Analysis of related factors of plasma antibody titer in convalescent patients with COVID-19 / 中国输血杂志

【Objective】 To study the relationship between the plasma IgG, IgM, neutralizing antibody titer and sex, age, collection interval in convalescent patients with COVID-19, so as to guide the plasma collection of convalescent patients with COVID-19. 【Methods】 COVID-19 convalescent plasma was collected to determine the antibody titer, and the difference and correlation of data in each group were analyzed by SPSS statistical analysis software. 【Results】 The median titers (AU/mL)of IgG, IgM and neutralizing antibodies in males and females were 484.24 vs 516.04, 2.13 vs 1.73, and 1 124.74 vs 1 143.99, respectively, and there was no significant difference(P>0.05) . Age had weak positive correlation with IgG and neutralizing antibody, and the Spearman correlation coefficient was 0.188 (P<0.05). The median titers (AU/mL) of IgG, IgM and neutralizing antibody at first donation of 30 repeated donors were 522.3, 2.64 and 1 174.6, respectively, but at second donation were 332.08, 0.63 and 708.96, showing significant difference (P<0.05). 【Conclusion】 There was no significant difference in the plasma IgG, IgM and neutralizing antibody titers in convalescent COVID-19 patients of different ages and genders, and the titers met the requirements of clinical treatment guidelines. Although the plasma antibody level of repeated donors has decreased, it still has clinical value.

Acurácia diagnóstica dos métodos sorológicos de detecção da COVID-19 / Diagnostic accuracy of serological methods for detecting COVID-19

A rápida caracterização do genoma do Coronavírus-2 (SARS-CoV-2) mobilizou a produção em larga escala de métodos diagnósticos. Agências reguladoras aprovaram condicionalmente o uso emergencial de vários deles. Na emergência de saúde, inúmeros exames foram utilizados sem o devido conhecimento da qualidade. O objetivo desta revisão narrativa foi destacar a acurácia diagnóstica dos métodos sorológicos de diagnóstico da COVID-19 em termos de sensibilidade e especificidade clínicas. A sensibilidade diagnóstica variou até 50% entre estudos, enquanto a especificidade apresentou menor variação; no entanto, uma mesma marca chegou a apresentar variação de 32%. Considerando-se o critério de especificidade >95% definido pelo FDA, apenas uma marca de ensaio para detecção de IgG e outra para IgM atingiram a meta. Para a detecção de IgA e de IgA+IgM, as únicas marcas apresentadas não atingiram a meta. Entre as cinco marcas para detecção de IgM+IgG, apenas uma não atingiu a especificidade clínica. Para Ig total, as duas marcas apresentaram especificidade aceitável. Considerando-se o critério de sensibilidade clínica >90%, apenas 6 dos 25 estudos com diferentes marcas de ensaios para detecção de IgG apresentam o desempenho especificado; destas, nenhuma é brasileira. Nenhuma das marcas de ensaios para detecção de IgM e IgM+IgG apresentaram o desempenho especificado. A única marca apresentada para detecção de IgA+IgM atingiu a meta especificada pelo FDA. Os ensaios imunocromatográficos apresentaram menor sensibilidade. Os resultados demonstraram o pobre valor diagnóstico dos imunoensaios, mas com potencial para estudos soroepidemiológicos. Mais estudos de validação analítica e acurácia diagnóstica de ensaios são essenciais, principalmente dos reagentes nacionais.

The rapid characterization of the coronavirus-2 (SARS-CoV-2) genome has mobilized the large-scale production of diagnostic methods. Regulatory agencies have conditionally approved the emergency use of several of them. In the health emergency, numerous tests were used without proper knowledge of quality. The aim of this narrative review was to highlight the diagnostic accuracy of serological methods for the diagnosis of COVID-19 in terms of clinical sensitivity and specificity. The diagnostic sensitivity varied up to 50% between studies, while the specificity showed less variation, however, the same brand even showed a variation of 32%. Considering the >95% specificity criteria defined by the FDA, only one test brand for detection of IgG and one for IgM reached the goal. For the detection of IgA and IgA+IgM, the only brands presented did not reach the goal. Among the 5 marks for detecting IgM+IgG, only one did not reach clinical specificity. For total Ig, both brands had acceptable specificity. Considering the criterion of clinical sensitivity >90%, only 6 of the 25 studies with different brands of assays for detection of IgG present the specified performance, none of which are Brazilian. None of the brands of assays for detecting IgM and IgM+IgG showed the specified performance. The only brand presented for detection of IgA+IgM reached the target specified by the FDA. Immunochromatographic assays showed lower sensitivity. The results demonstrated the poor diagnostic value of immunoassays, but with potential for seroepidemiological studies. More studies on analytical validation and diagnostic accuracy of assays are essential, especially for national reagents.

