Detection and analysis of antibodies against SARS-CoV-2 in blood donors at different periods in Guangzhou / 中国输血杂志

【Objective】 To detect the anti-SARS-CoV-2 antibody levels in blood donors in Guangzhou, so as to provide laboratory data support for the collection and clinical use of convalescent plasma. 【Methods】 Anti-SARS-CoV-2 antibodies were measured by ELISA in qualified donors. Among them, 326 donors who gave blood in February 2023 were tested for IgG antibodies, 444 donors were tested for neutralizing antibodies. In July 2023, 398 donors were tested for IgG and IgM. 【Results】 399 of 724 blood samples diluted with normal saline (1∶160) were IgG reactive, with a reactive rate of 55.11%. Chi-square test showed that there was a significant difference in the reactive rate of IgG among samples collected at different times (25.46% in February vs 79.40% in July, χ2=210.74, P<0.01, 95%CI: 7.97, 15.98), but there was no significant difference in the reactive rate between different genders and different age groups. IgM was detected in 5 of 398 blood samples, with a reactive rate of 1.26%. The IgG test results of these five blood donors were all reactive, whereas the nucleic acid test results were negative. Neutralizing antibody was detected in 440 of 444 blood samples, with a reactive rate of 99.10%, and 71.59% of the reactive donors had a neutralizing antibody level of 10 μg/mL or more. 【Conclusion】 Blood donors in Guangzhou have a high level of SARS-CoV-2 antibody, which is sufficient to provide convalescent plasma for clinical treatment.

Viral selection pressure and CD4+T cell epitope in HLA-DRB1 * 11:01 of HCV infected patients / 中国输血杂志

【Objective】 HLA-DRB1 * 11:01, as a class HLA-Ⅱ gene, was reported to be associated with spontaneous clearance of HCV in Han and Li population. Our study was to investigate the effects of viral selection pressure and CD4+T cell epitope on the natural outcome of HCV infection in HLA-DRB1 * 11:01 positive infected patients. 【Methods】 The positive selection sites and population growth of E1E2 and NS3 genes of common HCV 6a in HLA-DRB1 * 11:01 positive and negative groups in Guangdong were respectively analyzed. The peptide library covering the conserved regions of common HCV genotypes was used to stimulate HCV spontaneous clearance group and chronic infection group using ELISPOT method. Reactive peptides were obtained according to the number of spot-forming cells per well and the frequency of occurrence in different groups. 【Results】 The positive selection sites (PSSs) of E1E2 and NS3 of common HCV 6a in HLA-DRB1 * 11:01 negative group were greater than those in HLA-DRB1 * 11:01 positive group. Furthermore, the number of PPSs in CD4+T cell peptide in HLA-DRB1 * 11:01 negative group were also greater than those in HLA-DRB1 * 11:01 positive group; Both groups of HCV 6a had a population growth in Guangdong, and the expansion trend of HLA-DRB1 * 11:01 negative group was significantly higher than that of HLA-DRB1 * 11 :01 positive group. Compared to HCV chronic infection group, the response rate of HCV spontaneous clearance group to five peptides (C-52 E2691-707, C-119 NS31545-1560, C-134 NS4A1669-1684, C-154 NS4B1912-1927, C-159 NS4B1929-1944) was higher. However, the HCV chronic infection group showed a higher response rate to two of the peptides(C-111 NS31497-1512, C-130 NS31650-1665). When HLA-DRB1 * 11:01 typing was considered, there was no significant difference in HCV-specific immune response generated by PBMCs between HLA-DRB1 * 11:01 positive and HLA-DRB1 * 11:01 negative groups. 【Conclusion】 This study revealed the relationship between viral selection pressure of HLA-DRB1 * 11:01 HCV infected persons and CD4+T cell antigen epitopes. At the same time, CD4+ T cell antigen epitopes of HCV pan-genotype were obtained, providing basic data for the development of T cell vaccine suitable for HCV pan-genotype.

