8Evaluation MB Plasma Clots by Thromboelastometry SlowerMAXIMUM CLOT FIRMNESSStrength OKLess thrombinTHROMBIN GENERATIONCLOT FORMATIONCardigan R et al. Transfusion 2009;49:
9PI Plasma: The Differences SD Plasma↓Allergic reactions (1/50,000 units)↓TRALI [0 ?]NAT for non-enveloped viruses (HAV, B19)Reduction in HMW vWF + ADAMTS-13 retentionReduction in anticoagulant proteins thrombosis [?]MB PlasmaSlightly greater fibrinogen + F VIII reductionImplementation Increased use [?] Reduced TTP responseFrance: 11 severe allergic reactions (1 death)UV ± Photosensitizer PlasmaUVC alone: ↓ F XI (no clinical trials)Nubret K et al. Transfusion 2011;51:125-8.
10PI Platelets: The Similarities Some loss of platelets through process (small; manageable)UV light Identifiable platelet damageIncreased metabolic rateIncreased activation during storage(↓mt DNA transcription)
11Using UVC to Inactivate Control TreatedPlatelets 9.4± ±1.3 x 108/mLHSR ± ±8%pH ± ±0.05Aggr: Collagen 62± ±7%Glucose ± ±8 mg/dLLactate 12.5± ±1.0 mMIllumination: 0.4J/cm2Testing: Day 8Walker WH et al. Vox Sang 2007;93(suppl 2):69.
12In vitro Assessment of Functional Properties Intercept12Mirasol108ControlFibrinogen receptor expression, MFI642ControlTRAP-6 aggregation response,, %MirasolInterceptPicker SM et al. Transfusion 2009;49:
13Treatment Effect: Metabolic Changes Lactate, mMStorage time, daysPicker SM et al. Vox Sang 2009;97:26-33.
14PI Platelets: The Similarities Some loss of platelets through process (small; manageable)UV light Identifiable platelet damageIncreased metabolic rateIncreased activation during storageReduced recoveryReduced survival15-25%
15Clinical Trial: Amotosalen-Treated Platelets The euroSPRITE TrialTreated ControlUnits transfused/patient p > 0.05Count increment (109/L):1h post-transfusion p < 0.0224h post-transfusion p = 0.004Corrected count increments:1h post-transfusion , , p = 0.1124h post-transfusion , p = 0.02Because of the smaller doses received, the count increments were lower with treated platelets, not surprisingly. However, the corrected count increments were the same at 1hour after transfusion. The lower 24 hour CCI with treated platelets, however, may be reflective of their reduced survival. Understanding that an equal dose gave an equivalent count increment has focused attention on development of the system and on techniques that will reduce loss through the various manipulations.Van Rhenen D et al. Blood 2000;96:819a.
16Clinical Trial: Amotosalen-Treated Platelets The SPRINT TrialWHO Grade 2, 3 or 4 bleeding: No difference between groupsPlatelet content of treated units: 7.5% lessPost-transfusion counts: 22-26% lower in treated groupComparison by dose:Equivalent effect from similar doseThe true clinical effect of Intercept platelets was addressed in the US clinical trial that used bleeding as it endpoint. Patients receiving treated platelets had no more bleeding episodes than those receiving control platelets.Again, their increments were lower because the content of the units was lower.As Intercept platelets are moving into routine use in Europe, however, these blood centers are not experiencing an increase in platelet transfusions. I’m sure Dr. Cazenave will comment on this in his presentation.French/Belgian experience: No increase in usageLoss: 8%McCullough J et al. Blood 2001;98:450a.Murphy S et al. Transfusion 2006;46:24-33.
17Clinical Trial: Riboflavin-Treated Platelets The MIRACLE Trialn = 110CCI1h: 31% decrease (primary outcome measure)MAX75%MEAN50%25%MINCCI1hCCI24h50,00040,000CCI30,00020,00010,000-10,000Mirasol Control Mirasol ControlTransfusion 2010;50:
19Pathogen-Inactivated Platelets in Routine Use 3 yr before 3 yr after adoption of INTERCEPT platelets(Used in place of bacterial detection and gamma irradiation)Before AfterPatientsTransfusionsTransfusions/patientPlatelets collected/unit 6.6x x1011Storage period 5d 7dOutdating % 1.2%Osselaer JC et al. Transfusion 2007;47:19A.
