scholarly journals Serological testing for SARS-CoV-2 antibodies in clinical practice: a comparative diagnostic accuracy study

Author(s):  
Michael Horn ◽  
Hulda R. Jonsdottir ◽  
Daniel Brigger ◽  
Lauro Damonti ◽  
Franziska Suter-Riniker ◽  
...  

Background: Serological tests are a powerful tool in the monitoring of infectious diseases and the detection of host immunity. However, manufacturers often provide diagnostic accuracy data generated through biased studies and the performance in clinical practice is essentially unclear.  Objectives: We aimed to determine the diagnostic accuracy of various serological testing strategies for (a) identification of patients with previous coronavirus disease-2019 (COVID-19) and (b) prediction of neutralizing antibodies against SARS-CoV-2 in real-life clinical settings.  Methods: We prospectively included 2’573 consecutive health-care workers and 1’085 inpatients with suspected or possible previous COVID-19 at a Swiss University Hospital. Various serological immunoassays based on different analytical techniques (enzyme-linked immunosorbent assays, ELISA; chemiluminescence immunoassay, CLIA; electrochemiluminescence immunoassay, ECLIA; lateral-flow immunoassay, LFI), epitopes of SARS-CoV-2 (nucleocapsid, N; receptor-binding domain, RBD; extended RBD, RBD+; S1 or S2 domain of the spike [S] protein, S1/S2), and antibody subtypes (IgG, pan-Ig) were conducted. A positive real-time PCR test from a nasopharyngeal swab was defined as previous COVID-19. Neutralization assays with live SARS-CoV-2 were performed in a subgroup of patients to assess neutralization activity (n=201).  Results: The sensitivity to detect patients with previous COVID-19 was ≥85% in anti-N ECLIA (86.8%) and anti-S1 ELISA (86.2%). Sensitivity was 84.7% in anti-S1/S2 CLIA, 84.0% in anti-RBD+ LFI, 81.0% in anti-N CLIA, 79.2% in anti-RBD ELISA, and 65.6% in anti-N ELISA. The specificity was 98.4% in anti-N ECLIA, 98.3% in anti-N CLIA, 98.2% in anti-S1 ELISA, 97.7% in anti-N ELISA, 97.6% in anti-S1/S2 CLIA, 97.2% in anti-RBD ELISA, and 96.1% in anti-RBD+ LFI. The sensitivity to detect neutralizing antibodies was ≥85% in anti-S1 ELISA (92.7%), anti-N ECLIA (91.7%), anti-S1/S2 CLIA (90.3%), anti-RBD+ LFI (87.9%), and anti-RBD ELISA (85.8%). Sensitivity was 84.1% in anti-N CLIA, and 66.2% in anti-N ELISA. The specificity was ≥97% in anti-N CLIA (100%), anti-S1/S2 CLIA (97.7%), and anti-RBD+ LFI (97.9%). Specificity was 95.9% in anti-RBD ELISA, 93.0% in anti-N ECLIA, 92% in anti-S1 ELISA, and 65.3% in anti-N ELISA. Diagnostic accuracy measures were consistent among subgroups.  Conclusions: The diagnostic accuracy of serological tests for SARS-CoV-2 antibodies varied remarkably in clinical practice, and the sensitivity to identify patients with previous COVID-19 deviated substantially from the manufacturer’s specifications. The data presented here should be considered when using such tests to estimate the infection burden within a specific population and determine the likelihood of protection against re-infection.

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
G Del Castillo ◽  
A Castrofino ◽  
F Grosso ◽  
A Barone ◽  
L Crottogini ◽  
...  

Abstract Issue COVID-19 pandemic began in Italy on February 20th, 2020. Since the beginning of the emergency Healthcare Workers' (HCWs) involvement was prominent, mainly due to direct assistance to COVID-19 patients. Therefore, we implemented a prevention policy for HCW screening through serological and RT-PCR testing. Description of the problem HCW screening for SARS-CoV-2 infection is essential for prevention and control of the pandemic. Lombardy's Healthcare authorities settled a screening process for HCWs divided into three steps: 1) body temperature assessment at the beginning and the end of work shift, if fever > 37.5 °C was present the HCW was sent back home and a nasopharyngeal swab was performed; 2) progressive recruitment for serological testing; 3) on those positive to IgG a nasopharyngeal swab was performed and tested for viral RNA by RT-PCR. Results Among 79185 HCW tested, 9589 (12%) were positive on serological IgG testing. Of the 9589 positive a nasopharyngeal swab was performed on 6884. Of these 358 (5%) tested positive and the remaining 6526 (95%) negative to RT-PCR. We calculated a Positive Predictive Value of 5.2%. The rate of positive serological tests for each Healthcare facility varied between 0% and 78%. Five percent of all facilities, belonging to Brescia, Bergamo and Cremona area, reported a positivity rate higher than 40% in HCWs. A second cluster (18% of all facilities), involving the same geographical area, reported a rate between 20% and 40%, whereas the remaining facilities (76%) of the region a rate <20%. Lessons Serological IgG testing can be, if followed by immediate nasopharyngeal swab testing, a valid screening intervention on asymptomatic HCWs especially in a high infection prevalence setting. Key messages Serological IgG testing can be, if followed by immediate nasopharyngeal swab testing, a valid screening intervention on asymptomatic HCWs. Infection prevention in HCW may benefit from a screening campaign especially in high prevalence settings.


