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.

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.

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.

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.

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.

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

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.

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.

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.

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).

Diagnostic accuracy of a SARS-CoV-2 rapid test and optimal time for seropositivity according to the onset of symptoms / Acurácia diagnóstica de um teste rápido para SARS-CoV-2 e tempo ótimo para a soropositividade a partir do início dos sintomas / Precisión diagnóstica del test rápido SARS-CoV-2 y período óptimo para la seropositividad según la aparición de síntomas

Point-of-care serological tests for SARS-CoV-2 have been used for COVID-19 diagnosis. However, their accuracy over time regarding the onset of symptoms is not fully understood. We aimed to assess the accuracy of a point-of-care lateral flow immunoassay (LFI). Subjects, aged over 18 years, presenting clinical symptoms suggestive of acute SARS-CoV-2 infection were tested once by both nasopharyngeal and oropharyngeal RT-PCR and LFI. The accuracy of LFI was assessed in periodic intervals of three days in relation to the onset of symptoms. The optimal cut-off point was defined as the number of days required to achieve the best sensitivity and specificity. This cut-off point was also used to compare LFI accuracy according to participants' status: outpatient or hospitalized. In total, 959 patients were included, 379 (39.52%) tested positive for SARS-CoV-2 with RT-PCR, and 272 (28.36%) tested positive with LFI. LFI best performance was achieved after 10 days of the onset of symptoms, with sensitivity and specificity of 84.9% (95%CI: 79.8-89.1) and 94.4% (95%CI: 91.0-96.8), respectively. Although the specificity was similar (94.6% vs. 88.9%, p = 0.051), the sensitivity was higher in hospitalized patients than in outpatients (91.7% vs. 82.1%, p = 0.032) after 10 days of the onset of symptoms. Best sensitivity of point-of-care LFI was found 10 days after the onset of symptoms which may limit its use in acute care. Specificity remained high regardless of the number of days since the onset of symptoms.

Os testes sorológicos no local de atendimento (point-of-care) para a infecção pelo SARS-CoV-2 têm sidos utilizados para o diagnóstico da COVID-19. Entretanto, não está plenamente elucidada a acurácia dos testes ao longo do tempo em relação ao início dos sintomas. Nosso objetivo foi de avaliar a acurácia, no local de atendimento, do imunoensaio de fluxo lateral (LFI). Pacientes com ≥ 18 anos de idade que apresentavam sintomas clínicos sugestivos de infecção aguda pelo SARS-CoV-2 foram testados uma vez com RT-PCR da nasofaringe e orofaringe, além do LFI. A acurácia do LFI foi avaliada com intervalos periódicos de 3 dias a partir do início dos sintomas. O ponto de corte ótimo foi definido como o número necessário de dias para atingir a melhor sensibilidade e especificidade. Esse ponto foi utilizado também para comparar a acurácia do LFI de acordo com a situação do paciente (ambulatorial ou hospitalizado). Foram incluídos 959 pacientes, dos quais 379 (39,52%) testaram positivos para SARS-CoV-2 pelo RT-PCR e 272 (28,36%) pelo LFI. Foi atingido o melhor desempenho para o LFI com 10 dias a partir do início dos sintomas, com sensibilidade e especificidade de 84,9% (IC95%: 79,8-89,1) e 94,4% (IC95%: 91,0-96,8), respectivamente. Embora a especificidade não tenha sido diferente entre os grupos de pacientes (94,6% vs. 88,9%, p = 0,051), a sensibilidade foi mais alta nos pacientes hospitalizados que nos ambulatoriais (91,7% vs. 82,1%, p = 0,032) no dia 10 depois do início dos sintomas. A melhor sensibilidade do LFI no local de atendimento ocorre 10 dias depois do início dos sintomas, o que pode limitar seu uso no atendimento agudo. A especificidade permanece alta, independentemente do número de dias desde o início dos sintomas.

