The Significance of the Nucleic Acid Test (NAT) to Prevent Viral Contamination in Musculoskeletal Tissue Transplantation / A importância da realização do teste de ácidos nucleicos (NAT) para a prevenção de contaminação viral nos transplantes de tecidos musculoesqueléticos

Abstract Objective The present study aims to highlight the significance of the nucleic acid test (NAT) for musculoskeletal tissue donation and to compare the sensitivity of this test on the different available platforms. Method The present study is a retrospective survey in a human tissue bank database and an integrative literature review encompassing the last 10 years. The PubMed portal and the SCOPUS, CINAHL, and Web of Science databases were queried for articles. Results We found no specific studies on the use and sensitivity of NAT in braindead tissue donors. The information presented in the present study consists of specific contents intended for the Brazilian Blood Transfusion Network (Hemorrede Transfusional Nacional, in Portuguese) and internal retrospective data from a tissue bank located at a city in the state of São Paulo, Brazil. Conclusions The NAT is effective in blood samples from living patients. However, since biochemical reactions in braindead patients can be different, specific research, platforms, or both are crucial to tissue banks.

Resumo Objetivo Evidenciar a importância da realização do teste de ácido nucleico (NAT, na sigla em inglês) para doação de tecidos musculoesqueléticos, assim como comparar a sensibilidade deste exame nas diferentes plataformas existentes no mercado. Método Trata-se de um levantamento retrospectivo no banco de dados de um determinado Banco de Tecidos Humanos e de uma revisão integrativa da literatura, operacionalizada nos últimos 10 anos. As buscas de artigos ocorreram no portal PubMed e nas bases de dados SCOPUS, CINAHL e Web of Science. Resultados Não foram encontrados estudos específicos sobre a utilização e a sensibilidade do exame NAT em pacientes doadores de tecidos com morte encefálica (ME), sendo as informações apresentadas no presente estudo conteúdos específicos destinados à Hemorrede Transfusional Nacional e aos dados retrospectivos internos de um Banco de Tecidos do interior do estado de São Paulo, Brasil. Conclusões O exame NAT se apresenta efetivo em amostras de sangue de pacientes vivos. Porém, reações bioquímicas em pacientes com condições de ME podem se apresentar de formas diferenciadas, tornando-se indispensáveis a realização de pesquisas específicas e/ou a indicação de plataformas aos Bancos de Tecidos.

Initial screening and retest mode in apheresis platelet donors: a comparative analysis / 中国输血杂志

【Objective】 To investigate the effectiveness of current indicators in initial screening and retest before donation and access the optimal testing strategies. 【Methods】 Data of initial screening (rate method for ALT, colloidal gold method for HBsAg) and retest (rate method for ALT, ELISA for HBsAg) of 18 510 platelet donors in our center from January 2019 to December 2021 were collected, and the results were retrospectively analyzed and compared in terms of different years and number of donations. 【Results】 From 2019 to 2021, data of initial screening and retest of platelet donors were as follows: 1) the deferral rate of ALT and HBsAg was 12.98% (2 403/18 510) vs 0.26%(40/15 412); 2) the deferral rate of ALT was 13.19% (712/5 398) vs 0.20%(9/4 410)in 2019, 13.33% (873/6 549) vs 0.06%(3/5 387)in 2020 and 11.05% (725/6 563) vs 0.07%(4/5 615)in 2021; for initial screening, significant difference was noticed in ALT reactivity in 2021 as in comparison to other two years(P<0.05); 3) the reactive rate of HBsAg was 0.43% (23/5 398) vs 0.18%(8/4 410)in 2019, 0.66% (43/6 549) vs 0.20%(11/5 387)in 2020 and 0.41% (27/6 563) vs 0.09%(5/5, 615) in 2021. For initial screening, HBsAg deferral in 2021 was significantly different from 2019, while similar with 2020. 4) Among ALT deferral samples in the retest, 68.75% (11/16) were ALT≥45 U/L. Among HBsAg reactive samples, 91.67% (22/24) were reactive by single reagent. 【Conclusion】 Setting the threshold value of ALT for platelet donors in initial screening as less than 45 U/L can effectively reduce the reactive rate in the retest. HBsAg screening only for first-time platelet donors can reduce the detection cost. Adding pre-donation detection indicators according to local prevalence of transfusion transmitted diseases is conductive to reduce the discarding rate of platelets.

