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【Objective】 To analyze the difference of circulating threshold (Ct) of polymerase chain reaction (PCR) in blood station laboratories during the external quality assessment, and to put forward suggestions for the quality improvement of participating laboratories. 【Methods】 From 2018 to 2021, the blood station laboratories participated in the external laboratory quality assessment of CITIC including blood screening items with nucleic acid testing method. The data of Roche diagnostic reagent group were used as the source, and the detected Ct values of three groups of quality control samples of HBV A subtype (400 IU/mL), HCV 1b subtype (400 IU/mL) and HIV B genotype (500 IU/mL) were used as the objects. The data were grouped according to quality control (sample) batches, reagent batches and different laboratories. Using the statistical method of variance analysis (assuming P<0.05 as significant), the detected Ct value of each group was analyzed. 【Results】 For the three items (HBV/HCV/HIV), the grouping data involving 42 batches of quality control (13/12/17), 28 batches of reagent (11/8/9) and 57 laboratories (19/19/19) were selected. The grouping analysis of quality assessment batches shows that there was no significant difference between HBV and HCV quality assessment batches, and there was no significant difference between other HIV batches except the two batches of HIV quality assessment samples released in 2021. The grouping analysis of each reagent batch showed that there was no significant difference between each reagent batch for HCV and HIV detection, while there was significant difference between two batches of HBV reagents. After excluding the data groups with significant differences in the quality control batch groups and the reagent batch groups, the detected Ct value of each laboratory group had extremely significant differences in the three items of HBV, HCV and HIV. Through pairing analysis, it was found that four laboratories had significant differences with most other laboratories in the three items, mainly manifested in the high mean value of Ct. 【Conclusion】 For the blood station laboratories with correct test results of quality assessment samples, there are differences in Ct values detected by PCR, which may be mainly caused by the detection ability of the participating laboratories.
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【Objective】 To summarize and analyze the results of local laboratories participating in China International Transfusion Infection Control (CITIC) Nucleic Acid Testing (NAT) External Quality Assessment (EQA). 【Methods】 The basic situation, test reagents, and abnormal results of 9 domestic laboratories participating in NAT EQA from 2018 to 2020 were collected and analyzed. 【Results】 Among 7 545 testing results, submitted by 48 laboratories using 8 test reagents throughout 9 occasions of CITIC, 64% (4 830/7 545) used imported and 36% (2 715/7 545), domestic reagents. Thirty-one abnormal results were reported, with false negative in 61.29% (19/31), false positive 6.45% (2/31), and others 32.25% (10/31). False negative results only appeared in samples with low viral load of HBV A genotype(40 IU/mL), HCV 1b subtype(40 IU/mL) and HIV B genotype(250IU/mL), relatively concentrated in a few laboratories. The frequency of abnormal results was 0.08 per laboratory per CITIC test. 【Conclusion】 The detection capacity of domestic blood stations has been significantly improved along with the routine NAT practice and regular NAT EQA participation over 5~10 years, but laboratory management still needs to be further strengthened to ensure the reagent testing performance and blood safety.
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Objective To investigate the level of serum lipoprotein-associated phospholipase A2(Lp-PLA2) activity in healthy adults of Changsha area and establish the reference interval of serum Lp-PLA2activity. Methods A total of 424 healthy adults (175 males and 249 females) were classified into five groups by different age, including 20 to 29, 30 to 39, 40 to 49, 50 to 59 and over 60 years old group. Serum Lp-PLA2activity was measured by continuous-monitoring assay. According to the requirements of Clinical and Laboratory Standards Institute (CLSI) C28-A3, the reference interval of Lp-PLA2activity was established by nonparametric method.Results The levels of serum Lp-PLA2activities in both males and females showed normal distribution. The average of Lp-PLA2activity was (478± 135)U/L in 175 males and (402±116)U/L in 249 females with statistically significant difference (t＝6.184, P＜0.01). Z test result showed Z＞Z?, so the reference intervals of males and females were established respectively. There was no statistical difference of Lp-PLA2activities among the varied groups of males (F＝1.259, P＝0.288), but there were statistical differences among the varied groups of females (F＝9.341, P＜0.01). The females of the age over 40 years old showed higher activities than those of age under 40 years old (t＝5.732,P＜0.01). However, there was no statistical significance of serum Lp-PLA2activities in the females between the two groups of the age under 40 and the three groups of age over 40. Therefore, the reference intervals of serum Lp-PLA2activities in healthy adults were established as followed: 217-761 U/L for males, 168-566 U/L for the females of 20 to 39 years old and 203-702 U/L for the fe-males of 40 to 86 years old. Conclusion The reference interval of serum Lp-PLA2activity in physical examination of healthy adults in Changsha area was established.
