RESUMEN
【Objective】 To determine the ELISA kit for screening convalescence plasma with high potency of SARS-CoV-2 IgG by comparing and analyzing the plasma detection results of convalescent plasma collected in different periods via ELISA kits from two manufacturers and the results of mixed plasma with different potency via pseudovirus neutralization experiments. 【Methods】 Two ELISA kits from different manufacturers(named A, B) were used to detect the plasma of 269 convalescent patients collected from Feb.2020~Jan.2022. The correlation and concordance rate of the two results were analyzed to determine the kit preliminarily. According to the titers of diluted series of standard of the preliminary selected kit, 5 mixed plasma samples (G4-G128) with different potency were prepared. The correlation of ELISA IgG results of product A/B, as well as the pseudovirus neutralization test of the original strain, Omicron mutant BA.1 and BA.2 strains were analyzed. Combined with the outside-well dilution mode of the strongly positive samples, the kit for high potency of SARS-CoV-2 IgG screening was determined. 【Results】 When the internal control reference B2 was used as the standard, the detection sensitivity of product A and B was 1∶32 vs 1∶8; the detection sensitivity of product A was 4 times that of product B. The correlation Pearson r between the results given by two kits was 0.944 1(P<0.000 1). Product B with low sensitivity was primarily selected as an alternative kit. The ELISA IgG results of samples from mixed plasma showed that the order of correlation r between product A and B was 0.988. The correlation r between product A and neutralization antibody potency of the three viruses was original strain (0.978)>BA.2(0.970)>BA.1(0.799); the order of correlation r between ELISA IgG results of product B and neutralization antibody potency of the three viruses was original strain(0.994)>BA.2(0.968)>BA.1(0.804). If twice-diluted B2 was taken as the excellent standard, 55.4% of product B met the criterion, while 47.2% of product A met.For positive plasma with high IgG potency, the product B kit required a lower dilution of the sample, which was more convenient to operate. 【Conclusion】 Both of the ELISA IgG kit from product A and B can be used to screen IgG antibodies of SARS-CoV-2, while product B is more suitable for screening positive plasma with high IgG potency.
RESUMEN
【Objective】 To retrospectively analyze the safety and product quality of NGL XCF 3000 blood cell separator for collecting platelet-rich plasma (PRP) in 256 cases, so as to provide reference for safe collection and product quality control of PRP. 【Methods】 The data of 256 patients receiving PRP treatment in our hospital from June 2021 to June 2022 were statistically analyzed, and the differences in the collection time, circulating blood volume and the occurrence of adverse reactions to blood donation were analyzed when NGL XCF 3000 was used to collect autologous PRP among patients of different genders, ages and platelet counts. The differences in platelet content, red blood cell(RBC) contamination and white blood cell(WBC) residues in PRP products were analized. 【Results】 1) There were no significant differences in collection time, circulating blood volume and collection volume among patients of different genders, ages and platelet counts (P<0.05). 2) The contents of WBC, RBC and platelet were not significantly different between male and female patients after collection (P<0.05); 3) The WBC contents increased with the increase of age, and the WBC residue in the elder group[ 56 to78 years old, (0.64±0.41) ×109/L] was significantly higher than that in the younger group[group 1,18 to 40 years old, (0.50±0.35)×109/L], with significant difference was Statistically significant (P<0.05). 4) The residues of WBCs and RBCs in in low platelet group [group 1, (100-150)×109/L] were higher than those in other platelet count groups, and the difference was Statistically significant (P<0.05), and the platelet count in this product was significantly lower than that in other platelet count groups (P<0.05). Conclusion The NGL XCF 3000 blood cell separator is safe and stable for PRP collection in patients with different genders, ages and platelet counts of (100-450)×109/L, and the PRP products collected can meet clinical therapeutic needs.