新型冠状病毒肺炎特异性IgM抗体假阳性患者的临床特点分析

目的:分析我院新型冠状病毒肺炎(COVID-19)特异性IgM抗体假阳性患者的临床特点及预后,为疫情防控提供参考.方法:回顾分析2020年1月至2020年12月,首都医科大学附属北京安贞医院的COVID-19特异性IgM抗体假阳性的17例门、急诊及住院患者的流行病学病史、临床表现、辅助检查结果及预后,并与我院6例确诊的...     

核酸阳性新型冠状病毒肺炎中SARS-CoV-2特异性IgM/IgG抗体的临床表达

目的：探讨SARS-CoV-2特异性IgM/IgG抗体在核酸阳性的新型冠状病毒肺炎（COVID-19）患者中的表达特点及规律。方法：纳入176例核酸阳性的确诊COVID-19患者,以发病病程＜2、3、4周、＞5周为时间点抽取患者外周血样本,应用胶体金法检测其SARS-CoV-2特异性IgM/IgG抗体表达,分析其表达情况与性别、年龄、临床分型、就医间隔、发病病程、核酸复测结果等之间的关系,并监测19例患者SARS-CoV-2特异性IgM/IgG抗体的动态变化。结果：不同病程和年龄的患者SARS-CoV-2特异性IgG的表达之间比较,差异有统计学意义（均P<0.05）,而不同性别、临床分型、就医间隔、核酸复测结果的患者IgM、IgG的表达之间比较,差异无统计学意义（均P＞0.05）。发病病程在2周内、3周、4周、5周及以上的患者,IgM的阳性率分别为55.6%、47.4%、60.5%、52.7%（均P>0.05）;IgM抗体的阳性率在第4周左右达到最高值;IgG的阳性率分别为77.8%、84.2%、97.4%、100%,不同时间点的抗体水平之间的差异有统计学意义（均P<0.05）。接受动态抗体监测的19例患者中,8例患者在病情稳定或明显改善的情况下,其IgM表达转阴或减弱。结论：SARS-CoV-2特异性IgM/IgG抗体在COVID-19患者体内的变化规律具有明显的个体差异,与年龄、发病病程相关。     

HIV抗体确证试验假阳性1例分析

目的通过对1例艾滋病病毒（HIV）抗体确证试验阳性者进行随访检测,探讨目前HIV抗体筛查和确证检测技术存在的问题。方法对受检对象进行HIV抗体筛查和确证试验,并于3、6个月和1年随访检测。结果首次筛查试验PA试剂为阴性,第3代梅里埃ELISA试剂为阳性,确证试验WB试剂检测带型gp120p24,判为HIV-1抗体阳性。比较试验第4代梅里埃ELISA试剂为阳性,金豪、吉比爱ELISA试剂为阴性,雅培硒标试剂为弱阳性。病毒载量检测结果为阴性。3次随访检测,筛查试验结果与首次检测基本一致,确证试验带型分别为gp120p24、p24和p24p55,1年后的病毒载量检测结果为阴性,受检对象随访后结果定为阴性。4次血样集中检测显示,筛查试剂批间无明显差异,但不同试剂间有差异;确证WB试剂不同批号间带型存在差异。结论目前应用的WB确证试剂存在一定的批间差异,对弱阳性带型或阳性带型不常见的样本,需更换试剂批号重复进行确证检测;确证试验结果处于临界阳性状态者需进行流行病学史调查;WB确证试验若同时出现1条env带和p24带判为HIV抗体不确定,并进行随访。     

新型冠状病毒疫苗加强针接种对德尔塔感染者临床指标及血清特异性抗体影响的分析

目的探讨新型冠状病毒疫苗(新冠疫苗)接种剂次对新型冠状病毒德尔塔变异株感染者临床指标及血清特异性抗体的影响。方法本研究为病例对照研究。采用非随机抽样的方法, 纳入2021年12月至2022年2月于西安市胸科医院诊疗的317例新型冠状病毒感染患者(病例组)和同期进行健康体检的248名健康人群(健康对照组)。根据新型冠状病毒疫苗接种情况将病例组患者分为已接种加强针组(36例)、1针或2针组(249例)、未接种组(32例), 比较3组患者临床分型、C反应蛋白(CRP)、降钙素原(PCT)、淋巴细胞情况。比较病例组与健康对照组是否接种加强针的新型冠状病毒特异性抗体SARS-CoV-2-IgG、SARS-CoV-2-IgM水平。结果加强针组的普通型患者比例低于1或2针剂组及未接种组的普通型患者比例(19.4%比29.7%比37.5%), 但差异无统计学意义(χ2=2.75, P>0.05)。在发病第1、2周, 加强针组、1针或2针组及未接种组的SARS-CoV-2-IgG水平差异均有统计学意义(P值均<0.001);发病第3周, 3组SARS-CoV-2-IgG抗体水平比较差异无统计...     

