Importancia biológica de la microcistina en aguas de riego y alternativas en su detección y degradación / Biological importance of microcistin in irrigation and alternative waters in its detection and degradation

Introducción: Las cianobacterias son microrganismos fotosintéticos, con capacidad de sintetizar una gran diversidad de metabolitos secundarios de interés para la industria, pero también han llamado la atención en las últimas décadas las toxinas denominas cianotoxinas, metabolitos que causan distintas alternaciones fisiológicas hasta llegar ocasionar la muerte de diferentes especies. Metodología: La determinación del estado de arte para el tema de cianobacterias se basó en una búsqueda bibliográfica en la base de datos especializada como Elservier, Springer, Google académico y MDPI basadas en palabras clave en español e inglés "microcistinas", "degradación de MC" y "cuantificación y detección de MC". Resultados: En la presente revisión considera dos áreas de caracterización de la microcistinas (MCs) las propiedades fisicoquímicas y propiedades biológicas, para entender su comportamiento e importancia tóxica en los sembradíos agrícolas y en la salud humana. Además de comprender alternativas para su degradación, por métodos fisicoquímicos como fotocatálisis y la gradación biológica por bacterias. Finalmente se mencionará algunos métodos actuales y en desarrollo, para la detección y cuantificación de estas MCs en ambientes acuáticos. Conclusiones: Las MCs tienen el potencial contaminar fuentes de agua como ríos y lagunas, causando daños a la salud humana y a las plantas agrícolas, tienen la capacidad de tolerar distintos cambios drásticos en factores fisicoquímicos y biológicos. Entre las alternativas reportadas la degradación bacteriana promete ser la más confiable. Finalmente, entre los distintos métodos para la detección de MCs, entre los métodos más aplicados son los inmunoensayos, debido a su versatilidad y estabilidad del método.

Introduction: Cyanobacteria are photosynthetic microorganisms, with the capacity to synthesize a great diversity of secondary metabolites of interest to the industry, but toxins called cyanotoxins have also attracted attention in recent decades, metabolites that cause different physiological alterations until they cause the death of different species. Methodology: The determination of the state of the art for the subject of cyanobacteria was based on a bibliographic search in specialized databases such as Elservier, Springer, Google Scholar and MDPI based on keywords in Spanish and English "microcystins", "MC degradation " and "quantification and detection of MC". Results: In the present review, two areas of characterization of microcystins are considered: the physicochemical properties and biological properties of microcystins (MC), to understand their behavior and toxic importance in agricultural crops and in human health.In addition to understanding alternatives for their degradation, by physicochemical methods such as photocatalysis and biological grading by bacteria.Finally, some current and developing methods will be mentioned for the detection and quantification of these MCs in aquatic environments. Conclusions: MCs have the potential to contaminate water sources such as rivers and lagoon, causing damage to human health and agricultural plants, they have the ability to tolerate different drastic changes in physicochemical and biological factors. Among the reported alternatives, bacterial degradation promises to be the most reliable. Finally, among the different methods for the detection of MCs, among the most applied methods are immunoassays, due to their versatility and stability of the method.

Simultaneous measurement of HbA1C and Hemoglobin by Turbidimetric inhibition immunoassay from a single punch of dried blood spot samples

Hemoglobin and glycosylated hemoglobin (HbA1C) are frequently monitored health indicators in population based studies for information about the status of nutrition and diabetes control. We present here possibly for the first time the findings of simultaneous estimation of Hemoglobin and HbA1C on Dried blood spot (DBS) samples by a single test. Validation was done by turbidimetric inhibition immunoassay (TINIA) using Roche Integra 400 plus instrument. Paired whole blood and DBS samples were tested for HbA1C estimation by Integra 400 plus. Total hemoglobin values obtained during HbA1C estimation were compared with hemoglobin values estimated by Coulter AcT 5 Diff CP Hematology counter. Agreement in HbA1C and hemoglobin values between paired whole blood and DBS samples was found to be high with R2 values of 0.994 and 0.9349, respectively. Intra- and inter- assay precision was found to be within 10% for both parameters. Values obtained after assaying DBS samples prepared by spotting proficiency samples on Whatman 903 protein saver cards demonstrated acceptable standard deviation indices resulting in successful participation in EQAS programs for both these parameters. The results reveal the potential of TINIA for simultaneous estimation of hemoglobin and HbA1C from a single punch of the DBS samples.

