2019新型冠状病毒IgM和IgG抗体筛查在孕妇保健中的应用

目的探讨新型冠状病毒IgM和IgG抗体筛查在孕妇保健中的应用价值。方法采用直接化学发光法对疫情期间来本院孕期保健的2 061例孕妇开展2019-nCoV IgM和IgG抗体筛查,阳性者采用胶体金免疫层析法进行复查。同时采集孕妇的咽拭子和粪便标本作新型冠状病毒核酸检测,取COVID-19治愈者生产时的胎盘组织做组织细胞病理学检查。结果直接化学发光法初筛检出血清新型冠状病毒IgM阳性4例,IgG阳性11例。用胶体金免疫层析法复核,仅1例COVID-19康复孕妇两种方法IgG均阳性。血清抗体阳性的15例孕妇咽拭子和粪便标本新型冠状病毒核酸检测均阴性,排除新型冠状病毒感染。检测COVID-19康复孕妇生产时的胎盘血及新生儿静脉血新型冠状病毒抗体IgG阳性,IgM阴性,胎盘组织、羊水、新生儿咽拭子及粪便标本新型冠状病毒核酸阴性。病理检查胎盘组织病理诊断绒毛膜板下炎及绒毛膜羊膜炎Ⅱ期Ⅲ级,脐带血管壁及间质内见中性粒细胞浸润(脐带炎)。结论筛查血清新型冠状病毒IgM和IgG抗体简便易行,可在孕妇保健中与核酸检测互补。COVID-19康复孕妇新生儿新型冠状病毒IgG阳性,胎盘炎症是否由新型冠状病毒感染引起尚缺乏证据。     

新型冠状病毒肺炎确诊病例粪便标本的病毒核酸检测

目的了解新型冠状病毒肺炎(COVID-19)确诊病例粪便中2019-nCoV感染情况。方法收集36例确诊病例的粪便标本/肛拭子标本,采用实时荧光RT-PCR检测2019-nCoV载量,利用统计分析软件SPSS 19.0比较病例的带毒率。结果36份标本共检出2019-nCoV核酸阳性20份(55.56%),危重症病例(2/3)和重症病例标本阳性率均为66.67%(6/9)、普通肺炎病例阳性率为62.50%(10/16)、轻症肺炎病例阳性率为25.00%(2/8)。36例确诊病例包括男性22例、女性14例,检出率分别为54.55%和57.14%;病例年龄分布于17~86岁之间,平均为48.75岁。36份标本其中5份肛拭子标本检出阳性标本2份,31份粪便标本检出阳性标本18。临床分型、性别、年龄和标本类型各组间阳性检出率均无统计学差异。结论本研究发现COVID-19患者,无论重症、轻症患者粪便标本均存在2019-nCoV基因检测阳性,提示消化道可能是该病毒排泄渠道,因此可能存在粪-口传播途径,研究结果具有重要的临床和流行病学意义。     

胶体金法检测新型冠状病毒IgM及IgG抗体的价值

目的探讨胶体金法检测IgM及IgG抗体在检测新型冠状病毒肺炎中的价值。方法将26例确诊病例作为检测组,100例发热患者或密切接触者为对照组,采用胶体金法进行新型冠状病毒血清IgM及IgG抗体检测,并对26例病例进行持续的标本采集及抗体检测。结果发现3例核酸检测多次阴性而抗体为阳性的特殊病例;胶体金法检测IgM抗体敏感性为53.85%(14/26),特异性为99.00%(99/100),阳性预测值为93.33%(14/15)、阴性预测值为98.19%(99/111);IgG抗体敏感性为84.62%(22/26),特异性为100.00%(100/100),阳性预测值100.00%(22/22)、阴性预测值96.15%(100/104);发病7～67 d均可能检出IgM及IgG抗体,7 d后IgM阳性检出率大致维持在40.00%左右,IgG阳性检出率随发病天数逐渐升高,7周之后能达到96.55%。结论抗体检测作为核酸检测的补充对提高总的阳性检出率有重要价值,胶体金法适合条件有限的基层实验室。     