Characteristics analysis of HBV serological markers of NAT reactive blood donors under different HBsAg status / 中国输血杂志

【Objective】 To investigate the characteristics of HBV serological markers of NAT reactive blood donors under different HBsAg status. 【Methods】 NAT reactive samples, with HBsAg-, HBsAg+ /retest - and HBsAg+ by single reagent were collected from September 2021 to May 2022 in our laboratory. The TMA non-reactive samples were retested by Roche PCR, then HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc were detected by ECLI for statistical analysis. 【Results】 A total of 66 samples were collected, among which 55 were HBsAg-/NAT+. The positive rate of anti-HBc, anti-HBs+ anti-HBc, anti-HBe+ anti-HBc was 87.3% (48/55), 43.6% (24/55) and 45.5% (25/55), respectively. The positive rate of anti-HBs was 10.9% (6/55) and the overall negative rate was 1.8% (1/55). In 7 HBsAg+ initially/retest -/NAT+ samples, the positive rate of anti-HBc was 100%(7/7), and the positive rate of anti-HBe+ anti-HBc was 71.4%(5/7). In 4 HBsAg+ /NAT+ samples by single reagent, the positive rate of HBsAg+ anti-HBs+ anti-HBe+ anti-HBc was 50% (2/4), and positive rate of anti-HBe+ anti-HBc was100% (4/4). Samples, not reactive to TMA discriminatory and anti-HBc negative, were also non-reactive to individual PCR retest. There were significant differences in the positive rates of anti-HBe+ anti-HBc between HBsAg-/NAT+ samples and HBsAg+ /NAT+ (single reagent) samples (P<0.05). 【Conclusion】 Most HBsAg-/NAT+ blood donors were occult hepatitis B virus infection.The anti-HBe+ anti-HBc positive were correlated with HBV infection status. Non-reactivity discriminated by TMA plus anti-HBc negative do not exclude HBV DNA non-reactivity.

HBsAg non-reactive but HBV DNA reactive blood donors in Wuhu area: infection status and tracing results / 中国输血杂志

【Objective】 To detect and analyze the infection status of HBsAg non-reactive /HBV DNA reactive blood donors by individual donor-NAT (ID-NAT) and chemiluminescence technology, and to explore the feasibility and potential risks of reentry. 【Methods】 The blood screening results of blood donors in Wuhu from January 2018 to October 2021 were queried by blood station information management software. The blood donation information of all HBsAg non-reactive /HBV DNA reactive blood donors was collected and then recalled by telephone. After informed consent, samples were taken for HBV DNA nucleic acid single test, enzyme-linked immunoassay for HBsAg, chemiluminescence assay for HBV seromarkers(including HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc), and alanine aminotransferase (ALT) test. All the results were statistically analyzed. 【Results】 From January 2018 to October 2021, there were 142 051 donations, and the positive rate of sole HBV DNA was 0.06% (91/142 051), and 33 people (37 person-times) were successfully followed up. The yield rates of HBsAg, anti-HBs and anti-HBc were 6.06% (2/33), 39.39% (13/33) and 96.97% (32/33), respectively; None HBeAg was yielded. After two times of ID-NAT, 8 patients remained non-reactive to both systems, with a negative conversion rate of 24.24% (8/33). Meanwhile, 25 patients were at least once reactive to ID-NAT, and 23 of them were occult HBV infection with serologically reactivity. There were 2(6.25%) patients with HBsAg positive conversion and HBV DNA persistent reactivity, which were window period infection. One person was confirmed as false reactivity (no HBV infection) as he remained unreactive to both repeated ID-NAT and serological tests. 【Conclusion】 Chemiluminescence assay is more sensitive than ELISA in detecting HBV serum markers, which is beneficial to early detection of HBV samples in window period. The yielding rate of anti-HBc among HBsAg non-reactive/HBV DNA reactive blood donors detected by blood screening in this region is very high, and most of them are occulting infection, so the ID-NAT should be no less than 2 times in the reentry strategy.

Influencing factors of the repeat reactive (RR) rates of minipools implicated in minipool(MP) nucleic acid testing(NAT) in Xiamen / 中国输血杂志

