Uso de plasma de convalecientes de COVID-19 en pacientes hospitalizados por SARS-CoV-2 de moderada grave-dad en la Región de Los Ríos, Chile / Assessing Convalescent Plasma Efficacy in Moderate COVID-19 Hospitalizations: A Bicentric Retrospective Study

INTRODUCCIÓN: COVID-19 cobró millones de vidas especialmente en la era pre-vacunas. Estudios preliminares mostraban eficacia promisoria del plasma de personas convalecientes anti SARS-CoV-2 (PPC). Objetivo: evaluar la eficacia del PPC en hospitalizados por COVID-19 de moderada gravedad. MATERIAL Y MÉTODOS: Estudio retrospectivo, bicéntrico, en adultos hospitalizados por COVID-19 moderado (no crítico) que requirieron oxigenoterapia. Al plasma donado por sobrevivientes de cuadros leves (600 cc) se les realizó búsqueda de IgG anti SARS-CoV-2. Se evaluó su impacto en mortalidad, estadía hospitalaria (días) y necesidad de ventilación mecánica (VMI). RESULTADOS: De los 119 pacientes incluidos, 58% eran hombres (edad mediana 60 años), 88% poseía comorbilidad y 43% tenía "CALL score" de alto riesgo. 43 pacientes (36%) recibieron PPC, sólo 15 (12,6%) precozmente (< 7 días). 22 pacientes debieron trasladarse a unidad intensiva, 18 recibieron VMI y 15 fallecieron (12,6%). El uso de PPC no se asoció a cambios en la mortalidad (p = 0,16), necesidad de VMI (p = 0,79) ni en la estadía hospitalaria (p = 0,24). Su administración en forma precoz (< 7 días de síntomas) tampoco demostró asociación significativa. La presencia de cardiopatía y el requerir posteriormente VMI fueron factores independientes asociados a mortalidad. CONCLUSIONES: El uso de PPC en pacientes hospitalizados por COVID-19 de moderada gravedad no se asoció a menor mortalidad, estadía hospitalaria ni necesidad de VMI.

INTRODUCTION: COVID-19 claimed millions of lives, mainly in the pre-vaccine era. Preliminary studies showed promising efficacy of convalescent plasma against SARS-CoV-2 (CP). Objective: To evaluate the efficacy of CP in patients hospitalized for COVID-19 with moderate severity. METHODS: Retrospective, bicentric study including adults hospitalized for moderate (non-critical) COVID-19 who required oxygen therapy. CP donated by survivors of mild cases (600 cc) were searched for IgG anti-SARS-CoV-2. Its impact on mortality, hospital stay (days), and need for mechanical ventilation (IMV) was evaluated. RESULTS: Of the 119 patients included, 58% were men (median age 60 years), 88% had comorbidity, and 43% had a high-risk CALL score. Forty-three patients (36%) received CP, only 15 (12.6%) early (< 7 days). Twenty-two patients had to be transferred to the intensive care unit; 18 received IMV, and 15 died (12.6%). The use of CP was not associated with changes in mortality (p = 0.16), need for IMV (p = 0.79), or hospital stay (p = 0.24). Its early administration (< 7 days of symptoms) did not show a significant association either. The presence of heart disease and subsequently requiring IMV were independent factors of mortality. CONCLUSIONS: The use of CP in patients hospitalized for moderately severe COVID-19 was not associated with lower mortality, hospital stay, or the need for IMV.

Evaluación de los niveles de anticuerpos para COVID-19 en pacientes que concurrieron a un laboratorio de la Ciudad Autónoma de Buenos Aires / Evaluation of antibody levels for COVID-19 patients who attended a laboratory in Buenos Aires city