Recent progress on detection techniques for human hormones / 药学学报

Human hormones at trace levels play a vital role in the regulation of a variety of functions and systems in the body, and an imbalance in hormone levels can lead to the emergence and development of diverse diseases. Therefore, the development of reliable sample pretreatment methods and sensitive and accurate analytical techniques for human hormone detection could contribute to the prevention, diagnosis and treatment of diseases, providing significant improvement for human health. Human samples which are usually used to detecting hormones, such as blood, saliva, urine and other matrix are more complex, so sample pretreatment is an important step to ensure the accuracy and reliability in the detection of hormones. In this review three common sample pretreatment methods including solid phase extraction (SPE), liquid-liquid extraction (LLE) and protein precipitation (PP) methods are discussed. Then, recent research progress in conventional techniques like liquid/gas chromatography and liquid/gas chromatography-mass spectrometry (LC/GC-MS/MS), as well as some novel strategies, such as immunoassay including chemiluminescence immunoassay (CLIA), lateral-flow immunoassay (LFIA) and time-resolved fluoroimmunoassay (TRFIA), and sensor technology including electrochemical (EC), fluorescent (FL) and surface-enhanced Raman scattering (SERS) sensors, and microfluidic chip analysis are discussed for human hormone detection. Finally, the future perspective on the use of these methods for hormone detection is considered. It is hoped to provide powerful insights to researchers for the relevant researches.

Evolution of the newest diagnostic methods for COVID-19: a Chinese perspective / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Coronavirus disease 2019 (COVID-19) has continued to spread globally since late 2019, representing a formidable challenge to the world's healthcare systems, wreaking havoc, and spreading rapidly through human contact. With fever, fatigue, and a persistent dry cough being the hallmark symptoms, this disease threatened to destabilize the delicate balance of our global community. Rapid and accurate diagnosis of COVID-19 is a prerequisite for understanding the number of confirmed cases in the world or a region, and an important factor in epidemic assessment and the development of control measures. It also plays a crucial role in ensuring that patients receive the appropriate medical treatment, leading to optimal patient care. Reverse transcription-polymerase chain reaction (RT-PCR) technology is currently the most mature method for detecting viral nucleic acids, but it has many drawbacks. Meanwhile, a variety of COVID-19 detection methods, including molecular biological diagnostic, immunodiagnostic, imaging, and artificial intelligence methods have been developed and applied in clinical practice to meet diverse scenarios and needs. These methods can help clinicians diagnose and treat COVID-19 patients. This review describes the variety of such methods used in China, providing an important reference in the field of the clinical diagnosis of COVID-19.

Detection results of blood donors with HBsAg reactivity to single reagent: a retrospective analysis / 中国输血杂志

【Objective】 To retrospectively analyze the detection results of blood donors with HBsAg reactivity to single reagent detected by enzyme-linked immunosorbent assay (ELISA) in our center, so as to provide basis for further consolidating the blood donor team. 【Methods】 Samples of blood donors who had been deferred for at least 6 months due to HBsAg reactivity to sole ELISA assay were collected, and HBsAg ELISA and NAT were further performed. Meanwhile, HBsAg/HBsAb/HBeAg/HBeAb/HBcAb were detected by Roche electrochemiluminescence immunoassay, and the results were statistically analyzed. 【Results】 Among these 51 selected samples, 45 were negative to two assays, 6 were reactive to sole assay, with reactivity-yield rate at 11.76% (6/51). The results of NAT/ECLIA were all negative. For five indicators of hepatitis B virus infection, 23 samples were all negative and 28 were partially positive, mainly anti-HBs, anti-HBc and anti-HBe. 【Conclusion】 The follow-up detection of HBsAg ELISA sole-reagent reactive samples, supplemented with the detection of HBV serological markers, can reduce the number of deferred blood donors, increase the willingness to donate blood again, and protect the rights and interests of blood donors.

Development of lateral flow immunoassay for SARS-CoV-2 antigen detection / 中国胸心血管外科临床杂志

@#This article summarizes the development of lateral flow immunoassay for SARS-CoV-2 antigen detection. Lateral flow immunoassay is a rapid, low cost, and ease of use detection tool that has been widely applied in clinical and public health sectors. Since the outbreak of COVID-19, the technique has been adopted for rapid antigen diagnostic test of SARS-CoV-2, including commonly used colloidal gold nanoparticle-based lateral flow immunoassays as well as various fluorescence-based lateral flow immunoassays. With innovations in labelling methods, this detection technique has been in continuous development and is shifting from qualitative toward quantitative as well as gaining sensitivity.

Addressing the problem of hook effect in sandwich lateral flow immunoassay: review and impact on future solutions / 中华检验医学杂志

Lateral flow immunoassay (LFIA) is a rapid detection technique that allows researchers to move the antigen-antibody reaction from a test tube or laboratory vessel to a test strip. Due to the chromatographic effect of the test strip, the solution would move to a specified direction based on the test and complete the whole antigen-antibody specific reaction. A qualitative judgment can be made with the naked eye by observing the color change of the reagent strip at a specific location. Because of its advantages of being fast, simple, specific, inexpensive, and requiring no specialized personnel, LFIA is now widely used in medical testing, food quality monitoring, environmental monitoring, agriculture and animal husbandry. A major bottleneck for the development of LFIA technology is the hook effect. This paper summarizes the current methods, means and research progresses to combat the hook effect, hoping to provide a strong technical reference for researchers to design test strips, select suitable nanoparticles, and achieve quantitative LFIA detection.

