Authors: Shuoyan Ning, MD, FRCPC, DRCPSC; Amanda Nowry, BSc, MLT; Michelle Zeller, MD, FRCPC, DRCPSC
NOTE: This information reflects evidence available at time of publication. Please consult Canadian Blood Services' Circular of Information (COI) on APPT and untreated apheresis platelet in PAS-E (COIs available as of June 12, 2023), as well as Chapter 19 of the Clinical guide to transfusion for more information including additional resources (slide decks, narrated videos, animations).
The implementation of pathogen-reduced platelet components began with Pooled Platelet Psoralen-Treated (PPPT) in Ottawa in January 2022; as of June 2023, PPPT continues to roll-out to hospitals across the country. Following Health Canada approval in May 2023, Apheresis Platelet Psoralen-Treated (APPT) and untreated apheresis platelet in PAS-E are being implemented in Ottawa on June 12, 2023, with a national implementation to follow (see Customer Letter CL 2023-03).
APPT, like PPPT, are pathogen-reduced platelets that do not require irradiation prior to transfusion. The technology used for pathogen inactivation, component administration, and clinical use are the same for APPT as PPPT. Untreated apheresis platelet in PAS-E are not pathogen-reduced and will be available to order for limited indications.
This FAQ has been developed to assist hospitals in implementing APPT and untreated apheresis platelet in PAS-E.
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 pathogen-reduced and untreated platelets
|Component characteristic||Untreated pooled platelet||Untreated apheresis platelet||Untreated apheresis platelet in PAS-E||Apheresis platelet psoralen-treated (APPT)||Pooled platelet psoralen-treated (PPPT)|
|Untreated (not pathogen-reduced)||Pathogen-reduced|
|Mean unit volume (mL)||317||223||269||277||184|
|Number of donors in component||4||1||1||1||7‡|
|Mean plasma volume (mL)||317 (approximately 20 mL for 3 donors and + 257 mL plasma from one male donor)||173||113||116||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)
+ 40% plasma
|Approx. 60% Platelet Additive Solution (PAS-E)
+ 40% plasma
|Approx. 60% Platelet Additive Solution (PAS-E)
+ 40% plasma
|Bacterial screening performed by Canadian Blood Services||Yes||Yes||Yes||No||No|
|Typical time to release component to hospital after blood collection from donor||Day 3||Day 3||Day 3||Day 2||Day 2|
|Component shelf life (from day of blood collection)||7 days||7 days||7 days||7 days||7 days*|
|Viable lymphocytes present?||Yes, irradiation required for vulnerable patients¥||Yes, irradiation required for vulnerable patients¥||Yes, irradiation required for vulnerable patients¥||Viable lymphocytes not present, irradiation not 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.1
Canadian Blood Services uses the INTERCEPT Pathogen Inactivation Technology by Cerus to treat platelets. This technology uses a psoralen compound (amotosalen) and ultraviolet (UV) light to cause irreversible damage to genetic material present in pathogens, rendering them inactive.
Once APPT are implemented at a Canadian Blood Services site, the current untreated apheresis platelet component will no longer be produced by that site. Untreated apheresis in PAS-E will be available to order for limited indications. Please see question 12.
Yes, this is possible. Canadian Blood Services manages a national platelet inventory so hospitals could receive APPT 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 APPT production rolls out.
Yes, a paired dose can be issued to a hospital, if specifically requested and if available (e.g., a double dose apheresis platelet unit was collected). Standard platelet orders will be issued by the oldest expiry, unless otherwise indicated. If a single dose apheresis platelet unit was collected, then this would not be possible.
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. Please see question 12.
No, an APPT unit should not be volume-reduced (centrifuged and supernatant removed) prior to transfusion. Volume reduction may cause aggregation of platelets due to an increased surface area to volume ratio.
Yes, aliquots can be obtained if there is a minimal residual volume of 135 mL in the platelet bag. In other words, once there is 135 mL 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 more concentrated than APPT. The platelet yield (number of platelets in the bag) is comparable between PPPT, APPT, and untreated apheresis platelet in PAS-E. Please see Table 1 for more information.
Yes, once the bulb is removed, the remaining tubing length is approximately 8 cm. This should be sufficient for docking on another bag depending on the tube welder device used.
As Canadian Blood Services transitions to a pathogen-reduced national platelet inventory, untreated apheresis platelets in PAS-E will be available for limited indications. These indications include intra-uterine transfusions (as there is no published clinical data on pathogen-reduced platelets for these populations), and patients with a history of hypersensitivity reactions to amotosalen or other psoralen products.
Pathogen-reduced platelets 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. However, in Canada, phototherapy in the blue-green light with peak wavelength of 450–460 nm (safe range) is the current standard of care for treatment of neonatal hyperbilirubinemia.2,3
Hospitals can order untreated apheresis platelet in PAS-E via the Special Request Order Form from blood.ca, as well as by contacting the hospital’s local Canadian Blood Services Distribution department.
As these platelets are non-pathogen inactivated, they require bacterial testing. Canadian Blood Services will require a minimum of 3 days to fulfill these orders.
No, an untreated apheresis platelet in PAS-E unit should not be volume-reduced (centrifuged and supernatant removed) prior to transfusion.
Yes, aliquots can be obtained if there is a minimal residual volume of 100 mL in the platelet bag. In other words, once there is 100 mL or less remaining in the platelet bag, the platelet component can no longer be used and no further aliquots can be obtained.
No, untreated apheresis platelet in PAS-E components are less concentrated (numbers of platelets/L) than PPPT and of comparable concentration to APPT. The platelet yield (number of platelets in the bag) is comparable between PPPT, APPT, and untreated apheresis platelet in PAS-E. Please see Table 1 for more information.
Yes, CMV negative untreated apheresis platelet in PAS-E for intrauterine transfusion will be available from Canadian Blood Services.
National Advisory Committee on Blood and Blood Products. Recommendations for use of irradiated blood components in Canada. (2018).
Ebbesen, F., Donneborg, M.L., Vandborg, P.K., et al. Action spectrum of phototherapy in hyperbilirubinemic neonates. Pediatric research (2021).
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).