Allergy ◽  
2022 ◽  
Author(s):  
Michael P. Horn ◽  
Hulda R. Jonsdottir ◽  
Daniel Brigger ◽  
Lauro Damonti ◽  
Franziska Suter‐Riniker ◽  
...  

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1684
Author(s):  
Fabio Luigi Massimo Ricciardolo ◽  
Andrea Elio Sprio ◽  
Andrea Baroso ◽  
Fabio Gallo ◽  
Elisa Riccardi ◽  
...  

Asthma is a heterogeneous and complex condition characterized by chronic airway inflammation, which may be clinically stratified into three main phenotypes: type 2 (T2) low, T2-high allergic, and T2-high non-allergic asthma. This real-world study investigated whether phenotyping patients with asthma using non-invasive parameters could be feasible to characterize the T2-low and T2-high asthma phenotypes in clinical practice. This cross-sectional observational study involved asthmatic outpatients (n = 503) referring to the Severe Asthma Centre of the San Luigi Gonzaga University Hospital. Participants were stratified according to the patterns of T2 inflammation and atopic sensitization. Among outpatients, 98 (19.5%) patients had T2-low asthma, 127 (25.2%) T2-high non-allergic, and 278 (55.3%) had T2-high allergic phenotype. In comparison to T2-low, allergic patients were younger (OR 0.945, p < 0.001) and thinner (OR 0.913, p < 0.001), had lower smoke exposure (OR 0.975, p < 0.001) and RV/TLC% (OR 0.950, p < 0.001), higher prevalence of asthma severity grade 5 (OR 2.236, p < 0.05), more frequent rhinitis (OR 3.491, p < 0.001) and chronic rhinosinusitis with (OR 2.650, p < 0.001) or without (OR 1.919, p < 0.05) nasal polyps, but less common arterial hypertension (OR 0.331, p < 0.001). T2-high non-allergic patients had intermediate characteristics. Non-invasive phenotyping of asthmatic patients is possible in clinical practice. Identifying characteristics in the three main asthma phenotypes could pave the way for further investigations on useful biomarkers for precision medicine.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Hirsh Koyi ◽  
Gunnar Hillerdal ◽  
Olov Andersson ◽  
Karl-Gustav Kölbeck ◽  
Per Liv ◽  
...  

An increasing proportion of cancer patients are aged >65 years and many are aged >70 years. Treatment of the elderly with lung cancer has, therefore, become an important issue; so we performed a retrospective study of our patients to demonstrate how elderly patients with NSCLC are treated in real-life, clinical practice. All patients aged ≥70 years with NSCLC at our department were reviewed retrospectively. In total, 1059 patients (50.8% of all NSCLC patients). Of these patients, 243 (22.9%) received chemotherapy, 164 (70.4%) of whom were treated with a platinum doublet using carboplatin. Second- and third-line chemotherapy were given to 31.4% and 13.9% of patients, respectively. Median overall survival was 289 and 320 days for male and female patients, respectively. Patients with performance status (PS) 0 experienced significantly better survival than patients with PS1 or PS 2: 410, 314, and 204 days, respectively. Age was of less importance, with patients aged 70–79 years versus those aged ≥80 years. Treatment of elderly NSCLC patients with chemotherapy is feasible if they have a good PS and appears to prolong survival. In this study, we found no significant differences in survival either between age groups or genders.


2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Antonino Catalano ◽  
Federica Bellone ◽  
Nunziata Morabito ◽  
Diego Chila ◽  
Saverio Loddo ◽  
...  