化学发光法与胶体金法检测SARS-CoV-2抗体阳性率比较

目的　探讨化学发光法和胶体金法检测SARS-CoV-2抗体在2019冠状病毒病（coronavirus disease 2019, COVID-19）诊断中的应用价值。方法　收集51例COVID-19确诊患者和41例非COVID-19患者的血清,用化学发光法检测非COVID-19组血清中SARS-CoV-2抗体IgM、IgG及联合检测（IgM或IgG）的阳性率;用化学发光法和胶体金法检测COVID-19组血清中SARS-CoV-2抗体IgM、IgG及联合检测（IgM或IgG）的阳性率,比较2种方法的一致性。结果　COVID-19组平均发病时间为（16.9±5.4）d。其中22例IgM阳性,阳性率为43.1%;47例IgG阳性,阳性率为92.2%;49例联合检测（IgM或IgG）阳性,阳性率为96.1%。非COVID-19组中,1例IgM阳性,阳性率为2.4%;0例IgG阳性,阳性率为0;1例联合检测（IgM或IgG）阳性,阳性率为2.4%。在COVID-19组中,化学发光法与胶体金法检测SARS-CoV-2抗体联合检测（IgM或IgG）的阳性率分别为96.1%和68.6%,化学发光法优于胶体金法（P＜0.05）。结论　SARS-CoV-2抗体的检测对COVID-19诊断有重要的意义,且化学发光法检出率优于胶体金法。     

尿素解离试验在减少 新型冠状病毒抗体假阳性中的应用价值

[摘要]　目的　探讨尿素解离试验在减少自身免疫性疾病患者新型冠状病毒（severe acute respiratory syndrome coronavirus 2, SARS-CoV-2）IgM/IgG抗体假阳性中的应用价值。方法　选取2020 年2月1日—2021年2月28日在重庆市公共卫生医疗救治中心和重庆医科大学附属第一医院诊治的350例患者和健康体检者作为研究对象，其中自身免疫性疾病患者（自免组）200例、新型冠状病毒肺炎（coronavirus disease 2019, COVID-19）患者（COVID-19组）100例和健康体检者（健康组）50例。采用胶体金免疫层析法和化学发光法检测SARS-CoV-2 IgM和IgG 抗体，对抗体阳性标本进行尿素解离试验。结果　健康组SARS-CoV-2 IgM和IgG抗体特异度均为100%（50/50）；自免组SARS-CoV-2 IgM和IgG抗体特异度分别为100%（200/200）和97%（194/200）；胶体金免疫层析法检测COVID-19组SARS-CoV-2 IgM和IgG抗体敏感度，分别为56%（56/100）和77%（77/100），IgM/IgG抗体总敏感度为85%（85/100）。尿素解离试验将自免组SARS-CoV-2 IgG抗体的特异度从97% （194/200）提高到 99.5%（199/200），将COVID-19组1例发病7 d内的弱阳性SARS-CoV-2 IgG抗体转为阴性。结论　尿素解离试验有助于减少自身免疫性疾病患者SARS-CoV-2 IgG抗体假阳性问题，但可能会影响其敏感度。     

ELISA法和胶体金免疫层析法在乙肝表面抗原检测中的对比研究

目的探讨ELISA法和胶体金免疫层析法(GICA法)在乙肝表面抗原检测中的优缺点和应用价值。方法随机选取进行血清检测的600例血清标本,同时采用ELISA法和胶体金免疫层析法检测乙肝表面抗原,比较两种检测方法的灵敏度及差异性。结果 ELISA法检测阳性率为5.33%,灵敏度为96.97%,特异度为100%;胶体金免疫层析法检测阳性率为5.0%,灵敏度为90.90%,特异度为99.82%;两种方法检测阳性结果符合率为90.63%。结论胶体金免疫层析法灵敏度低,特异性基本一致,ELISA法检测的阳性率准确、灵敏度高为突出优点,是目前各级实验室应用最广泛的HBsAg检测方法。     

胶体金免疫层析快速诊断法在羊鼠疫疫情处理中的应用

目的评价胶体金免疫层析快速诊断试剂盒在动物鼠疫疫情处理中的应用价值。方法采集病羊血清,用胶体金免疫层析法(GICA)、检测鼠疫FI抗体,并与间接血凝法(IHA)检测结果比较。死亡羊尸检取脏器作细菌分离和培养,并做GICA和反应间接血凝(RIHA),检测FI抗原。结果检测藏系绵羊、西藏山羊血清1 073份,GICA与IHA法结果一致,抗体阳性率均为6.15%;检测脏器标本的阳性率分别为35.71%和50.00%,差异有显著性(P<0.05)。结论GICA方法简便,诊断快速,适合现场应用。     

