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Published on: June 26, 2018
Supernatant from stored red blood cell primes inflammatory cells: influence of prestorage white cell reduction
1Research Unit, Australian Red Cross Blood Service, Melbourne, Victoria, Australia. rsparrow@arcbs.redcross.org.au
Background:
The contribution of RBC transfusion to adverse patient outcomes is controversial. There is conflicting clinical data and limited biologic data that provide an underpinning biologic rationale for any adverse impacts from RBC transfusion. This study used in-vitro measures of PMN stimulation to determine the ability of supernatant from RBCs to stimulate allogeneic WBCs and to determine the influence of residual donor WBCs and storage time on the proinflammatory potential of RBCs.
Study Design And Methods:
Three types of RBCs were assessed: standard non-WBC-reduced RBCs (S-RBCs), buffy coat-poor RBCs (BCP-RBCs), and prestorage WBC-filtered RBC (LF-RBCs). Supernatant was collected weekly up to Day 42 of storage. PMN priming by supernatant from RBCs was determined by three methods: induction of CD11b expression on PMNs, induction of IL-8 release from PMNs, and the chemotactic effect of supernatant on PMNs.
Results:
Supernatant from S-RBCs induced the expression of CD11b on PMNs, primed PMNs to release IL-8, and was chemotactic for PMNs. The magnitude of this PMN-priming progressively amplified with storage time. In contrast, supernatant from BCP-RBCs or LF-RBCs did not significantly prime PMNs. The PMN-priming effect of supernatant from RBCs correlated more closely with the level of MNCs in the RBCs than PMN content.
Conclusion:
Supernatant from stored S-RBCs prime unstimulated allogeneic PMNs in vitro. Prestorage buffy-coat WBC reduction was as effective as WBC depletion in abrogating this proinflammatory response elicited by supernatants from RBCs. The clinical consequences, if any, of these findings for transfusion recipients are unknown.
Insights
Supernatant from stored standard red blood cells (RBCs) primes neutrophils, increasing inflammation. Reducing white blood cells (WBCs) in RBCs before storage effectively eliminates this effect, though clinical impact remains unknown.
Area of Science:
- Hematology
- Immunology
- Transfusion Medicine
Background:
- The role of red blood cell (RBC) transfusions in adverse patient outcomes is debated, with limited biological data.
- This study investigates the in vitro proinflammatory potential of RBCs and its relation to white blood cell (WBC) content and storage duration.
Purpose of the Study:
- To assess the ability of RBC supernatant to stimulate allogeneic white blood cells (WBCs).
- To determine the influence of residual donor WBCs and storage time on the proinflammatory potential of RBCs.
Main Methods:
- Assessed standard RBCs (S-RBCs), buffy coat-poor RBCs (BCP-RBCs), and prestorage WBC-filtered RBCs (LF-RBCs).
- Collected supernatant weekly up to 42 days of storage.
- Measured PMN priming via CD11b expression, IL-8 release, and chemotaxis.
Main Results:
- Supernatant from S-RBCs induced PMN priming (CD11b expression, IL-8 release, chemotaxis), which amplified with storage time.
- Supernatant from BCP-RBCs and LF-RBCs did not significantly prime PMNs.
- PMN-priming correlated more closely with mononuclear cell (MNC) levels than PMN content.
Conclusions:
- Stored S-RBC supernatant primes unstimulated allogeneic PMNs in vitro.
- Prestorage WBC reduction (buffy coat or filtration) abrogated the proinflammatory response.
- The clinical significance for transfusion recipients is currently unknown.