Preliminary identification of CD4 T cell epitopes in genotype 1 and 6 of hepatitis C virus / 中国输血杂志

【Objective】 To study the CD4 T cell epitopes in Core and NS3 protein of genotype 1(GT1) and 6(GT6) of hepatitis C virus(HCV). 【Methods】 A total of 298 overlapping peptides(16-mer) spanning Core and NS3 protein of GT1 and GT6 HCV were synthesized. Peripheral blood mononuclear cells(PBMCs) from 17 HCV+ and 7 healthy blood donors were stimulated by peptide pools, followed by evaluating T cell response by IFN-γ ELISPOT, by which 21 peptides with positive results were found. These peptides were further applied to individually stimulate 20 HCV+ and 18 healthy PBMCs. The differences of responsive frequencies to the 21 positive peptides between the two study groups were compared. 【Results】 Pooled and individual peptide stimulation tests showed that HCV+ PBMCs were responsive to the stimulation of 5 peptides(GT1 NS31273-1288 and NS31315-1330; GT6 NS31033-1048, NS31087-1102 and NS31351-1366), with a responsive frequency ranging 18.9%-27.0%. In contrast, healthy PBMCs were not or low responsive(0%-4.0%) to these five peptides. The responsive frequencies were statistically different between the two groups(P<0.05). No reported epitopes in IEDB were found identical with these 5 peptides via sequence alignment. 【Conclusion】 Our study identified novel CD4 T cell epitopes in NS3 protein of GT1 and GT6 HCV, which has potential application value for the research and development of HCV vaccine.

HCV evolution and positive selection sites of HCV NS5B region among intravenous drug users in Guangdong / 中国输血杂志

【Objective】 To learn the situation of the evolution process of HCV virus population and the selection pressure of HCV NS5B in intravenous drug users (IDUs) in Guangdong. 【Methods】 141 blood samples from hepatitis C virus (HCV) RNA-positive blood donors and 58 from HCV patients in Guangdong were randomly collected for HCV NS5B sequence amplification, combined with HCV NS5B sequences from blood donors and IDUs obtained by sequencing previously(between 2009 and 2011). Homology analysis was performed by Molecular Evolutionary Genetics Analysis (MEGA) software, evolutionary analysis were performed by Bayesian Evolutionary Analysis Sampling Trees (BEAST) software package. Selection pressure analysis was performed on sequences isolated from IDUs by Datamonkey online software package with Mixed Effects Model Evolution (MEME) method, and the population expansion of species were analyzed using Tajima and Fu neutrality test by Arlequin software. 【Results】 The comparison results of internal homology among different subtypes of IDUs in this group were as follows : HCV-3b had the highest homology (97%), followed by HCV-3a (96%), HCV-6a (95%) and HCV-1b (94%); HCV evolution rate analysis showed that HCV-1b had the fastest evolution rate [2.17E-03 substitutions/site/year (y/y/y)], followed by HCV-3b (2.12E-0 y/y/y), HCV-3a (1.58E-03 y/y/y) and HCV-6a (1.28E-03 y/y/y). The analysis on effective population of HCV: 1980~1990 was rapid growth period for HCV-6a, 1990~1995 period for HCV-1b, and 2000~2007 period for HCV-3a. HCV population genetic characteristics was as follows: HCV-1b, 3a, 3b and 6a experienced population expansion, among which 3a and 3b were the most obvious. As to the analysis of HCV selection pressure, two positive selection sites (235 and 243)were found in the 339 nucleotide fragment of the NS5B sequence in injecting drug users, but mutation only occurred at position 316 [mutation rate 1.24% (14/1 130)] among 5 direct antiviral drug (DAA) sites in this gene. 【Conclusion】 The evolution of HCV-3b in Guangdong has showed an obvious trend of population expansion, with a high proportion and homology especially in the local IDUs. HCV-3b should be the focus of HCV prevention and control in this region. Given that the positively selected sites of the HCV NS5B gene region of IDUs in Guangdong are non-DAA binding sites, DAA is expected to demonstrate a good effect on these patients.

CMV-IgG yeild in Guangzhou blood donors and comparison of different test reagents / 中国输血杂志