肺炎支原体快速鉴定培养法对成人支原体肺炎早期诊断价值的研究

目的探讨咽拭子肺炎支原体（MP）快速鉴定培养法对成人社区获得性肺炎支原体肺炎的早期诊断价值。方法应用肺炎支原体快速鉴定培养基对住院的105例社区获得性肺炎（CAP）患者的咽拭子标本进行肺炎支原体快速鉴定培养。同时对所有病例于发病后7~14 d检测血清MP-IgM抗体。结果 105例住院CAP患者咽拭子MP快速鉴定培养,阳性23例,阳性率21.9%。MP-IgM抗体检测阳性19例,阳性率18.1%。MP-IgM抗体检测阳性的19例患者MP快速培养均为阳性。结论咽拭子肺炎支原体快速鉴定培养法可以实现肺炎支原体肺炎的早期诊断,及时正确治疗。     

新型冠状病毒肺炎实验室诊断方法进展

在应对新型冠状病毒肺炎(COVID-19)全球大流行疫情过程中,实验室诊断发挥了至关重要的作用。本文对现有COVID-19实验室诊断方法,包括常用的核酸检测和血清学抗体检测进行分析总结,以便医务人员及时了解该领域进展,选择合适的检测试剂和筛查策略,共同抗击这场大流行疫情。     

四川省钩端螺旋体病高发县报告病例的准确性调查研究北大核心CSCD

目的了解四川省钩端螺旋体病高发地区报告钩体病例准确性,为进一步控制钩体病流行提供科学依据。方法采集2012年钩体病高发地区报告临床诊断病例血清进行钩体菌培养,血清学诊断,对钩体病检测结果为阴性的标本进行乙脑、出血热和立克次体检测。结果共采集87例报告病例的血清标本,培养出4株钩体菌,钩体菌培养阳性率为4.6%。采集64份病例急性期和恢复期双份血清进行钩体病检测,其中54例阳性,阳性率为84.4%,采集23份病例单份血清,其中6份钩体菌检测阳性,阳性率为26.1%。对27份钩体检测阴性标本进行乙脑ELISA检测,阳性1例,出血热、立克次体检测结果均为阴性。结论四川省钩体病高发地区临床诊断钩体病准确性较高,但依然需要加强病例双份血清采集和检测。     

Comparative Detection of Measles Specific IgM Antibody in Serum and Saliva by an Antibody-Capture IgM Enzyme Immunoassay (EIA)

Laboratory diagnosis of acute measles is usually achieved by serology assays for measle-specific IgM antibody. For comparison of measle-specific IgM antibody in saliva and serum, 95 paired blood and saliva samples were collected 1-14 days after the onset of rash. The specimens were tested for specific IgM antibody by an IgM antibody-capture Enzyme Immunoassay (EIA). Measles IgM antibody was detected in 89 (93.7%) of serum samples and in 85(89.5%) of saliva specimens. Of the 6(6.3%) serum samples that were IgM antibody-negative, 2 (2.1%) of the paired saliva samples were IgM antibody-positive. The sensitivity and specificity of saliva testing compared with serum was 95.5% and 66.7% respectively. Positive predictive value (PPV) and negative predictive value (NPV) of saliva testing were 97.7% and 50.0% respectively and the accuracy of saliva testing was 93.7%. Our results indicate that saliva samples provided Enzyme Immunoassay results that were in good agreement with results from serum samples. Salivary IgM antibody detection is a suitable non-invasive method for diagnosing recent measles infections and epidemiological studies, especially in children.     

胶体金免疫层析法检测结核分枝杆菌特异性IgG/IgM抗体对结核病诊断的应用价值

目的 评价胶体金免疫层析法检测血清中结核分枝杆菌特异性IgG/IgM抗体在结核病诊断中的应用价值。方法 收集结核病患者和健康人的血清样本共332份及其背景资料,采用胶体金法检测血清中特异性结核抗体IgG/IgM,与临床诊断和细菌学检测结果比较,使用SPSS 22.0统计软件对结果进行比较分析,以P<0.05为差异具有统计学意义。结果 胶体金免疫层析法检测结核病患者中特异性结核抗体IgG/IgM的灵敏度为41.15%、特异性为91.67%,检测菌阳和菌阴结核病患者的敏感性分别为51.38%和33.77%。在全部结核病患者中,特异性结核抗体IgG/IgM检测检出率(41.15%)显著高于痰涂片法(18.84%)和痰菌培养法(36.15%)(P<0.05)。结核抗体检测、痰涂片法和痰培养法三种方法联合检测阳性率为61.54%,高于单种方法检测或其中两种方法联合检测。结论 胶体金免疫层析法检测血清中结核分枝杆菌抗体具有灵敏、特异、快速和简便等优点,可用于结核病的筛查,同时该方法也具有一定的局限性,敏感度和特异度有待进一步的提高,因此不可单独用于诊断结核病,可配合痰细菌学、影像学和临床表现等进行辅助诊断。     

