scholarly journals Potential Impact of Different Cytomegalovirus (CMV) IgM Assays on an Algorithm Requiring IgM Reactivity as a Criterion for Measuring CMV IgG Avidity

2014 ◽  
Vol 21 (6) ◽  
pp. 813-816 ◽  
Author(s):  
Harry E. Prince ◽  
Mary Lapé-Nixon ◽  
Andrew Brenner ◽  
Nancy Pitstick ◽  
Marc Roger Couturier
Keyword(s):  
Cmv Infection ◽  
Serum Samples ◽  
Immunofluorescent Assay ◽  
Negative Results ◽  
Igg Avidity ◽  
Positive Serum ◽  
Chemiluminescent Immunoassay ◽  
Potential Impact ◽  
The Impact ◽  
Positive Results

ABSTRACTThe measurement of cytomegalovirus (CMV) IgG avidity is a powerful tool for identifying individuals with recent CMV infection. Because such patients are expected to be positive for CMV IgM, several investigators have suggested that CMV IgG-positive sera first be screened for CMV IgM and then only the IgM-reactive sera be tested for avidity. We investigated the impact of different CMV IgM assays on such a reflexing algorithm using a panel of 369 consecutive IgG-positive serum samples submitted for avidity testing. A bead-based immunofluorescent assay (BIFA) identified 105 IgM-positive serum samples, whereas an IgM-capture enzyme immunoassay (EIA) identified 48 IgM-positive serum samples; this marked difference led us to evaluate additional CMV IgM assays. An enzyme-linked immunofluorescent assay (ELFA) and a chemiluminescent immunoassay (CIA) were used to test all sera with discordant BIFA/EIA results, all sera with concordant positive results, and selected sera with concordant negative results. The findings indicated that the ELFA would identify 74 CMV IgM-positive samples and the CIA would identify 64. Of the 23 low-avidity serum samples, 2 were IgM negative by BIFA, 3 by ELFA and CIA, and 4 by EIA; of the 23 intermediate-avidity serum samples, 6 were IgM negative by BIFA, 10 by ELFA, and 15 by EIA and CIA. In both these avidity groups, BIFA IgM-negative sera were also negative by the other 3 assays. These findings demonstrate that an algorithm requiring CMV IgM reactivity as a criterion for CMV IgG avidity testing does not identify all low-avidity sera and thus misses some cases of acute CMV infection.

scholarly journals NSF Science of Science Proposal: Randomized Trial of Registered Reports

2020 ◽  
Author(s):  
Brian A. Nosek ◽  
David Thomas Mellor ◽  
Timothy M. Errington ◽  
Courtney K. Soderberg ◽  
Tina Krall ◽  
...  
Keyword(s):  
Randomized Trial ◽  
Standard Of Care ◽  
Research Process ◽  
Status Quo ◽  
Negative Results ◽  
Statistical Inferences ◽  
Transformative Impact ◽  
The Impact ◽  
Positive Results ◽  
Rate Research

In theory, Registered Reports eliminate publication bias against negative results because publication decisions are made without knowledge of the results; increase clarity between planned (hypothesis testing; confirmatory) and unplanned (hypothesis generating; exploratory) analyses, thereby increasing the diagnosticity of statistical inferences; and, leverage peer review expertise more effectively to foster better research methodology and more informative outcomes--regardless of whether they are positive or negative results, or are consistent or inconsistent with hypothesized outcomes. With the RRs published to date, there is observational evidence for some of these expectations. But, given the potentially transformative impact of RRs on the research process, we believe that it is essential to conduct a randomized trial to evaluate the model’s qualities. By collaborating with journals, we can conduct a randomized trial of RRs in an ecologically valid context. Authors who receive revise-and-resubmit decision letters asking for an additional study will be invited to participate in the trial. Those that opt-in will be randomized to either a status quo (i.e., standard of care) or RR condition for their resubmission with the additional study. We will examine the impact of RRs on publication (e.g., acceptance rate), research outcomes (e.g., rate of positive results), and qualities of methodology (e.g., sample size, transparency, rigor).

scholarly journals Evaluation of 2-column agglutination versus conventional tube technique for antibody screening

2021 ◽  
Vol 9 (3) ◽  
pp. 407-412
Author(s):  
A. Abou Jabal ◽  
T. Shubeilat ◽  
F. Hajjiri
Keyword(s):  
Serum Samples ◽  
Antibody Screening ◽  
Negative Results ◽  
Specificity And Sensitivity ◽  
Low Concentrations ◽  
Indirect Antiglobulin Test ◽  
Antiglobulin Test ◽  
Screening And Identification ◽  
Clinically Significant ◽  
Positive Results