【Objective】 To investigate the CMV-IgG positive yeild among blood donors in Guangzhou and explore the differences in the efficacy of three test reagents, aimed at improving blood safety and service capacity of blood centers. 【Methods】 A total of 630 blood samples from eligible blood donors from July to October 2020 in our center were randomly selected and screened for CMV-IgG by one ELISA reagent.Among them, 180 samples were tested in parallel using three reagents (two ELISA reagents and one ECLIA reagent), and those tested negative were conducted quantitative CMV-DNA detection.The test results of different reagents were compared and analyzed. 【Results】 Out of the 630 samples, a total of 598 positive samples were screened out, including 180 samples yielded by three reagents, 171 and 175 by the two ELISA reagents, respectively, and 175 by ECLIA.The results given by three reagents were consistent (Kappa>0.4), and no significant difference in the positive yeild by three reagents was found.In the 180 samples, 11 were negative, among which 3, 2 and 6 samples were negative by all three reagents, two reagents and one reagent (ELISA), respectively.All the 11 samples were tested negative for CMV-DNA. 【Conclusion】 The yeild of positive CMV-IgG in blood donors was 94.9% (598/630), suggesting a high prevalence of CMV in Guangzhou. CMV serologically negative blood should be considered when providing blood products to immunocompromised patients to improve the safety of recipients.The detection results of ELISA reagents and ECLIA reagent for CMV- IgG are consistent, but ECLIA reagent has better detection efficacy.

Correlation of peripheral myeloid-derived suppressor cells with hepatitis c virus infection / 中国输血杂志

【Objective】 To investigate the correlation of peripheral myeloid-derived suppressor cells (MDSC) with hepatitis c virus (HCV) infection. 【Methods】 109 voluntary blood donors who donated blood during February 2018 to September 2020 at Guangzhou Blood Center were recruited in this study. They were assigned to chronic hepatitis c (CHC) group (n=48), spontaneous clearance (SC) group (n=29) and healthy donors (control) group (n=32) according to the results of anti-HCV and HCV RNA tests. Blood samples were drawn from the participants and peripheral blood mononuclear cells (PBMC) were freshly isolated, followed by staining with fluorescently-labeled antibody against cell surface markers of MDSC, which were then applied to the detection of monocytic- (M) and polymorphonuclear (PMN)-MDSC by flow cytometry. Parameters for liver function including alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyl transpeptidase (GGT), total bilirubin (TBIL) and direct bilirubin (DBIL) were also measured. One-way ANOVA tests were applied to compare the differences of M- and PMN-MDSC and liver function between three study groups. For pairwise comparisons, P values were adjusted for multiple comparisons by Bonferroni correction (Pc). 【Results】 The frequencies of M-MDSC (%) in CHC, SC and HC were 1.39±0.86, 0.85±0.63 and 0.57±0.23, respectively (P0.05). In addition, AST (34.4±19.2 vs 23.0±7.78 U/L) and GGT (40.8±31.4 vs 22.3±7.40 U/L) level were higher in CHC compared with control (Pc<0.05 and Pc<0.01, respectively). 【Conclusion】 The level of peripheral M-MDSC was significantly elevated in chronic HCV infected donors, which would related to the progression of chronicity after HCV infection.

Full-length sequencing and baseline resistance-associated substitution of hepatitis C virus subtype 3b / 临床肝胆病杂志

ObjectiveTo investigate the application of next-generation sequencing (NGS) in determining the full-length sequence and baseline resistance-associated substitution (RAS) of hepatitis C virus (HCV) subtype 3b. MethodsNucleic acid was extracted from plasma of a HCV RNA-positive blood donor, and after sequence-independent amplification, a sequencing library was constructed and NGS was performed using Illumina Hiseq. Bioinformatics methods were used to analyze full-length HCV sequence, viral genotype, and baseline RAS to direct-acting antivirals (DAAs). ResultsA total of 8.4 Gb data with more than 56 million reads were obtained. The full-length HCV sequence was obtained by bioinformatics analysis, with an average sequencing depth of 488 007 and a genotype of 3b subtype. A total of 12 RASs were identified in HCV amino acid sequence, i.e., Y56H, Q80K, Q80R, and A156G located in NS3, M28G, Q/A30G, Q/A30K, L31F, L31M, and Y93H located in NS5A, and S282T and V321A located in NS5B, among which Q/A30K and L31M located in NS5A had high frequencies of 99.16% and 98.37%, respectively, while the other 10 RASs had low frequencies of ＜0.5%. ConclusionNGS can be used to determine the full-length sequence and genotype of HCV subtype 3b and identify baseline RASs, which has great significance in the epidemiological study of HCV subtype 3b and the development of DAA treatment regimens.

