Authors: Shuoyan Ning, MD, FRCPC, DRCPSC; Bryan Tordon, MD, FRCPC; Michelle Zeller, MD, FRCPC, DRCPSC; Waseem Anani, MD
Last updated: July 11, 2023
NOTE: This information reflects evidence available at time of publication. This information is specific to Pooled Platelet Psoralen-Treated (PPPT) components, which are being implemented nationally one distribution site at a time. See Chapter 19 of the Clinical guide to transfusion for more information including additional resources (slide decks, narrated videos, animations).
See Table 1 for a comparison of component characteristics (this table is excerpted from Chapter 19 of the Clinical guide to transfusion).
Table 1: Component characteristics of PPPT and untreated platelets
|Component characteristic||Untreated pooled platelet||Untreated apheresis platelet||Pooled platelet psoralen-treated (PPPT)|
|Untreated (not pathogen-reduced)||Pathogen-reduced|
|Mean unit volume (mL)||317||223||184|
|Number of donors in component||4||1||7‡|
|Mean plasma volume (mL)||317 (approximately 20 mL for 3 donors and + 257 mL plasma from one male donor)||173||75 (approximately 11 mL per donor)|
|Approximate platelet count
(x109 platelets per L)
|Approximate platelet yield
(x109 platelets per unit)
|Resuspension solution||Plasma||Plasma||Approx. 60% Platelet Additive Solution (PAS-E) +
|Bacterial screening performed by Canadian Blood Services||Yes||Yes||No|
|Typical time to release component to hospital after blood collection from donor||Day 3||Day 3||Day 2|
|Component shelf life (from day of blood collection)||7 days||7 days||7 days*|
|Viable lymphocytes present?||Yes, irradiation required for vulnerable patients¥||Yes, irradiation required for vulnerable patients¥||Viable lymphocytes not present, irradiation not required for vulnerable patients¥|
‡ PPPT components are manufactured from 7 donor (male or female) buffy coats, which are pooled together and then divided into 2 separate units for transfusion. Note the lower platelet yield of the PPPT component compared to the untreated pooled platelet component.
* The shelf life of PPPT was increased from 5 to 7 days on April 24, 2023.
¥ See the National Advisory Committee on Blood and Blood Products’ Recommendations for Use of Irradiated Blood Components in Canada.
Canadian Blood Services uses the INTERCEPT Pathogen Inactivation Technology by Cerus to treat platelets. This technology uses a psoralen compound (amotosalen) and UV light to cause irreversible damage to genetic material present in pathogens, rendering them inactive.
Once PPPT are implemented at a Canadian Blood Services site, the current untreated pooled platelet component will no longer be produced by that site.
Yes, this is possible. Canadian Blood Services manages a national platelet inventory so hospitals could receive PPPT even though their local Canadian Blood Services site has not yet implemented the manufacturing of this component.
Yes, this is possible. Canadian Blood Services manages a national platelet inventory. It is possible that hospitals may receive untreated components to meet inventory demands as PPPT production rolls out across the country.
Untreated apheresis platelets will remain available. However, Canadian Blood Services will be implementing pathogen-reduced apheresis platelets (called apheresis platelet psoralen-treated or APPT) on June 12, 2023 in Ottawa with a national implementation to follow. Non pathogen-reduced platelets (untreated apheresis platelet in PAS-E) will be available for limited indications. For more information, see Canadian Blood Services' Circular of Information and the FAQ on APPT and untreated apheresis platelet in PAS-E.
Yes, a paired dose can be issued to a hospital, if specifically requested and if available. Standard platelet orders will be issued by the oldest expiry, unless otherwise indicated.
Canadian Blood Services will be monitoring for changes in platelet component demand, wastage, and inventory changes.
Health Canada is expected to evaluate the residual leukocyte content, pH, and platelet yield, as well as sterility testing at time of expiration.
As of November 2022, Canadian Blood Services began performing automated isohemagglutinin titre testing (anti-A1 and anti-B) on all whole blood and apheresis donors. Pathogen-reduced platelets that meet the low-titre criteria will be labelled "Low Anti-A/B" (please see the FAQ on donor high titre isohemagglutinin testing for more information). For pooled platelets, all donors contributing to a platelet pool must be low titre for the component to be labelled as "Low Anti-A/B". Since PPPT platelets are manufactured from 7 donors, a minority of these platelets are expected to be labelled as low titre.
For pathogen-reduced platelet components that are not labelled as "Low Anti-A/B", Canadian Blood Services cannot make any claims about ABO titres. However, it is expected that ABO antibody concentration in PPPT will decrease compared to untreated (not pathogen-reduced) platelets due to the removal of approximately 60% of the plasma and addition of Platelet Additive Solution (PAS). Hospitals can make a segment from the sampling pouch line and use it to prepare a titration if desired.
The psoralen added to the platelets is very effectively removed by a compound adsorption device at the end of the manufacturing process. The residual psoralen that may be left (trace amounts) and the pathogen inactivation process has no impact on laboratory investigations.
Adverse reaction reporting for pathogen-reduced platelets follows the process used to report an adverse reaction to a blood component manufactured by Canadian Blood Services. See Canadian Blood Services' Guide to reporting adverse transfusion reactions for more information (see the reporting algorithm for blood components in Figure 1).
Untreated (pooled or apheresis) platelet components need to be irradiated as per standard practices when clinically indicated. Canadian Blood Services will continue to provide irradiated untreated platelet components to hospitals. Pathogen reduced platelet components should not undergo irradiation and are safe to use for recipients requiring irradiated blood components.