The study aimed to determine the specificity and sensitivity of the Ortho BioVue two-column agglutination system for the detection of low concentrations of clinically significant antibodies in serum. The BioVue system was compared with the conventional tube technique [LISS-Coombs indirect antiglobulin test], and the two-stage Papenzyme test was used to resolve discrepancies between the two methods. We tested 3000 serum samples from randomly selected patients at King Hussein Medical Centre. Both the antibody screening and identification gave negative results in 2952 patients and positive results in 48 patients. We found the BioVue system to be the more sensitive technique. However, if papain enzyme-treated cells were included in the conventional tube technique when applied to antibody screening and identification, both methods would be of comparable sensitivity

scholarly journals Usefulness of real-time PCR assay targeting lipL32 gene for diagnosis of human leptospirosis in Uruguay

2013 ◽  
Vol 7 (12) ◽  
pp. 941-945 ◽  
Author(s):  
Sabina González ◽  
Juan Pablo Geymonat ◽  
Elba Hernández ◽  
Juan Martín Marqués ◽  
Felipe Schelotto ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Dna Amplification ◽  
Diagnostic Sensitivity ◽  
Analytical Sensitivity ◽  
Serum Samples ◽  
Initial Management ◽  
Negative Results ◽  
Acute Infections ◽  
Positive Results

Introduction: Assays based on DNA amplification can provide information that contributes to the initial management of patients with leptospirosis. However, these have not been adopted in Uruguay. Our aim was to evaluate the performance of the lipL32 real-time PCR (qPCR) for diagnosis of leptospirosis. Methodology: We analyzed by microscopic agglutination test (MAT) and lipL32 qPCR serum samples from 183 patients with suspected leptospirosis. To establish the analytical sensitivity of the qPCR, experimentally spiked samples with known amounts of Leptospira interrogans were analyzed. Results: The analytical sensitivity of the qPCR was 102 leptospires/mL. In 98 patients MAT results were negative meanwhile 85 showed positive reactions, revealing acute infections. Twenty six acute-phase sera of these 85 patients showed a positive signal by qPCR (diagnostic sensitivity 30%). In these patients the average time between onset of symptoms and collection of the first sample was 8 days. In patients with negative results for qPCR and positive MAT results (n=59) the average interval between onset of symptoms and collection of the first sample was 13 days. The qPCR did not yield false positive results. Conclusions: The qPCR had a lower diagnostic sensitivity than MAT and a higher cost. However, it allowed to make an early diagnosis in 26 patients. In patients with confirmed acute infections and negative results by qPCR, more than 8 days had elapsed between the onset of the illness and extraction of the first serum sample. Our data support that the qPCR from sera have clinical utility within the first week of illness.

scholarly journals The Reliability of a Novel Automated System for ANA Immunofluorescence Analysis in Daily Clinical Practice

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammed Alsuwaidi ◽  
Margit Dollinger ◽  
Martin Fleck ◽  
Boris Ehrenstein
Keyword(s):  
Clinical Practice ◽  
Clinical Care ◽  
Daily Clinical Practice ◽  
Automated System ◽  
Visual Interpretation ◽  
Serum Samples ◽  
Negative Results ◽  
Automated Interpretation ◽  
Reading System ◽  
Positive Results

Automated interpretation (AI) systems for antinuclear antibody (ANA) analysis have been introduced based on assessment of indirect immunofluorescence (IIF) patterns. The diagnostic performance of a novel automated IIF reading system was compared with visual interpretation (VI) of IIF in daily clinical practice to evaluate the reduction of workload. ANA-IIF tests of consecutive serum samples from patients with suspected connective tissue disease were carried out using HEp-2 cells according to routine clinical care. AI was performed using a visual analyser (Zenit G-Sight, Menarini, Germany). Agreement rates between ANA results by AI and VI were calculated. Of the 336 samples investigated, VI yielded 205 (61%) negative, 42 (13%) ambiguous, and 89 (26%) positive results, whereas 82 (24%) were determined to be negative, 176 (52%) ambiguous, and 78 (24%) positive by AI. AI displayed a diagnostic accuracy of 175/336 samples (52%) with a kappa coefficient of 0.34 compared to VI being the gold standard. Solely relying on AI, with VI only performed for all ambiguous samples by AI, would have missed 1 of 89 (1%) positive results by VI and misclassified 2 of 205 (1%) negative results by VI as positive. The use of AI in daily clinical practice resulted only in a moderate reduction of the VI workload (82 of 336 samples: 24%).