Uso da citometria de fluxo no diagnóstico sorológico da COVID-19 / The use of flow cytometry for the serological diagnosis of COVID-19

A pandemia da COVID-19 tem tido um impacto devastador em todo o mundo e levou ao rápido desenvolvimento de testes diagnósticos. Diferentes tecnologias vêm sendo utilizadas para a detecção de imunoglobulinas frente à infecção por SARS-CoV-2. Ensaios imunoenzimáticos (ELISA), quimioluminescentes e imunocromatográficos estão disponíveis e, no geral, apresentam poder diagnóstico limitado, principalmente para a detecção de IgA. A citometria de fluxo tem surgido como alternativa para o desenvolvimento de métodos sensíveis e específicos para a COVID-19 aplicados para diagnóstico, triagem e estratificação da doença. A citometria de fluxo é uma tecnologia óptica baseada em laser que detecta características físico-químicas de células ou partículas em um fluido heterogêneo. O artigo explora a citometria de fluxo para o diagnóstico da COVID-19 em duas estratégias para a detecção de anticorpos no soro ou plasma, uma utilizando antígenos virais expressos na superfície de células de mamíferos e outra com estes elementos imobilizados em microesferas (beads). A possibilidade de detecção rápida de múltiplos anticorpos simultaneamente, com pequeno volume de amostra e elevada sensibilidade e especificidade, torna a citometria de fluxo uma metodologia promissora para o laboratório clínico, como ferramenta de referência para auxiliar na contenção do processo pandêmico da COVID-19 e futuros eventos similares.

The COVID-19 pandemic has had a devastating impact around the world and has led to the rapid development of diagnostic tests. Different technologies have been used to detect immunoglobulins produced against SARS-CoV-2 infection. Immunoenzymatic (ELISA), chemiluminescent and immunochromatographic assays are available and, in general, they have limited diagnostic accuracy, especially for the detection of IgA. Flow cytometry has emerged as an alternative for the development of sensitive and specific methods for COVID-19 applied for diagnosis, screening and stratification of the disease. Flow cytometry is a laser-based optical technology that detects physicochemical characteristics of cells or particles in a heterogeneous fluid. The article explores flow cytometry for the diagnosis of COVID-19 in two strategies for detecting antibodies in serum or plasma, the first one using viral antigens expressed on the surface of mammalian cells and the other one with these elements immobilized on microspheres (beads). The possibility of rapid detection of multiple antibodies simultaneously, with a small sample volume and high sensitivity and specificity, makes flow cytometry a promising methodology for the clinical laboratory, as a reference tool to help stop the COVID-19 pandemic process and similar future events.

Hepatitis E virus seroprevalence among blood donors in Liuzhou, China / 中国输血杂志

【Objective】 To investigate the hepatitis E virus(HEV) infection among voluntary blood donors in Liuzhou, Guangxi. 【Methods】 Qualified blood donations in Liuzhou from October to November 2019 were tested for anti-HEV IgG and IgM and.HEV antigen. HEV RNA test was performed on samples positive for HEV antigen and/or anti-HEV IgM. and the test results were analyzed statistically. 【Results】 The seroprevalence rates of HEV antigen and anti-HEV IgG and IgM among 5 751 qualified donations were 0, 26.03% (1497/5 751), and 1.67% (96/5 751), respectively.None of the 91 anti-HEV IgM positive samples was positive for HEV RNA, whereas 60.41% of anti-HEV IgM positive samples were anti-HEV IgG positive. The HEV antibody prevalence varied significantly by gender, age, and nationality (P<0.05). 【Conclusion】 The prevalence of anti-HEV IgG / IgM among blood donors in Liuzhou was higher than that in other domestic regions. Significant increase in HEV antibody prevalence was observed among ethnic minorities, such as Miao and Dong, and age group of more than 45 years.Follow-up studies with larger sample size could be conducted to estimate potential risks of HEV transmission by blood transfusion, which may provide references for selective screening of HEV infection marker among high-endemic population.