Resumen A fines de 2019 se describieron en China los primeros casos de neumonía asociada a SARS-CoV-2. La OMS la llamó COVID-19 y declaró emergencia sanitaria internacional en enero de 2020, ante la rápida diseminación de la infección a nivel mundial. En la Argentina los primeros casos se detectaron en marzo de 2020 y casi inmediatamente comenzaron a utilizarse métodos directos para detección de SARS-CoV-2 (RT PCR, LAMP, entre otros). Los métodos para detección de anticuerpos fueron aprobados posteriormente y no son de elección para realizar el diagnóstico de la enfermedad. En este laboratorio estos últimos comenzaron a utilizarse durante la primera ola de COVID-19 y con estos datos se realizó un estudio observacional retrospectivo de una serie de pacientes con resultados de anticuerpos IgG positivos. Se calculó la tasa de notificación al Sistema Integrado de Información Sanitaria Argentino (SISA) y se evaluaron los niveles de anticuerpos, agrupándolos de acuerdo a: si estaban notificados y si tenían resultado de RT PCR/LAMP, los síntomas presentados y el tiempo transcurrido post RT PCR/LAMP. No fue posible demostrar diferencias entre los pacientes con RT PCR/LAMP detectable y no detectable, tampoco con el tipo de síntomas declarados ni con respecto a los días transcurridos posinfección. Sin embargo, se observó que existía una diferencia significativa entre el grupo de pacientes notificados y no notificados y una alta tasa de pacientes con anticuerpos positivos que no fueron declarados en SISA, por lo que su detección podría considerarse como marcador subrogante de contacto cuando no fuera posible arribar al diagnóstico por métodos moleculares.

Abstract At the end of 2019 the first cases of SARS-CoV-2-associated pneumonia were reported in China. Consequently, the World Health Organization (WHO) named it COVID-19 and in January 2020, it declared the international health emergency due to the worldwide rapid spread of the infection. The first cases in Argentina were detected in early March 2020. Molecular tests like RT PCR and LAMP were immediately used. Serological tests for antibody detection were approved a few months later; however, these are still not the preferred evidiagnostic method for the disease. In our laboratory, the latter began to be used during the first wave of COVID-19. With the results obtained in that moment, an observational retrospective study in a cohort of patients who came voluntarily to test for SARS-CoV-2 IgG antibodies and whose results were positive was performed. The notification rate to the Argentine Integrated System for Health Information (SISA for its acronym in Spanish) was calculated and antibody levels were evaluated, clustering them according to the following facts: if the event had been notified to the SISA and if they had a previous RT PCR/LAMP result, the symptoms experienced by these patients and the time elapsed between RT PCR/LAMP and antibody test results. It was not possible to demonstrate differences between patients with detectable and undetectable RT PCR/LAMP, neither with the type of declared symptoms nor with respect to the days elapsed post-infection. However, it was found that there was a significant difference between notified and non-notified patients, and a high rate of non-notified patients with positive antibodies. Therefore, antibodies level might be considered as a surrogate marker of SARS-CoV-2 contact when a diagnosis through molecular methods is not available.

Resumo No final de 2019 foram reportados na China os primeiros casos de pneumonia associados a SARS-CoV-2. A Organização Mundial da Saúde (OMS) chamou-a de COVID-19 e declarou emergência sanitária internacional em janeiro de 2020, frente à rápida disseminação da infecção em nível mundial. Na Argentina os primeiros casos foram detectados no início de março de 2020 e de forma quase imediata, começaram a ser utilizados métodos diretos para detectar SARS-CoV-2 (RT PCR, LAMP, entre outros). Os métodos para detectar anticorpos foram posteriormente aprovados e não são de eleição para realizar o diagnóstico da doença. Em nosso laboratório, a utilização destes últimos começou durante a primeira onda de COVID-19 e com os resultados obtidos nesse momento foi realizado um estudo observacional retrospectivo de uma série de pacientes com resultados de anticorpos IgG positivos. Foi calculada a taxa de notificação ao Sistema Integrado de Informação em Saúde da Argentina (SISA) e foram avaliados os níveis de anticorpos agrupando- os de acordo a: se estavam notificados e se eles tinham resultado de RT PCR/LAMP, os sintomas apresentados e o tempo decorrido pós RT PCR/LAMP. Não foi possível demonstrar diferenças entre pacientes com RT PCR/LAMP detectável e não detectável, nem com o tipo de sintomas declarados nem com relação aos dias decorridos após a infecção. No entanto, verificou-se que existia uma diferença significativa entre o grupo de pacientes notificados e não notificados, e uma alta taxa de pacientes com anticorpos positivos que não foram declarados no SISA, portanto, sua detecção poderia ser considerada como um marcador substituto de contato quando não fosse possível chegar ao diagnóstico por métodos moleculares.