Impact of Results of Methicillin-Resistant Staphylococcus, aureus Surveillance Culture of Nasal Specimens on Subsequent Antibiotic Prescribing Patterns

2010 ◽  
Vol 31 (8) ◽  
pp. 842-845
Author(s):  
Jörg J. Ruhe ◽  
Barry Kreiswirth ◽  
David C. Perlman ◽  
Donna Mildvan ◽  
Brian Koll
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Prescribing Patterns ◽  
Antibiotic Prescribing ◽  
Carrier Status ◽  
Surveillance Culture ◽  
Methicillin Resistant ◽  
Negative Results ◽  
Potential Impact ◽  
Positive Results

We studied the potential impact of results of methicillin-resistant Staphylococcus aureus (MRSA) surveillance culture of nasal specimens on physicians' vancomycin-prescribing habits. We compared 116 case patients who had positive results with 116 matched control subjects who had negative results. On multivariate analyses, a positive MRSA carrier status remained strongly predictive of vancomycin use within the subsequent 12 weeks.

scholarly journals Performance of a Cytomegalovirus IgG Enzyme Immunoassay Kit Modified To Measure Avidity

2014 ◽  
Vol 21 (6) ◽  
pp. 808-812 ◽  
Author(s):  
Harry E. Prince ◽  
Mary Lapé-Nixon ◽  
Susan M. Novak-Weekley
Keyword(s):  
Enzyme Immunoassay ◽  
Package Insert ◽  
Reference Laboratory ◽  
High Avidity ◽  
Serum Samples ◽  
Detection Rates ◽  
Igg Avidity ◽  
Chemiluminescent Immunoassay ◽  
Evaluation Panel ◽  
Definition Of

ABSTRACTThe measurement of cytomegalovirus (CMV) IgG avidity accurately discriminates recent and past CMV infections. We sought to determine if the Wampole Laboratories CMV IgG enzyme immunoassay (EIA) could be modified to measure avidity. The evaluation panel consisted of 156 serum samples we used in 2002 to validate a laboratory-developed EIA, in which 78 serum samples exhibited low avidity, 7 exhibited intermediate avidity, and 71 exhibited high avidity. The qualitative agreement between the two avidity assays was 94% (147/156); all 9 sera with discordant results exhibited intermediate avidity in one of the assays. The avidity index (AI) values in the two assays showed excellent correlation (r= 0.96,P< 0.0001). The definition of high avidity was verified for the Wampole assay by demonstrating high avidity in 91/93 (98%) recently collected CMV IgG-positive/IgM-negative serum samples. The performance of the Wampole avidity assay in a reference laboratory setting was assessed using 470 consecutive serum samples submitted for CMV IgG avidity testing. Surprisingly, 101 serum samples were negative when screened for CMV IgG using the Wampole kit per the package insert; 98 of these 101 serum samples were tested using a CMV IgG chemiluminescent immunoassay, and only 5 were positive. Of the 369 CMV IgG-positive samples, 6% exhibited low IgG avidity, 6% exhibited intermediate avidity, and 88% exhibited high avidity; CMV IgM detection rates were inversely related to AI levels. These findings show that (i) the Wampole CMV IgG EIA can be modified to measure CMV IgG avidity, (ii) many samples are apparently submitted for avidity testing without knowledge of their CMV IgG status, and (iii) most CMV IgG-positive sera submitted for avidity testing exhibit high avidity.

scholarly journals Prevalence and Recurrence Rates of Cytomegalovirus Infection among Patients with Hematological Diseases of the Brazilian Western Amazon

2021 ◽  
Author(s):  
Jean Melo Silva ◽  
Renato Pinheiro-Silva ◽  
Regiane Costa de Oliveira ◽  
Carlos Eduardo De Castro Alves ◽  
Anderson Nogueira Barbosa ◽  
...  
Keyword(s):  
Low Socioeconomic Status ◽  
Recurrent Infection ◽  
Lymphocytic Leukemia ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cmv Infection ◽  
Serum Samples ◽  
Recurrence Rates ◽  
Hematological Diseases ◽  
Igg Avidity ◽  
Study Population

Abstract Purpose: Cytomegalovirus (CMV) is a worldwide distributed pathogen that may cause serious complications in patients with hematological diseases. This study aimed to serologically characterize the CMV infection in patients suffering from hematological diseases in Amazonas, Brazil. Methods: Serum samples from 323 patients were tested for the presence of anti-CMV IgM or IgG antibodies by an enzyme-linked immunosorbent assay. Positive samples for IgM were submitted to the IgG avidity test to differentiate primary infection from recurrent infection. An epidemiological questionnaire was administered to collect sociodemographic information of the study population. Results: The overall prevalence of CMV infection verified in this study was 91.3%. The highest rates were found in patients suffering from platelet disorders (94.5%), anemia (93.3%), or leukemia (91%). The study population was predominantly composed of individuals with low socioeconomic status. Blood transfusions were more often in patients with anemia or leukemia, but it was not correlated with the positivity for CMV infection. Measurement of IgG avidity in patients positive for anti-CMV IgM demonstrated a recurrent infection rate of 5.2% (17/323). Over 80% of recurrent infection occurred in patients with acute lymphocytic leukemia (ALL) or anemia. Conclusions: Our findings indicated that CMV infection is highly prevalent in patients with hematological diseases from the Brazilian western Amazon. The prevalence observed progressively rose with increasing age, whereas anemia or ALL disease figured as risk factors for the recurrence of CMV infection.

