DiaSys presented poster at EuroMedlab 2022

The 24th EuroMedLab took place in Munich between 10th and 14th, April. In third presentation session, on Wednesday 13th, the DiaSys Diagnostic GmbH through Ms. Leoni Wey, Mr. Thomas Masetto and Prof. Dr. Matthias Grimmler presented the poster about COVID-19 and its self-developed serological test SARS-CoV-2 UTAB FS for the quantitative measurement of anti-SARS-CoV-2 total antibody titer in human serum. The SARS-CoV-2 UTAB FS is a particle enhanced immunoturbidimetric assay, based on the virus´ S-RBD protein. It can measure all immunoglobulin classes (IgM, IgE, IgA and IgG) built in the body upon infection with SARS-CoV-2 and it is also suitable for the quantitative characterization of the vaccine-related immunoresponse.

The poster presented at EuroMedLab aimed to highlight the superior performances of the SARS-CoV-2 UTAB FS. In particular, the good immunoreactivity of the test with the alpha and gamma variants (VOC) has been analysed through a specific inhibition test, proving that the DiaSys´ test is suitable to diagnose also the antibodies generated by possible infection of one or both these two variants. Furthermore, the standardization of the UTAB FS TruCal calibrator versus the “First WHO International Standard Anti-SARS-CoV-2 Immunoglobulin (Human)” (code 20/136) has been described. The standardization showed excellent results between 0 and 250 AU/mL, referring to 250 BAU/mL of the WHO International Standard isotypes (conversion factor AU/mL – BAU/mL = 1.01), despite the quantification of all antibodies.

Furthermore, the poster reported the characterization of the PETIA immunoresponse through the isotype differentiation obtained through a self-developed ELISA test. The ELISA could differentiate among IgM and IgG and showed that the influence of the IgM pentameric structure on the PETIA performance is stronger than the IgG monomeric one. The PETIA reactivity was maximal in correspondence of the IgM peak. However, both isotypes were measured successful by the DiaSys PETIA technology. About approximately 6 weeks after vaccination the signals decreased despite the isotype determined. This phenomenon is also reflected by the anti-SARS-CoV-2 PETIA´s absorbances. Much interest arose during the poster presentation, as testified by the numerous questions asked by the visitors, what in turn highlights the importance of accurate, standardized and at the same time easy to perform and quick serological analysis to detect both wild type and VOC derived antibodies. The development of SARS-CoV-2 UTAB FS was also the main topic of Ms. Wey´s Master thesis. In addition to the aspects presented in the poster at EuroMedLab, Ms. Wey´s work showed how to rationally design a PETIA through the employment of the bioinformatics, to choose the most specific and sensitive SARS-CoV-2´s antigen, and the use of statistical design of experiments (DoE) to accelerate and optimize the development process, what results especially relevant in the pandemic situation.


The poster abstract is accessible at: L. Wey, T. Masetto, C. Kochem, D. Ziska, M. Grimmler. SARS-COV-2 UTAB FS: A PARTICLE ENHANCED IMMUNOTURBIDIMETRIC ASSAY (PETIA) - SUITABLE FOR WHO STANDARDIZATION AND THE DETECTION OF VARIANT DERIVED ANTIBODIES. Poster Abstracts – EuroMedLab Munich 2021 – Munich, April 10–14, 2022 • Total Testing Process, including standardisation, preanalytical process. DOI 10.1515/cclm-2021-5036. Clin Chem Lab Med CCLM. 2021 Nov 1;59[s1]:s933–63.