【Objective】 To analyze the influencing factors of the repeat reactive (RR) rates of minipools implicated in minipool (MP) nucleic acid testing(NAT) in Xiamen Blood Center, in order to provide reference for NAT. 【Methods】 Samples of blood donors from January 1, 2019 to October 31, 2022 were collected in Xiamen Blood Center and tested by MP-NAT(pools of six). Statistical analysis and comparison of MP-NAT RR rates was performed among different years, testers, reagent batches, instrument combinations, CT values of MP-NAT reactive pools and sample backgrounds. 【Results】 A total of 234 715 blood samples were tested by MP-NAT, and 428 pools were reactive, in which 248 pools were individual-donor NAT reactive, with a MP-NAT RR rate of 57.9%. The difference of MP-NAT RR rates were not statistically significant among different years, testers, reagent batches, instrument combinations, and sample backgrounds (P> 0.05). The difference of MP-NAT RR rates among different CT values of MP-NAT reactive pools was statistically significant (χ2=69.587, P<0.05). Significantly abnormal RR rate accurred in two months in 2022, and returned to normal after timely handling. 【Conclusion】 The MP-NAT RR rates is one of the important indicators to monitor the quality of NAT. Once there is a significant change in the MP-NAT RR rates, comprehensive analysis and timely handling should be carried out to ensure the quality of blood detection.

Following up and re-entry of HBV reactive blood donors in Yantai area / 中国输血杂志

【Objective】 To analyze the preliminary screening and follow-up testing data of HBV in Yantai area, and discuss the rationality of following up and re-entry program of HBV reactive blood donors. 【Methods】 Donors who were single reagent reactive by enzyme-linked immunosorbent assay (ELISA) in initial screening but non-reactive by nucleic acid testing (NAT) were followed up. Individual NAT(ID-NAT) was performed for HBV DNA, ELISA for HBsAg, HBsAb, HBeAb, HBeAg and HBcAb, and ECLIA for the detection of HBsAg. 【Results】 A total of 547 blood donors were HBsAg ELISA-/NAT+, and 97 were followed up, among which 24 met the requirements of re-entry while 73 did not. Of the 24 blood donors who met the re-entry requirements, 13 donated blood again, with test results all qualified. 【Conclusion】 The combination of ELISA, ID-NAT, and ECLIA methods for following up detection for HBsAg ELISA+ blood donors is recommended. Blood donors with HbsAb S/CO ≥ 10 and negative results for other tests met the re-entry requirements, with a re-entry rate at 24.74%, and the re-donation qualified rate of blood donors after re-entry was 100%.

Performance verification of domestic nucleic acid testing system in blood stations based on T/CSBT / 中国输血杂志

【Objective】 To explore the performance verification of the Shengxiang automatic NAT system for HBV DNA, HCV RNA and HIV RNA-1 using PCR-fluorescence in the laboratories of blood stations, in order to meet the requirements of T/CSBT and ensure the quality of nucleic acid detection. 【Methods】 Samples used in the external quality assessment (EQA) of National Center for Clinical Laboratories of the year 2022 were taken to verify the concordance. The standard materials of HBV DNA, HCV RNA and HIV RNA-1 were used to verify the analytical sensitivity, endogenous interfering substances, repeatability, anti-cross contamination ability and stability. 【Results】 The concordance rate of 20 EQA samples was 100%. The analytical sensitivity of HBV DNA, HCV RNA and HIV RNA-1 were all reactive and met T/CSBT. The yielding of HBV DNA, HCV RNA and HIV RNA-1 was affected little with lipemia at 3g/L and hemolysis at 4g/L. The coefficients of variation(CV) of intra-assay and inter-assay which met T/CSBT were all less than 5%, and the intra-assay variation coefficient was less than the inter-assay variation coefficient. The test results of 40 negative samples tested for cross contamination resistance were 100% negative, and 40 positive samples of HBV with 10 000 IU/mL were 100% positive. The stability verification results showed that the detection rate of weak positive samples was 100%. The coefficient of variation of the test results of the reagent after 1 and 5 freeze-thaw cycles were less than 5%,and the difference between the detection Ct value of reagent underwent once freeze-thaw and five-time freeze-thaw was not statistically significant. 【Conclusion】 The analytical sensitivity,endogenous interfering substances, repeatability,anti-cross contamination ability,stability and the compliance rate of domestic Shengxiang Gene automatic NAT system and supporting reagents by PCR-fluorescence method all meet T/CSBT, so it can be used for nucleic acid detection in blood screening in blood station laboratory.