20PI Platelets: The Similarities Some loss of platelets through process (small; manageable)UV light Identifiable platelet damageIncreased metabolic rateIncreased activation during storageReduced recoveryReduced survivalInteraction with leukocytes’ DNA Reduction in alloimmunizationConsideration of replacement of γ-irradiation
21Prevention of Alloimmunization MECHANISM INHIBITED BY PHOTINACTIVATED PIMECHANISM NOT INHIBITED BY PHOTINACTIVATED PIMarschner S et al. Transfusion 2010;50:
22Prevention of Graft versus Host Disease Adducts:Amotosalen + UV 1/83 base pairsGamma irradiation 1/37,000 base pairsPrevention of GvHD in murine modelInhibition of APC functionInhibition of cytokine productionR Dodd Vox Sang 2002;83(Suppl 1):Osselaer JC et al. Blood 2007;110:849a.
23PI Platelets: Concerns SPRINT Trial (FDA)Respiratory distress: 5 test vs. 0 control (n=671)Independent, blinded review of all (148) pulmonary events No association with PI plateletsCorash L et al. Blood 2011;117:
24Expected: ≥ 2 plt transfusions PI Platelets: ConcernsHOVON TrialHeme/Onc pts (n=295)Expected: ≥ 2 plt transfusionsPlasma (n=99)357 transfusion events292 per protocolPAS III (n=94)381 transfusion events278 per protocolPR – PAS III (n=85)391 transfusion events257 per protocolEarly cessation:Lower CCI1hrIncreased bleedingPrimary endpoint: CCI1hrSecondary endpoints: CCI24hr, bleeding, transfusion needsand intervals, reactionsKerkoffs J-LH et al. BJH :
25Expected: ≥ 2 plt transfusions PI Platelets: ConcernsHOVON TrialHeme/Onc pts (n=295)Expected: ≥ 2 plt transfusionsPlasma (n=99)357 transfusion events292 per protocolPAS III (n=94)381 transfusion events278 per protocolPR – PAS III (n=85)391 transfusion events257 per protocolSPONTANEOUSLYREPORTED; UNBLINDED TRIALPrimary endpoint: CCI1hrSecondary endpoints: CCI24hr, bleeding, transfusion needsand intervals, reactionsKerkoffs J-LH et al. BJH :
26APPROPRIATE TO COMBINE? PI Platelets: ConcernsMaximum grade of bleeding (%)Plasma PAS III PR – PAS IIIGrade % 11% %Grade % % %Grade % %APPROPRIATE TO COMBINE?CLINICALSIGNIFICANCE?Kerkoffs J-LH et al. BJH 2010.
276-7d Storage of Amotosalen-Treated Platelets Untreated PI PlateletsPatientsCCI1hr 9, ,163CI1hr 21, ,400/μLCI24hr 15, ,100Interval dHSCT: 67%p < 0.05Δ = 17% (<30%)p < 0.05NS6d: 20% 7d: 80%Lozano M et al. ISBT 2010.