Evaluación en condiciones de campo de una prueba serológica rápida para detección de anticuerpos IgM e IgG contra SARS-CoV-2 / Evaluation of a rapid serological test for detection of IgM and igG antibodies against SARS-CoV-2 under field conditions

RESUMEN Objetivos: Determinar el rendimiento diagnóstico adicional de una prueba serológica rápida que detecta anticuerpos IgM e IgG contra SARS-CoV-2 en relación a la reacción en cadena de polimerasa reversa en tiempo real (RT-PCR). Materiales y métodos: Se realizó un estudio transversal incluyendo pacientes hospitalizados por COVID-19 en tres hospitales, trabajadores de salud expuestos a la infección y pacientes ambulatorios que cumplían criterios de caso sospechoso, a quienes se les realizó la prueba molecular (RT-PCR) y la prueba serológica rápida. Se evaluó el rendimiento diagnóstico adicional de las prueba serológica rápida en relación a la molecular. Asimismo, se realizó la estimación de sensibilidad y especificidad de dichas pruebas. Resultados: Se incluyeron 144 personas. La prueba serológica rápida obtuvo un 19,4% de resultados positivos en comparación con un 11,1% en la prueba molecular (p=0,03). La prueba serológica rápida detectó 21 casos que habían resultado negativos por el RT-PCR inicial y el rendimiento diagnóstico adicional fue de 56,8% en comparación al RT-PCR. El rendimiento diagnóstico adicional fue 50,0% durante la primera semana, 70,0% durante la segunda y 50,0% durante la tercera semana de inicio de síntomas. La sensibilidad de la prueba serológica rápida fue de 43,8% y la especificidad del 98,9%. Conclusiones: La prueba serológica rápida logró detectar un mayor número de casos respecto a la molecular, sobre todo a partir de la segunda semana de inicio de síntomas. Además, presentó una alta especificidad. Los resultados mostrarían su utilidad como prueba complementaria a la prueba molecular, especialmente durante la segunda y tercera semana de enfermedad.

ABSTRACT Objective: To determine the additional diagnostic performance of a rapid serological test for detection of IgM and IgG antibodies compared to the real-time polymerase chain reaction (RT-PCR) test; for detection of SARS-CoV-2. Materials and methods: A cross-sectional study was carried out including patients hospitalized for COVID-19 in 3 hospitals, health workers exposed to the infection and outpatients who met suspicious case criteria, all of which underwent the molecular test (RT-PCR) and the rapid serological test. The additional diagnostic performance of rapid serological test was evaluated in comparison to molecular tests. Likewise, an approximation was made to the sensitivity and specificity of the rapid serological test. Results: 144 people were included. With the rapid test, 19.4% of positive results were obtained compared to 11.1% in the molecular test (p = 0.03). The rapid serological test detected 21 cases that had been negative by the initial (RT-PCR), providing an additional diagnostic performance of 56.8% compared to the RT-PCR. The additional diagnostic performance was 50.0% during the first week, 70.0% during the second week and 50.0% during the third week of symptom onset. The sensitivity of the rapid serological test was 43.8% and the specificity of 98.9%. Conclusions: The rapid serological test was able to detect a greater number of cases than those detected by the molecular test especially after the second week of onset of symptoms. It also showed high specificity. It is therefore useful as a complementary test to RT-PCR, especially during the second and third week of illness.

Standardizing Diagnosis of Helicobacter pylori Infection to Improve Diagnostic Accuracy / 胃肠病学

Eradication of Helicobacter pylori (Hp) is important for the prevention and treatment of chronic gastritis, peptic ulcer and gastric cancer. The Chinese consensus on the management of Hp infection has taken "confirmed Hp infection" as an indication for eradication. The World Gastroenterology Organisation global guideline states the "test-and-treat strategy" for Hp infection. Accurate diagnosis of Hp infection is a prerequisite for standardized eradication. There are many methods to diagnose Hp infection. Each has its advantages and disadvantages. Different methods are suitable for different diseases and patients, and each method has strict requirements for reagents, equipment, testers and patients. Therefore, increasing the awareness of physicians and testers about the standardized diagnosis of Hp infection is essential to improve the diagnostic accuracy.

Presencia de anticuerpos IgG antihelicobacter pylori en suero no se relaciona a factores de riesgo y síntomas de la enfermedad ácido-péptica en adultos jóvenes / Presence of anti-helicobacter pylori IgG antibodies in serum is not related to risk factors and symptoms of acid-peptic disease in young adults