A multicenter study assessing the efficacy of various preoperative/pre-transfusion screening methods for blood transmitted disease / 中华检验医学杂志

Objective:This multi-centre study was conducted to assess the efficacy of various preoperative/pre-transfusion screening methods for blood transmitted disease.Methods:From July 2021 to December 2021, plasma samples of patients admitted to 10 hospitals were collected for screening preoperative/pre-transfusion blood transmitted disease. Nucleic acid detection technology was used to detect hepatitis B virus (HBV) DNA, hepatitis C virus (HCV) RNA and human immunodeficiency virus (HIV)(1+2) RNA, and the results were compared with the immuno-serological methods. χ 2 test and Kappa test were used to analyze the efficacy of these two methods. Results:A total of 8 655 valid specimens were collected from 10 hospitals. There was a statistically significant difference in the positive detection rate of HCV between the two methods ( P<0.001). There was no significant difference in the positive detection rate of HBV and HIV assessed by the two methods ( P>0.05), but the number of positive cases detected by HBV DNA and HIV RNA (218 and 4 cases) was significantly higher than the corresponding serological results (216 and 2 cases). At the same time, there were HBV, HCV and HIV immuno-serological omissions by the immuno-serological methods, among which 28 cases were HBsAg negative and HBV DNA positive, 2 cases were HCV antibody negative and HCV RNA positive, and 2 cases were HIV antigen/antibody negative and HIV RNA positive. In addition, in the 66 samples with inconsistent results from the two detection methods, 83.3% (55/66), 68.2% (45/66), 63.6% (42/66) and 62.1% (41/66) of patients aged was>45 years, tumor, surgery and male, respectively. Conclusions:Compared with immuno-serological tests, nucleic acid tests have the advantage in terms of sensitivity on detecting HBV, HCV and HIV infection and could reduce missed detection. The risk of transmission can be reduced by adding HBV, HCV, and HIV nucleic acid tests to preoperative/pre-transfusion immuno-serological tests screening for patients over 45 years of age and tumor patients.

A Case Control Study of Vitamin D Levels in Chronic Obstructive Pulmonary Disease Patients and Healthy Volunteers in South Gujarat, India

Introduction: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) programme states that COPD is a common, treatable, and preventable disease that is characterized by a persistent airflow restriction that usually progresses and is connected to an exaggerated chronic inflammatory response in the airways and the lung to harmful particles or gases. The combined severity of a patient's co-morbid illnesses and exacerbations increases. The purpose of the study was to assess the vitamin D status of COPD patients and healthy participants. Methodology: This case-control study was conducted among 75 cases and 75 control at the Surat Municipal Institute of Medical Education and Research General Medicine department. Result: The mean vitamin D of subjects in cases was 32.21 � 12.68 and it was 52.05 � 1.99 in controls. The difference in vitamin D between the two groups was statistically significant (P Value<0.001). Conclusion: COPD patients had lower amounts of vitamin D. As COPD severity increases, vitamin D levels decrease. Along with a rise in COPD exacerbations, vitamin D levels are also decreasing

Padronização de um ELISA indireto a partir da utilização de uma proteína de superfície do vírus da anemia infecciosa equina como antígeno para o diagnóstico dessa enfermidade / Standardization of an indirect ELISA using a surface protein of the equine infectious anemia virus as an antigen for the diagnosis of this disease

A anemia infecciosa equina é uma importante enfermidade que acomete os equídeos em todo o mundo, se apresentando de forma aguda, crônica e assintomática causando grandes prejuízos para a economia tanto para criadores que vivem do trabalho desses animais quantos aos criadores que investem no melhoramento das raças, impedindo o acesso ao mercado tanto nacional quanto internacional. O Ministério da Agricultura, Pecuária e Abastecimento considera o IDGA como teste oficial para diagnóstico dessa enfermidade, porém essa técnica é demorada e muita vez acaba sendo subjetiva, dependendo da experiencia particular de cada Laboratorista. Além de não conseguir detectar animais no início da infecção. Logo, a necessidade de se buscar novas técnicas como o ELISA indireto que aperfeiçoem o tempo de análise dos resultados, facilita a automação e obtém resultados confiáveis. O estudo realizado teve como objetivo padronizar uma técnica de ELISA indireto utilizando uma proteína de envelope viral GP90 como antígeno para diagnóstico da anemia infecciosa equina. Avaliando o desempenho do teste a partir da sensibilidade, especificidade e valores preditivos positivo e negativo. Os valores obtidos foram: 91,11%, 93,33%, 91,11% e 93,33% respectivamente. Concluiu-se que o teste apresenta bom desempenho, além da possibilidade de detectar amimais positivos no início da infecção.

