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Updated: Jun 9, 2026
Routine Screening Method for Microparticles in Platelet Transfusions
Published on: January 31, 2018
Red blood cell microparticles show altered inflammatory chemokine binding and release ligand upon interaction with
Zeyu Xiong1, John Cavaretta, Lirong Qu
1Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Background:
Storage of red blood cells (RBCs) under standard blood bank conditions results in reduced structural integrity leading to membrane budding and release of microparticles. Microparticles express the blood group Duffy antigen known to bind multiple inflammatory chemokines, but the functional chemokine binding properties of microparticles are not known.
Study Design And Methods:
We determined whether storage-induced microparticles show inflammatory chemokine binding through the expression of the Duffy antigen, comparing the binding properties to intact RBCs, and assessed microparticle interactions with platelets (PLTs) that release chemokines upon activation.
Results:
Intact RBCs retained similar equilibrium dissociation constants for CCL2 (Kd = 7.4 ± 0.9 nmol/L), CXCL8 (Kd = 7.9 ± 1.0 nmol/L), and CXCL1 (Kd = 4.4 ± 1.0 nmol/L) throughout storage. In contrast, microparticles increased in relative counts with storage, showed higher percentages of surface phosphatidylserine, and demonstrated impaired Duffy-dependent chemokine binding affinity with wider variability in dissociation constant for CXCL1(Kd = 362 ± 328 nmol/L; range, 0.6-2000 nmol/L). The altered chemokine binding affinity of RBC microparticles was associated with a propensity to release ligand upon incubation with PLTs. Relative quantification of microparticles, based on criteria of glycophorin A expression and size, underestimated particle numbers with functional chemokine binding, suggesting that glycophorin A-negative particles and nanoparticles contribute to overall chemokine binding capacity.
Conclusion:
Microparticle burden in transfusates, as determined by functional chemokine binding, is considerable. Altered membrane properties of RBC microparticles enhance PLT interactions to increase inflammatory chemokine bioavailability in vitro.
Insights
Red blood cell microparticles released during storage exhibit altered Duffy antigen binding, impacting inflammatory chemokine interactions. This suggests a significant, underestimated microparticle burden in transfusions that affects platelet activation.
Area of Science:
- Hematology
- Immunology
- Biochemistry
Background:
- Red blood cell (RBC) storage leads to microparticle formation, which express the Duffy antigen.
- The functional chemokine binding properties of these storage-induced microparticles are not well understood.
Purpose of the Study:
- To investigate the inflammatory chemokine binding capacity of RBC microparticles.
- To compare microparticle chemokine binding to intact RBCs.
- To assess microparticle interactions with activated platelets (PLTs).
Main Methods:
- Determined Duffy antigen-mediated chemokine binding of microparticles and intact RBCs.
- Assessed microparticle interactions with PLTs.
- Quantified microparticles based on glycophorin A expression and size.
Main Results:
- Microparticles showed impaired Duffy-dependent chemokine binding affinity compared to intact RBCs.
- Increased microparticle counts and surface phosphatidylserine were observed with storage.
- Altered microparticle binding affinity promoted ligand release upon PLT incubation, suggesting increased chemokine bioavailability.
- Standard quantification methods underestimated the functional chemokine binding capacity of microparticles.
Conclusions:
- The microparticle burden in transfusates, assessed by functional chemokine binding, is substantial.
- Altered membrane properties of RBC microparticles enhance PLT interactions, increasing inflammatory chemokine bioavailability in vitro.
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