新型冠状病毒抗体检测在疑似病例排查中的应用研究

目的 比较不同原理抗体检测试剂对新冠疑似病例诊断的准确性,对新冠疑似病例提出高效的排查方案,进一步为建立高风险人群的临床筛查路径提供科学依据。方法对76例由于IgM抗体初检阳性被转入定点医院隔离观察的新冠疑似病例,进行鼻咽拭子核酸检测,血清微量病毒中和抗体和3种市售不同原理抗体检测试剂检测,以及肺部CT检查,结合临床症状等信息,综合判断新冠确诊或排除情况,并将3种血清学抗体检测试剂与临床判断结果进行对比分析,比较3种检测方法结果的差异。结果通过综合判断,76例疑似病例中有3例为确诊病例,73例为排除病例。与临床确诊/排除结果比较,3种血清学抗体检测方法中,化学发光总抗体对3例病例入院不同时间点共9份样本均能检出,对73例排除病例入院第1天采集样本的检测特异性为97.26%,高于化学发光法IgM/IgG和胶体金法IgM/IgG单独检测(入院第1 d样本检测特异性均为73.97%)。结论化学发光法检测新冠总抗体具有高灵敏度和高特异性,可以用于疑似病例抗体检测的初筛。针对重点人群筛查,应首先进行2019-nCoV核酸检测,若核酸检测阴性,则采用检测血清总抗体为主要指标的筛查路径。     

Antibody responses to SARS-CoV-2 nucleocapsid and spike proteins in hospitalized patients with COVID-19: A multicenter,retrospective, cross-sectional study in Japan

BackgroundThere are many commercially available automated assays for assessing coronavirus disease 2019 (COVID-19) immune responses; however, owing to insufficient data, their validities remain unknown. Here, we examined antibody responses during acute-phase COVID-19 using four assays that detect anti-spike protein IgM (S-IgM), anti-nucleocapsid protein IgG (N-IgG), anti-spike protein total Ig (S-total Ig), and anti-spike protein IgG (S-IgG).MethodsWe measured antibody levels in 1154 serum samples collected from 286 hospitalized patients with confirmed COVID-19 by a gene amplification method between February and December 2020 in Japan. Sera from 860 healthcare workers were used as negative controls.ResultsThe antibody positivity rates increased on week 2, peaked, and then started to plateau by the beginning of week 3 after symptom onset. On week 1, there were some significant differences in seropositivity rates between assays (p = 0.032): 14.9% (11.0%–19.4%) for S-IgM and 8.9% (6.0%–12.7%) for N-IgG. The seropositivity for the S-total Ig (10.6% [7.3%–14.6%]) assay was considerably better than that for the S-IgG (6.9% [4.3%–10.4%]) assay, although the difference was not statistically significant (p = 0.150). The levels of S-IgM antibodies and the three others peaked on weeks 3 and 5, respectively. All four assays showed high specificities (>99%).ConclusionsAll four assays had good specificities and were suitable for seropositivity detection after week 3 of symptom onset. Assays of IgM alone or total Ig (containing IgM) were better than those of IgG alone as an adjunct serological test for early-stage COVID-19 diagnosis, albeit the use of a serological assay alone is insufficient.     

Comparative Sensitivity of Rapid Antigen Tests for the Delta Variant (B.1.617.2) of SARS-CoV-2

Rapid antigen tests (RATs) for COVID-19 based on lateral flow immunoassays are useful for rapid diagnosis in a variety of settings. Although many kinds of RATs are available, their respective sensitivity has not been compared. Here, we examined the sensitivity of 27 RATs available in Japan for the detection of the SARS-CoV-2 delta variant. All of the RATs tested detected the delta variant albeit with different sensitivities. Nine RATs (ESPLINE SARS-CoV-2, ALSONIC COVID-19 Ag, COVID-19 and Influenza A+B Antigen Combo Rapid Test, ImmunoArrow SARS-CoV-2, Fuji Dri-chem immuno AG cartridge COVID-19 Ag, 2019-nCoV Ag rapid detection kit, Saliva SARS-CoV-2(2019-nCoV) Antigen Test Kit, and Rabliss SARS-CoV-2 antigen detection kit COVID19 AG) showed superior sensitivity to the isolated delta variant. Although actual clinical specimens were not examined, the detection level of most of the RATs was 7500 pfu, indicating that individuals whose test samples contained less virus than that would be considered negative. Therefore, it is important to bear in mind that RATs may miss individuals shedding low levels of infectious virus.     