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。     

糖皮质激素在新型冠状病毒肺炎治疗中的应用

目前,新型冠状病毒肺炎(COVID-19)疫情已蔓延至全国各地及国外200多个国家和地区。临床一线对COVID-19患者的救治,争议最大的莫过于糖皮质激素的应用。本文旨在从COVID-19的发病机制探讨糖皮质激素应用的时机与方法,以期供临床参考。     

1例HIV抗体初筛试验假阳性原因分析

人类免疫缺陷病毒（HIV）抗体检测可用于HIV感染的诊断、监测和血液筛查,我国的常规HIV抗体检测程序分为筛查试验（包括初筛和复检）和确证试验。但在日常检测中,仍不可避免地出现筛查试验阳性-确证试验阴性,即筛查假阳性现象[1]。本文对我院2011年1月出现的1例HIV抗体检测初筛试验和复核试验结果不吻合,后经过广西壮族自治区疾病预防控制中心确证试验为阴性的标本进行分析。     

新型冠状病毒Delta变异株感染患者早期实验室检查指标变化及疫苗保护作用观察

目的 观察新型冠状病毒(新冠病毒)Delta变异株感染患者外周血早期实验室检查指标及疫苗接种对新冠病毒Delta变异株感染患者的保护作用,为疫情防控提供参考.方法 2021年11月成都本土疫情中诊断为新冠病毒Delta变异株感染的年龄>18岁的新型冠状病毒肺炎(新冠肺炎)非重型患者25例,记为实验组,22例在感染前接种...     

Characterizing Kinetics and Avidity of SARS-CoV-2 Antibody Responses in COVID-19 Greek Patients

In-depth understanding of the immune response provoked by SARS-CoV-2 infection is necessary, as there is a great risk of reinfection and a difficulty in achieving herd immunity due to a decline in both antibody concentration and avidity. Avidity testing, however, could overcome variability in the immune response associated with sex or clinical symptoms, and thus differentiate between recent and past infections. In this context, here, we analyzed SARS-CoV-2 antibody kinetics and avidity in Greek hospitalized (26%) and non-hospitalized (74%) COVID-19 patients (N = 71) in the course of up to 15 months after their infection to improve the accuracy of the serological diagnosis in dating the onset of the infection. The results showed that IgG-S1 levels decline significantly at four months (p = 0.0239) in both groups of patients and are higher in hospitalized ones (up to 2.1-fold, p < 0.001). Additionally, hospitalized patients’ titers drop greatly and are equalized to non-hospitalized ones only at a time-point of twelve to fifteen months. Antibody levels of women in total remain more stable months after infection, compared to men. Furthermore, we examined the differential maturation of IgG avidity after SARS-CoV-2 infection, showing an incomplete maturation of avidity that results in a plateau at four months after infection. We also defined 38.2% avidity (sensitivity: 58.9%, specificity: 90.91%) as an appropriate “cut-off” that could be used to determine the stage of infection before avidity reaches a plateau.     

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。     

Diagnostic Potential of a Luminex-Based Coronavirus Disease 2019 Suspension Immunoassay (COVID-19 SIA) for the Detection of Antibodies against SARS-CoV-2

Due to the current, rapidly increasing Coronavirus disease 2019 (COVID-19) pandemic, efficient and highly specific diagnostic methods are needed. The receptor-binding part of the spike (S) protein, S1, has been suggested to be highly virus-specific; it does not cross-react with antibodies against other coronaviruses. Three recombinant partial S proteins of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) expressed in mammalian or baculovirus-insect cells were evaluated as antigens in a Luminex-based suspension immunoassay (SIA). The best performing antigen (S1; amino acids 16-685) was selected and further evaluated by serum samples from 76 Swedish patients or convalescents with COVID-19 (previously PCR and/or serologically confirmed), 200 pre-COVID-19 individuals (180 blood donors and 20 infants), and 10 patients with acute Epstein-Barr virus infection. All 76 positive samples showed detectable antibodies to S1, while none of the 210 negative controls gave a false positive antibody reaction. We further compared the COVID-19 SIA with a commercially available enzyme immunoassay and a previously evaluated COVID-19 rapid antibody test. The results revealed an overall assay sensitivity of 100%, a specificity of 100% for both IgM and IgG, a quantitative ability at concentrations up to 25 BAU/mL, and a better performance as compared to the commercial assays, suggesting the COVID-19 SIA as a most valuable tool for efficient laboratory-based serology.     

