Objective: To explore the types and levels of exosomes in cryoprecipitate from donors of different blood types, genders, and age groups, and to preliminarily characterize their specific proteins. Methods: Exosomes were extracted from cryoprecipitate using the polymer precipitation method. The exosomes were identified by particle size analysis, transmission electron microscopy, and Western blot. Finally, the specific proteins CD63, CD81, CD9, Cytochrome C, Syntenin-1, and VLA-4 of exosomes were characterized using Luminex. Results: The purified exosomes exhibited a double-membrane vesicle structure under microscopy, appearing saucer-shaped or as hemispheres with a concave side. They specifically expressed the CD63 and TSG101 proteins, while the endoplasmic reticulum protein Calnexin was not expressed. The particle sizes(nm) of exosomes from blood types A, B, O, and AB were 119.6±47.5, 120.5±47.4, 133.3±54.1 and 103.1±35.3, respectively. Taking the exosomal specific protein CD63 as an example, its expression levels(pg/mL) in cryoprecipitate from female and male donors were 128.22±63.52 and 117.39±40.84, respectively; the expression(pg/mL) levels in the 20-40 and 40-60 age groups were 114.20±37.28 and 131.41±64.98, respectively; and the expression levels(pg/mL) in the four blood types A, B, O, and AB were 109.58±37.79, 127.45±44.46, 131.89±40.59, and 122.29±78.68, respectively. The expression levels of CD63 in exosomes from different blood types, genders, and age groups were similar, with no statistically significant differences (all P>0.05). The distribution of the other five exosomal-specific proteins was also comparable among the normal blood donors. Conclusion: The expression levels of exosomal-specific proteins in cryoprecipitate from normal blood donors are not associated with blood type, gender, and age group.

Objective To establish a new program of blood cell processing apparatus(NGL-BBS)for the preparation of washed mixed plateletsand to study the effect on biological activity of platelets compared with tradi-tional manual method.Methods Mixed concentrated platelets were separated and prepared from whole blood by white membrane method.Blood cell processing apparatus with new program set(experimental group)and manual method(control group)was used for thepreparation of washed mixed platelets.The expression rate of CD62P and CD63 in the two groups of washed mixed platelets was compared by flow-cytometry.Thrombus elastography(TEG)was used to measure and compare the MA value between the two groups.Results The expression rate of CD62P and CD63 in the experimental group was lower than that in the control group(t = 4.11,P<0.01;t = 10.78,P<0.01).TheTEG MA valueof the experimental group was higher than that of the control group(t = 6.67,P<0.01).Conclusion The present study demonstrates that the use of NGL-BBS for the preparation of washed mixed plate-lets has a lesser impact on biological activity compared to manual preparation methods.

【Objective】 To develop a new approach for the preparation of 0.7~0.8 hematocrit concentrated washed red blood cells(RBCs) for fetal anemia in utero transfusion and apply it in clinical. 【Methods】 The erythrocyte suspension and frozen stored erythrocytes within expiry date in Guangzhou Blood Center from March 2020 to February 2021 were taken to prepare concentrated washed RBCs. According to the derivation formula, corresponding weight of RBC preservation solution was added to obtain 0.7~0.8 hematocrit concentrated washed RBCs. Routine blood test data were statistically analyzed by single-sample t test, and P<0.05 was considered statistically significant. Qualified Rh-negative/ O-type 0.7~0.8 hematocrit concentrated RBCs within expiry date were used in clinical intrauterine blood transfusion. 【Results】 The hematocrit of concentrated washing RBCs prepared by the new approach could reach 0.7~0.8. The RBCs count (8.389 ±0.808)×1 0¹²/ L and hemoglobin content(233.730±15.498)g/L were higher while the erythrocyte count (0.732±0.469)×10⁹ /L and platelets count(26.000±26.276)×10⁹/L were lower than the normal values of adults. The mean erythrocyte volume(fL), hemoglobin content(pg) and concentration(g/L )were 88.123±6.359, 30.004±2.809 and 339.980±11.865, respectively, which were normal values of adults. Fetal anemia was significantly improved and the prognosis was good after intrauterine blood transfusion. 【Conclusion】 The 0.7~0.8 hematocrit concentrated washed RBCs prepared by the new approach is consistent with the special blood requirements during fetal anaemia transfusion, meets the clinical treatment standards, and can be applied in clinical.

Objective To analyze the status of human metapneumovirus in children with respiratory tract infection in Shenz-hen and Shantou and the clinical characteristics of the diseases with hMPV infection.Methods The viral nucleic acid of 1 217 samples were amplified by RT-PCR(1 137 from children with respiratory tract infection,80 from health children),and five positive PCR products were chosen randomly for sequencing.Nucleotide sequences alignment and phylogenetic analysis were performed with DNAstar software.The clinical data of the children with hMPV infection were analyzed.Results The positive rate of hMPV infection identified from 1 137 children wtith respiratory tract infection was 4.49% (51/1 137), hMPV was significantly prevalent in February,March and April.Most of the positive cases was under 3 years old.Five hMPV gene fragments of sequence were closely related to hMPV in the GenBank.Similarity of hMPV partial N gene with which published at nucleotide levels varied from 80.8%~98.4%.Phylogenetic tree of nucleotide revealed two different gen-otypes.All hMPV positive patients suffered from fever,cough and wheezing.The clinical diagnoses were wheezing pneumo-nia (17),bronchiolitis (9).None of the nasal swabs from 80 healty subjects were tested hMPV specific gene fragment.Con-clusion hMPV is an important viral pathogen in children with respiratory tract infection in Shenzhen and Shantou.Two genotypes may circurate in these areas.