Los puestos de atención para pruebas serológicas del SARS-CoV-2 han sido usado para la diagnosis de la COVID-19. No obstante, su precisión a lo largo del tiempo, en lo que respecta a la aparición de los síntomas, no se ha comprendido completamente. Nuestro objetivo fue evaluar la precisión de un puesto de atención de inmunoanálisis de flujo lateral (LFI). Se hizo pruebas a individuos ≥ 18 años, presentando síntomas clínicos compatibles con una infección aguda de SARS-CoV-2, tanto vía nasofaríngea y orofaríngea RT-PCR, como LFI. La precisión de LFI fue evaluada en intervalos periódicos de 3 días con respecto a la aparición de los síntomas. El punto óptimo de corte se definió como el número de días requerido para alcanzar la mejor sensibilidad y especificidad. Este punto también se usó para comparar la precisión del LFI, según el estatus de los participantes: ambulatorios u hospitalizados. Se incluyeron a 959 pacientes, 379 (39,52%) dieron positivo en las pruebas de SARS-CoV-2 RT-PCR, y 272 (28,36%) fueron positivos en los LFI. Se alcanzó el mejor rendimiento de los LFI tras 10 días de la aparición de los síntomas, con una sensibilidad y especificidad de un 84,9% (IC95%: 79,8-89,1) y 94,4% (IC95%: 91,0-96,8), respectivamente. A pesar de que la especificidad no fue diferente (94,6% vs. 88,9%, p = 0,051), la sensibilidad fue mayor en pacientes hospitalizados que en los ambulatorios (91,7% vs. 82,1%, p = 0,032) tras 10 días desde la aparición de los síntomas. La mejor sensibilidad LFI del puesto de cuidado se produce tras 10 días de la aparición de los síntomas, lo que quizás limite su uso en el cuidado de urgencias. La especificidad permanece alta independientemente del número de días desde la aparición de los síntomas.

Can we use Ki67 expression to predict prostate cancer aggressiveness? / Podemos usar a expressão de Ki67 para prever a agressividade do câncer de próstata?

ABSTRACT Introduction: specialists have an urge for biomarkers that can discriminate indolent prostate cancer from aggressive tumors. Ki67 is a proliferation marker, and its expression is associated with the aggressiveness of several cancers. Objective: analyze the expression of Ki67 in prostate cancer samples correlating with the aggressiveness of the disease. Methods: Ki67 mRNA levels were determined utilizing data from a TCGA cohort (Tumor(n)=492 and control(n)=52). The protein expression was determined on 94 biopsies from patients by immunohistochemical assay. Results: in mRNA, the Ki67 upregulation is associated with cancer tissue (p<0.0001) and worst disease-free survival (p=0.035). The protein upregulation is associated with increase of the ISUP score (p<0.0001), cancer stage (p=0.05), biochemical recurrence (p=0.0006) and metastasis (p<0.0001). We also show a positive correlation between Ki67 expression and ISUP score (r=0.5112, p<0.0001) and disease risk stratification (r=0.3388, p=0.0009). Ki67 expression is a factor independently associated with biochemical recurrence (p=0.002) and metastasis (p<0.0001). Finally, the patients with high Ki67expression shows better survival regarding biochemical recurrence (p=0.008) and metastasis (p=0.056). Patients with high Ki67 expression are 2.62 times more likely to develop biochemical recurrence (p=0.036). Conclusion: Ki67 upregulation is associated with prostate cancer aggressiveness.

RESUMO Introdução: especialistas precisam biomarcadores que podem discriminar o câncer de próstata indolente de tumores agressivos. Ki67 é um marcador de proliferação, e sua expressão está associada à agressividade de vários tumores. Objetivo: analisar a expressão do Ki67 em amostras de câncer de próstata correlacionando com a agressividade da doença. Métodos: os níveis de mRNA de Ki67 foram determinados utilizando dados de uma coorte de TCGA (Tumor(n)=492 e controle(n)=52). A expressão da proteína foi determinada em 94 biópsias de pacientes por ensaio imuno-histoquímica. Resultados: no mRNA, a superexpressão Ki67 está associada ao tecido canceroso (p<0,0001) e à pior sobrevida livre de doença (p=0,035). A superexpressão proteica está associada ao aumento do escore ISUP (p<0,0001), estágio de câncer (p=0,05), recorrência bioquímica (p=0,0006) e metástase (p<0,0001). Também mostramos uma correlação positiva entre a expressão Ki67 e o escore ISUP (r=0,5112, p<0,0001) e a estratificação de risco de doença (r=0,3388, p=0,0009). A expressão Ki67 é um fator independentemente associado à recorrência bioquímica (p=0,002) e metástase (p<0,0001). Finalmente, os pacientes com alta expressão de Ki67 expression mostram melhor sobrevivência em relação à recorrência bioquímica (p=0,008) e metástase (p=0,056). Os pacientes com alta expressão de Ki67 são 2,62 vezes mais propensos a desenvolver recorrência bioquímica (p=0,036). Conclusão: a superexpressão Ki67 está associada à agressividade do câncer de próstata.