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Objective To compare the treatment effect of calcium hydroxide and formocresol applied in root canal disinfection after root canal preparation.Methods 283 patients with 388 teeth diagnosed as chronic periapical were selected.Calcium hydroxide and formocresol were applied after opening of pulp chamber,pulp removed and root canal preparation.Calcium hydroxide was piped into the root canal by screw conveyor to fill the root canal in calcium hydroxide group,and formocresol cotton twist was setted in the root canal after dried in formocresol group.Tampons and ZOE were used for temporary closure.Treatment effects in both groups were compared in a week.Results The total effective rate in calcium hydroxide group was 96.39％,while 79.90％ in formocresol group.The total effective rote in calcium hydroxide group was higher than that in formocresol group(x2 =53.792,P ＜ 0.05).Conclusion Calcium hydroxide was safe,periapical tissue irritation and reliable effect was reached.It was worthy of clinical application.
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The aim of this study was to observe the difference in respect to the leukocyte reduction efficiency and quality of fresh-frozen plasma (FFP) from filtered whole blood between two types of in-line filters wherein only filter materials were surface modified by the two methods respectively. Whole blood was kept in refrigerator and filtered within 6 h of collection at ambient temperature. Samples were taken pre- and post filtration for analysis of WBC numbers, coagulation factors and complement activation (n = 8 for each type of filter). All filtered units contained < 2. 5 x 10(6) residual leucocytes. RBCs recovery was over 93%. No significant difference between group A and B was seen. But group B appeared to take longer time for filtration than did group A (9'29" vs. 8'01"). Neither group A nor group B showed statistically significant losses of total protein, album, IgG, IgM, fibrin, factors VIII, IX, vWF and C3 (P > 0.05). Factor V, XI and AT-III decreased significantly in two group filters. Group B showed more significant losses of IgA content and factor V activity than did group A, which appeared to be related to the difference in surface character between group A and group B filters. These two types of filters could remove leukocytes effectively, and no significant changes were observed in the quality of FFP from the filtered whole blood. It is presumed that the filter material with better bio-compatibility will give a high recovery of plasma protein and coagulation factors after filtration.
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Humans , Blood Coagulation Factors , Metabolism , Filtration , Methods , Leukocyte Count , Leukocyte Reduction Procedures , MethodsABSTRACT
Objective To study the degradation of hepatitis C virus(HCV) genome before and after methylene blue photochemistry(MB-P) treatment of the plasma.Methods MB was added to HCV positive plasma to a final concentration of 1.0?mol/L.The plasma was then exposed to 30000 Lux fluorescence.Plasma samples were then collected at different times of exposure.Real-time PCR was used to quantitatively study the course of the HCV-RNA degradation.The whole genome was screened for integrity by RT-PCR with 8 pairs of specific primers which targeted sequential overlapping sections of HCV genome.Results Results of real-time PCR showed that the copy number of HCV-RNA was continuously decreasing during MB-P treatment.RT-PCR results showed that the reactivity of different sections of the HCV genome to MB-P was significantly different and indicated that the 5' end and 3' end were more stable. Conclusion MB-P treatment could degrade HCV RNA with various sensitivities to different sections of the genome.RNA degradation may play an important role in plasma virus inactivation.Detection of HCV genomic RNA might be clinically useful to monitor the process and efficiency of virus inactivation.