结核抗体检测对活动性肺结核的诊断价值评价

目的 评价结核抗体检测对活动性肺结核的诊断价值。方法 收集2016年8月至2017年8月在重庆市公共卫生医疗救治中心结核科住院的495例活动性肺结核患者(观察组)和158例非结核呼吸道疾病患者(对照组),均为综合患者的临床表现、胸部影像、痰细菌病原学检测或诊断性抗结核药物治疗有效等资料临床确诊后进行血清学诊断。分析血清MTB免疫球蛋白G(immunoglobulin G,IgG)、免疫球蛋白M(immunoglobulin M,IgM)、脂阿拉伯甘露聚糖(lipoarabinomannan,LAM),以及相对分子质量16000(以下采用“16kD”表示)和相对分子质量38000(以下采用“38kD”表示)的蛋白抗体的检测资料,以及单独及联合检测不同结核抗原(LAM、38kD和16kD)的结果,评价两组患者结核抗体检测的敏感度、特异度、阳性预测值、阴性预测值,以及对活动性肺结核的诊断效能。结果 495例观察组患者血清结核抗体检测阳性率[68.7%(340/495)]明显高于158例对照组患者[34.8%(55/158)],差异有统计学意义(χ ²=57.50,P<0.01);菌阴肺结核患者血清结核抗体检测阳性率[64.0%(210/328)]明显低于菌阳肺结核患者[77.8%(130/167)],差异有统计学意义(χ ²=9.83,P<0.01)。观察组340例结核抗体阳性患者中,LAM、38kD、IgG抗体联合检测同时均阳性的患者最多[61.8%(210/340)];对照组55例结核抗体阳性患者中,单一IgG抗体阳性最高[67.3%(37/55)]。以临床诊断为标准,血清结核抗体对活动性肺结核的诊断敏感度、特异度、阳性预测值和阴性预测值、总符合率、约登指数分别为68.7%(340/495)、65.2%(103/158)、86.1%(340/395)和39.9%(103/258)、67.8%(443/653)、0.34。 结论 血清结核抗体检测活动性肺结核患者具有较高的阳性率和敏感度,对诊断活动性肺结核具有一定的辅助价值,其中菌阳肺结核患者的检测阳性率高于菌阴肺结核,LAM、38kD和IgG联合检测可提高活动性肺结核的诊断阳性率。     

量子点标记免疫层析技术检测布鲁氏菌病的方法研究

目的 通过研究量子点标记免疫层析技术检测布鲁氏菌病抗体,制备量子点免疫层析试纸条,验证快速检测布鲁氏菌病的可行性。方法 将蛋白A和布鲁氏菌全菌蛋白分别作为质控线和检测线喷涂在硝酸纤维素膜上,以量子点标记布鲁氏菌全菌蛋白,稀释后喷涂在玻璃纤维素膜上,最后进行组装、切割制成检测用试纸条。应用该试纸条检测布鲁氏菌病患者样本102例,健康人血清47例,以试管凝集试验为对照,比较两组方法的符合率。结果 建立的量子点免疫层析试纸条性能较好,布鲁氏菌病抗体的检测敏感性为99.0%,特异度为95.8%,两者符合率为98.0%;将阳性血清稀释至128倍,通过荧光检测仪仍可检测到T线荧光值,该纸条重复性好,储存时间30 d内稳定性较好,其变异系数为4.1%。结论 该方法操作简单、快速稳定、灵敏度高、成本低,15 min内完成检测,血清用量低,可实现现场快速检测,在布鲁氏菌病的早期检测中具有良好前景。     

Detection of IgM antibody against region IV flagellin of Salmonella paratyphi A

Salmonella paratyphi A is a pathogenic bacterium that causes paratyphoid fever. The current laboratory diagnostic techniques are unsatisfactory. To improve diagnosis, a plasmid (pSK-8E) encoding phase 1 flagellin gene nucleotide position 452-890 from S. paratyphi A has been constructed. The recombinant protein expressed from the plasmid has been used to develop an indirect ELISA for IgM antibody detection. Sera from patients with hemoculture positive for S. paratyphi A, S. typhi, other gram-positive and gram-negative bacteria, and dengue hemorrhagic fever as well as from healthy control subjects were tested. Sensitivity, specificity, positive and negative predictive values of the test were 56.9%, 98.8%, 90.6% and 92.1%, respectively. Since the sensitivity was low, the explanation for this result was investigated. It was found that the sensitivity of the test could be increased to 83.3% if the sera were obtained 9-12 days after onset of fever. The sera obtained earlier or later gave only 33.3% and 66.6% sensitivity, respectively. This result suggests that the IgM antibody detection assay which we have developed is a valuable tool for diagnosis of S. paratyphi A infection when the serum samples are taken at the appropriate time.