Study on Continuation of Antibody Prevalence Six Months after Detection of Subclinical Severe Acute Respiratory Syndrome Coronavirus 2 Infections

Objective To examine the continuation of antibody prevalence and background factors in antibody-positive subjects after asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods A study was carried out to investigate the SARS-CoV-2 antibody (IgG) prevalence. SARS-CoV-2 antibodies (IgG) were measured and analyzed with immunochromatographic tests. Patients Among 1,603 subjects, comprising patients, physicians, and nurses at 65 medical institutes in Kanagawa, Japan, 39 antibody-positive subjects received follow-up for 6 months. Results Of the 33 subjects who consented to the follow-up (23 patients and 10 medical professionals), continued positivity of IgG antibodies was confirmed in 11 of 32 cases (34.4%) after 2 months, 8 of 33 (24.2%) after 4 months, and 8 of 33 (24.2%) after 6 months. A significant difference was found in the sleeping time, drinking habits, hypertension, and use of angiotensin-receptor blockers on comparing subject background characteristics among three groups: patients with antibody production that continued for six months after the first detection of positivity, patients in whom antibody production stopped at four months, and patients in whom antibody production stopped at two months. Conclusion The continuation rate of IgG antibody prevalence was 24.2% at 6 months after the first detection of antibody positivity in cases with asymptomatic coronavirus disease 2019 (COVID-19) infections. This percentage is low compared with the antibody continuation rate in patients who have recovered from symptomatic COVID-19 infection.     

Avidity of IgG to SARS-CoV-2 RBD as a Prognostic Factor for the Severity of COVID-19 Reinfection

The avidity index (AI) of IgG to the RBD of SARS-CoV-2 was determined for 71 patients with a mild (outpatient) course of COVID-19, including 39 primarily and 36 secondarily reinfected, and 92 patients with a severe (hospital) course of COVID-19, including 82 primarily and 10 secondarily infected. The AI was shown to correlate with the severity of repeated disease. In the group of outpatients with a mild course, the reinfected patients had significantly higher median AIs than those with primary infections (82.3% vs. 37.1%, p < 0.0001). At the same time, in patients with a severe course of COVID-19, reinfected patients still had low-avidity antibodies (median AI of 28.4% vs. 25% in the primarily infected, difference not significant, p > 0.05). This suggests that the presence of low-avidity IgG to RBD during reinfection is a negative prognostic factor, in which a patient’s risk of developing COVID-19 in a severe form is significantly increased. Thus, patients with IgG of low avidity (AI ≤ 40%) had an 89 ± 20.5% chance of a severe course of recurrent COVID-19, whereas the detection of high-avidity antibodies (AI ≥ 50%) gave a probability of 94 ± 7.9% for a mild course of recurrent disease (p < 0.05).     

The Proportion of Long-term Response to Anti-N IgG Antibody after 12 Months for COVID-19 Subclinical Infections and a Longitudinal Survey for COVID-19 Subclinical Infections in 2021

Objective To examine the continuation of antibody prevalence status after 12 months and background factors in antibody-positive subjects following asymptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods We initially determined the SARS-CoV-2 anti-nucleocapsid protein immunoglobulin G (anti-N IgG) antibody prevalence in 1,603 patients, doctors, and nurses at 65 medical institutions in Kanagawa Prefecture, Japan. We then obtained consent from 33 of the 39 subjects who tested positive and performed follow-up for 12 months. Results Follow-up for up to 12 months showed that a long-term response of the anti-N IgG antibody could be detected in 6 of the 33 participants (18.2%). The proportions with hypertension, using an angiotensin-receptor blocker, and without a drinking habit were higher among the participants with a long-term anti-N IgG antibody response for up to 12 months than among those without a long-term antibody response. Conclusions The proportion of individuals with subclinical COVID-19 who continuously had a positive result for the anti-N IgG antibody at 12 months was low.     

Autoimmune liver diseases and SARS-CoV-2

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing coronavirus disease 2019 (COVID-19), can trigger autoimmunity in genetically predisposed individuals through hyperstimulation of immune response and molecular mimicry. Here we summarise the current knowledge about auto-immune liver diseases (AILDs) and SARS-CoV-2, focusing on: (1) The risk of SARS-CoV-2 infection and the course of COVID-19 in patients affected by AILDs; (2) the role of SARS-CoV-2 in inducing liver damage and triggering AILDs; and (3) the ability of vaccines against SARS-CoV-2 to induce autoimmune responses in the liver. Data derived from the literature suggest that patients with AILDs do not carry an increased risk of SARS-Cov-2 infection but may develop a more severe course of COVID-19 if on treatment with steroids or thiopurine. Although SARS-CoV-2 infection can lead to the development of several autoimmune diseases, few reports correlate it to the appearance of de novo manifestation of immune-mediated liver diseases such as autoimmune hepatitis (AIH), primary biliary cholangitis (PBC) or AIH/PBC overlap syndrome. Different case series of an AIH-like syndrome with a good prognosis after SARS-CoV-2 vaccination have been described. Although the causal link between SARS-CoV-2 vaccines and AIH cannot be definitively established, these reports suggest that this association could be more than coincidental.