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 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)|
|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||5 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.|
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, untreated apheresis platelets, which are currently suspended in plasma, will be suspended in platelet additive solution pending Health Canada submission and review. Canadian Blood Services also plans to pathogen reduce most of our apheresis platelets in the future (pending Health Canada submission and review); these will be called Apheresis Platelet Psoralen-Treated (APPT).
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.
Currently, the INTERCEPT Pathogen Inactivation Technology licensed in Canada is for a shelf life of 5 days. Cerus is actively working on obtaining a 7-day shelf life approval with Health Canada.
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.
While the ABO antibody concentration will decrease due to the removal of approximately 60% of the plasma and addition of Platelet Additive Solution (PAS), Canadian Blood Services cannot make any claims about ABO titres of the final PPPT components. 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.
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.
Both HLA and HPA matched platelets will continue to be manufactured without pathogen reduction at this time. In the future, Canadian Blood Services plans to pathogen reduce most of our apheresis platelet inventory (including HLA and HPA matched platelets). Non pathogen-reduced platelets will remain available for select populations, including patients with psoralen allergies. Once pathogen reduced apheresis platelet components are implemented, orders for untreated HPA matched platelets will require advanced notice.
No, PPPT 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 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.
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 450-460nm is the current standard of care for treatment of neonatal hyperbilirubinemia in Canada.1
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.2
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.3