scholarly journals EXPRESS: Clinical performance of the Elecsys® Anti-SARS-CoV-2 combined in an algorithm with two specific anti-IgG immunoassays for the evaluation of the serological response of patients with COVID-19 in a population with a high prevalence of infection

2021 ◽  
pp. 000456322110380
Author(s):  
Xavier Gabaldó-Barrios ◽  
Simona Iftimie ◽  
Anna Hernández-Aguilera ◽  
Isabel Pujol ◽  
Frederic Ballester ◽  
...  
Keyword(s):  
Immune Response ◽  
Polymerase Chain Reaction ◽  
Predictive Value ◽  
Clinical Performance ◽  
Polymerase Chain Reaction Test ◽  
Serological Response ◽  
Chain Reaction ◽  
Automated Assay ◽  
High Prevalence ◽  
Polymerase Chain

Background: Anti-SARS-CoV-2 antibodies have been used in the study of the immune response in infected patients. However, differences in sensitivity and specificity have been reported, depending on the method of analysis. The aim of the present study was to evaluate the diagnostic accuracy of an algorithm in which a high-throughput automated assay for total antibodies was used for screening and two semi-automated IgG-specific methods were used to confirm the results, and also to correlate the analytical results with the clinical data and the time elapsed since infection. Methods: We studied 306 patients, some hospitalized and some outpatients, belonging to a population with a high prevalence of COVID-19. One-hundred and ten patients were classified as SARS-CoV-2 negative and 196 as positive by polymerase chain reaction. Results: The algorithm and automated assay alone had a specificity and a positive predictive value of 100%, although the sensitivity and negative predictive value of the algorithm was higher. Both methods showed a good sensitivity from day 11 of the onset of symptoms in asymptomatic and symptomatic patients. The absorbance of the total antibodies was significantly higher in severely symptomatic than in asymptomatic or mildly symptomatic patients, which suggests the antibody level was higher. We found 15 patients that did not present seroconversion at 12 days from the onset of symptoms or the first polymerase chain reaction test. Conclusion: This study highlights the proper functioning of algorithms in the diagnosis of the immune response to COVID-19, which can help to define testing strategies against this disease.

scholarly journals Head-to-Head Comparison of Rapid and Automated Antigen Detection Tests for the Diagnosis of SARS-CoV-2 Infection

2021 ◽  
Vol 10 (2) ◽  
pp. 265
Author(s):  
Julien Favresse ◽  
Constant Gillot ◽  
Maxime Oliveira ◽  
Julie Cadrobbi ◽  
Marc Elsen ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Performance ◽  
Antigen Detection ◽  
Clinical Validation ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Viral Loads ◽  
Automated Assay ◽  
Polymerase Chain ◽  
Asymptomatic Subjects

(1) Background: The detection of SARS-CoV-2 RNA in nasopharyngeal samples through real-time reverse transcription-polymerase chain reaction (RT-PCR) is considered the standard gold method for the diagnosis of SARS-CoV-2 infection. Antigen detection (AD) tests are more rapid, less laborious, and less expensive alternatives but still require clinical validation. (2) Methods: This study compared the clinical performance of five AD tests, including four rapid AD (RAD) tests (biotical, Panbio, Healgen, and Roche) and one automated AD test (VITROS). For that purpose, 118 (62.8%) symptomatic patients and 70 (37.2%) asymptomatic subjects were tested, and results were compared to RT-PCR. (3) Results: The performance of the RAD tests was modest and allowed us to identify RT-PCR positive patients with higher viral loads. For Ct values ≤25, the sensitivity ranged from 93.1% (95% CI: 83.3–98.1%) to 96.6% (95% CI: 88.1–99.6%), meaning that some samples with high viral loads were missed. Considering the Ct value proposed by the CDC for contagiousness (i.e., Ct values ≤33) sensitivities ranged from 76.2% (95% CI: 65.4–85.1%) to 88.8% (95% CI: 79.7–94.7%) while the specificity ranged from 96.3% (95% CI: 90.8–99.0%) to 99.1% (95% CI: 95.0–100%). The VITROS automated assay showed a 100% (95% CI: 95.5–100%) sensitivity for Ct values ≤33, and had a specificity of 100% (95% CI: 96.6–100%); (4) Conclusions: Compared to RAD tests, the VITROS assay fully aligned with RT-PCR for Ct values up to 33, which might allow a faster, easier and cheaper identification of SARS-CoV-2 contagious patients.

