ABSTRACT
【Objective】 To monitor the positive rates of IgM and IgG antibodies and the changes in S/CO values over time in voluntary blood donors infected with SARS-CoV-2 after recovery, in order to provide theoretical basis and data support for ensuring clinical blood safety. 【Methods】 A total of 54 platelet donors who met the inclusion criteria were selected for this study, and 359 blood samples (plasma) from T1 to T7 (at 7 time points, spanning 14 to 15 weeks) were continuously monitored for SARS-CoV-2 IgM and IgG antibodies using fully automated chemi-luminescence method. 【Results】 Among 359 blood samples (plasma) from 54 donors, 349 were with valid test results.Eleven donors were tested positive for IgM, with a positive rate of 20.37%, and IgM antibody S/CO value gradually increased during T1-T3, but gradually decreased during T4-T7. Fifty-four donors were tested positive for IgG, with the positive rate of 100%, and the S/CO value of IgG antibody gradually decreased over time. During the period of T1 -T7, there was no significant difference in SARS-CoV-2 IgG antibody S/CO value between gender (male/female) or age group (18-39 years old /40-60 years old). 【Conclusion】 The positive rate of SARS-CoV-2 IgG antibody in platelet donors after recovery from SARS-CoV-2 infection was 100% during 2-14 weeks, and the IgG S/CO value gradually decreases over time. The long-term dynamic changes of SARS-CoV-2 serologically specific IgG and IgM antibodies in blood donors are worthy of further study.
ABSTRACT
【Objective】 To compare the current standards and explore the influencing factors for hemolysis rate of leukocyte-reduced red blood cells at the end of the preservation period, in order to formulate reasonable internal control indicators. 【Methods】 A retrospective analysis was performed on hemolysis rate of 427 samples of leukocyte-reduced red blood cells at the end of the preservation period in Nanning Blood Center from 2015 to 2022. Compared with the current standard for hemolysis rate at the end of the preservation period (GB 18469-2012 Quality Requirements for Whole Blood and Component Blood), the differences were analyzed, and the factors influncing the hemolysis rate were analyzed in terms of different blood donor groups. 【Results】 1) Among the 427 samples, the hemolysis rate of 418 (97.89%) did not exceed 0.4%, all lower than 0.8%; 2)the hemolysis rate of the male group was higher than that of the female group; 3) the hemolysis rate of the 18-29 years old group was lower than that of the 30-39 year old group and the 40-60 year old group, with statistically significant difference; 4) in terms of occupation, the hemolysis rate of students was the lowest, and the differences between groups were statistically significant; 5) no statistical significance was found in ethnicity and blood type. 【Conclusion】 Statistics indicated that gender, age, blood donation volume and occupation of blood donors were the influencing factors of hemolysis rate. The current standard is obviously higher in the qualified range of blood quality control in Nanning. It is advisable to formulate a reasonable quality control strategy with internal control index of hemolysis rate set <0.4%, which is conducive to making accurate evaluation of internal quality control and ensuring blood safety.