Background/Case Studies: Cannabis contains many chemical compounds called cannabinoids and has long been used for medical purposes and its recreational use has recently been legalized in Canada. A recent study has reported cannabis users among blood donors and 13.8% of them stated they had used it 72 hours preceding their blood donation. Combined with the absence of a deferral criterion, this high prevalence raises concern about the potential impact of cannabis use on the quality of blood products. Thus, the main objective of this project was to assess the impact of an exposition to a mixture of cannabinoids on the quality of red blood cells and platelets from collection and processing to their storage.
Study
Design/Methods: To mimic pre-donation use of cannabis, whole blood was collected and exposed to varying concentrations a cannabinoid mixture (CM; from 24 µg/mL to 1 µg/mL). The whole blood was then incubated at 37˚C, 5% CO2 overnight. Afterwards, blood was centrifuged to isolate the platelets-rich plasma (PRP) and Red Blood Cells unit (RBC). PRP was then transferred into pooling platelet bags and kept stirring at room temperature (RT) for 7 days. As for RBC, a 1:2 volume ratio of additive solution (SAG-M) was added before proceeding with the leuko-reduction. Then, RBC were transferred into storage bags and stored at 4˚C during 42 days. Flow cytometry analyses, hemolysis measurement and biochemical analyses were performed during the processing stage and throughout storage.
Results/Findings: The addition of CM to whole blood increased free hemoglobin levels in a dose-dependent manner in the plasma. The percentage of hemolysis observed in CM-exposed RBC was significantly more pronounced compared to the CM-free controls, both after processing and throughout storage. In addition, methemoglobin level was significantly higher in CM-exposed RBC than non-treated, also throughout processing and storage. Furthermore, relative to CM-free controls, CM-exposed platelets had significantly lower counts and exhibited a reduced expression of CD62P on day 7 post-transformation. Aggregation potential (as measured by ATP concentration) was significantly lower in CM-exposed platelets than CM-free controls after the processing and throughout storage. Conclusions: Our results suggest that cannabis use prior to blood donation could favour RBC hemolysis and reduce their ability to transport oxygen. This exposition could also lead to a reduced platelets number and functionality and thus, support the possibility that pre-donation cannabis use could alter the quality of blood products.
Importance of research: To our knowledge, this study is the first evidence that brief ly exposing (in vitro) whole blood to cannabinoids impairs the quality of blood products. Specifically, cannabinoids triggered RBCs hemolysis and impaired the capacity of platelets to aggregate, despite their rapid elimination after being spiked to whole blood. These impairments persisted following separation of whole blood into RBCs and PRP and throughout storage, as routinely carried out by blood banks.