Pathogen-reduced platelets do not require irradiation, as leukocytes are inactivated by the pathogen inactivation process. However, if a pathogen-reduced platelet is irradiated in error, it may still be transfused as per manufacturer's recommendations.
At this time, both HLA and HPA matched platelets will continue to be manufactured without pathogen reduction. However, Canadian Blood Services will be implementing pathogen-reduced apheresis platelets (called apheresis platelet psoralen-treated or APPT) on June 12, 2023 in Ottawa with a national implementation to follow. Non pathogen-reduced platelets (untreated apheresis platelets in PAS-E) will be available for limited indications. Moving forward, the majority of HLA and HPA matched platelets will be pathogen inactivated. Untreated apheresis platelets in PAS-E that are HLA or HPA matched are available to order for limited indications. For more information, see the FAQ on APPT and untreated apheresis platelet in PAS-E.
Yes, aliquots can be obtained as long as a minimal residual volume of 135mL remains in the platelet bag. In other words, once there is 135mL or less remaining in the platelet bag, the platelet component can no longer be used and no further aliquots can be obtained.
No, untreated platelet components are less concentrated than PPPT. The final concentration of the PPPT component is approximately 1.4 times more concentrated than untreated pooled platelets. Please see Table 1.
Yes, once the bulb is removed, the remaining tubing length is approximately 8 cm. This should be sufficient for docking another bag depending on the tube welder device used.
Yes, patients may receive both untreated platelets and PPPT to meet their transfusion requirements.
Yes, both PPPT and untreated (apheresis or pooled) platelets can be hung in the same line, provided the tubing has not expired.
No, PPPT can be transfused at the same rate as untreated (apheresis or pooled) platelets. The rate should follow hospital policy.
Microaggregates have bene reported in some units. Aggregates should dissipate following agitation. Placing units in landscape orientation on agitator may help reduce aggregate formation. Platelets containing visible particles are not inferior to particle-free concentrates.1
Premedication is not specifically required for transfusion of PPPT components.
For adults, a PPPT component will be equivalent to an untreated (pooled or apheresis) platelet component.
For both PPPT and untreated platelet components the recommended doses for pediatric and neonatal platelet transfusions are provided in the Canadian Blood Services Circular of Information.
PPPT are not indicated for neonatal patients treated with phototherapy devices that emit a peak energy wavelength less than 425 nm or have a lower bound of the emission bandwidth less than 375 nm, due to the potential for erythema resulting from interaction between ultraviolet light and amotosalen. Phototherapy in the blue-green light with peak wavelength of 450-460 nm is the current standard of care for treatment of neonatal hyperbilirubinemia in Canada.2
There is a theoretical risk of white blood cell inactivation following transfusion of large platelet volumes combined with ECP or PUVA – if patient is exposed to the wavelength ranges with peak energy wavelength less than 425 nm or have a lower bound of the emission bandwidth less than 375 nm. There are no published case reports of harm.
The current evidence suggests that absolute count increments (ACI) and corrected count increment (CCI) are lower for PPPT components compared with untreated platelets. For 24 hour ACI, mean difference in published studies are -4.1 (95% CI -7.16 to -1.04) and -8.3 (95% CI -9.82 to -6.06) in single and multiple platelet transfusion studies, respectively. There were no differences in bleeding outcomes, and only 7% of hematology oncology patients transfused with pathogen-reduced platelets required additional platelet transfusions compared to patients transfused with untreated platelets.3
No, the current evidence does not suggest an increased risk of HLA alloimmunization. There are conflicting data regarding alloimmunization rates due to the varying preparations of pathogen-reduced platelets and technologies deployed in clinical trials. Overall, there appears to be no change in alloimmunization rate with INTERCEPT platelets.4
There is no published data on the safety of transfusing pathogen-reduced platelets to patients with psoralen allergies, including psoralen food allergies. Hemovigilance data has shown a reduced risk of allergic reactions among patients receiving pathogen-reduced platelets compared to untreated platelet components overall. While the compound adsorption device removes amotosalen leaving trace amounts in the product, there is a theoretical risk of allergic/anaphylactic transfusion reactions if patients with psoralen allergies are transfused with pathogen-reduced platelets.
For patients with psoralen allergies, a request for non-pathogen reduced platelets can be made through Canadian Blood Services but requires a minimum of 3 days to fill the order (see question #11 in the FAQ on apheresis platelet psoralen-treated, When might non-pathogen reduced platelets [i.e., untreated apheresis platelet in PAS-E] be needed?). In emergency situations, the risks and benefits of transfusion should be assessed on an individual basis and considerations for interventions such as pre-medication can be made.
Feys B, D.R., De Pourcq K, et al. Apheresis platelet concentrates containing visible particles are not inferior to particle-free concentrates, in vitro. Vox sanguinis 105(Suppl. 1), 11 (2013).
Barrington KJ, S.K., Canadian Paediatric Society, Fetus and Newborn Committee. Guidelines for detection, management and prevention of hyperbilirubinemia in term and late preterm newborn infants (35 or more weeks' gestation) - Summary. Paediatr Child Health 12, 401-418 (2007).
Estcourt, L.J., Malouf, R., Hopewell, S., et al. Pathogen‐reduced platelets for the prevention of bleeding. Cochrane Database of Systematic Reviews 30(2017).
McCullough, J., Vesole, D.H., Benjamin, R.J., et al. Therapeutic efficacy and safety of platelets treated with a photochemical process for pathogen inactivation: the SPRINT Trial. Blood 104, 1534-1541 (2004).