Performance evaluation of nucleic acid testing system for blood screening in high-altitude areas / 中国输血杂志

【Objective】 To validate the performance of a nucleic acid testing(NAT) system for blood screening in the high-altitude Nagqu region of Tibet, in order to assess the capability of NAT in high-altitude areas and further enhance blood safety. 【Methods】 Various methods were employed to evaluate the analytical sensitivity, reproducibility, ability to prevent cross-contamination, and comparison between different NAT systems. 【Results】 The NAT system in the Nagqu region of Tibet achieved a 100% detection rate for high-concentration HBV DNA and HIV-1 RNA samples, and over 90% for medium-concentration samples. PROBIT analysis revealed the lower limits of detection (LOD) for HBV DNA and HIV-1 RNA to be 8.29 IU/mL (95% CI, 5.88~20.55 IU/mL) and 40.52 IU/mL (95% CI, 30.26~85.92 IU/mL), respectively. For HCV RNA genotype 2a, the LOD was 97.14 IU/mL (95% CI, 71.00~182.67 IU/mL), all of which were lower than the declared minimum detectable concentrations in the instructions. Reproducibility analysis demonstrated a 100% level of consistency within the system. Cross-contamination performance verification showed a strong ability to resist cross-contamination. Comparative analysis of repeated testing of low-concentration HBV DNA samples and multi-system testing in plain areas revealed consistency rates of 77.78%(14/18) and 77.27%(17/22), respectively, indicating certain differences between the NAT system in Nagqu region and other systems. 【Conclusion】 The NAT system exhibited excellent performance in blood screening at high altitudes. The results of performance validation in high-altitude blood screening NAT systems were largely consistent with those in plain areas, providing a reliable basis for enhancing blood safety in high-altitude regions.

Analysis of Ct value of HBV nucleic acid detection in different blood donors / 中国输血杂志

【Objective】 To analyze the difference of Ct value of HBsAg-/HBV DNA + in blood samples from different types of voluntary blood donors by double ELISA and HBV DNA (MP6) detection, and to investigate the correlation between Ct value and the frequency of repeated blood donation, the first nucleic acid reactivity and the interval time of previous blood donation, so as to provide reference for laboratory evaluation of the effectiveness of nucleic acid testing(NAT) strategy for repeated blood donors occult hepatitis B virus infection(OBI). 【Methods】 The Ct value and information of blood donors from February 2019 to January 2022 in our laboratory were collected. According to the cumulative number of blood donations, they were divided into two groups:first-time blood donor group (Group A) and repeated blood donor group (Group B). Group B was subdivided into Group C 1( twice of blood donation) and group C 2(three or more times of blood donation) according to the cumulative times of blood donation, and Group D 1(< 1 year), Group D 2(1-3 years), Group D 3(3 years or more) according to the first NAT reactivity and the time of previous blood donation, the difference of Ct value and resolution yeild of HBV DNA in each group was compared. The yeild of HBV DNA in two groups was compared by chi-square test, and the difference of Ct values were compared by Nonparametric test. 【Results】 From February 2019 to January 2022, a total of 270 283 blood donors were tested, including 135 695 in Group A and 134 588 in Group B. The yeild of HBV DNA in Group A was 0.150% (203/135 695), which was higher than that in Group B [0.083% (111/134 588)] (P <0.05).All Ct values were non-normal distribution by normal distribution test, and were expressed as median (quartile), the median values of MP6 and resolution Ct were 37.0(35.9,38.2) and 35.5(33.7,36.9) in Group A, 37.2(36.4,38.1) and 36.5(35.5,37.6) in Group B, respectively. Ct values of MP detection and resolution in Group A, of MP detection and resolution in group B, and of resolution in group A and B were all significant (P<0.05) From the cumulative number of blood donations to compare, the median values of MP detection and resolution Ct were 37.5(36.6,38.3) and 36.5(35.4,37.6) in Group C1,37.1(36.4, 37.9) and 36.6(35.6,37.8) in Group C2, respectively. Significant difference in resolution Ct value between Group A and Group C1, Group A and C2 was noticed(P<0.05), the median values of MP detection Ct in D1, D2 and D3 groups were 37.2(36.3,38), 37.1(36.5,37.9), 37.8(36.6.38.9),respectively, with median resolution CT values at 37.0(35.7,37.8), 35.9(34.8,36.9), 36.9(36.1,37.7), respectively. There was a significant difference in the resolution Ct values between between Group A and D1 and D3 groups (P<0.05), and there was a significant difference between the MP detection and resolution Ct values in D2 Group (P<0.05). The resolution Ct values in D2 and D3 Group were lower than those in D1 Group (P<0.05).The interquartile distribution of Ct values in Group A was wider than that in other groups, and the interquartile distribution of Ct values in Group B was more concentrated. Conclusion The Ct value of HBV DNA detected by nucleic acid in blood donors was correlated with different times of blood donation and different intervals of blood donation. The laboratories of blood station should pay attention to the nucleic acid test results of different types of blood donors to ensure blood safety.