scholarly journals Severe acute respiratory syndrome coronavirus 2 reinfection in a coronavirus disease 2019 recovered young adult: a case report

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Hussein Awada ◽  
Hasan Nassereldine ◽  
Adel Hajj Ali
Keyword(s):  
Immune Response ◽  
Polymerase Chain Reaction ◽  
Severe Acute Respiratory Syndrome ◽  
Healthcare Providers ◽  
Polymerase Chain Reaction Test ◽  
Chain Reaction ◽  
Positive Polymerase Chain Reaction ◽  
Serology Test ◽  
Polymerase Chain ◽  
Chain Reaction Test

Abstract Background Coronavirus disease 2019 has been a public health threat and a worldwide emergency for more than a year. Unfortunately, many questions concerning the pathophysiology, management, and long-term side effects remain unanswered, and novel aspects of the disease keep on emerging. Of concern to healthcare providers are the recent reported cases of reinfection. Serum coronavirus disease 2019 antibodies have been detected within a few days after onset of the disease. However, it remains unclear whether this immune response is universal, or whether it can lead to latent immunity. Case presentation A previously healthy 27-year-old white man presented with fever, chills, back pain, and other constitutional symptoms, 2 days after being exposed to coronavirus disease 2019 positive patients. His severe acute respiratory syndrome coronavirus 2 polymerase chain reaction was positive, and his symptoms resolved over the next 2 weeks. One month after a confirmatory negative severe acute respiratory syndrome coronavirus 2 polymerase chain reaction, he was found to be ineligible for plasma donation as his anti-severe acute respiratory syndrome coronavirus 2 serology was negative. The patient redeveloped symptoms similar to his first infection 3 weeks after the negative serology test. He and his wife both tested positive via polymerase chain reaction. Their symptoms resolved over the next few days, and they had a negative polymerase chain reaction test 10 days after the positive polymerase chain reaction. Conclusion While studies showed that anti-severe acute respiratory syndrome coronavirus 2 immunoglobulins start to develop early after infection, our healthy young patient’s immune system failed to mount latent immunity against the virus. This left him, especially amid widespread social and medical misconceptions, vulnerable to reinfection by severe acute respiratory syndrome coronavirus 2. Our case disputes the timelines for immune response that were set and supported by research studies. Our case also raises questions regarding prioritizing vaccinating other individuals over those with prior infection.

scholarly journals Clinical Performance of (1,3) Beta-D Glucan for the Diagnosis of Pneumocystis Pneumonia (PCP) in Cancer Patients Tested With PCP Polymerase Chain Reaction

2018 ◽  
Vol 69 (8) ◽  
pp. 1303-1309 ◽  
Author(s):  
Sejal Morjaria ◽  
John Frame ◽  
Alexandra Franco-Garcia ◽  
Alexander Geyer ◽  
Mini Kamboj ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Cancer Patients ◽  
Predictive Value ◽  
Clinical Performance ◽  
Reference Method ◽  
Pneumocystis Pneumonia ◽  
Clinical Syndrome ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
High Risk Cancer

Abstract Background Serum (1,3)-beta-D glucan (BDG) is increasingly used to guide the management of suspected Pneumocystis pneumonia (PCP). BDG lacks specificity for PCP, and its clinical performance in high-risk cancer patients has not been fully assessed. Polymerase chain reaction (PCR) for PCP detection is highly sensitive, but cannot differentiate between colonization and infection. We evaluated the diagnostic performance of serum BDG in conjunction with PCP PCR on respiratory samples in patients with cancer and unexplained lung infiltrates. Methods We performed a retrospective analysis of adult patients evaluated for PCP at our institution from 2012 to 2015, using serum BDG and PCP PCR. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the serum BDG at different thresholds were evaluated using PCP PCR alone or in conjunction with clinical presentation in PCP PCR–positive patients. Results With PCP PCR alone as the reference method, BDG (≥80 pg/mL) had a sensitivity of 69.8%, specificity of 81.2%, PPV of 34.6%, and NPV of 95.2% for PCP. At ≥200 pg/mL in patients with a positive PCR and a compatible PCP clinical syndrome, BDG had a sensitivity of 70%, specificity of 100%, PPV of 100%, and NPV of 52.0% for PCP. Conclusions Patients negative by both BDG and PCR were unlikely to have PCP. In patients with a compatible clinical syndrome for PCP, higher BDG values (>200 pg/mL) were consistently associated with clinically-significant PCP infections among PCP PCR–positive oncology patients.