Abstract Electrolytes disturbances are commonly observed in clinical practice. However, magnesium (Mg) disorders are often poorly considered. Our primary aim was to update the prevalence and the incidence of hypomagnesemia and hypermagnesemia in a real-life scenario. The secondary aim was to investigate the association of Mg disturbances with age and gender. Data from patients whose Mg serum levels were measured between January 2015 and December 2017 at our University Hospital were recorded. Hypomagnesemia was defined by Mg levels &lt;1.5 mg/dL and hypermagnesemia by levels&gt; 3.8 mg/dL. Hypo and hypermagnesemia cases were considered according to age, gender, year of observation and setting of subjects including outpatients and inpatients. In particular, inpatients were recruited from a total of 25 Hospital Divisions (i.e. Cardiology, Endocrinology, Geriatrics, Hematology, Intensive Care, Internal Medicine, Infectious Disease, Nephrology, Neonatal Intensive Care, Neurology, Neuropsychiatry, Neuroradiology, Oncology, Pulmonology, Pediatrics, Psychiatry, Rheumatology and Surgical Area that included 8 Units). Over the observation period, we recognized 12,696 patients whose Mg levels were checked. Prevalences of hypomagnesemia and hypermagnesemia were 8.43% (n=1071) and 1.78% (n=226) respectively. Hypomagnesemia was encountered more frequently in female [53.3% (n=560)] rather than in male patients [47.7 % (n=511)] (χ2= 4.03, p&lt;0.045) and was significantly influenced by age: the higher prevalence of hypomagnesemia was found in patients over 65 yr. [59.01% (n=632)], whereas a lower prevalence was detected in the other age groups, specifically in 9.52 % (n=102) of patients aged 0-18 yr. and in 31.46 % (n=337) of patients between 19 and 65 yr. (χ2= 592.64; p&lt;0.0001). Incidence of hypomagnesemia decreased over time with a borderline significance only in subjects over 65 yr. (r=-0.99; p=0.07). Geriatrics, Oncology and Intensive Care Division showed the highest incidences of hypomagnesemia. The hypermagnesemia prevalence was observed higher in outpatients in comparison with inpatients from any other Hospital Division and the hypermagnesemia incidence did not significantly change over time (r=0.96; p=0.16). Mg disorders, mainly hypomagnesemia, are quite common in clinical practice particularly in older hospitalized patients. Among the other electrolytes’ disturbances, Mg disorders, because of life-threatening significances, may be checked and corrected.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Maria Kahn ◽  
Lukas Schuierer ◽  
Christina Bartenschlager ◽  
Stephan Zellmer ◽  
Ramona Frey ◽  
...  

Abstract Objectives The gold standard for diagnosing an infection with SARS-CoV-2 is detection of viral RNA by nucleic acid amplification techniques. Test capacities, however, are limited. Therefore, numerous easy-to-use rapid antigen tests based on lateral flow technology have been developed. Manufacturer-reported performance data seem convincing, but real-world data are missing. Methods We retrospectively analysed all prospectively collected antigen tests results performed between 23.06.2020 and 26.11.2020, generated by non-laboratory personnel at the point-of-care from oro- or nasopharyngeal swab samples at the University Hospital Augsburg and compared them to concomitantly (within 24 h.) generated results from molecular tests. Results For a total of 3630 antigen tests, 3110 NAAT results were available. Overall, sensitivity, specificity, NPV and PPV of antigen testing were 59.4%, 99.0%, 98.7% and 64.8%, respectively. Sensitivity and PPV were lower in asymptomatic patients (47.6% and 44.4%, respectively) and only slightly higher in patients with clinical symptoms (66.7% and 85.0%, respectively). Some samples with very low Ct-values (minimum Ct 13) were not detected by antigen testing. 31 false positive results occurred. ROC curve analysis showed that reducing the COI cut-off from 1, as suggested by the manufacturer, to 0.9 is optimal, albeit with an AUC of only 0.66. Conclusion In real life, performance of lateral-flow-based antigen tests are well below the manufacturer's specifications, irrespective of patient’s symptoms. Their use for detection of individual patients infected with SARS-CoV2 should be discouraged. This does not preclude their usefulness in large-scale screening programs to reduce transmission events on a population-wide scale.


ESMO Open ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. e000885
Author(s):  
Grazia Arpino ◽  
Carmine De Angelis ◽  
Pietro De Placido ◽  
Erica Pietroluongo ◽  
Luigi Formisano ◽  
...  

BackgroundImmunosuppression induced by anticancer therapy in a COVID-19-positive asymptomatic patient with cancer may have a devastating effect and, eventually, be lethal. To identify asymptomatic cases among patients receiving active cancer treatment, the Federico II University Hospital in Naples performs rapid serological tests in addition to hospital standard clinical triage for COVID-19 infection.MethodsFrom 6 to 17 April 2020, all candidates for chemotherapy, radiotherapy or target/immunotherapy, if negative at the standard clinical triage on the day scheduled for anticancer treatment, received a rapid serological test on peripheral blood for COVID-19 IgM and IgG detection. In case of COVID-19 IgM and/or IgG positivity, patients underwent a real-time PCR (RT-PCR) SARS-CoV-2 test to confirm infection, and active cancer treatment was delayed.ResultsOverall 466 patients, negative for COVID-19 symptoms, underwent serological testing in addition to standard clinical triage. The average age was 61 years (range 25–88 years). Most patients (190, 40.8%) had breast cancer, and chemotherapy with or without immunotherapy was administered in 323 (69.3%) patients. Overall 433 (92.9%) patients were IgG-negative and IgM-negative, and 33 (7.1%) were IgM-positive and/or IgG-positive. Among the latter patients, 18 (3.9%), 11 (2.4%) and 4 (0.9%) were IgM-negative/IgG-positive, IgM-positive/IgG-negative and IgM-positive/IgG-positive, respectively. All 33 patients with a positive serological test, tested negative for RT-PCR SARS-CoV-2 test. No patient in our cohort developed symptoms suggestive of active COVID-19 infection.ConclusionRapid serological testing at hospital admission failed to detect active asymptomatic COVID-19 infection. Moreover, it entailed additional economic and human resources, delayed therapy administrationand increased hospital accesses.


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