Titulación de hemolisinas en concentrados plaquetarios obtenidos a partir de buffy coat de donantes voluntarios de sangre de grupo O Rh D positivo / Hemolysin titration in platelet concentrates obtained from buffy coat of voluntary blood donors of group O Rh D positive

Los posibles efectos adversos que se producen en transfusiones incompatibles ABO son un riesgo latente en el uso de concentrados de plaquetas grupo O, por lo que la titulación de hemolisinas anti-A/B constituye una de las estrategias para su prevención. El objetivo de este estudio fue determinar la frecuencia de títulos de hemolisinas de isotipos IgG e IgM anti-A/B en donantes de sangre. Se trató de un estudio descriptivo, transversal y aleatorio simple con un tamaño muestral de 308 muestras. Se aplicó la metodología en tubo, gel salino y anti-inmunoglobulina IgG y, mediante soluciones seriadas, se evidenció el título. Adicionalmente, se realizó una encuesta sobre los posibles factores de riesgo para el aumento de estos títulos. Se aplicó estadística descriptiva mediante el uso del software informático SPSS versión 22.0 y la relación entre variables independientes a través del análisis estadístico de Chi-cuadrado y, para establecer la concordancia de las lecturas visuales de las tarjetas de gel, se aplicó el índice kappa. Se determinó la existencia de hemolisinas de isotipo IgG e IgM anti-A/B de títulos superiores a 1/64. Existió una relación estadísticamente significativa entre embarazos y títulos de IgG anti-A/B >1/128 y el aumento de hemolisinas de isotipo IgM y la ingesta de probióticos. Los resultados demostraron la necesidad de implementar la titulación de hemolisinas previo a la transfusión de concentrados plaquetarios no isogrupo, por lo que se recomienda una investigación de riesgo-beneficio y el seguimiento de pacientes con transfusiones de concentrados plaquetarios incompatibles ABO.

The possible adverse effects that occur in incompatible ABO transfusions are a latent risk in the use of group O platelet concentrates, so the titration of anti-A/B hemolysins is one of the strategies for its prevention. The objective of this study was to determine the frequency of hemolysins titers IgG and IgM anti-A/B isotypes in blood donours. It was a simple randomized descriptive cross-sectional study with a sample size of 308 samples. The methodology was applied in tube, saline gel and anti-IgG anti-immunoglobulin and by means of serial solutions the title was verified. Additionally, a survey was conducted on the possible risk factors for the increase in securities. Descriptive statistics were used through the application of the SPSS version 22.0 software and the relationship between independent variables through the Chi-square statistical analysis and the kappa index was applied to match the visual readings of the gel cards. The existence of IgG and IgM anti-A/B isotype hemolysins of titers greater than 1/64 was determined. There was a statistically significant relationship between pregnancies and anti-A/B IgG titres>1/128; and the increase in IgM isotype hemolysins and probiotic intake. The results demonstrate the need to implement hemolysin titration prior to transfusion of non-isogroup platelet concentrates, so a risk-benefit investigation and follow-up of patients with transfusions of ABO incompatible platelet concentrates is recommended.

Os possíveis efeitos adversos que ocorrem em transfusões incompatíveis ABO são um risco latente no uso de concentrados de plaquetas do grupo O, portanto a titulação de hemolisinas anti-A/B é uma das estratégias para sua prevenção. O objetivo deste estudo foi determinar a frequência de títulos de hemolisinas de isotipos IgG e IgM anti-A/B em doadores de sangue. Trata-se de um estudo descritivo transversal aleatório simples, com tamanho de amostra de 308 amostras. A metodologia foi aplicada em tubo, gel salino e anti-imunoglobulina IgG e utilizando soluções em série, o título foi verificado. Além disso, foi realizada uma pesquisa sobre os possíveis fatores de risco para o aumento destes títulos. A estatística descritiva foi utilizada através da aplicação do software informático SPSS versão 22.0 e a relação entre variáveis independentes por meio da análise estatística do qui-quadrado e, para estabelecer a concordância com as leituras visuais dos cartões de gel, o índice kappa foi aplicado. Foi determinada a existência de hemolisinas de isotipo IgG e IgM anti-A/B de títulos maiores que 1/64. Existiu uma relação estatisticamente significante entre gestações e títulos de IgG anti-A/B>1/128; e o aumento de hemolisinas do isotipo IgM e a ingestão de probióticos. Os resultados demonstram a necessidade de implementar a titulação da hemolisina antes da transfusão de concentrados de plaquetas não isogrupo, por isso, recomenda-se uma investigação de risco-benefício e acompanhamento de pacientes com transfusões de concentrados de plaquetas incompatíveis com ABO.