Analysis of related factors of extremely preterm infants'abnormal neurological findings / 中华儿科杂志

<p><b>OBJECTIVE</b>To observe the effect of intrapartum and postpartum factors on abnormal neurological findings in the extremely preterm infants.</p><p><b>METHOD</b>Clinical data of 62 premature infants (33 of male, 29 of female) were retrospectively analyzed. None of the premature infants had birth defect; their gestational ages were all less than 28 weeks (23(+ 6)-27(+ 6) weeks). They were hospitalized within 12 hours after birth in the neonatal intensive care unit (NICU) of BAYI Children's Hospital from November 2010 to June 2013. The blood gas, birth condition, complications, the mechanical ventilation and the ultrasonic encephalography were recorded. The 62 cases were divided into 2 groups, alive group and died group. Meanwhile, all cases of survial were divided into brain injuries group and normal brain group. Data were analyzed with t-test, Chi square test and Spearman correlation analysis.</p><p><b>RESULT</b>Fifty-six cases were alive, and 6 cases died (3 were during the treatment and 3 were after parents gave up). The average birth weight of brain injuries group was (954 ± 182) g; and that of the normal brain group was (1 071 ± 136) g. There were significant differences between the two groups in gender (χ(2) = 4.314, P = 0.038), gestational age (χ(2) = 11.622, P = 0.001), birth weight (t = 2.728, P = 0.009), which had significant correlation with neurological outcomes. The Spearman correlative coefficients were -0.278, 0.456 and 0.364 respectively. And P values were 0.038, 0.000 and 0.006. The rates of multiple pregnancy, lung hemorrhage and surgical operation in brain injuries group were 45%(9/20), 55%(11/20), 40%(8/20), which were significantly higher than those in normal brain group, 3%(1/36), 17%(6/36), 11%(4/36)(χ(2) = 12.800, 8.936, 4.773, P all < 0.05). These three factors were the high risk factors for adverse neurological outcomes, the odds ratios were 28.64, 6.11 and 5.33 respectively. There was no significant difference in delivery mode, amniotic fluid, maternal infection, asphyxia, necrotizing enterocolitis, patent ductus arteriosus, sepsis, mechanical ventilation, inhaled nitric oxide therapy, blood glucose, blood gas analysis, doses of dopamine between brain injuries group and normal brain group. The birth weight in alive group was (1 029 ± 163) g, which was significantly higher than those in died group (870 ± 144)g (r=0.29, P=0.022). There was no significant difference in other factors between alive group and died group(P all>0.05).</p><p><b>CONCLUSION</b>Gender, gestational age and birth weight may have relation with the neurological outcomes of extremely preterm infants. Multiple pregnancy, pulmonary hemorrhage and surgical operation are the risk factors of brain injuries. Birth weight is related to the survival of extremely preterm infants.</p>

Correlation of IL-28B gene polymorphism and natural outcome of hepatitis C / 中国免疫学杂志

Objective:To explore the association between interleukin(IL)-28B single nucleotide polymorphisms and natural outcome of hepatitis C virus.Methods:The IL-28B rs12979860 locus was genotyped in 266 HCV infected volunteer blood donors(107 spontaneous cleared and 159 chronic infection) and 97 healthy controls using Sanger sequencing assay.The difference in rs12979860 genotypes and allele frequencies between the six groups(107 spontaneous cleared and 159 chronic infection,266 HCV infection and 97 healthy controls,159 chronic infection and 97 healthy controls) were analyzed by statistics.Results:159 HCV chronic infection,107 spontaneous cleared and 97 healthy controls,were shown more CC genotype,accounting for 83.6%,95.3%and 86.6%,respectively, while the CT genotype accounted for 16.4%,4.7%and 13.4%respectively.No TT genotype was found.The CC/CT genotype was not significant difference between HCV infection and healthy controls,chronic infection and healthy controls(χ2=0.204,P=0.652;χ2=0.406,P=0.524),but between chronic infections and spontaneous clearance had statistically significant(χ2=8.474,P=0.004),the frequence of C allele in spontaneous cleared was higher than HCV chronic infection(χ2=7.949,P=0.005).Conclusion: The gene polymorphism of IL-28B rs12979860 is not related to HCV susceptibility,but there are differences in chronic infection and spontaneous cleared,showing the C allelic in favor of HCV spontaneous cleaed.