Objetivo: determinar el valor diagnóstico de anticuerpos IgG anti-Helicobacter pylori ante sospecha clínica de enfermedad ácido-péptica en adultos jóvenes. Sujetos y métodos: estudiantes de la Carrera de Medicina de la Universidad Central del Ecuador que consintieron participar en una encuesta en línea y extracción de sangre venosa que fue sometida a una prueba inmunoenzimática para detección de anticuerpos. Resultados: se incluyeron 225 partícipes con un una edad promedio de 20 años; el estudio inmunoenzomático fue positivo en el 32,88% de muestras. La existencia de IgG anti-H. pylori no se relacionó estadísticamente a la presencia o ausencia de antecedentes patológicos personales, familiares o sociales. La acumulación de dos o tres síntomas no se relacionó con el hallazgo serológico. Conclusión: las pruebas serológicas para diagnóstico de gastritis o para tamizaje no son adecuadas para éste grupo de edad, toda vez que su positividad no se relaciona a síntomas, factores de riesgo conocidos de infección gástrica o desarrollo de patologías

Aims: to determine the diagnostic value of anti-Helicobacter pylori IgG antibodies in case of clinical suspicion of acid-peptic disease in young adults. Subjects and methods: students of the Medicine School of the Central University of Ecua- dor who agreed to participate in an online survey and venous blood collection that was sub- jected to an immunoenzymatic test for antibody detection. Results: 225 participants with an average age of 20 years were included; the immunoen- zomatic study was positive in 32.88% of samples. The existence of IgG anti H.pylori was not statistically related to the presence or absence of personal, family or social pathological his- tory. The accumulation of two or three symptoms was not related to the serological finding. Conclusion: serological tests for diagnosis of gastritis or screening are not suitable for this age group, since its positivity is not related to symptoms, known risk factors of gastric infec- tion or development of pathologies.

Performance of a rapid diagnostic test for the detection of visceral leishmaniasis in a large urban setting

Introduction Rapid diagnostic tests (RDTs) may improve the early detection of visceral leishmaniasis (VL), but their real-world performance requires additional study. Therefore, we evaluated the performance of an rK39-based RDT (Kalazar Detect™) for the detection of VL in an endemic, large urban area. Methods Data were collected from a registry of rK39 RDT performed at 11 emergency care units in Belo Horizonte, Brazil, and from a national database of reportable communicable diseases of the Sistema de Informação de Agravos de Notificação (SINAN). Results The rapid rK39 test was performed in 476 patients, with 114 (23.9%) positive results. The analysis of rK39 RDT performance was based on 381 (80%) cases reported to the SINAN database, of which 145 (38.1%) were confirmed cases. Estimates for sensitivity and specificity were 72.4% (95% CI: 64.6-79%) and 99.6% (95%CI: 97.6-99.9%), respectively. Positive and negative predictive values were estimated at 99.1% (95%CI: 94.9-99.8%) and 85.5% (95%CI: 80.8-89.1%), respectively. In addition, close agreement between the rK39 RDT and indirect immunofluorescence was observed. Conclusions In summary, the rK39 RDT showed a high specificity but only moderate sensitivity. In endemic areas for VL, treatment may be considered in cases with clinical manifestations and a positive rK39 RDT, but those with a negative test should be subjected to further investigation. .

The Comparison between Serologic Tests and Magicplex HepaTrio Real-time PCR in the Diagnosis of Viral Hepatitis

BACKGROUND: Magicplex HepaTrio Real-time PCR (Magicplex, Seegene, Korea) simultaneously detects and distinguishes each type of hepatitis A, hepatitis B, and hepatitis C viruses. We investigated the diagnostic performance of Magicplex in comparison with that of serologic test. METHODS: We tested and analyzed 184 serum samples for hepatitis A IgM antibody (IgM antiHAV), hepatitis B virus surface antigen (HBsAg), and anti-hepatitis C virus antibody (antiHCV). Serologic markers including IgM antiHAV, HBsAg, and antiHCV were tested with electrochemiluminescence immunoassay method. We calculated positive rates of the test results and concordance rates between serologic tests and Magicplex. RESULTS: The positive rates of IgM antiHAV, HBsAg, and antiHCV using serologic methods were 15.2% (28/184), 13.6% (25/184), and 8.2% (15/184), respectively. The positive rates of the corresponding viral nucleic acid detection by Magicplex were 18.5% (34/184), 16.3% (30/184), and 4.3% (8/184), respectively. The concordance rates between serologic test and Magicplex were 95.7% (176/184) in hepatitis A, 97.3% (179/ 184) in hepatitis B, and 96.2% (177/184) in hepatitis C. CONCLUSIONS: In our study, the concordance rates between Magicplex and traditional serologic tests are over 95%. Magicplex could not yet totally replace traditional serologic tests because there are some possibilities of cross reaction among the hepatitis viruses and false negative results in hepatitis C. If Magicplex resolves these problems, it would be a useful tool for screening test for the diagnosis of viral hepatitis as it provides an automated, easy, and simultaneous detection of the 3 major hepatitis viruses.