Clinical research of auricular gold-needle therapy in treatment of chronic fatigue syndrome of deficiency constitution / 中国针灸

OBJECTIVE@#To observe the clinical therapeutic effects of auricular gold-needle therapy on chronic fatigue syndrome of deficiency constitution and explore its potential mechanism.@*METHODS@#A total of 120 patients were randomized into an auricular gold-needle therapy group, an auricular point pressure therapy group and a Chinese herb group, 40 cases in each one. Additionally, a health control group (40 cases) was set up, without any intervention. In the auricular gold-needle therapy group, the gold needle was used to stimulate the auricular points on one side and the cowherb seed pressure therapy on the other side. In the auricular point pressure therapy group, the cowherb seed pressure therapy was adopted only on one side. The auricular points were shen (CO), xin (CO), fei (CO), pizhixia (AT), etc. in the two groups. The auricular points on both sides were used alternatively. The treatment was given once a week, 4 treatments as one course and the consecutive 3 courses of treatment were required. In the Chinese herb group, was prescribed for oral administration, 6 g, twice a day, the medication for 1 month was as one session and the consecutive 3 sessions of medication were required. Before and after treatment, separately, the clinical symptom score, the levels of the serum immunoglobulins, i.e. IgA, IgG and IgM were observed in the patients of the three groups. The therapeutic effects were evaluated in the three groups.@*RESULTS@#The total effective rate was 90.0% (36/40) in the auricular gold-needle therapy group, better than 80.0% (32/40) in the auricular point pressure therapy group and 82.5% (33/40) in the Chinese herb group (both <0.05). Before treatment, the clinical symptom scores of the patients in the three groups were obviously higher than the health control group (all <0.001). After treatment, the symptom scores were all reduced as compared the scores before treatment in the three groups (all <0.001) and the symptom scores in the auricular gold-needle therapy group were better than the auricular point pressure therapy group and the Chinese herb group (both <0.01). Before treatment, the levels of serum IgA, IgG and IgM of the patients in the three groups were lower than the health control group (all <0.001). The levels were all improved after treatment in the three groups (all <0.01), and the levels in the auricular gold-needle therapy group was better than the auricular point pressure therapy group and the Chinese herb group (all <0.05).@*CONCLUSION@#The auricular gold-needle therapy achieves the significant therapeutic effects on chronic fatigue syndrome of deficiency constitution and its mechanism is probably related to the regulation of immune function.

Evaluation of QuantiFERON-TB Gold in- Tube and Immunological Tests for TB Diagnosis in Iraqi Patients.

Aims: Tuberculosis is an infectious disease caused by the bacillus Mycobacterium tuberculosis and other related species. It typically affects the lungs (pulmonary TB) but can affect other sites (extra-pulmonary TB). A profusion of articles have been published on the accuracy and uses of interferon-gamma releasing assays for detection of this disease. Experimental Design: A prospective study. Place and Duration of Study: This study was done in Kirkuk city between November 2012 to February 2013. Methodology: The present study included 50 individuals (40 suspected tuberculosis patients and 10 healthy controls). The patient were examined for the presence of TB by using QuantiFERON-TB Gold In-Tube(QFT-GIT) assay, polymerase chain reaction (PCR) and compared them with certain new and routine tests like AFB smear, OnSite TB rapid test, erythrocyte sedimentation rate and chest X-ray. Result: The present study showed a relation between QFT-GIT and OnSite TB rapid test, and they were positive in 25(86%) at the same time; QFT-GIT positive and OnSite TB rapid test were negative in 4(14%) of patients; QFT-GIT negative and OnSite TB rapid test positive were seen in 5(45%); while QFT-GIT and OnSite TB rapid test were negative in 6(55%) of patients. In the control group only one QFT-GIT positive but it was OnSite TB test negative. 9(100%) of individuals for both tests were negative, 29 were males and 21 were females. Conclusion: The study highlighted the sensitivity of IGRAs for diagnosis of active TB in combination with the rapid IgM/lgG tests for TB.The QFT assay appeared to be a more specific indicator of latent TB infection than TST. The association with blood groups and vaccination is also significant.