28Bacterial Reduction by Antimicrobial Peptides Antimicrobial Peptides StudiedThank you for the opportunity to present my views on how this country has succeeded – and fallen short – in addressing the problem of bacterial contamination of blood components, particularly platelets.Before I begin my remarks on this subject, I would like to clarify for whom I am - and am not – speaking.Mohan KVK et al. Transfusion 2010;50:
29Bacterial Reduction by Antimicrobial Peptides Mohan KVK et al. Transfusion 2010;50:
30Methods: Available or Approaching PlasmaQuarantined plasmaSolvent/detergent treatmentMethylene blue + lightAmotosalen + UVRiboflavin + UVPlateletsAmotosalen + UVRiboflavin + UVUV aloneRed cellsS-303Riboflavin + UV
31S-303 Mechanism of Action t1/2 = 25 min pH ACIDIC S-300- NEUTRAL ACTIVATIONS-300-NO NUCELIC ACIDINTERACTIONSSimilar to amotosalen but no UV activation required
32Effect of S-303 on RBC Recovery and Survival 11 full-unit reinfusions 35d storageTreated Control24h Recovery % % p = 0.048Survival d d p > 0.05n = 29, paired11 full-unit reinfusionsIf we have effective methods for treating plasma and platelets, what about the most-frequently transfused component, red cells? Here, ultraviolet light cannot help us as it cannot penetrate a red cell unit. Cerus develop a compound, S-303, that could interact with and react and bind to nucleic acids without requiring ultraviolet activation. When the initial process was examined in radiolabeled recovery studies, it appeared that, again, there was some toll from the treatment with reduced recovery, although survival was maintained. However, unlike with platelets, a problem of immunologic reactivity was found in chronic transfusion studies.Rios et al. Transfusion 2006;46:
33Y Y Problems with RBC Pathogen Inactivation NEOANTIGENAs S-303 is reacting with pathogens and chemically altering them so that they cannot infect or multiply, it can also react with the surface of red cells, placing the acridine ring there to be recognized by natuuralyl occuring antibodies, which some people have, or to be recognized by the immune system. Some recipients of S-303-treated red cells were found to have demonstrable antibodies that would interact with the treated red cells. While these antibodies did not have any activity in a monocyte monolayer assay, there was concern that they might shorten the circulation of treated red cells.It appeared that these antibodies were anti-acridine antibodies, blockable in in vitro testing through the addition of acridine. Thus although it was not clear that these antibodies had clinical significance, finding them indicated that an modified approach needed to be developed.ACRIDINEYYNo Monocyte Mononuclear Assay activity.North A et al. Vox Sang 2007; 93(suppl 1):167-8.
34Y Problems with RBC Pathogen Inactivation Modified S-303 Process: Glutathione: 2 20mM at neutral pHYANTI-ACRIDINEA modified process has been developed that uses a higher concentration of glutathione at a neutral ph. This technique does not result in modification of the surface of red cells that is detectable by potent anti-acridine antibodies. The modified process is now entering radiolabled autologous reinfusion trials.
35S-303 Treatment and Immunogenicity Augmented Rabbit Model Recently completed: Blinded crossover autologous reinfusion trialUNTREATED RBCsmS-303TRMTS-303TRMTRBCRecovery(log scale)Rabbits immunized with S KLHTimeNorth A et al. Vox Sang 2007; 93(suppl 1):168.
36Riboflavin Treatment and Immunogenicity Baboon Model90Unlabeled infusions: Days 0, 21, 42, 4951Cr infusion: Day 56Quinacrine mustard trmtRiboflavin + UVControl RBCsRBCRecovery(%)807060504030No Ab demonstrated2010Ab demonstratedTime (h)Goodrich RP et al. Transfusion 2009;49:64-74.
37Pathogen Reduction Methods Current Status ofPathogen Reduction MethodsYes, PI works.But can the system accommodate?
38Impact of Conversion to PI Platelets All PatientsHematology PatientsBefore PIAfter PIPlatelet Transfusions RequiredOsselaer JC et al. Transfusion 2009;49:
39“If someone says it’s not about the money, it’s about money!”Intercept Platelet conversion experience - StrasbourgKit cost: 75€/apheresis unitPersonnel time: 3€Costs avoided:Bacterial detection: 30€Per new test: 10€For France: Cost neutral with apheresis proportion85% 55%Cazenave JP et al. Vox Sang 2007; 93(suppl 1):51-2.
40Reduction of Economic Impact APHERESISPLATELETTREATEDAPHERESISPLATELETAPHERESISPLATELETTREATEDAPHERESISPLATELETTREATEDPOOLEDPLTSPltWHOLEBLOODPltDOUBLEPOOLPltTREATEDPOOLEDPLTS
41An opportunity to improve patient safety simplify blood banking. Pathogen Inactivation TechnologiesAn opportunity to improve patient safetyandsimplify blood banking.From my perspective, pathogen inactivation technologies offer a wonderful opportunity to improve patient safety while, at the same time, greatly simplifying our approaches, and thus I look forward to their implementation.Thank you.