Differential Diagnosis of Secondary Glomerulonephritis / 대한내과학회지

Early diagnosis of glomerulonephritis is important in initiating appropriate treatment and controlling chronic glomerular injury that may eventually lead to end-stage renal disease. Although many patients with glomerular disease have only renal involvement, systemic presentations are not uncommon, as frequently resulted from an underlying systemic disease or a factor such as infections, drugs, or metabolic diseases. The presence of an underlying secondary reason should be investigated in each glomerular disease independent of its histopathologic type. Laboratory tests may include C3, C4, ANA, dsDNA, antineutrophil cytoplasmic antibody titers, a streptozyme test, HBV and HCV serologies, and in some cases, blood cultures, anti-glomerular basement membrane antibodies, and cryoglobulins. Although serologic tests may be helpful in establishing a diagnosis in some patients, a renal biopsy is usually performed even if serologic testing is positive. In addition, serologic test may assist in interpretation of the renal pathology.

A Study to Verify the Stability of Currently Stored Blood Donor Samples (A First Year Study) / 대한수혈학회지

BACKGROUND: The Korean Red Cross (KRC) has stored blood donor samples for 10 years under -20degrees C since 2004. These samples have been used for investigating transfusion related infections and for Look-back studies. We designed an experimental scheme to verify the stability of stored blood samples. METHODS: We collected and prepared samples such as blood donor samples (HBV, HCV, HIV nucleic acid positive; n=90), the HIV infected patient samples (n=20), the WHO nucleic acid international standards serologic positive samples (HBsAg, anti-HCV, anti-HIV; n=120) and the negative samples (n=20). The samples were aliquoted in cryo tubes with volumes of 0.5~5 mL and they were stored at -20~-30degrees C and -70~-80degrees C. We used enzyme immunoassay, chemiluminescence immunoassay and quantitative PCR for the base line and the follow up studies. The linear mixed statistical model using SAS 9.1 for windows was used for statistical analysis. RESULTS: The results of the baseline test of the stored samples showed a variable range of viral load (10(1)~10(7) IU/mL or copies/mL) and optical density (S/CO 3.0~500). The results of the stored samples after 6 month (n=82) did not show any significant differences compared to the baseline data for the viral loads (P>0.05) and the qualitative serologic tests. CONCLUSION: We established an experimental scheme to verify the stability of the stored blood donor samples. From now on, the stability of the stored samples is going to be monitored by every 6 month for 10 years.

Practical Application of Quantitative HiSens Auto Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination for Diagnosing Syphilis; Comparison Analysis between Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination Test and Rapid Plasma Reagin Car / 감염과화학요법

BACKGROUND: The purpose of this study was to evaluate validity of quantitative RPR LTIA, HiSens Auto RPR LTIA (HBi Corp., South Korea) and to decide an adequate cutoff value for syphilis screening. MATERIALS AND METHODS: A total of 549 serums or plasma specimens from patients were tested with RPR LTIA and RPR card tests. Degree of agreement between the two methods was analyzed, and validity of RPR LTIA test was analyzed by receiver operating characteristic (ROC) curves. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and ROC statistics of the RPR LTIA test were analyzed to decide an adequate cutoff value. RESULTS: Agreement analysis showed slight to moderate agreement (k=0.093-0.588, P=0.000). Kappa value had its highest value at the cutoff value of 1.3 and 1.6 (k=0.588, P=0.000). Kappa value at the cutoff value of 1 ranked second (k=0.578. P=0.000). A plot of ROC curve showed a statistically valid result to differentiate between a syphilis test positive group and a syphilis test negative group (AUC=0.92, P=0.000). The cutoff values in RPR LTIA test ranged between 0.65 and 1.15 when both sensitivity and specificity were higher than 80%. CONCLUSION: HiSens Auto RPR LTIA test showed statistically valid result to differentiate between syphilis test groups. Considering the importance of sensitivity in screening for syphilis and the degree of agreement with RPR card test, the cutoff value of 1 in HiSens Auto RPR LTIA test is thought to be adequate.