Detection of dengue virus 4 from central India.

Background & objectives: Dengue is an important arboviral disease. All four dengue virus serotypes are reported to be circulating in India. It is also known that different serotypes, genotypes and clades of genotype determine outbreak severity. Dengue affected children are known to have serious disease outcome. We carried out this study to give reliable diagnosis of dengue infection in children and to detect circulating serotype in central India. Methods: Samples collected from paediatric patients suspected to have dengue fever were subjected to IgM and IgG ELISA to determine dengue virus infection. Samples collected within 0-5 days of onset of illness and positive by IgM ELISA were tested by nested reverse transcription polymerase chain reaction (nRT-PCR). The PCR products were sequenced and analyzed. Results: Of the 89 samples tested, 18 and 7 were positive for dengue IgM and IgG, respectively. Dengue activity was observed in both Jabalpur city and adjoining rural settings. One sample found positive by nRT-PCR was further sequenced to confirm dengue virus 4 as aetiological agent. Interpretation & conclusions: Our findings demonstrated dengue virus infection in children and adolescent in central India. Because of continuous changing epidemiology, it is important to monitor dengue virus activity at both serological and molecular level in this part of the country for better patient care and management.

Chromosome Analysis of Abortuses in Recurrent Spontaneous Aborters with Serum Anticardiolipin Antibodies / 대한산부인과학회잡지

OBJECTIVE: It has been suggestes that various mechanism of fetal loss are associated with anticardiolipin(ACA) and humoral immunity in the patients with recurrent spontaneous abortion. Thus we have investigated the relationship between ACA and chromosomal anomaly to know the clinical impact of ACA to early fetal loss as comparing to the chromosomal anomaly in the patients of recurrent spontaneous abortions. MATERIALS AND METHODS: Patients(n=88) with a history of recurrent spontaneous abortion (2 or more) between January 1, 1994 and June 30, 1999 were included in this study. Quantitative measurement of serum ACA was performed by ELISA and chromosomal analysis of chorionic villi obtained from aborted conceptuses was done by using standard G-banding technique. RESULTS: The incidence rate of ACA positive was 27%(24/88) and that of chromosomal abnormality was 57%(50/88). The incidence rate of abnormal karyotype was 54% (13/24) in ACA positive. Among 24 ACA positive, 10 had IgG-ACA positive, 10 had IgM-ACA positive and 4 had both types of ACA. The incidence rate of chromosomal anomalies was 30% (3/10) in IgG-ACA positive, 90%(9/10) in IgM-ACA positive and there was significant difference between these two groups (p=0.02). The incidence rate of chromosomal trisomy was 59% (23/37) in ACA negative, 62% (8/13) in ACA positive and there was no significance between two groups. CONCLUSIONS: The significantly low incidence of chromosomal abnormalities in conceptal products of patients with IgG-ACA comparing that of patients with IgM-ACA suggests that this isotype of antibody have influence on the genesis of spontaneous abortions in genetically normal pregnancy. In further studies, additional trials are mandatory for obtaining a definitive conclusions about relationship between pathologic changes of conceptal products and pathophysiologic effects of IgG-ACA.

Seroprevalence of rubella antibodies and effects of vaccination among healthy university women students in Korea

Since the introduction of rubella vaccination in Korea in 1982, several outbreaks of rubella have occurred. In order to examine the current seroepidemiology of rubella virus infection in Korean women of child-bearing age, the healthy university women students of Yonsei University in Seoul aged 18 approximately 26 years were chosen as a model population. A survey was carried out in the time of routine annual physical check-up. Serum specimens of 242 volunteers of healthy women university students were randomly sampled for screening rubella-specific IgG/IgM antibodies by an automated enzyme immunoassay system (Vitek System VIDAS, bioMerieux Vitek, Inc., Lyon, France). A total of 177 subjects were positive for rubella-specific IgG antibody, giving a prevalence of 73.1%. The mean +/- standard deviation of rubella-specific IgG antibody was 99.3 +/- 95.3 IU/mL. In this study, the efficiency of a vaccination was about 88%. With such a relative high proportion of susceptibility (26.9%) among university women students in child-bearing age, a extensive rubella vaccination program should be enforced to prevent possible outbreaks of congenital rubella syndrome in the future.