Equine infectious anemia is an important disease that affects horses all over the world, presenting in an acute, chronic and asymptomatic way, causing great damage to the economy, both for breeders who live off the work of these animals and for breeders who invest in the improvement of breeds, preventing access to both national and international markets. The Ministry of Agriculture, Livestock and Food Supply considers AGID to be the official test for diagnosing this disease, but this technique takes time and often ends up being subjective, depending on the particular experience of each laboratory worker. In addition to not being able to detect animals at the beginning of the infection. Therefore, the need to seek new techniques such as indirect ELISA that improve the time of analysis of results, facilitate automation and obtain reliable results. The aim of this study was to standardize an indirect ELISA technique using a GP90 viral envelope protein as an antigen for the diagnosis of equine infectious anemia. Evaluating test performance based on sensitivity, specificity and positive and negative predictive values. The values obtained were 91.11%, 93.33%, 91.11 and 93.33 respectively. It was concluded that the test performs well, in addition to the possibility of detecting positive animals at the beginning of the infection.

Evaluación de la prueba Aspergillus Galactomannan Ag VircliaR Monotest como alternativa a kit Platelia ™ Aspergillus EIA / Evaluation of the Aspergillus Galactomannan ag VircliaR Monotest test as an alternative to Platelia™ Aspergillus EIA kit

INTRODUCCIÓN: La prueba Aspergillus galactomannan Ag Virclia® (GM-VClia) es una técnica de galactomanano monotest, auto-matizada, basada en inmunoensayo quimioluminiscente (CLIA). OBJETIVO: Evaluar el desempeño del test de GM-VClia en muestras de suero y lavado bronquioalveolar (LBA) procesadas previamente con el kit Platelia™ Aspergillus EIA (GM-Plat). MATERIALES Y MÉTODOS: Se estudiaron 56 muestras de suero y 40 de LBA, correspondientes a un total de 59 pacientes (algunos con determinación de galactomamano en ambas muestras) con enfermedades pulmonares, hematológicas, LES, Covid-19 y tumores, entre otros. Trece pacientes tuvieron aspergilosis invasora (1 probada y 12 probables). RESULTADOS: La correlación entre ambos métodos para suero y LBA fue r = 0,8861 p < 0,0001 y r = 0,6368 p < 0,001, respectivamente. Hubo una concordancia global de 67,7% (65/96), siendo de 85,7% (48/56) en sueros y 42,5,0% (14/49) en LBA. Al subir el punto de corte en LBA por GM-VClia la concordancia aumentó a 85,7%. CONCLUSIONES: Se observó una mayor correlación y concordancia en sueros que en LBA. El kit GM-VClia presentó una mayor sensibilidad y valor predictor negativo (VPN), que el kit GM-Plat. Las desventajas de GM-VClia, la constituyen la categoría "dudoso", que dificulta la interpretación y que, con los puntos de corte actuales en LBA, la correlación con GM-Plat es menor. Las ventajas son su mayor sensibilidad, facilidad de procesamiento y una mayor rapidez en los resultados.

BACKGROUND: The Aspergillus Galactomannan Ag Virclia® (GMVClia) test is a monotest and automated galactomannan technique based on chemiluminescent immunoassay (CLIA). AIM: To evaluate the performance of the GM-VClia test in serum and bronchioalveolar lavage (BAL) samples previously processed with the Platelia ™ Aspergillus EIA kit (GM-Plat). METHODS: 56 samples of serum 40 from BAL (some of them with galactomaman determination in both samples), from patients with pulmonary diseases, hematological diseases, SLE, Covid-19 and tumors, among others, were studied. Thirteen patients had invasive aspergillosis (1 proven and 12 probable). RESULTS: The correlation between both methods for serum and BAL was r = 0.8861 p < 0.0001 and r = 0.6368 p < 0.001, respectively. There was a global concordance of 67.7% (65/96), being 85.7% (48/56) in sera and 42.5.0% (14/49) in BAL. By raising the cut-off point in LBA by GM-VClia, the agreement increased to 85.7%. CONCLUSION: A greater correlation and concordance was observed in sera than in BAL. The GM-VClia kit had a higher sensitivity and NPV than the GM-Plat kit. The disadvantages of GM-VClia are the "doubtful" category, which makes interpretation difficult and that with the current cut-off points in LBA the correlation with GM-Plat is lower. The advantages are its greater sensitivity, ease of processing and faster results.

Low performance of a SARS-CoV-2 point-of-care lateral flow immunoassay in symptomatic children during the pandemic