Technical performance of a lateral flow immunoassay for detection of anti-SARS-CoV-2 IgG in the outpatient follow-up of non-severe cases and at different times after vaccination: comparison with enzyme and chemiluminescent immunoassays

ABSTRACT This study assessed the technical performance of a rapid lateral flow immunochromatographic assay (LFIA) for the detection of anti-SARS-CoV-2 IgG and compared LFIA results with chemiluminescent immunoassay (CLIA) results and an in-house enzyme immunoassay (EIA). To this end, a total of 216 whole blood or serum samples from three groups were analyzed: the first group was composed of 68 true negative cases corresponding to blood bank donors, healthy young volunteers, and eight pediatric patients diagnosed with other coronavirus infections. The serum samples from these participants were obtained and stored in a pre-COVID-19 period, thus they were not expected to have COVID-19. In the second group of true positive cases, we chose to replace natural cases of COVID-19 by 96 participants who were expected to have produced anti-SARS-CoV-2 IgG antibodies 30-60 days after the vaccine booster dose. The serum samples were collected on the same day that LFIA were tested either by EIA or CLIA. The third study group was composed of 52 participants (12 adults and 40 children) who did or did not have anti-SARS-CoV-2 IgG antibodies due to specific clinical scenarios. The 12 adults had been vaccinated more than seven months before LFIA testing, and the 40 children had non-severe COVID-19 diagnosed using RT-PCR during the acute phase of infection. They were referred for outpatient follow-up and during this period the serum samples were collected and tested by CLIA and LFIA. All tests were performed by the same healthcare operator and there was no variation of LFIA results when tests were performed on finger prick whole blood or serum samples, so that results were grouped for analysis. LFIA's sensitivity in detecting anti-SARS-CoV-2 IgG antibodies was 90%, specificity 97.6%, efficiency 93%, PPV 98.3%, NPV 86.6%, and likelihood ratio for a positive or a negative result were 37.5 and 0.01 respectively. There was a good agreement (Kappa index of 0.677) between LFIA results and serological (EIA or CLIA) results. In conclusion, LFIA analyzed in this study showed a good technical performance and agreement with reference serological assays (EIA or CLIA), therefore it can be recommended for use in the outpatient follow-up of non-severe cases of COVID-19 and to assess anti-SARS-CoV-2 IgG antibody production induced by vaccination and the antibodies decrease over time. However, LFIAs should be confirmed by using reference serological assays whenever possible.

Validation of the COVID-19 IgG/IgM Rapid Test Cassette (BNCP ­ 402 and BNCP402) in a South African setting

Background: Different diagnostic tools could improve early detection of coronavirus disease 2019 (COVID-19). A number of antibody-based serological point-of-care tests have been developed to supplement real-time reverse transcriptase polymerase chain reaction (RT-PCR)-based diagnosis. This study describes the validity of an antibody test, namely the immunoglobulin G (IgG)/immunoglobulin M (IgM) Rapid Test Cassette® (BNCP ­ 402 and BNCP402), manufactured by Spring Healthcare Services. Methods: A prospective cohort validation study was undertaken at Chris Hani Baragwanath Academic Hospital between 16 July 2020 and 12 August 2020. A total of 101 patients admitte as COVID-19 cases under investigation were included in the study. They were divided into two categories depending on time since symptom onset: testing performed within seven days (early cohort) and after seven days (late cohort). The rapid antibody test was compared to the RT-PCR. Results: Overall, the test has a sensitivity and specificity of 85.2% and 80.0%, respectively, for a combination of IgG and IgM. Sensitivity and specificity of IgG testing alone were 81.5% and 85%. Sensitivity improved for testing with increasing time from symptom onset; however, specifity was not significantly different. Conclusion: The study data adds to the body of evidence that because of relatively low sensitivity and specificity, there is a limited role for antibody-based point-of-care testing in the acute phase of COVID-19 infection, as was the case with this IgG/IgM Rapid Test Cassette (BNCP ­ 402 and BNCP402). There may exist a role for such testing in patients recovered from prior COVID-19 infection or in seroprevalence studies; however, additional evaluations at later timepoints from symptom onset are required.