Analysis of Klebsiella pneumoniae infection in 75 preterm infants / 中华围产医学杂志

Objective To analyze the clinical characteristics of Klebsiella pneumoniae infection in preterm infants. Methods Clinical data of 75 preterm infants infected with Klebsiella pneumoniae treated in BaYi Children's Hospital from February 6,2008 to February 10,2010 were retrospectively analyzed.The difference of auxiliary examination between early-onset and late-onset infection group were compared by two independent samples t test.Spearman correlation analysis and non-conditional Logistic regression analysis were used to analyze the high risk factors and the prognostic factors of Klebsiella pneumoniae infection in preterm infants. Results The incidence of Klebsiella pneumoniae infection was 2.8％ (75/2721) in preterm infants,and the mortality rate was 9.3％ (7/75). There were 71 cases of Klebsiella pneumoniae sepsis and 4 cases of Klebsiella pneumoniae pneumonia.Among 75 cases,63 cases were early-onset infection (onset age≤72 h) and 12 were late-onset infection (onset age＞72 h).All patients presented with poor response,heart rate during quiet sleep ＞ 160/min and low oxygen saturation.The mean corpuscular volume and mean corpuscular hemoglobin concentration in early-onset Klebsiella pneunoniae infection cases were higher than those in late-onset neonates [(128.87±24.60) fl vs (113.72±13.54) fl,t=-2.07,P＜0.05and (38.11±2.15) pg vs (36.98±1.05) pg,t=-2.76,P＜0.05].Low birth weight and caesarean section were associated with early-onset Klebsiella pneumoniae sepsis (r=0.250 and -0.240,P＜0.05). The prognosis of Klebsiella pneumoniae infection was associated with hospital stay and duration of premature rupture of membranes (r=0.368 and 0.318,P＜0.05). Conclusions There were no specific clinical manifestations for Klebsiella pneumoniae infection in preterm infants.Preterm infants with low birth weight,long duration of premature rupture of membranes,delivered by caesarean section and received invasive operation are likely to develop Klebsiella pneumoniae infection.

Risk factors of brain injury in very low birth weight infants / 临床儿科杂志

Objective To investigate the incidence and high risk factors of brain injury in very low birth weight infants(VLBWI),to reduce the morbidity of brain injury,and improve the developmental outcome of VLBWI. Methods Data of 181 VLBWI admitted in the neonatal intensive care unit(NICU)between October 2008 and September 2009 were retrospectively analyzed. The difference in basic information,maternity diseases,treatment and complication were analyzed between two groups(brain injury group and normal newborn group),and Logistic regression analysis was adopted to analyze the risk factors for brain injury. Results Seventy-eight of the 181 neonates(43.09%)were found to have brain injury,including 67 neonates(37.01% )with periventricular/intraventricular hemorrhage(43 with intraventricular hemorrhage(IVH)gradeⅠ,12 with IVH grade Ⅱ,10 with IVH grade Ⅲ,and 2 with IVH grade Ⅳ)and 12 neonates(6.63%,one complicated with IVH grade Ⅲ)with periventricular leukomalacia. The younger the gestational age,the higher the brain injury rate was observed. Concerning the brain injury rate,there were no differences in gender,single birth/plural births,birth weight,the mode of delivery,fetal distress,premature rupture of membrane,hypertension during pregnancy,placenta abruption,and intrauterine growth restriction(IUGR)between these two groups(P ＞ 0.05). The difference in therapeutic measures such as pulmonary surfactant therapy,nasal continuous positive airway pressure(nCPAP),conventional mechanical ventilation,and high-frequency oscillatory ventilation was significant(P ＜ 0.05),except aminophylline therapy(P ＞ 0.05). As to the complication,there were significant differences in the incidences of asphyxia,neonatal respiratory distress syndrome(NRDS),hypercapnia,metabolic acidosis,hyperglycemia,anemia,and personal digital assistant(PDA)(P < 0.05). However,there was no difference in the incidences of hypoglycemia,sepsis,thrombocytopenia,apnea,pulmonary hemorrhage,and hyperbilirubinemia between these two groups(P ＞ 0.05). Further Logistic regression analysis showed that NRDS,high-frequency oscillatory ventilation,and PDA were the main risk factors for brain injury in VLBWI. Conclusions VLBWI is the high-risk population of brain injury. Pulmonary surfactant therapy,nCPAP,conventional mechanical ventilation,high-frequency oscillatory ventilation,asphyxia,NRDS,hypercapnia,metabolic acidosis,hyperglycemia,anemia,and PDA were confirmed to be the high-risk factors for brain injury in VLBWI. And,NRDS,high-frequency oscillatory ventilation and PDA were main risk factors.