Abstract Objective: to evaluate the accuracy of an antibody point-of-care lateral flow immunoassay (LFI -Wondfo Biotech Co., Guangzhou, China) in a pediatric population. Methods: children and adolescents (2 months to 18 years) with signs and symptoms suggestive of acute SARS-CoV-2 infection were prospectively investigated with nasopharyngeal RT-PCR and LFI at the emergency room. RT-PCR was performed at baseline, and LFI at the same time or scheduled for those with less than 7 days of the clinical picture. Overall accuracy, sensitivity and specificity were assessed, as well as according to the onset of symptoms (7-13 or ≥14 days) at the time of the LFI test. Results: In 175 children included, RT-PCR and LFI were positive in 51 (29.14%) and 36 (20.57%), respectively. The overall sensitivity, specificity, positive and negative predictive value was 70.6% (95%CI 56.2-82.5), 96.8% (95%CI 91.9-99.1), 90.0% (95%CI 77.2-96.0), and 88.9% (95%CI 83.9-92.5), respectively. At 7-13 and ≥14 days after the onset of symptoms, sensitivity was 60.0% (95%CI 26.2-87.8) and 73.2% (95%CI 57.1-85.8) and specificity was 97.9% (95%CI 88.7-99.9) and 96.1% (95%CI 89.0-99.2), respectively. Conclusion: Despite its high specificity, in the present study the sensitivity of LFI in children was lower (around 70%) than most reports in adults. Although a positive result is informative, a negative LFI test cannot rule out COVID-19 in children.

Verificación del desempeño general del método Elecsys® Chagas en la detección de anticuerpos específicos contra Trypanosoma cruzi / Verification of the general performance of the Elecsys® Chagas method in the detection of specific antibodies against Trypanosoma cruzi

Resumen La enfermedad de Chagas es una parasitosis producida por Trypanosoma cruzi, prevalente principalmente en el continente americano, y observada en regiones no endémicas, producto de viajes y migraciones. El objetivo de este estudio fue comparar el desempeño del ensayo Elecsys® Chagas (Roche Diagnostics Alemania) (ECLIA) para el diagnóstico de la infección chagásica crónica con el método estándar y evaluar su posible empleo en reemplazo del método automatizado existente. Se estudiaron 77 muestras de sueros pertenecientes a pacientes con diagnóstico presuntivo de enfermedad de Chagas, procesadas por los distintos métodos disponibles en la Sección Parasitología del Hospital Muñiz: inmunoensayo quimioluminiscente de micropartículas (CMIA) (Abbott), enzimoinmunoanálisis de adsorción (ELISA) (Wiener) y hemaglutinación indirecta (HAI) (Lab. Lemos S.R.L.). Los resultados de los métodos ELISA y HAI fueron comparados con los obtenidos en la prueba ECLIA, y estos a su vez con el método automatizado disponible. De las muestras analizadas, 22 (28,57%) presentaron IgG anti-T. cruzi y 55 (71,43%) resultaron negativas. Con el método ECLIA se logró un 100% en los parámetros de desempeño, con diferencias en los intervalos de confianza. La razón de verosimilitud positiva y la razón de verosimilitud negativa clasificaron al ensayo como excelente y la potencia global del test apoyó esa afirmación. Los métodos inmunológicos automatizados ayudan a la performance diagnóstica en la etapa crónica de la enfermedad de Chagas, permiten minimizar errores, favorecen la velocidad de emisión de los resultados y, debido a su alta sensibilidad y especificidad, en ciertos escenarios podrían proponerse para usar como única técnica.

Abstract Chagas disease is a parasitosis caused by Trypanosoma cruzi, prevalent mainly in the American continent, and observed in non-endemic regions as a result of travel and migration. The objective of this study was to compare the performance of the Elecsys® Chagas (Roche Diagnostics Alemania) (ECLIA) assay for the diagnosis of chronic Chagas infection with the diagnostic standard, and to evaluate its possible use as a replacement for the existing automated method. A total of 77 serum samples belonging to patients with a presumptive diagnosis of Chagas disease were evaluated, processed by the different methods available in the Parasitology Section of Hospital Muñiz: microparticle chemiluminescent immunoassay (CMIA) (Abbott), enzyme-linked immunosorbent assay (ELISA) (Wiener) and indirect hemagglutination (HAI) (Lab. Lemos S.R.L). The results of the ELISA and HAI methods were compared with those obtained in the ECLIA test, and these in turn with the available automated method. Of the samples analysed, 22 (28.57%) presented IgG anti-T. cruzi and 55 (71.43%) were negative. With the ECLIA method, 100% was achieved in the performance parameters, with differences in the confidence intervals. The positive likelihood ratio and the negative likelihood ratio classify the essay as excellent, and the overall power of the test supports this statement. Automated immunological methods help diagnostic performance in the chronic stage of Chagas disease, allow minimising errors, favour the speed of issuance of results, and due to the high sensitivity and specificity, in certain scenarios, they could be proposed for use as single technique.