scholarly journals A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fatemeh Khatami ◽  
Mohammad Saatchi ◽  
Seyed Saeed Tamehri Zadeh ◽  
Zahra Sadat Aghamir ◽  
Alireza Namazi Shabestari ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Ct Scan ◽  
Predictive Value ◽  
Meta Analysis ◽  
Chest Ct ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

scholarly journals Peripheral Blood Leukocytes and Serum Nested Polymerase Chain Reaction Are Complementary Methods for Monitoring Active Cytomegalovirus Infection in Transplant Patients

2013 ◽  
Vol 24 (3) ◽  
pp. e69-e74 ◽  
Author(s):  
PD Andrade ◽  
MT Fioravanti ◽  
EBV Anjos ◽  
C De Oliveira ◽  
DM Albuquerque ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Cytomegalovirus Infection ◽  
Clinical Symptoms ◽  
Peripheral Blood Leukocytes ◽  
Active Infection ◽  
Chain Reaction ◽  
Blood Leukocytes ◽  
Polymerase Chain

BACKGROUND: Human cytomegalovirus is an important cause of morbidity and mortality in immunocompromised patients. Qualitative polymerase chain reaction (PCR) has proven to be a sensitive and effective technique in defining active cytomegalovirus infection, in addition to having low cost and being a useful test for situations in which there is no need for quantification. Real-time PCR has the advantage of quantification; however, the high cost of this methodology makes it impractical for routine use.OBJECTIVE: To apply a nested PCR assay to serum (sPCR) and to evaluate its efficiency to diagnose active cytomegalovirus infection compared with PCR of peripheral blood leukocytes (L-PCR).METHODS: Samples of 37 patients were prospectively evaluated. An internal control was created and applied to sPCR to exclude false-negative results.RESULTS: In total, 21 patients (57%) developed active cytomegalovirus infection. After analyzing the two methods for the diagnosis of active infection, higher sensitivity and negative predictive value of the L-PCR versus sPCR (100% versus 62%), and higher specificity and positive predictive value of sPCR versus L-PCR (81% versus 50% and 72%, respectively) were observed. Discordant results were observed in 11 patients who were L-PCR-positive but sPCR-negative for active cytomegalovirus infection, five of whom developed clinical symptoms of cytomegalovirus. Clinical symptoms were observed in 14 patients, 12 of whom were diagnosed with active infection by nested L-PCR (P=0.007) and seven by nested sPCR (P=0.02). Higher specificity and a positive predictive value for sPCR were observed.CONCLUSION: Nested L-PCR and sPCR were considered to be complementary methods for the diagnosis and management of symptomatic cytomegalovirus infection.

scholarly journals Clinical Evaluation of a 16S Ribosomal RNA Polymerase Chain Reaction Test for the Diagnosis of Lymph Node Tuberculosis

2006 ◽  
Vol 43 (7) ◽  
pp. 855-859 ◽  
Author(s):  
Fernando Osores ◽  
Oscar Nolasco ◽  
Kristien Verdonck ◽  
Jorge Arevalo ◽  
Juan Carlos Ferrufino ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Lymph Node ◽  
Rna Polymerase ◽  
Ribosomal Rna ◽  
Polymerase Chain Reaction Test ◽  
Chain Reaction ◽  
Reaction Test ◽  
Polymerase Chain ◽  
Lymph Node Tuberculosis ◽  
Chain Reaction Test
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