Confirmation of HBV infection of HBsAg-negative NAT suspicious sample from blood donors / 中国输血杂志

【Objective】 To explore the HBV infection of initially reactive but discriminatory test non-reactive (NAT suspicious) samples of voluntary blood donors after PANTHER individual nucleic acid testing (ID-NAT) in Tianjin. 【Methods】 From January to August 2021, after routine testing and PANTHER ID-NAT, a total of 66 HBsAg-NAT reactive but discriminatory test non-reactive samples(referred to as NAT suspicious samples) were tested from 69 362 blood samples. Among which, 23 samples were selected by simple random sampling method and enriched by ultra-high speed centrifugation. HBV DNA was detected by supersensitive fluorescence quantification PCR (qPCR)and ID-NAT, and electrochemiluminescence was supplemented for two and half pairs of hepatitis B detection. 【Results】 Among 23 suspicious NAT samples, 14 were confirmed HBV DNA positive by serological and molecular biological tests, and the anti-HBc positive rate of HBV infected individuals was 92.8%. 92.8% (13/14) of the infected individuals were occult hepatitis B virus infection(OBI). A total of 10 samples were detected for viral load by qPCR, of which 5 were quantifiable, with viral load of (11~464) IU/mL and a median of 15.4 IU/mL. 【Conclusion】 60% of the NAT suspicious samples were detected as HBV DNA positive. Anti-HBc testing can exclude most OBI undetectable by NAT, and the sensitivity of NAT should be improved to ensure the safety of blood transfusion.

SARS-CoV-2 total antibody detection results in blood donors from Shenzhen during different periods of COVID-19 epidemic prevention and control / 中国输血杂志

【Objective】 To analyze the SARS-CoV-2 detection results among blood donors in different periods of COVID-19 pandemic control in Shenzhen and assess the antibody levels and infection status of blood donors in different periods, so as to provide reference for subsequent blood testing strategies. 【Methods】 A total of 4 768 plasma samples of blood donors were subjected to pooled testing by nucleic acid testing(NAT) with 8 samples per pool. Additionally, these samples were subjected to a 1000-fold dilution, and the detection of SARS-CoV-2 total antibody was performed by enzyme-linked immunosorbent assay (ELISA). The 4 768 plasma samples were collected from blood donors at different time points in Shenzhen, with inquiries made to determine whether donors during the COVID-19 pandemic were in the convalescence. The antibody positive rates in blood screening samples during different periods of the pandemic and samples from individuals in the convalescence of COVID-19 infection were analyzed. Furthermore, the antibody levels were examined for differences based on gender, age, and blood type. 【Results】 All 4 768 plasma samples from blood donors were negative by NAT, while 2 342 samples were detected positive by the SARS-CoV-2 total antibody detection, with a positive rate of 49.1%. These samples from four periods (September 30 to October 3, 2022; November 3 to 6, 2022; December 27 to 31, 2022; January 6 to 18, 2023) were subjected to a 1 000-fold dilution for COVID-19 antibody detection, and the positive rates were 21.3%, 15.8%, 65.9%, and 93.9%, respectively. 【Conclusion】 The prevalence of COVID-19 antibodies among blood donors in Shenzhen during different periods of the pandemic varied significantly. There was no difference in antibody prevalence among different genders and blood types, while younger individuals exhibited a higher prevalence of antibodies. The risk of COVID-19 transmission through blood transfusion was found to be extremely low.

Preparation of national reference panel of HBV for nucleic acid testing donor screening / 中国生物制品学杂志

@#Objective To prepare the national reference panel of hepatitis B virus(HBV) for nucleic acid testing(NAT)donor screening.Methods A number of plasma samples from donors positive for HBV antibody and patients with HBV infection collected from blood centers,plasma stations and biological products companies in Shanghai,Gansu,Henan,Hunan,Hubei and other regions were tested for HBV DNA viral load agent,and negative and positive reference candidates were screened;The HBV DNA national standard was diluted to 10~3 IU/ml with human negative plasma,as a candidate for limit of detection(LOD).National negative and positive reference candidates of HBV for NAT donor screening and LOD reference to be calibrated were distributed to 8 enterprise laboratories for joint detection of HBVHCVHIV NAT donor screening.The homogeneity and stability of the national reference panel were investigated.Results A total of 8 negative samples with HBV viral load of 0 were screened as negative references and 9 positive samples with viral load of 10~3～10~4 IU/mL were used as positive references;One LOD reference was calibrated with WHO HBV DNA standard,and the virus content was 1.0 × 10~3 IU/ml.The national reference panel showed good stability and the homogeneity inspection met the requirements.Conclusion The national reference panel of HBV DNA for NAT donor screening was prepared,which provided a basis for the quality control and standardization of HBV DNA reagents for donor screening.

