Key Points• Chaperones, antioxidants, ironsequestering proteins, and cathepsin S exhibited increased abundance in thalassemic EVs.• Haptoglobin and hemopexin are reduced in thalassemic patients' EVs, reflecting hemolysis. These could be used as clinical biomarkers.Hemoglobin E (HbE)/b-thalassemia has a wide spectrum of clinical manifestations that cannot be explained purely by its genetic background. Circulating extracellular vesicles (EVs) are one factor that likely contributes to disease severity. This study has explored the differences in protein composition and quantity between EVs from HbE/b-thalassemic patients and healthy individuals. We used tandem mass tag labeling mass spectrometry to analyze the EV proteins isolated from the plasma of 15 patients compared with the controls.To reduce biological variation between individuals, the EV proteins isolated from randomly assigned groups of 5 HbE/b-thalassemic patients were pooled and compared with 5 pooled age-and sex-matched controls in 3 separate experiments. Alpha hemoglobin-stabilizing protein had the highest fold increase. Catalase, superoxide dismutase, T-complex proteins, heat shock proteins, transferrin receptor, ferritin, and cathepsin S were also upregulated in thalassemic circulating EVs. Importantly, haptoglobin and hemopexin were consistently reduced in patients' EVs across all data sets, in keeping with the existing hemolysis that occurs in thalassemia. The proteomic data analysis of EV samples isolated from 6 individual HbE/b-thalassemic patients and western blotting results corroborated these findings. In conclusion, we have successfully identified consistent alterations of protein quantity between EVs from HbE/b-thalassemic and healthy individuals. This work highlights haptoglobin, hemopexin, and cathepsin S as potential clinically relevant biomarkers for levels of hemolysis and inflammation. Monitoring of these plasma proteins could help in the clinical management of thalassemia.

Background and Aims Platelet transfusion refractoriness is well aware to be associated with poor clinical outcomes. Patients with the alloantibody causing refractoriness required cross‐matched compatible products to improve the platelet number. This study aims to evaluate the effectiveness and availability of platelet crossmatching provided by the solid‐phase red cell adherence (SPRCA) technique in the context of a tertiary university hospital. Methods A retrospective chart review was performed of the records of 214 patients with platelet refractoriness in Siriraj Hospital, a tertiary university hospital in Thailand, between January 1, 2017, and December 31, 2020. Results The SPRCA technique successfully provided cross‐matched compatible platelets to 114 patients (69.7%). Platelet crossmatching significantly improved the platelet counts, as shown by the increased 1‐ and 24‐h corrected‐count increments ( p < 0.0001). No acute transfusion reactions were observed in these patients. Of the 114 patients who received cross‐matched platelets, 82 patients (71.9%) survived at 30‐day posttransfusion; whereas, 16 patients (14.0%) died within 7‐day posttransfusion. Conclusion The SPRCA method can provide a high availability rate of cross‐matched platelets, which is effective at stopping and preventing clinical bleeding conditions. This method is appropriate to apply for platelet crossmatching in the context of a hospital blood bank.