Resumo A doença de Chagas é uma parasitose causada pelo Trypanosoma cruzi, prevalente principalmente no continente americano, e observada em regiões não endêmicas em decorrência de viagens e migrações. O objetivo deste estudo foi comparar o desempenho do ensaio Elecsys® Chagas (Roche Diagnostics Alemanha) (ECLIA) para o diagnóstico da infecção crônica de Chagas com o método padrão e avaliar seu possível uso em substituição do método automatizado existente. Foram avaliadas 77 amostras de soro pertencentes a pacientes com diagnóstico presuntivo de doença de Chagas, processadas pelos diferentes métodos disponíveis na Seção de Parasitologia do Hospital Muñiz: imunoensaio quimioluminescente de micropartículas (CMIA) (Abbott), ensaio imunoenzimático de adsorção (ELISA) (Wiener) e hemaglutinação indireta (HAI) (Lab. Lemos S.R.L). Os resultados dos métodos ELISA e HAI foram comparados com os obtidos no teste ECLIA, e estes por sua vez com o método automatizado disponível. Das amostras analisadas, 22 (28,57%) apresentaram IgG anti-T. cruzi e 55 (71,43%) foram negativos. Com o método ECLIA, foram obtidos 100% nos parâmetros de desempenho, com diferenças nos intervalos de confiança. A razão de verossimilhança positiva e a razão de verossimilhança negativa classificam o ensaio como excelente, e a potencia geral do teste conformou essa afirmação. Os métodos imunológicos automatizados auxiliam no desempenho diagnóstico na fase crônica da doença de Chagas, permitem minimizar erros, favorecem a rapidez na emissão dos resultados e, devido à alta sensibilidade e especificidade, em determinados cenários, poderiam ser propostos para uso como técnica única.

Results of a sample-to-cutoff ratio using Abbott Architect rHTLV-I/II assay allow to predict detection of HTLV-1 and HTLV-2 proviral DNA by real-time PCR / Resultados da razão sinal da amostra sobre o cutoff da reação no ensaio Abbott Architect rHTLV-I/II permite prever a detecção de DNA proviral por PCR em tempo real

The present study aims to correlate the sample-to-cutoff ratios (S/CO) distributions of reactive results for HTLV-1/2 antibodies with the detection of proviral DNA in a population of blood donor candidates. It was carried out a retrospective data search of 632 HTLV-1/2 reactive samples, submitted to confirmatory testing from January 2015 to December 2019. Serological screening was performed by chemiluminescent microparticle immunoassay Architect rHTLV-I/II, whereas confirmatory testing was performed by in-house real-time polymerase chain reaction method. 496 out of 632 samples (78%) had undetectable HTLV-1/2 proviral DNA and 136 (22%) had detectable proviral DNA. HTLV infection was not confirmed in any individual for whom the S/CO ratio value was <4, and proviral DNA detection rates gradually escalated as S/CO ratio values increased. The sensitivity and predictive positive value found for the Architect rHTLV-I/II was 100% and 22%, respectively. The receiver operating characteristic (ROC) curve analysis showed that the optimal S/CO ratio value for predicting the presence of HTLV-1/2 was 18.11. High S/CO ratios were more associated with the detection of proviral DNA. The S/CO ratio value <4 suggests excluding true HTLV infection and the risk of blood transmission (AU).

O estudo tem como objetivo correlacionar às distribuições das razões sample-to-cutoff (S/CO) de resultados reagentes para anticorpos HTLV-1/2 com a detecção de DNA proviral em uma população de candidatos à doação de sangue. Realizou-se uma busca retrospectiva de dados de 632 amostras reagentes para HTLV-1/2 submetidas à testagem confirmatória entre janeiro de 2015 a dezembro de 2019. A triagem sorológica foi realizada pelo imunoensaio quimioluminescente de micropartículas Architect rHTLV-I/II, enquanto o teste confirmatório foi realizado pelo método de PCR em tempo real in-house. 496 de 632 amostras (78%) apresentaram DNA proviral indetectável e 136 (22%) apresentaram DNA proviral detectável. A infecção por HTLV não foi confirmada em nenhum indivíduo com valor de S/CO <4 e as taxas de detecção de DNA proviral escalonaram gradualmente à medida que as razões S/CO aumentaram. A sensibilidade e valor preditivo positivo encontrados para o Architect rHTLV-I/II foram 100% e 22%, respectivamente. Utilizando análise de curva ROC, o valor de razão S/CO ideal para predizer a presença de DNA proviral foi de 18,11. Razões S/CO elevadas foram mais associadas à detecção de DNA proviral. Em suma, o valor de S/CO <4 sugere a exclusão de infecção por HTLV e o risco de transmissão pelo sangue (AU).

Detection and analysis of hepatitis B virus serum markers in children treated in Wuhan Children's Hospital / 公共卫生与预防医学

