Factors associated with aggregate formation in cold-stored platelets.

Publication Title

Vox sanguinis

Authors

• Samantha Huang
• Yuko Mishima
• S Lawrence Bailey
• Aastha Chauhan
• José Quesada
• Pat Klotz
• Tyler Morrow, Department of Blood Transfusion Service, Swedish Medical Center, Cherry Hill Campus, Seattle, Washington, USA.Follow
• Kathryn Provencher, Department of Blood Transfusion Service, Swedish Medical Center, Cherry Hill Campus, Seattle, Washington, USA.
• Junmei Chen
• José A López
• Tsung-Lin Tsai
• Sandhya Panch
• Moritz Stolla

Document Type

Article

Publication Date

5-24-2026

Keywords

cardiothoracic surgery; cold‐stored platelets; platelet storage; platelet transfusion.; washington; swedish; seattle

Abstract

BACKGROUND AND OBJECTIVES: Cold-stored platelets (CSPs) can form aggregates, ultimately rendering them unusable. The causes of these aggregates and how to prevent them are poorly understood. This study aimed to identify potential factors associated with aggregate formation in CSPs stored in plasma for up to 14 days.

MATERIALS AND METHODS: We obtained CSPs from 79 unique donors during a clinical trial. We retrospectively analysed aggregate rates among donors of different sexes, ages and blood groups. In a subgroup, samples were also tested by enzyme-linked immunosorbent assay for markers of thrombosis and inflammation. Platelets from mice lacking von Willebrand factor (VWF) and human apheresis platelets treated with VWF and caplacizumab were stored and assessed for platelet count and aggregate formation by visual inspection and flow cytometry.

RESULTS: Forty-five (57%) units developed aggregates, and 34 (43%) did not. Units with aggregates had significantly lower soluble thrombomodulin levels and higher VWF levels approaching significance. In a multivariate analysis, platelets from female donors and donors with ABO type A were significantly more likely to form aggregates than those from male donors and donors with ABO type O, respectively. In the oldest donor cohort, units with aggregates were significantly less common than those without. Interfering with VWF levels and VWF function during storage did not reliably cause or prevent aggregates.

CONCLUSION: Donor sex, age, ABO type and thrombomodulin were significantly associated with aggregate formation or prevention.

Area of Special Interest

Cardiovascular (Heart)

Specialty/Research Institute

Hematology

Specialty/Research Institute

Surgery

Specialty/Research Institute

Cardiology

DOI

10.1111/vox.70294