Comparison of Rapid Influenza Diagnostic Tests With Digital Readout Systems and Conventional Rapid Influenza Diagnostic Test for Influenza Virus Detection

@#Introduction: Rapid diagnosis for influenza virus infection is essential for proper patient management, delivering prompt treatment and reducing unnecessary antiviral therapy. Early diagnosis helps in disease prevention and control. Real-time reverse transcription-polymerase chain reaction (RT-PCR) assay yields high sensitivity and specificity in detecting influenza virus infection. However, it is relatively expensive and requires trained personnel and special equipment. In this study, we compared two rapid influenza diagnostic tests (RIDTs): digital readout systems (STANDARD™ F Influenza A/B FIA, fluorescence immunoassay) and conventional visual confirmation (QuickNavi™-Flu2, chromatography immunoassay) with the real-time RT-PCR assay. Methods: Two hundred ninety-eight respiratory samples were obtained from patients suspected of influenza infection at Siriraj Hospital from December 2018 to December 2019. Results: Real-time RT-PCR results showed the detection of influenza A virus in 99 samples (60%), influenza B virus in 61 samples (37%) and co-infection by both viruses in 5 samples (3%) by the real-time RT-PCR assay. The QuickNavi™-Flu2 sensitivity for detecting influenza A and B viruses were 81.73% and 84.85%, and the specificity was 100%. The STANDARD™ F Influenza A/B FIA sensitivity for detecting influenza A and B viruses were 84.62% and 83.33%, respectively. The specificity for influenza A virus detection was 99.25% and 94.74% for influenza B virus. Conclusion: The STANDARD™ F Influenza A/B FIA and the QuickNavi™-Flu2 showed acceptable and comparable sensitivity and specificity. Both RIDTs are potential alternative methods of real-time RT-PCR for rapid screening of influenza virus infection.

Study on specific antibodies in patients infected with SARS-CoV-2 and recipients of inactivated vaccine / 中华微生物学和免疫学杂志

Objective:To detect the serum levels of SARS-CoV-2-specific IgM and IgG antibodies in patients infected with SARS-CoV-2 and recipients of inactivated vaccine in different periods for understanding their variation patterns in vivo. Methods:Chemiluminescence immunoassay was used to detect the levels of SARS-CoV-2-specific IgM and IgG antibodies in 144 serum samples of 44 COVID-19 patients, 381 serum samples of 118 asymptomatic infected cases and 398 serum samples of 273 inactivated vaccine recipients collected at different periods. The results were statistically analyzed together with basic characteristics and vaccination status.Results:The positive rates of IgM antibody in COVID-19 patients, asymptomatic infected cases and inactivated vaccine recipients were 52.27% (23/44), 23.73% (28/118) and 14.29% (39/273). The positive rate of IgM antibody was higher in COVID-19 patients than in asymptomatic infected cases and vaccine recipients (χ 2=12.106, P=0.001; χ 2=34.755, P<0.001). The positive rates of IgG antibody in the three populations were 100.00% (44/44), 97.46% (115/118) and 98.81% (166/168), and the differences were not statistically significant (χ 2=2.944, P=0.229). In COVID-19 patients, the concentration of IgM antibody in <40 years old group was lower than that in ≥40 years old group (Waldχ 2=6.609, P=0.010), and the concentration of IgG antibody in patients with vaccination was higher than that in patients without vaccination (Waldχ 2=12.402, P<0.001). In asymptomatic infected cases, the concentration of IgG antibody was higher in people with vaccination than in those without vaccination (Waldχ 2=4.530, P=0.033). In SARS-CoV-2 vaccine recipients, the concentration of IgG antibody in <40 years old group was higher than that in ≥40 years old group (Waldχ 2=9.565, P=0.002). Dynamic analysis of antibody levels showed that from week 1 to week 9, the concentrations of IgM and IgG antibodies in COVID-19 patients were higher than those in asymptomatic infected cases and vaccine recipients. Conclusions:The concentrations of IgM and IgG antibodies in COVID-19 patients were higher than those in asymptomatic infected cases and inactivated vaccine recipients. COVID-19 patients aged ≥40 years had higher level of IgM antibody. COVID-19 patients and asymptomatic infected cases who had received vaccination had higher concentration of IgG antibody. Inactivated vaccine showed good immunogenicity after whole course of immunization, and the IgG antibody level in <40 years old group was higher.