Practical Application of Quantitative HiSens Auto Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination for Diagnosing Syphilis; Comparison Analysis between Rapid Plasma Reagin Latex Turbidimetric Immunoagglutination Test and Rapid Plasma Reagin Car / 감염과화학요법

BACKGROUND: The purpose of this study was to evaluate validity of quantitative RPR LTIA, HiSens Auto RPR LTIA (HBi Corp., South Korea) and to decide an adequate cutoff value for syphilis screening. MATERIALS AND METHODS: A total of 549 serums or plasma specimens from patients were tested with RPR LTIA and RPR card tests. Degree of agreement between the two methods was analyzed, and validity of RPR LTIA test was analyzed by receiver operating characteristic (ROC) curves. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and ROC statistics of the RPR LTIA test were analyzed to decide an adequate cutoff value. RESULTS: Agreement analysis showed slight to moderate agreement (k=0.093-0.588, P=0.000). Kappa value had its highest value at the cutoff value of 1.3 and 1.6 (k=0.588, P=0.000). Kappa value at the cutoff value of 1 ranked second (k=0.578. P=0.000). A plot of ROC curve showed a statistically valid result to differentiate between a syphilis test positive group and a syphilis test negative group (AUC=0.92, P=0.000). The cutoff values in RPR LTIA test ranged between 0.65 and 1.15 when both sensitivity and specificity were higher than 80%. CONCLUSION: HiSens Auto RPR LTIA test showed statistically valid result to differentiate between syphilis test groups. Considering the importance of sensitivity in screening for syphilis and the degree of agreement with RPR card test, the cutoff value of 1 in HiSens Auto RPR LTIA test is thought to be adequate.

Usefulness of the serum Helicobacter pylori IgG antibody test during routine check-up / 대한내과학회지

BACKGROUND/AIMS: The serum Helicobacter pylori IgG antibody test has been widely used by primary care physicians for over two decades. We assessed its usefulness as a screening strategy for organic gastrointestinal disease in routine check-up. METHODS: We retrospectively reviewed the medical records of 10,080 subjects who received a routine check up at the Kangnam St. Mary's Hospital from January 2004 to April 2005. All subjects underwent the H. pylori IgG antibody test and upper gastrointestinal endoscopy or a barium contrast study. RESULTS: The overall seropositive rate for H. pylori detection was 61.0% (6,150/10,180). The 13C-urea breath test (UBT) was performed in 340 subjects. The H. pylori antibody test showed 55% accuracy in comparison to the standard 13C-UBT. The number of patients with peptic ulcer in the seropositive group was 475 (7.7%) compared to only 168 patients (4.3%) in the seronegative group (p<0.001). Stomach cancer was observed in eight (0.1%) and two (0.1%) patients in the seropositive and seronegative groups, respectively. The positive and negative likelihood ratios for the H. pylori IgG antibody test for peptic ulcer were 1.22 and 0.66, respectively, compared to 1.31 and 0.26 for stomach cancer. CONCLUSIONS: In view of its low accuracy and likelihood ratios, we do not recommend the H. pylori antibody test as a diagnostic tool for H. pylori infection or as a screening strategy for organic gastrointestinal disease during routine check-ups.

Serologic Test for Syphilis by Mediace RPR Test for Chemistry Autoanalyzer / 임상검사와정도관리

BACKGROUND: Mediace RPR test for chemistry autoanalyzer, a nontreponemal serologic test for syphilis, was recently introduced in Korea. We evaluated the performance of Mediace RPR test. METHODS: For the evaluation of precision, within-run and total coefficient variations were analyzed. Two hundred and one sera were tested by Mediace RPR test to investigate the distribution of Mediace RPR titers in healthy subjects. Mediace RPR test was compared with RPR card test using 126 sera. RESULTS: Total coefficient variations for positive control, negative control and pooled sera were 9.1%, 46.6% and 35.3%, respectively. The results of Mediace RPR test in healthy subjects showed 0.44+/-0.28 (mean+/-standard deviation) RPR unit (RU), and the positive rate was 3.5% (7/201). The agreement between Mediace RPR test and RPR card test was 73%. In some of the sera with a result of greater than 4.0 RU, Mediace RPR test showed markedly lower results than that of RPR card quantitative test. CONCLUSION: Mediace RPR test has the advantages that it is useful for screening large number of samples and the results are objective. Mediace RPR test can be used as a quantitative test in sera with low titers. Dilution is needed to determine high titers in sera. Adjusting cutoff for the setting of individual hospital is maybe helpful.