Classification management of HIV reactive blood donors based on test results / 中国输血杂志

【Objective】 To explore the viability of classification management of HIV reactive blood donors based on test results in blood screening laboratory. 【Methods】 According to the HIV test results of blood donors (including twice ELISA and once NAT), the HIV reactive blood donors were divided into three groups. Group 1 was all-test reactive (both ELISA and NAT were reactive), group 2 serological reactive (only ELISA was reactive), and group 3 NAT reactive (only NAT was reactive). The HIV test results of 191 628 blood donors from May to December 2017 were analyzed. Samples with positive RIBA results and / or the repeated reactive NAT results were determined as HIV true positive. The yielding rates of HIV true positivity in each group were analyzed. Receiver operating characteristic curve (ROC curve) was used to elevate the S/CO limit under 99% specificity as the blood donor deferral limit for ELISA. 【Results】 A total of 180 HIV reactive samples were detected out of 191 628 blood donors, including 77 positive cases in group 1, 100 in group 2 and 3 in group 3. 1) The HIV reactive results were diverse. Among the 82 true positive blood donors, 4 were early HIV infection (3 HIV antibody+ antigen window period yield, 1 HIV antibody window period yield), 2 were suspected elite controllers, and 76 cases were both serology and NAT reactive. 2) The overall yielding rate of HIV was 47.67%, with group 1 (100%) = group 3 (100%) > group 2 (2.17%), showing statistically significant (P0.05). All true positive blood donors in group 1 and group 2 could be accurately screened by using the blood donor deferral limit for ELISA1 and ELISA2 simultaneously. 【Conclusion】 The composition of HIV results among blood donors is diverse and complex. It is necessary to continuously improve the awareness of HIV prevention and control. The classification of HIV reactive blood donors is conducive to conduct fine and scientific management. The blood donors in group 1 and group 3 should be permanently deferral, and the suspected HIV elite controllers in group 2 should be paid attention to and permanently deferral.

Detection ability of nucleic acid screen laboratory in blood bank based on NCCL external quality assessment data / 中国输血杂志

【Objective】 To evaluate the laboratory's NAT ability by analyzing the feedback reports of nucleic acid test (NAT) results of external quality assessment (EQA) of National Center for Clinic Laboratories (NCCL), so as to improve the laboratory management details and ensure blood safety. 【Methods】 The data of NCCL NAT EQA of blood screening laboratory of Tianjin Blood Center (a total of five occasions from Jan 2019 to Jun 2021) were statistically analyzed. 【Results】 From Jan 2019 to Jun 2021, the laboratory participated in EQA for five times and all the results were qualified. The test results of NAT EQA HIV RNA/HCV RNA/HBV DNA detected by R1, R2 and R4 were consistent with the reference results. R3 showed false positive results (CT value 40.46) in the single donation detection of sample No.1925 in HCV RNA. Unreported data of the laboratory was that in the first EQA in 2021, the R4 showed false positive results (CT value 35.8) in in the single donation detection of sample No.2113 in HIV RNA. 【Conclusion】 The performance of each NAT screening system in our laboratory is relatively stable except occasional false positive results influenced by every factor. Potential problems can be found and continuously improved by assaying EQA reports and the extended experimental results of EQA samples to further improve the detection ability.

Analysis of influencing factors on re-entry of HBV DNA reactive blood donors / 中国输血杂志

【Objective】 To explore the factors affecting NAT reactive blood donors re-entry, so as to provide data support for formulation of scientific and reasonable strategy. 【Methods】 The basic data and laboratory test results of 174 NAT reactive returning blood donors from January 2019 to August 2021 were collected and statistically analyzed by logistic regression. 【Results】 Among 174 HBV DNA reactive blood donors applying for re-entry, 81 (46.6%) were eligible for re-entry. Blood donation type and deconstructed Ct value were independent influencing factors of blood donors’ re-entry (P0.05). No significant difference was observed in Ct values of deconstruction test, first re-entry test and second re-entry test (P<0.05). 【Conclusion】 In view of the low re-entry rate of NAT reactive blood donors, it is necessary to establish a set of safety criteria to lessen workloads. Donors with exceeding minipool-Ct-values, repeat reactive by two NAT reagents, failure in the first re-entry test are suggested to be deferred permanently.