scholarly journals ‘False positive’ complement fixation with psittacosis—trachoma antigens due to antibodies in complement preparations

1964 ◽  
Vol 62 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Alexander L. Terzin
Keyword(s):  
Guinea Pig ◽  
False Positive ◽  
Guinea Pigs ◽  
Technical Assistance ◽  
Complement Fixation ◽  
Experimental Studies ◽  
Serum Samples ◽  
Positive Serum ◽  
Set Up ◽  
Positive Results

Complement-fixation tests with psittacosis-trachoma group antigens, if set up with complement prepared from guinea-pigs cross-infected with any of the Bedsonia agents, may give completely false positive results. The use of C.F. positive or C.F. inhibition positive samples of guinea-pig sera as a source of complement can induce also a significant increase or decrease, respectively, of the actual C.F. titres in Bedsonia-positive serum samples tested. Observations made both in routine serology and in experimental studies show the necessity of testing carefully, for possible presence of Bedsonia titres, individual sera of guinea-pigs intended for use as source of complement in C.F. tests performed with Bedsonia group antigens.I have pleasure in thanking Dr F. B. Gordon and Dr E. Weiss for the valuable suggestions made and HM3 C.O. Wiese for the technical assistance.

scholarly journals Evaluation of rapid, cassette immunochromatographic tests in the serological diagnosis of COVID-19

2021 ◽  
pp. 25-37
Author(s):  
Waldemar Rastawicki ◽  
Klaudia Płaza ◽  
Adam Pietrusiński
Keyword(s):  
Low Cost ◽  
Lateral Flow ◽  
Serological Diagnosis ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Serological Tests ◽  
Negative Results ◽  
Lateral Flow Assays ◽  
Low Sensitivity ◽  
Positive Results

Introduction: Lateral flow assays (LFIA) are the technology behind low-cost, simple, rapid and portable detection devices popular in biomedicine. Lately, they are very common used in serodiagnosis of SARS-CoV-2 infections. The aim of the presented study was to assess the usefulness of selected LFIA in serological diagnosis of COVID-19. Methods: The usefulness of seven lateral flow assays in the serodiagnosis of COVID-19 was evaluated (VAZYME, DIAGNOSIS, PCL, INGEZIM, BIOSENSOR, ACCU-TELL, NOVAtest). The study used 107 serum samples obtained from 74 individuals with current SARS-CoV-2 infection confirmed by RT-PCR. The ELISA-IgG (Euroimmun) was used as the reference assay for sensitivity and specificity testing. Results: The highest percentage of positive results was obtained when searching for IgG antibodies with the NOVAtest (40.6%) and DIAGNOSIS (39.2%) sets and the lowest detection for the PCL set - 25.5%. In the case of searching for IgM antibodies in all sets, significantly lower percentages of positive results compared to the IgG class were recorded. In general, all lateral flow assays showed low sensitivity in relation to the Euroimmun ELISA-IgG. The DIAGNOSIS kit (64.5%) was characterized by the highest sensitivity, and the PCL kit was the lowest (38.7%). On the other hand, the specificity of all kits was very high, almost 100% in almost all cases. Conclusions: Lateral flow assays due to their low sensitivity are not suitable for quick diagnosis of the current SARS-CoV-2 infections and cannot be an alternative to genetic or even antigen tests. They may be used only to retrospectively test the presence of IgG antibodies. However, a negative results of LFIA in suspected disease or after vaccination should be confirmed by more sensitive serological tests.

scholarly journals Dengue antibodies can cross-react with SARS-CoV-2 and vice versa-Antibody detection kits can give false-positive results for both viruses in regions where both COVID-19 and Dengue co-exist

2020 ◽  
Author(s):  
Himadri Nath ◽  
Abinash Mallick ◽  
Subrata Roy ◽  
Soumi Sukla ◽  
Keya Basu ◽  
...  
Keyword(s):  
False Positive ◽  
Virus Antigen ◽  
Definitive Diagnosis ◽  
Antibody Detection ◽  
Serum Samples ◽  
Positive Serum ◽  
Antigen Tests ◽  
Positive Results

AbstractFive of thirteen Dengue antibody-positive serum samples, dated 2017 (pre-dating the COVID-19 outbreak) produced false-positive results in SARS-CoV-2 IgG/IgM rapid strip tests. Our results emphasize the importance of NAT and/or virus antigen tests to complement sero-surveillance for definitive diagnosis of COVID-19/Dengue in regions where both viruses are co-endemic.

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