Expression of Tp0453 recombinant protein of Treponema pallidum and development of the indirected ELISA for diagnosing syphilis / 中华检验医学杂志

Objective To clone.and express Tp0453 outer membrane protein of Treponema pallidum and develop an indirect ELISA for sero diagnosis of syphilis. Methods The immuno-dominant epitope of Tp0453 was amplified by PCR and subcloned into the expression vector pQE32.The recombinant protein was expressed in E.coli M15 and purified with Ni-NTA affinity chromatography columns. Indirect ELISA was developed to detect the antibody to Tp in human sera.Results 60 control sera was tested by ELISA.The sensitivities was 100%(30/30), and the specificities was 100%. While detecting uninfected and infected T. pallidum human sera, the sensitivities of ELISA was 96.8% compared with the results of the TPPA tests, and the specificities was 100% when the results of ELISA was compared with those of the TPPA test. The concordance of results between the ELISA test and the TPPA test was 98.2%.Conclusion The recombinant Tp0453 outer membrane protein showed excellent immuno-reactive activity, and were suitable for development of ELISA for sero-diagnosis of syphilis.

Clinical Usefulness of Various Methods for the Diagnosis of Tuberculosis / 대한임상병리학회지

BACKGROUND: In the diagnosis of tuberculosis, methods that have high sensitivity and specificity such as polymerase chain reaction and serologic test of tuberculosis have been introduced recently. Thus, we performed AFB stain, culture, PCR-ybridization and serologic test of tuberculosis to determine the clinical usefulness of each method in patients who were diagnosed as having pulmonary and extrapulmonary tuberculosis. METHODS: With the study subjects of 72 patients (57 with pulmonary tuberculosis, 15 with extrapulmonary tuberculosis) and controls of 60 persons, we performed the AFB stain, culture, PCR-ybridization and serologic test using an ICT(R) tuberculosis kit (AMRAD, Australia). Then, we compared diagnostic results in each tests and the effect of multiple tests among various methods. RESULTS: In 57 pulmonary tuberculosis patients, 42 (73.7%) showed positive with AFB stain, 40 (70.2%) with culture, 53 (93.0%) with PCR-ybridization, 47 (82.5%) with serologic test. And in 15 extrapulmonary tuberculosis patients, 4 showed positive (26.7%) with AFB stain, 5 (33.3%) with culture, 7 (46.7%) with PCR-ybridization method, and 12 (80.0%) with serologic test. In 72 tuberculosis patients, 67 (93.1%) showed positive for any of more than 2 tests among the 4 testing methods; and among 3 testing methods combined in different ways, 53 (73.6%) to 60 (83.3%) showed positive of any of more than 2 tests. CONCLUSIONS: We think that using the traditional method of detecting bacteria together with PCR-ybridization or serologic test would be a fast and accurate method of diagnosing tuberculosis. Especially, in those cases with extrapulmonary tuberculosis or taking a specimen of sputum is difficult, we think that serologic test would help in the diagnosis.

Clinical Usefulness of Various Methods for the Diagnosis of Tuberculosis / 대한임상병리학회지

BACKGROUND: In the diagnosis of tuberculosis, methods that have high sensitivity and specificity such as polymerase chain reaction and serologic test of tuberculosis have been introduced recently. Thus, we performed AFB stain, culture, PCR-ybridization and serologic test of tuberculosis to determine the clinical usefulness of each method in patients who were diagnosed as having pulmonary and extrapulmonary tuberculosis. METHODS: With the study subjects of 72 patients (57 with pulmonary tuberculosis, 15 with extrapulmonary tuberculosis) and controls of 60 persons, we performed the AFB stain, culture, PCR-ybridization and serologic test using an ICT(R) tuberculosis kit (AMRAD, Australia). Then, we compared diagnostic results in each tests and the effect of multiple tests among various methods. RESULTS: In 57 pulmonary tuberculosis patients, 42 (73.7%) showed positive with AFB stain, 40 (70.2%) with culture, 53 (93.0%) with PCR-ybridization, 47 (82.5%) with serologic test. And in 15 extrapulmonary tuberculosis patients, 4 showed positive (26.7%) with AFB stain, 5 (33.3%) with culture, 7 (46.7%) with PCR-ybridization method, and 12 (80.0%) with serologic test. In 72 tuberculosis patients, 67 (93.1%) showed positive for any of more than 2 tests among the 4 testing methods; and among 3 testing methods combined in different ways, 53 (73.6%) to 60 (83.3%) showed positive of any of more than 2 tests. CONCLUSIONS: We think that using the traditional method of detecting bacteria together with PCR-ybridization or serologic test would be a fast and accurate method of diagnosing tuberculosis. Especially, in those cases with extrapulmonary tuberculosis or taking a specimen of sputum is difficult, we think that serologic test would help in the diagnosis.