Objective To investigate the status of hepatitis B virus (HBV) infection in children in Wuhan, and to analyze the expression pattern and distribution of serum markers. Methods Five serum markers of HbsA, HbsAb, HbeAg, HbeAb and HBcAb were detected by electrochemiluminescence immunoassay in 67 027 children aged 0-18 years including inpatients, outpatients, and physical examinees in Wuhan Children's Hospital. SPSS24.0 statistical software was used to analyze the results by age and gender. Results The “all negative” detection rate of all 67,027 children was 18.98%. There was a significant difference in the positive rate of HBcAb between male and female. The positive rate of HBcAb was higher in 0~28 days and 1~12 months group and decreased significantly after 1 year old. The positive rate of HBcAb was 5.02% in 1-14 years old but increased slightly in 15-18 years old. Among HBsAb positive children, the positive rate of HBsAb reached the peak of 95.65% in 1~2 years old group and the lowest of 68.90% in 6~14 years old group, and gradually decreased before 15 years old. Among the children with HBsAb concentration ≥100 IU/L, the proportion of 1~2 years old group was the highest (76.99%), and the proportion of 6~14 years old group was the lowest (40.99%). A total of 20 HBsAb serum marker expression patterns were detected, and the detection rates of “single HBsAb+”, “all negative”, “HBsAb+/HBcAb+”, and “HBsAb+/HBeAb+/HBcAb+” were 71.40%, 18.98%, 4.80% and 4.20%, respectively. Among them, 11 kinds of uncommon expression patterns were detected, and 9 kinds of uncommon expression patterns were detected in neonates, with a detection rate of 1.21%, which was higher than that in other age groups. Among all serological patterns, only the detection rate of “single HBcAb+” showed a statistical difference between male and female. Conclusion The HBV infection rate in all ages of 0~18 years old children in Wuhan is low. “Single HBsAb+” is the main serological pattern, and the concentration distribution of HBsAb is mostly in the range of 100-999 IU /L. There is a high “all negative” detection rate. School-age children should be inoculated with hepatitis B vaccine, which may be beneficial to reduce the risk of infection.

Orthogonal quantification of soluble inducible T-cell costimulator(ICOS)in healthy and diseased human serum / 药物分析学报

Inducible T-cell costimulator(ICOS),a homodimeric protein expressed on the surface of activated T-cells,is being investigated as a potential therapeutic target to treat various cancers.Recent studies have re-ported aberrant increases in the soluble form of ICOS(sICOS)in human serum in disease-state patients,primarily using commercial ELISA kits.However,results from our in-house immunoassay did not show these aberrant increases,leading us to speculate that commercial sICOS ELISAs may be prone to inter-ference.We directly tested that hypothesis and found that one widely used commercial kit yields false-positives and is prone to human anti-mouse antibody interference.We then analyzed a panel of healthy,cancer,chronic hepatitis C virus,systemic lupus erythematosus,and diffuse cutaneous systemic sclerosis human serum using our in-house immunoassay and reported the measured sICOS concentrations in these populations.Since even well characterized immunoassay methods are prone to non-specific interference,we also developed a novel sICOS LC-MS/MS method to confirm the results.Using these orthogonal approaches,we show that sICOS is a low abundance soluble protein that cannot be measured above approximately 20 pg/mL in human serum.

Study on Reentry Evaluation Mode for Blood Donors Used to be HBV Reactive in Jiangsu Province / 中国实验血液学杂志

OBJECTIVE@#To evaluate the risk of reentry in HBV reactive blood donors and feasibility of HBV reentry strategy.@*METHODS@#HBsAg+ or HBV DNA+ donors who had been quarantined for more than 6 months in Jiangsu Province could propose for reentry application. Blood samples were routinely screened by dual-ELISA for HBsAg, anti-HCV, HIV Ab/Ag, and anti- Treponema pallidum and those non-reactive ones were tested by minipool nucleic acid testing (NAT) for three times. To identify occult HBV donors, samples of NAT non-reactive were further tested by electrochemiluminescence immunoassay (ECLIA) for HBV seromarkers (including HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb). Donors of only 4 ECLIA patterns were accepted to reentry, including all 5 HBV seromarkers negative, anti-HBs only but having history of hepatitis B vaccine injection, HBcAb only, HBsAb+ / HBcAb+ with HBsAb more than 200 IU/L. Additionally, the detection rate of HBV infection was compared between routine screening mode and ECLIA, as well as the reentry qualified rate of HBsAg+ and HBV DNA+ blood donors.@*RESULTS@#From Oct. 2016 to Aug. 2019, a total of 737 HBV reactive donors had applied for reentry, including 667 HBsAg+ reactive and 70 HBV DNA+ reactive donors. Among 3 screening methods, the highest HBV detection rate (43.15%, 318/737) was observed on ECLIA, while only 4.75% (35/737) on ELISA and 3.12% (23/737) on NAT, respectively. Among 4 qualified patterns of HBV serological markers, the highest proportion was found in the all negative group (22.90%, 155/677), followed by the group with HBsAb+ only and history of hepatitis B vaccine injection (19.35%, 131/677), and the median concentration of HBsAb was 237.7 IU/L. The unqualified rate of HBV DNA+ donors was 82.86%, which was significantly higher than 47.98% of HBsAg+ donors.@*CONCLUSION@#Routine screening tests merely based on ELISA and NAT could miss occult HBV donors and may not be sufficient for blood safety. HBsAb concentration and vaccine injection history should be included in the evaluation of HBV reactive donors who intend to apply for reentry. There is a relatively larger residual risk of occult HBV infection in blood donors quarantined for HBV DNA reactive.