Impact of blood screening strategies for Hepatitis C virus on blood safety / 中国输血杂志

【Objective】 To establish a reasonable and effective blood screening strategy for Hepatitis C virus (HCV), so as to reduce the risk of blood transfusion transmission, ensure blood safety and improve the quality of blood screening. 【Methods】 In order to evaluate HCV screening strategies comprehensively, the unqualified blood donations due to anti-HCV alone positivity in Dalian from 2017 to 2021 was tracked, with combined detection methods of electro-chemiluminescence immunoassay (ECLIA) and HCV-RNA nucleic acid test (NAT). 【Results】 A total of 851 (0.20%) unqualified donations due to anti-HCV alone positivity were screened from 2017 to 2021, with a decreasing trend in both numbers and rate. Among them, the unqualified rate of samples with anti-HCV reactivity in both dural-ELISA-reagent and NAT decreased significantly (P<0.05). A total of 117(0.028%) samples were anti-HCV reactive in dural-ELISA-reagent but nonreactive in NAT; 664 reactive in one-ELISA-reagent, with 70(10.54%) in Reagent Ⅰ and 594(89.46%) in Reagent Ⅱ; 122 (35.88%) out of 340 donations were reactive in ECLIA. Among the 28 participants in the follow-up test, 15 still were reactive in ELISA and 2 reactive in ECLIA. 【Conclusion】 Although the unqualified rate of HCV is decreasing, serological screening of anti-HCV is still an important method for ensuring blood safety, and its complementarity with HCV-RNA NAT should be evaluated. As a new serological assay, ECLIA has high sensitivity and specificity. Miss detection may occur if only one ELISA reagent is adopted for anti-HCV detection. Appropriate ELISA and NAT system for HCV screening should be reasonably chosen, and HCV screening strategy should be developed and adjusted according to the local conditions.

Performance verification of nucleic acid testing project based on ISO 15189 / 中国输血杂志

【Objective】 To explore the performance verification of NAT and its procedures for HBV DNA, HCV RNA and HIV RNA-1 using PCR-fluorescence via Cobas s201 automatic NAT system and supporting MPX V2.0 reagents that applied in the laboratories of blood stations, in order to satisfy ISO 15189 accreditation requirements and ensure the accuracy of NAT results. 【Methods】 Samples used in external quality assessment(EQA) of year 2020 were taken to verify the concordance, Performance evaluation panel and sensitivity verification panel of Roche second-generation NAT system were used to verify the sensitivity/ specificity and the lower limit of detection, respectively.And HBV DNA, HCV RNA and HIV RNA-1 quality control products were used to verify the anti-interference ability. 【Results】 The concordance rate of 40 EQA, samples was 100%. The sensitivity and specificity of Cobas s201 automatic NAT system and supporting MPX V2.0 reagents in detecting HBV DNA, HCV RNA and HIV RNA-1 were all 100%. The lower detection limit for HBV DNA, HCV RNA and HIV RNA-1 all met the requirements of reagent instructions. The yielding of HBV DNA, HCV RNA and HIV RNA-1 were affected little with hemolysis at 500 mg/dL but interfered seriously as lipemia reached 3 300 mg/dL. 【Conclusion】 The concordance rate, sensitivity, specificity and lower detection limit of the Cobas s201 fully-automatic NAT system and MPX V2.0 reagents by PCR-fluorescence method all met the requirements of reagent instructions. The verification of anti-interference ability demonstrated the requirements of ISO 15189 and the needs of blood station laboratories could be satisfied, and the detection methods and procedures can ensure the accuracy of NAT results.

Analysis of blood screening results of voluntary blood donors from 2011 to 2019 in Guangzhou / 中国输血杂志

【Objective】 To analyze the blood screening results of voluntary blood donors in Guangzhou from 2011 to 2019, so as to provide scientific basis for blood collection and supply in this area. 【Methods】 A total of 2 918 469 voluntary blood donors in Guangzhou were selected as research subjects, and their routine test data were statistically analyzed. 【Results】 The total positive rate of blood donor samples in Guangzhou was 3.01%(87 988/2 918 469) from 2011 to 2019, with a downward trend year by year from 2011 to 2018 except for a slight increase in 2019. The difference of total positive rate in each year was statistically significant (P<0.05). The ELISA-yielding rate(1.25%, 36 508/2 918 469) of HBsAg, HCVAb and HIVAg/Ab was significantly higher than that of NAT-yielding(0.62%, 18 086/2 918 469)(P<0.05). In terms of annual positive rate of various tests, ALT was the highest (1.28%, 37 451/2 918 469), followed by HBsAg (0.82%, 23 827/2 918 469), and NAT (0.62%, 8 086/2 918 469), anti-TP (0.39%, 11 468/2 918 469), anti-HCV (0.31%, 9 155/2 918 469), HIVAg/Ab(0.12%, 3 526/2 918 469) and anti-HTLV (0.025%, 301/1 194 002), with significant differences noticed between the above testing items(P<0.05). And 0.20% (5 947/2 918 469) of the samples were ELISA(-)/NAT(+ ), among which 30.02%(1 785/5 947)were discriminated as positive, including 99.38% (1 774/1 785) HBV positive, 0.28%(5/1 785) HCV positive, and 0.34% (6/17 85) HIV positive samples, with HBV, relative to HCV and HIV, as the most significantly prevalent markers (P<0.05). 【Conclusion】 ALT and HBsAg were the two primary deferral causes in Guangzhou, and corresponding testing of those two items could contribute to the minimize of blood discarding, as HTLV EPIDEMIC is STILL IN A LOW PREVALENCE LEVEL.ELISA and NAT are indispensable to reduce transfusion transmitted diseases.