An Epidemiologic study of syphilis prevalence in serum and cerebrospinal fluid in institutionalized subjects / 대한피부과학회지

BACKGROUND: Institutionalized subjects were assumedly suggested to be a high-risk for the infectious source of syphilis. OBJECTIVE: Our purpose was to study the syphilis prevalence institutionalized subjects who were admitted in Taegu Hope Village for the poor or crippled and to evaluate the presence of neurosyphilis among them. MEHTODS: We conducted the serologic tests for syphilis with the qalitative and quantative VDRL and TPHA tests in 1558 subjects(M:936, F:622). The trend of the rcactive rate was compared with those of the two studies dong, in the same institute in 1983-1985 and 1988. The cerebrospinal fluid (CSF) examination was perfarmed among the reactive subjects. RESULTS: There were 97(6.2%) reactive subjects. There were 80(82.5%) reactive subjects with titers of 1:4 or below and 17(17.5%) with titers of 1:8 or over The biologic false positive rate of VDRL test was 12.6%, showing 92.3% with the titer below 1:4. The reatest number of the subjects were in their 40s and 50s in both sexes. The rate in subjects in their 40s or over was 3 times higher than in the younger groups. The CSF examination showed 5(5.2%) with significant neurosyphili;ic findings. There were 1 male and 4 females, with an avechge age of 47.8 years. Four had asymplomatic and 1 meningovascular forms. The CSF findings revealed an increased number of white cells in 4 and an increased total protein level in 3. The CSF-VE)RL titers were trended lower than seum titers. From the comparison of the results since 1983, i.e., 11,6% in 1983-1985, 7.5% in 1988 and 6.2 % in 1992, the reactive rate of syphilis was gradually decreasing, but still remained high. CONCLUSION: The drastic control in the sociomedical aspect is needed n institutionalized subjects who are at high-risk for syphilis was well as the CSF examination for the presence of neurosyphilis among the reactive subjects.

Reactivity of Serologic Test for Syphilis in Normal Male Rabbits in Korea / 대한피부과학회지

The present study has been undertaken, using 307 seemingly "normal" male rabbits sold in Korea, which were tested for sysphilis with two serologic tests, the RPR card test and the TPHA test. Among thc rabbits which were seropositive in these tests, 10 rabbits were selected for further tests, namely, the FTA test a.nd FTA-ABS test. The following results have been obtained. Nine rabbits(2.9%) were reactive in both the RPR card test and the TPHA test; 10(3.2%) were reactive in the RPR card test and non-reactive in the TPHA test; 8(2. 6%) were reactive in the TPHA test and non-reactive in the RPR card test, and 27(8.7%) were reactive in either tests. 2. The rabbits which were reactive in the TPHA test were also reactive in the FTA and FTA-ABS test. As can be seen in the results, 8.7% of the normal male rabbits sold in Korea are seropositive in the serologic tests for syphilis. Cnnsequently, all rabbit's undergoing syphilis experiments should be screened for possible reactive serologic tests and excluded from the experiments.

Statistical Analysis of Serologic Test for Syphilis in Normal Population (1981 ~ 1984) / 대한피부과학회지

Serologic tests for syphilis including VDRL and TPHA tests were carried out in 5,413 VISA applicants for emigration, from January, 1981 to December, l984 The results are summarized as follows: 1. In 5,413 VISA applicants, the reactive rate of VDRL test was 2,0% totally. The reactive rate of VDRL test of male was 2. 6%, and that of female was 1. 6% 2. The reactive rate of 1983 was 1.4% and that was the lowest in annual incidence, but there was no statistically significant differences in comparing the annual incidences. 3. The reactive rate increased with age, and males above the 5 th decade revealed an especially high reactive rate. 4. The biologic false positive rate of VDRL teet was 16. 5%, in gl VDRL reactive persons, using TPHA as standard. 5. The quantitative test of VDRL showed low titer below 1: 4 in 88. 4%, and high titer above 1: 8 in 11. 6% of the applicants.

New Developments in the Immunological Understanding and of Serodiagnosis in Syphilis

There are many serologic tests for syphilis. By means of the usual serologic tests, it is not possible to differentiate between patients who need therapy and those who are cured. In this paper I want to discuss the scientific developments and demonstrate the results of immunologic research in syphilis, which makes it possible to differentiate between treated and untreated cases.