Case report of pseudoelevated serum testosterone in women and literature review / 中华检验医学杂志

Objective:The characteristics of women with false elevated testosterone were analyze and the literature was reviewed to provide reference for clinical laboratory identification of false elevated testosterone.Methods:The characteristics of three patients with false elevated testosterone in Peking Union Medical College Hospital were analyzed retrospectively, and the results of different detection platforms and methods for the determination of testosterone levels were compared. International and domestic literatures related to false elevation of testosterone and detection methods of testosterone were searched for a comprehensive analysis from PUBMED and CNKI.Results:The levels of testosterone in 3 female patients were elevated by immunoassay and normal by mass spectrometry. They were excluded from the diagnosis of hyperandrogenemia. A total of 38 literatures related to testosterone detection were retrieved, of which 9 case reports of pseudohyperandrogenemia, among which 12 cases of pseudohyperandrogenemia were reported in 2 domestic literatures in 2021. All cases were confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Previous studies have clearly indicated that the result of routine immunoassay in clinical laboratory for the determination of female testosterone have poor correlation with the results of LC-MS/MS, with varying degrees of deviation.Conclusions:Immunoassay tests for female testosterone is susceptible to interference and lead to elevated false results. It is suggested that clinical laboratories evaluate the detection methods used and establish a identification program, and confirm samples with suspected pseudoelevated testosterone elevation using other immune platforms or LC-MS/MS.

Performance evaluation of some domestically produced biochemical reagents / 中华检验医学杂志

Objective:To evaluation the performance of a total of 40 clinical biochemical reagents from three domestic manufacturers and two foreign manufacturers, and evaluate their clinical application value.Methods:The Beckman AU5400 automatic biochemical analyzer was used to verify the performance of 40 kinds of commonly used clinical biochemical reagents from three domestic manufacturers of Sichuan Maccura, Ningbo Medical System, and Shanghai Fosun Long March, and two foreign imported manufacturers of Roche and Japan′s Hitachi. The analysis samples were selected from the serum of patients who underwent clinical testing in Nanjing Drum Tower Hospital hospital from December 2021 to June 2022. Refer to China′s national health industry standards, China′s national pharmaceutical industry standards, the US Clinical Laboratory Standards Institute (CLSI) for the performance evaluation standards of in vitro diagnostic reagents, and the methods recommended in the relevant regulations of China′s State Food and Drug Administration on the management of in vitro diagnostic reagents. The precision, linear range, open bottle stability, interchangeability of calibrators and accuracy from different batches of 40 reagents were evaluated and validated. Simple linear regression analysis was used for linear regression, and P<0.05 indicated that the regression was statistically significant. Results:The overall precisions of 40 reagents were fine, except for one domestic reagent with low-level intra-batch coefficient of variation ( CV) exceeding the range declared in the specification. The intra-and inter-batch CVs of the remaining reagents were all smaller than those declared in their respective specifications. The linear ranges of domestic reagents and imported ones have achieved the linear ranges declared by each manufacturer. There were no statistical differences on the measurements between the reagents from open bottle of 30 days and the corresponding new ones for 40 reagents( P>0.05). The test values of domestic reagents and imported reagents after exchange of different batches of calibrators were within the ranges declared by each manufacturer. Both domestic reagents and imported reagents have passed the accuracy verification. Conclusions:The performance index of 27 biochemical detection indicators of the three domestic manufacturers are basically consistent with those of imported reagents, meeting the requirements of clinical biochemical laboratories. However, the bottle opening stability and anti-interference performance of some detection reagents needs to be improved.

Establishment and verification validation of plasma free metanephrines measurement by chemiluminescence immunoassay / 中华检验医学杂志

Objective:To establish a chemiluminescence immunoassay method for free metanephrines measurement in plasma, and verify its performance.Methods:The samples (calibrator, plasma, and quality control sample) were extracted and acylated, the processed analyte samples were then competed with the immobilized specific antigens of metanephrine (MN), normetanephrine (NMN) respectively, to combine specific antibodies marked by Horseradish Peroxidase (HRP), the immobilized antigens-antibody-HRP immune reaction product was then formed through the immune reaction, which could be detected through measurement of HRP catalytic substrate luminescence. Performance verification was performed using specificity, sensitivity,precision,thermally accelerated stability, and accuracy metrics.Results:The established detection methods for MN and NMN have no obvious cross-reactions when detecting multiple structural analogs; the limit of blank, limit of detection and functional sensitivity of the MN detection reagent was 10.51, 21.15 and 25.76 ng/L, and the performance of the NMN detection reagent was 11.54, 28.43 and 31.29 ng/L; the coefficients of variation of the detection reagents for MN and NMN were 2.41%-5.38% and 1.61%-3.22% respectively; the accelerated stability test of the two detection reagents showed that the reagents could be stored stably for 1 year at 2-8 ℃; and the measurement results of this method can be traced to the mass spectrometer.Conclusion:In this study, a chemiluminescence immunoassay detection method for free metanephrines in plasma is successfully established.