NAT10 Promotes Cervical Cancer Cell Malignant Behavior via N4-acetylcytidine Modification of DDR1 mRNA / 中国生物化学与分子生物学报

N-acetyltransferase 10 (NAT10) is a key enzyme involved in the acetylation of mRNA, which regulates the expression of target genes and biological functions of various cancers via ac4C (N4-acetylcytidine) acetylation. However, whether NAT10 is involved in regulating the malignant behavior of cervical cancer is rarely reported. This study investigated the effects and specific mechanism of NAT10 on the growth activity, proliferation capacity, migration and invasion capacity of cervical cancer cells. First, we found a highly expression of NAT10 in cervical cancer and was associated with poor patient prognosis by TCGA database analysis. MTT assays and colony formation assays showed that overexpression of NAT10 promoted the growth activity (P<0. 05) and proliferation ability (P<0. 001) of cervical cancer cells; Transwell migration and invasion assays showed that overexpression of NAT10 promoted the migration (P<0. 01) and invasion (P<0. 05) ability of cervical cancer cells; Western blotting showed that overexpression of NAT10 increased the mesothelial cell marker vimentin and resulted in a decrease in the epithelial cell marker E-cadherin. Bioinformatics analysis exhibited that discoidin domain receptor 1 (DDR1) might be a downstream target gene of NAT10. RNA binding protein immunoprecipitation (RIP) assays showed that NAT10 could directly bind to DDR1 mRNA (P<0. 05), Western blotting and RT-qPCR experiments showed that overexpression of NAT10 significantly increased the expression and mRNA levels of DDR1 (P<0. 05). Furthermore, RNA acetylation co-immunoprecipitation experiments showed that overexpression of NAT10 promoted the acetylation level of DDR1 mRNA (P<0. 001), and EGFP reporter assays confirmed that NAT10 recognized the acetylation site of DDR1 mRNA. The results of mRNA half-life experiments showed that NAT10 increased the stability of DDR1 mRNA (P<0. 05). In conclusion, our research confirms that NAT10 promotes the growth activity, and migration and invasion ability of cervical cancer cells and its specific mechanism is to extend the stability of DDR1 by acetylation modification, thereby increasing its expression levels, which might provide new insights into the molecular mechanism of acetylation modification of mRNA on the pathogenesis of cervical cancers.

Environmental monitoring in NAT laboratory / 中国输血杂志

【Objective】 To analyze the environmental monitoring results of NAT laboratory from 2016 to 2019 and evaluate the influence of environmental quality on blood screening. 【Methods】 Monthly/Quarterly environmental monitoring was carried out in NAT laboratory regularly by means of air deposition and surface wiping. The monitoring results were statistically analyzed and comprehensively evaluated in combination with the pool/multiplexNATreactiverate and discriminatory/resolutionrate. 【Results】 A total of 48 batches of environmental monitoring tests were conducted from 2016 to 2019, 11 (25 reactive sites) were unqualified, including 15 reactive sites (60%) as the hallway doorknob or access control, which were the public areas shared with serology laboratory, and these sites were not reactive for 6 consecutive months after intensive cleaning and disinfection. In Nov.2017, the air deposition in biosafety cabinet and surface wiping of Cobas s 201 were reactive, and the restwere the doorknobs. Pearson correlation analysis showed that there was no correlation between the positive rate of environmental monitoring and the detection amount, the pool/ multiplex NAT reactive rate and discriminatory/resolution rate. 【Conclusion】 The accidental environmental pollution in the laboratory is not related to the detection amount and positive rate, indicating that the cleaning and anti-pollution measures are timely and effective to ensure the accuracy and reliability of the screen results. NAT laboratory should gradually establish and improve the environmental monitoring system according to the layout and environment so that the environmental quality meets the testing conditions.